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5 Breeding strategies for Kenyan zebu


5.1 Animal production systems
5.2 Goal traits in genetic improvement of Kenyan zebu
5.3 Open nucleus breeding schemes
5.4 Options for improved use of the Kenyan zebu
5.5 Development of a breeding programme

This chapter outlines breeding strategies for the improved use of the Kenyan zebu breeds. The principles discussed, however, are also applicable when improvement in exotic breeds is sought. A good breeding strategy should be that which addresses the opportunities, limitations, expectations and values of its target group. Furthermore, a breeding strategy should utilise resources that are readily available and consider the expectations and values of the target group. An effective breeding strategy that will deliver benefits to the farmers should be a simple organisation capable of being implemented within the constraints of the local farming conditions. It should result in animals with changed genotypes, without animals losing adaptation to the local stresses and should result in faster improvement in animal production, which is evident as soon as possible. In addition, a breeding strategy should be accompanied by improvements in management, animal health, marketing of products and extension support from well-trained extension agents. Development of any breeding strategy requires description of the animal production systems prevailing in the target area. The type of animal production system has a great influence on the goal traits and the type of breeding structures to be adopted.

5.1 Animal production systems

In Kenya, animal production systems can be classified based on three factors—product, economy and climate (Peeler and Omore 1997). The scale of production and intensity or degree of commercialisation of production, determine the economic characteristic of a system. As far as the scale of production is concerned, large-scale production can be either wholly commercial or almost entirely subsistence (pastoral). Small-scale production might range from predominately subsistence to largely commercial.

For the purpose of this discussion, animal production systems can either be subsistence or commercial. Subsistence animal production is also referred to as the ‘low input production system’. In most of the tropics, subsistence production systems are more common than commercial systems. For example, in Africa the subsistence sector supplies food to 80% of Africa’s population that lives in rural areas. Sub-sectors of the subsistence sector include: pastoral, crop–livestock systems in semi-arid areas; crop–livestock systems in the wet and cool highlands; and landless (requiring little land) production systems (Jahnke 1982). Despite the importance of the subsistence sector, no breeding strategies have been developed for this sector. Breeding strategies for this sector are likely to be different from those in temperate regions. Most of the information reported in Chapters 3 and 4 were gathered in typically subsistence type production systems. Therefore, using this information, attempts will be made to develop a generic breeding programme and to outline various options for improved use of the Kenyan zebu in this kind of system.

In commercial production systems, production levels are higher than in the subsistence sector. These systems can match those in industrialised countries. Therefore, with some small modifications the breeding strategies defined for temperate environments can be applied in these systems. As in temperate animal agriculture, the aims would be to improve on quantity and quality of desired products, to increase viability and to increase reproductive performance. This can be translated into components such as body size, feed intake and nutrient partitioning, longevity, and fertility and fecundity. While heat tolerance and disease resistance are also important, especially in extensive commercial production systems, commercial farmers have plentiful resources and use high inputs to manipulate the environment.

5.2 Goal traits in genetic improvement of Kenyan zebu

A well-defined breeding objective is the first requirement of any genetic improvement programme. Breeding objectives comprise those traits targeted for improvement in the breeding programme based on their influence on returns and costs to the producer. However, defining objectives in economic terms, which is difficult enough in temperate agriculture, becomes even more of a problem in the tropics because of the greater environmental and managerial complexity (Franklin 1986). Breeding objectives should align closely with the overall objectives of the target groups who are the critical link in the use of genetically improved animals (Amer et al. 1998). Formulating an objective without incorporating the needs and interests of the target group will stand the serious risk that it may be ignored as being unsustainable or alienating to the breeding objective, animal breeding methods and technologies in general of the target group. The wishes of the target group can be included either by expanding the range of traits in the selection criteria so that results of selection contribute directly to sustainability of the system, or by reducing the costs of existing traits, which contribute to improved sustainability.

The goal traits are those that the farmers would like improved genetically. The list of goal traits discussed here is based on the characterisation of the animal production system undertaken in Chapter 3. Some ingenuity is needed to identify the component traits that contribute to the various functions of zebu cattle identified in the survey. These traits are shown in Table 17 together with the functions performed by indigenous zebu breeds. The overlapping of component traits was expected given the preference for a dual-purpose animal. As already alluded to in Chapter 3, zebu cattle provide milk for home consumption and sale, and are used as a direct source of income by exchanging animals with cash for other purposes. Therefore, an improvement in milk production traits translates into an increase in income realised from the sale of milk. Similarly, income accrued from exchange of cattle can only improve when there are surplus animals and these are of good body condition as a result of improvements in beef production traits.

Table 17. Function played by indigenous zebu breeds and the identified component traits.

Functions of indigenous zebu breeds

Component traits

Draft

Traction capacity/strength, good feet and legs, and ease of handling

Milk production, income

Lactation milk yield, persistence of milk production, calving interval, lactation length, age at first calving, productive herdlife, preweaning survival rates, post-weaning survival rates (survival to maturity), resistance to diseases and ability to utilise poor quality pastures

Beef production, income

Calving rate, calving ease, age at first calving, calving interval, weaning rate, preweaning survival rates, post-weaning survival rates (survival to maturity), preweaning daily gain, post-weaning daily gain, mature live weight, resistance to diseases, ability to utilise poor quality pastures and feed intake

Apart from the component traits for draft, all others shown in Table 17 are essentially the conventional traits. Carcass traits, usually very important in breeding for meat production in the industrialised world, did not feature at all. This could be due to the payment system for meat currently being applied in the areas where the zebu cattle breeds/strains predominate. In these areas, payment is based on weight rather than quality. However, this might change in the near future.

The justification of inclusion of some production traits (e.g. lactation milk yield, productive ) is obvious in some instances. A shorter calving interval is necessary in order to have a large number of calves in a cow’s lifetime. In the study area, calving interval was found to be rather long. Preweaning survival rate is important because it contributes to higher net calf crop (number of calves weaned per cow). A higher net calf crop coupled with a higher post-weaning survival rate results in a higher proportion of animals reaching breeding age and hence being available as replacements in the herd. Both calf survival rate and annual cow survival rate (the latter influences productive herdlife) are traits of major importance in the tropics because the cost of production is largely influenced by the ability of animals to cope with the prevailing environmental conditions (Franklin 1986; Baker and Rege 1994).

Both preweaning and post-weaning growth rates determine the age at which cattle reach a given market weight. In the study area, disease stress is a major problem (Figure 5), and income from both milk and meat is desired. When compared with growth rate, survival is much more important (Baker and Rege 1994). High growth rate may produce cows that require heavier body weights to achieve puberty. This can prolong the age at first calving and compound the already existing problem of extended age at first calving (Table 9). High growth rate also means high mature live weight, which has a significant impact on feed requirement.

The indigenous zebu breeds were preferred in the present survey, primarily because of their adaptation to the local stresses of poor nutrition and disease challenges (Table 6). There are two options for improving both the production and the adaptation of animals. One is to concentrate on selection for production traits in the presence of environmental stress, thus allowing adaptation to respond as a correlated set of traits. The other is to attempt to understand the biology of adaptation and its relationship with production, and so develop criteria that are directed at improving both adaptation and production (Franklin 1986), e.g. index selection. The second approach requires good estimates of genetic and phenotypic parameters for production and adaptive characteristics. While production can be measured in terms of quantity and quality of product, the greatest difficulty comes in identifying the adaptive traits. Several adaptive traits are considered important in these kinds of environments. These include heat tolerance and resistance to diseases. While heat tolerance is least amenable to managerial solutions, disease problems may be overcome by vaccination, and eradication of parasites or their vectors. A complete programme of disease control could include breeding for disease resistance as well as preventive management and treatment. Breeding for disease resistance as opposed to the two latter approaches has an advantage in that once achieved, it remains part and parcel of the animal population and is passed on to succeeding generations. Thus it is more or less ‘permanent’, although only a partial solution.

All of the component traits shown in Table 17 cannot qualify as breeding goal traits. Breeding goal traits must have the following characteristics: (a) reasonably large genetic variability and ; (b) easily and cheaply measurable; (c) if not easily and cheaply measurable then, must have a high genetic correlation with a trait (indicator trait) that is easily measurable, has a higher heritability or can be measured earlier in life than the goal trait it represents; and (d) desirable economic value, either as a marketable commodity or as a means of reducing production costs. Table 18 shows the derived list of breeding goal traits in four groups. It should be noted that traits such as calving interval, preweaning and post-weaning survival rates have been included here despite the fact that their heritabilities are low. As already noted, calving interval is usually quite long in the tropics.

Table 18. A suggested list of breeding goal traits in the improvement of the Kenyan zebu breeds.

Milk production

Female fertility

Growth

Longevity and survival

Lactation milk yield

Age at first calving

Preweaning daily gain

Preweaning survival rate

Lactation length

Calving interval

post-weaning daily gain

post-weaning survival rate

   

Mature live weight

Productive herdlife

Since production and marketing conditions are normally dynamic and change over time, these goal traits can be combined differently in breeding objectives to suit a particular production environment. For example, we can have a breeding objective that is comprised of only milk production traits or one comprised of these traits and female fertility with no record available for calving interval. Before being established, a breeding programme should be optimised by varying the goal traits, their economic values and selection criteria using appropriate analytical procedures. Computer programs are available for such evaluation (e.g. ZPLAN developed at Hohenheim University in Germany). This will give a fair picture of the effect of changes in these variables on expected genetic gains, returns, costs and profits.

5.3 Open nucleus breeding schemes

Breeding structures provide systems for gathering information about assessment of animals in the production system and conditions that allow selection of parents (males and females) of future progeny, and the matings of these animals in a desired manner (van der Werf 1999). A breeding programme must consider and address how superior animals will disseminate their genes quickly throughout the whole population. When answering this question, production systems, farmers’ constraints and available infrastructure must be considered seriously if the breeding programme is to be sustainable.

As shown in Chapter 3, farmers in the study area practise selection of breeding animals despite the fact that they do not keep records. Breeding programmes will only be implemented successfully where accurate recording is possible. Accurate record keeping in field populations requires money, expertise and a well-developed infrastructure (transport and communication structures), which is partially or completely lacking in most parts of Kenya where the zebu breeds are predominant. Nucleus breeding schemes were developed to circumvent the high costs arising from performance recording and selection. They do not require expensive infrastructure because recording is only done in the nucleus herd. Therefore they can be a good strategy for genetic improvement in non-industrialised countries which lack the expertise and structure required for operating an efficient genetic improvement programme based on AI and recording in the whole population (Smith 1988). The best males are kept for breeding in the nucleus while the remaining selected males are used for breeding in the co-operating herds.

Cunningham (1980) described an open nucleus-breeding scheme (ONBS) which, in the absence of AI and/or recording, was appropriate for subsistence production systems. Bondoc and Smith (1993) recommended the establishment of two-tier open nucleus breeding systems (Figure 12) to maximise genetic improvement, reduce inbreeding rate and reduce the total cost of recording in the participating herds. Although recording is not essential in these herds, record keeping can gradually be introduced as part of the extension programme of the scheme. Open nucleus systems provide approximately 10% more genetic gain than a closed system because there are more animals which are potential candidates for selection. Such a system will integrate farmers’ resources, reduce overhead costs and encourage more farmer participation (Bondoc and Smith 1993). Smith (1988) described the advantages and disadvantages of opening the nucleus.

In an open nucleus breeding system (Figure 12):

  1. The nucleus is the tier that generates genetic gain and where sire selection is the main activity.
  2. There is movement of bulls from the nucleus to sire progeny in the field populations.
  3.  In the nucleus, there is introduction of dams born in the participating herds, which are selected subjectively based (depending on the breeding objective) on easily and cheaply measured traits.
  4. There is no selection in the participating herds. The bulls born in the nucleus are used to produce cows and to sire bull calves that are kept for use to mate a proportion of the cows in this sector. The dams in the participating herds are used to produce both bulls and cows in this sector.

Figure 12. Two-tier open nucleus breeding structure with selection in nucleus and possibly in the participating herds, and downward and upward migration of genetic material.

How can a nucleus be established and the system introduced without severe organisational problems? Establishment of such a system requires full co-operation of farmers. Farmers should be assured of the potential benefits of participating in the breeding programme. Several questions would have to be addressed. The first would be which criteria to use when enrolling farmers in the programme. After enrolment, the challenge would be to find out how the problem of small herd sizes (Table 8) can be solved. Small herd sizes imply that the scope for selection amongst replacements is small, thus limiting the potential for movement of cows from the commercial to the nucleus herd. Another important question is what incentive should farmers be given to contribute their best animals to the nucleus? These questions are addressed later in this chapter.

5.4 Options for improved use of the Kenyan zebu

The use of Kenyan zebu cattle cannot be discussed without knowing the long-term production and marketing conditions; however, these are hard to predict. Nonetheless, assumptions can be made and these could be modified as more information becomes available. Chapter 4 has provided a method by which the diverse range of Kenyan zebu cattle could be classified. The current results indicate that the breeds/strains studied could possibly be placed into three groups. Although not conclusive, the results provide a good starting point.

Different hereditary characteristics of breeds and even types within a breed have resulted in differences in reactions to environmental stimuli. These reactions are intimately associated with anatomical–physiological characteristics, which have developed as the result of natural selection. Therefore, despite the classification based on objective criteria, e.g. gene and marker frequencies, within each group, certain breeds/ strains posses certain desirable characteristics. For example, the Orma Boran has a reduced susceptibility to trypanosomosis and a lesser requirement for drug therapy or prophylaxis (Dolan 1993). The Nandi Zebu is tolerant to ticks, lice, biting flies and tick-borne diseases and has genetic potential for milk production (Payne 1970). Developing sustainable genetic improvement programmes for such breeds/strains that take into account these characteristics will conserve such genetic diversity.

Options for improved use are presented under the following assumed scenario and where necessary specific examples of possible herds in Kenya that can be used for each option are given:

In case 1, continuous use of exotic germplasm will lead to an increasingly higher proportion of exotic blood. Local Kenyan zebu genes will continually disappear in the livestock industry in these areas. This has already been observed with the Kikuyu Zebu, which is listed among those breeds that are endangered. Cross-breeding with the exotic European breeds is either by AI or natural service. Genes of zebu cattle are essential for breeding schemes under the conditions of cases 2 to 4. Results of various cross-breeding trials, however, have shown that, with an improvement in nutrition and disease control, crossbreds between B. taurus and B. indicus survive and show superior performance under some of these conditions.

5.4.1 Options for case 2

Starting with herds that have experience with crossbred cattle and are familiar with recording, a testing and selection scheme could be established aimed at creating a dual-purpose (meat and milk) synthetic population. Choice of the foundation breeds to be used in the formation of synthetic breeds should be based on performance under environmental conditions similar to those in which the synthetic breed will be maintained. Inclusion of the maximum number of breeds of demonstrated potential in the synthetic population would result in retention of the highest proportion of the original. In this case, the location of the herds determined the choice of the zebu breeds/strains to use. Thus if the herd is located in the coastal region, then use should be made of the zebu breeds/strains found in the coastal area. In this area, herds belonging to the Mariakani and Mtwapa Regional Research Centres (RRC) of KARI can be used. These herds could act as pilot nucleus herds intended to breed sires for the next generation.

The first step would be to decide on the proportionate contribution of each chosen breed to the synthetic to obtain the desired biological type. This is determined by the degree of environmental modification. The percentage of heterozygosity retained is high when the contribution of the foundation breeds in the synthetic breed is equal. Hence it is desirable to have equal contributions by each breed if this can be done, while at the same time achieving optimum additive genetic composition. For example, for a synthetic breed based on equal contributions by four breeds, the proportion of mean F1 heterozygosity would be:

1 – [(0.25)2 + (0.25)2 + (0.25)2 + (0.25)2] = 0.75

A synthetic breed based on unequal contributions by four breeds would retain a lower proportion of mean F1 heterozygosity, or:

1 – [(0.375)2 + (0.375)2+ (0.125)2 + (0.125)2] = 0.688

However, the ultimate genotypic composition must be based on the performance, which is a combination of both the additive genetic contributions and the heterosis.

A two-breed synthetic breed is recommended because of its organisational simplicity. The B. taurus breeds of choice would be the Ayrshire, Brown Swiss or Friesian. Analysis of economic data from a large-scale farm in coastal (Kilifi Plantations) Kenya showed that there were no significant differences in the additive breed effects of these breeds for economic performance (Kahi et al. 2000). In the first instance, the objective would be to have a stabilised genotype with equal proportions (50% B. taurus, 50% zebu) of genes from each foundation breed. With such a genotype, it would be easy to increase or decrease the gene proportion of each breed (or even include a third breed) as additional genotypes are evaluated or in response to changes in production circumstances. Although synthetic populations show maximum recombination loss, theoretically, their response to selection can be greater than that of parental breeds because of the increased genetic variation (Dickerson 1973).

Developing a synthetic breed is a long-term process that needs many resources, a large number of animals, detailed recording and analytical facilities. Consequently, development of synthetic breeds has often been carried out on one unit with many cattle, and where feeding and management is likely to be better than in the field. To ensure that a synthetic breed is in harmony with the conditions in which it is expected to perform and therefore acceptable to the farmers, it should be formed using field populations but with matings being carried out in a central nucleus herd. Figure 13 shows how this could be done.

At the very beginning, sires of purebred exotic breeds could be used to provide the participating herds with 50% crossbred bulls produced out of indigenous cows. With such an arrangement, the percentage of temperate genes in the field population will not increase above 50% in subsequent generations. The indigenous cows would be screened to form the nucleus herd. Screening is a two-step selection procedure, divided into foundation selection and a continuation selection procedure (Gearheart et al. 1989). Foundation screening involves initial screening to form the nucleus herd, while continuation selection is implemented when the nucleus is established, keeping the nucleus open. In cases where nucleus herds of higher genetic merit than the base herds are available, then foundation selection is not necessary.


Squares = sires; circles = dams.
Figure 13. Diagrammatic depiction of a breeding plan to create a two-breed synthetic breed using participating herds.

Since formation of a synthetic breed would require several generations of co-operation between the nucleus and the field population, this would also serve as a channel for delivering improved genetics to the participating farmers. It is expected that some of the farmers would not participate in this process. For them, the nucleus would simply serve as a source of superior genetic material to suit their production and marketing needs. Sire selection should not wait until the breed has stabilised, but should be part of the process. Indeed, sires used at each stage should be evaluated objectively, as should cows. As the performance of daughters is a major prerequisite for proper estimation of sires’ breeding values, a relatively large proportion of recorded cows is required. Therefore, the nucleus should gradually be expanded up to a proportion of about 30% to 40% of cows recorded in the population.

Alternatively, the herds can be used as nucleus herds for improvement of the indigenous cattle breeds through within-breed selection using a dual-purpose breeding objective. A herd meeting the identified criteria for the area (e.g. the Eastern Province and neighbouring areas of the Coast Province) could be established at KARI’s Kiboko RRC located in Makueni District and used as nucleus for this purpose. Screening of the field population for superior animals to be introduced into the nucleus during the foundation stage would be the first step. The nucleus should be kept open in subsequent generations. The advantage in rate of genetic gain through opening the nucleus has to be balanced against the extra cost of recording in and continuous selection from the field population.

5.4.2 Options for case 3

The improved Kenyan Boran breed is a good starting point to establish a national breeding scheme for beef cattle. Trail and Gregory (1981) reported the milk and beef production potential of the Boran breed under a range of African environments. Some stud herds originally established by European ranchers still exist. Based on these as a nucleus, a purebred selection scheme could be established. Such a scheme could be possible if it was run without physically relocating animals. A well conceived, properly managed selection programme run by the Boran Cattle Breeders Society is an excellent option that needs to be explored and, if feasible, facilitated.

Rarely will commercially run livestock ranches accept being used for this purpose. Alternatively, use can be made of stations belonging to KARI or Egerton University, which will have to purchase or lease the improved Boran from these ranches and from farmers. The KARI Lanet (Lanet Beef Research Centre), Garissa and Marsabit RRCs provide existing facilities for such an undertaking. The Chemeron Station of Egerton University (located in Baringo District) is a possibility, but would require additional resources to ensure adequate supply of feed in most of the year; otherwise, it is well secured for disease control. This station could be combined with the Kimose Station (also located in Baringo District) under the Ministry of Agriculture and Rural Development to create one nucleus herd. With such an arrangement, each station would be required to keep animals belonging to a certain age class. For example, the breeding females (with their suckling calves) and the breeding bulls would be kept in Kimose Station. After weaning, the young animals would be moved to Chemeron where they would stay up to a certain age (e.g. 2–3 years) undergoing performance testing. After finishing the performance testing, the best males would be selected to replace the breeding males in Kimose while the others would be sent to the participating herds. Most of the females would be allowed to breed in Kimose, in order to be performance tested with respect to other traits (e.g. age at first calving).

As beef traits (e.g. daily body weight gains, mature live weights etc.) to be improved are measurable on both sexes, a progeny testing scheme is not needed and the proportion of the nucleus cows can be much lower (less than 5%) than in a scheme for case 1. A relatively fast genetic gain is expected in a pure-breeding scheme, as most of the beef traits are highly heritable and there will be large variation in the nucleus especially when it is made up of animals from different sources.

There can also be progressive substitution of an indigenous zebu breed/strain with another. For example, if the overall objective is to increase beef production in the coastal area, superior genes from the improved Boran could be introduced by using Boran bulls in a nucleus having cows belonging to the ‘Coastal group’ to produce half-bred bulls for natural mating in the participating herds. Continuous use of these bulls in these herds would lead to a cow population with 50% of genes from the improved Boran. If the farmers accept the performance of these crossbred cows, then crossbred cows from the participating herds can be screened and introduced into the nucleus. The bulls used in the nucleus would continue to be purebred improved Boran and this would result in the cows in the field population moving gradually to 100% new genes.

The use of bulls from exotic B. taurus breeds (e.g. Charolais or Simmental) is not recommended except for terminal crossing to produce crossbred animals for feedlots, if there is a market for this. Trials in use of bulls of foreign beef zebu breeds (e.g. Brahmans from the USA or Australia) are open for discussion, as not much of this has been done in Kenya, and results are not available.

5.4.3 Options for case 4

Socio-economic, logistical and infrastructural restrictions will probably continue to preclude possible establishment of any meaningful breeding programme under the conditions of pastoral and migratory communities. The breeding objectives under these extremely harsh and highly variable conditions are quite complex. ‘Hardiness’ remains one of the most important considerations to reduce animal losses. However, cattle in these systems are also milked and slaughtered for meat on special occasions. Obviously, herders practise some kind of selection.

It is expected that, if any, there will be erratic and unpredictable requests for genetically improved bulls from breeding schemes established under the conditions described in cases 2 and 3. Pastoral herds may thus benefit from these breeding programmes as the third tier. This is also beneficial for these breeding schemes as pastoral herds can be considered as an extension of clients and thus of their economic level, which is important for their cost-efficiency. These herds (which account for a large proportion of the national zebu herd) could also represent a potentially important source of animals, which could be screened at the start of the breeding programme under cases 2 and 3.

Breeding programmes involving pastoralists will only be successful when governments accept pastoralism as an integral part of their economic systems, and accordingly allocate resources for its development. Failure to involve pastoralists in inception and implementation of projects is a major factor contributing to the high rate of failure of projects designed for them.

From the foregoing discussion, it is clear that there is the need for a strategy on how cattle production in different production systems can be improved. However, the major questions yet to be answered are who will be responsible for organising and establishing the breeding programmes (breeding organisations do not exist in most of the tropics), who will fund their establishment, and who will make them self-sustaining? This calls for concerted efforts of all stakeholders in the livestock industry. These stakeholders need to be identified and their roles defined clearly in order to avoid confusion in the running of the breeding programmes.

A well-developed and operational breeding programme for the Kenyan zebu breeds/ strains will translate into improved animal offtakes, meat and milk, and hence income to the producers. Currently, trends towards trade liberalisation in a globalised market favour agricultural exports, which contribute to enhanced development perspectives, and those exports that are produced ecologically. Under Kenyan conditions, it is inevitable that the zebu breeds/strains will continue to be raised under grazing conditions without supplementation. Experience shows that there is a demand for lean, grass-fed beef in USA, most European countries and the Middle East. This results from consumers’ fears of the residues that are found in beef when animals consume feeds containing additives or feeds manufactured from contaminated products, or from the extensive use of veterinary drugs. Some of these residues may cause diseases or abnormal conditions in humans. Livestock and their products can be exported only if they meet the expectations of importers and consumers.

Demand for live animals is increasing in the USA and Australia where some Kenyan zebu breeds/strains (e.g. the improved Boran) are being used in the development of synthetic populations. The Boran is also currently a subject of long-term germplasm evaluation studies at the Clay Centre, Nebraska, USA. Better access to these international markets would be possible if farmers had the opportunity, through their organisations, to use the infrastructure and logistics of the nucleus herds and of some parastatal organisations, e.g. the Agricultural Development Corporation (ADC) and the Kenya Meat Commission (KMC), which is currently under receivership.

5.5 Development of a breeding programme

When talking about development of breeding programmes, one should distinguish between genetic and structural designs of the breeding programme. Genetic aspects of designing a breeding programme include the development of breeding objectives, compiling information on genetic parameters and estimating economic values of goal traits. The structural design normally answers the questions of how the genetic superiority gathered can be disseminated throughout the whole population and how the breeding structures can be established and made to work. The example breeding programme discussed in the remainder of this chapter is based on the information on system characteristics identified in Chapter 3 and the tentative classification framework based on genetic distinctiveness presented in Chapter 4. The programme assumes that both the genetic and structural considerations for a breeding programme are in place.

5.5.1 Genetic design of a breeding programme

Development of breeding objectives

The first phase in the genetic design of a breeding programme is that of developing the breeding objective. As noted previously, breeding objectives comprise those traits, which one attempts to improve genetically because they influence returns and costs to the producer. Development of these objectives is made up of the following four phases (Ponzoni 1986; Ponzoni 1988): (a) specification of the production and marketing system; (b) identification of sources of income and expense; (c) determination of biological traits influencing revenue and cost; and (d) calculation of the economic value of each trait in the breeding objective. Breeding objectives should be comprehensive in terms of incorporating the needs and economic interests of the producer as well as ecological conditions (Sölkner et al. 1998). They should define the animal most suitable for the livestock producer under given production conditions. Therefore, the choice of traits in the breeding objective can only be made in close consultation with the farmers, taking into account their needs (see Chapter 3).

Production and marketing system. Very little economic evaluation of breeding objectives has been attempted in the tropics. Breeding objectives should account for inputs, such as feed, husbandry and marketing costs, as well as for outputs, such as income from sale of milk, surplus offspring and cows. These are difficult to quantify under most tropical conditions. While farmers are able to identify important attributes in their animals, actual economic data is difficult to come by. However, in any animal production system’s characterisation exercise, attempts should be made to collect information using simple procedures if the results are to be utilised fully for designing genetic improvement programmes.

Identification of sources of revenue and cost. The development of a profit function for a production system requires identification of the actual sources of revenue and costs. Profit (P) is a function of revenue (R) and cost (C).

P = R C

R and C should be derived on a cow-year basis as functions of all items contributing to R or C. Box 1 gives an example for the Kenyan zebu.

Biological traits influencing revenue and cost. The biological traits assumed to have some influence on revenue and costs are those identified as the goal traits in Table 18. Resistance to disease is a biological trait, which was identified as an attribute desired by farmers. However, its inclusion as a trait in the breeding objective would require definition of easy-to-measure selection criteria genetically correlated with disease resistance (i.e. a suitable indicator trait), or identification of loci that allow marker assisted selection. Survival to a certain age (in the presence of disease challenge) may be an indirect measure of resistance to disease.

Box 1. Sources of revenue and cost for the Kenyan zebu

Revenue (R) = (culled heifers value per individual) + (bulls value per individual) + (amount of milk (kg) price of one kg of milk) + (cull-for-age cows value per cow).

Costs (C) = calf feed costs + heifer feed costs + bull feed costs + cow feed costs + calf health costs + heifer health costs + bull health costs + cow health costs + heifer reproduction costs + cow reproduction costs + heifer labour costs + bull labour costs + cow labour costs + fixed costs.

Fixed costs are those incurred by the producer independent of the level of herd production. All the other costs are variable costs and are influenced by the level of herd production.

Derivation of economic values of traits in the breeding objectives. The main aim of any producer is to maximise returns/profits from the enterprise, which should be more efficient relative to the enterprises of other producers. There are possibilities to define the efficiency function of the production system (Harris 1970):

In defining breeding objectives, definition of efficiency function has to correspond with the individual livestock producer’s interest, which is to maximise profit rather than to minimise cost per unit of product. However, given the diversity in production systems, generally both maximisation of profit and minimisation of costs per unit of product are important (Groen and Ruyter 1990).

Economic values have to be derived by changing genetic merit of the trait, but allowing no simultaneous change in genetic merit of the other traits. Methods for deriving economic values can be grouped into two categories (Elsen et al. 1986; Groen 1989): normative approaches, also referred to as bio-economic modelling; and positive approaches, which involve analysis of field data. In both approaches, a production function (also referred to as a profit function), that must include all economic traits, is required. Normative methods enable modelling of future market conditions, while the positive approach uses current prices and is therefore less suitable in deriving economic values. Generally, using the normative approach (data simulation), economic values are derived by studying the behaviour of the system as a reaction to changes in levels of the endogenous elements that represent genetic merit of the animals. There are numerous possibilities for applying different prices and efficiency functions, levels and sizes of the production system (Groen 1989). Box 2 describes the different methods used in deriving economic values.

Box 2. Methods of deriving economic values

Generally, there are two methods that are used in deriving economic values from profit function: (a) by accounting for unit changes in returns (marginal returns) and of costs (marginal costs) arising from improvement of a trait (marginal profit method, also referred to as partial budgeting method); and (b) by partial differentiation of the function with respect to the trait of interest. In the partial budgeting method, profitability of the herd is compared before and after genetic improvement. For example, if P is the profit of a cow in a herd and P is the profit after incrementing by one unit the trait in question, then the economic value of that particular trait is P P. 

Moav and Hill (1966) first applied the partial differentiation to derive economic values on a farm scale (accounting for size of the enterprise) for within-line selection. Since profit (P) is always defined as revenue minus cost, fixed costs can be ignored when estimating economic values using this method. This is because terms not involving the traits in the breeding objec- tive disappear when obtaining the partial derivative of P with respect to the trait of interest. However, if revenue and cost are combined as a ratio, fixed cost would be required in esti- mation of economic values, but its effect would be small in practice (Smith et al. 1986).

Genetic and phenotypic parameters

Unbiased heritability estimates and accurate correlations (genetic and phenotypic) among performance traits in the breeding objective and the selection criteria are required to design selection programmes for livestock. Reliable estimates of genetic parameters and economic values would allow for development of optimal linear selection indices that are directly applicable to programmes selecting for improved performance.

Genetic and phenotypic parameter estimates normally apply directly to the specific population and environment from which the data were collected. Thus, estimates may vary from one population to another depending on gene frequency, previous selection, and environment and past history of the population. Definitions of heritability, and genetic and phenotypic correlations are given in Box 3.

5.5.2 Structural design of a breeding programme: general considerations

There are major limitations that must be recognised before any breeding programme is designed for the Kenyan zebu breeds. Field recording and AI are normally not feasible in the areas where these breeds are predominant. However, there are occasional settings where AI may be used and therefore the breeding plan (proposed later in this chapter) welcomes such a possibility. Breeding programmes must therefore be built on alternative methods of recording, on different selection methods and on natural service. This leads to the conclusion that recording and selection should be done in nucleus herds where a certain proportion of the dams born in the participating herds are brought to participate in an open nucleus breeding scheme (Figure 12). In this type of scheme, as a result of recording, selection and planned matings, superior genes are passed to the field population via natural service bulls.

Box 3. Heritability and genetic and phenotypic correlations

Heritability refers to that portion of the phenotypic variance of a population that is due to heredity. Heritability may be used in either a narrow or a broad sense. In the narrow sense, heritability includes additive gene actions or the average effects which individual genes have in that population. Heritability in the broad sense includes all of the effects of the entire heredity of each individual. That is, in addition to variation due to additive gene action, heritability in the broad sense includes that variation which is due to dominance and epistasis. 

A correlated response is any indirect response in unselected traits occurring simultaneously with response in the trait under selection. A correlated response can be either positive or negative. Phenotypic correlations among traits are the gross correlations that include both the environmental and the genetic portions of the covariances. They are important because they directly affect the size of the selection differentials when several traits are used in the selection index, especially when the correlations are high. Genetic correlations among traits indicate how the same genes affect two traits, that is the correlation between the additive genetic values of two traits. In any selection programme, genetic correlations should be taken into account because of the following reasons (Blair 1989): 

  • If two traits are related, the consequence of increasing one upon the response in the other can be assessed. 
  • Through the use of information on all related traits to estimate the breeding value for any one trait, selection accuracy is improved. 
  • If traits are related, there may be an opportunity to select for one character and bring about a related or correlated response in a second character, which might in itself be difficult or expensive to measure.

The question would be how such a nucleus could be established and the system introduced without severe organisational problems. This will only be possible if organisational lessons are learnt from the experiences of the few examples of nucleus breeding schemes (open or closed) in the tropics (Galal et al. 1999). The first step in the establishment of a nucleus breeding scheme would be to introduce a nucleus on institutional or government cattle stations. The second would be to open the nucleus by finding farmers who are willing to join the scheme. The specific needs and social circumstances, as well as constraints of such farmers must then be incorporated in the breeding objective (Sölkner et al. 1998). Use should be made of existing advisory services, and existing structures and means of knowledge transfer to further select farmers based on certain criteria. These may include: (a) property rights on land; (b) ease of access to farm (e.g. by car, motorcycle or other available means); (c) access to water source; (d) size of herd; (e) ability to keep basic records, to follow prophylactic programmes and to supplement their animals during critical periods; and (f) willingness to allow their best animals to be introduced into the nucleus or to be used for elite matings with semen from the nucleus, and to contribute (or sell) the resulting progeny to the nucleus. Similar criteria were applied in the establishment of an open nucleus breeding scheme for Djallonké sheep in Côte d’Ivoire (Yapi-Gnaoré et al. 1997).

Most farmers may be reluctant to give out their best animals. However, incentive schemes have been shown to work (Galal et al. 1999). Such incentives may include: (a) passing on to farmers profits accrued from the sale of milk from their animals; (b) incorporating the animal in the nucleus on a temporary basis (and then returning it later when it is pregnant or accompanied by a heifer calf, having been mated to ‘superior sire’); and (c) leasing the animal to the nucleus (at an agreed price). Disease prevention may be a problem in the latter case (Gall 1997). Alternatively, farmers could retain their best animals and elite ‘nucleus’ matings could be done in the field population with migration of semen or sires from the nucleus to these herds. This would rely on good pedigree and performance information, which the farmer would be expected to keep under the supervision of the nucleus.

In most zebu dominated areas, herd sizes are generally small (Table 8). Therefore, the scope for selection among replacements within farms is small. Consequently, the potential of opening the nucleus for replacements from these herds may be limited, especially when an individual farm unit is considered. To circumvent this problem, use can be made of village herds each comprised of several individual farm units with a considerable number of cows from which replacements can be selected. Such a village-level programme would be particularly useful given the communal use of breeding bulls.

The nucleus can also be established in the form of a private enterprise, which can initially be funded by loans from financial institutions or governments, and/or farmers who are willing to join. The selection work in such an enterprise would be relevant because farmers will be involved in its operation or even in owning the stock, as in group breeding schemes or co-operatives (Smith 1988). Increased revenues from sale of genetic material would absorb the costs of such an enterprise. For the enterprise to sustain itself, a compromise would have to be reached on what would be the cost of this genetic material leaving the nucleus. This genetic material would be in the form of young, untested bulls. Young bull schemes have lower costs and are simpler to run than old bull schemes that use progeny-tested bulls (Mpofu et al. 1993; Nitter 1998; Syrstad and Ruane 1998). In an old bull scheme, only progeny tested (proven) bulls are used in the nucleus and participating herds. Experiences from a progeny-testing scheme in a herd of Sahiwal cattle in Kenya confirm that such schemes can be inefficient in practice (Rege and Wakhungu 1992).

In a young bull scheme, untested bulls are used to sire dams both in the nucleus and participating herds. Two types of young bull schemes need to be distinguished: one with semen storage or waiting bulls; and the other one without these possibilities. When AI is possible, the bulls are slaughtered after a limited amount of semen has been collected; the semen is stored until daughter records are available to select semen from the best bulls for planned matings. In the absence of AI, the bulls are maintained (waiting bulls) until daughter records are available and the inferior ones slaughter thereafter. The rate of gain in such schemes would suffer because it takes a long time for the bull’s daughters to be recorded. The problems and costs of using deep frozen semen or of maintaining waiting bulls should also not be underestimated. A young bull system without semen storage or waiting bulls has successfully been applied in a programme to genetically improve the N’Dama breed in the Gambia (Dempfle and Jaitner 1999). The use of young, untested bulls for AI or natural mating in the participating herds leads to a substantial reduction in the time-lag required for dissemination of the genetic superiority of the nucleus to this sector.

5.5.3 Stakeholders and their potential roles

The number, type and roles of stakeholders vary depending on the stage of development of the breeding programme. In countries with well-developed and functioning breeding programmes, there may be many stakeholders each with well-defined roles. A very important aspect in starting up a breeding programme is identifying and defining roles of key players and how they interact. This is because activities related to the breeding programme have to take place at different locations but are interdependent. This requires interaction and communication between stakeholders. Figure 14 shows the classification of the key stakeholders into four broad groups.

As can be seen in this figure, some subgroups are represented in more than one group. Breed societies, farmer co-operatives or research stations owned by national agricultural research systems (NARS) can own the nucleus herds. NARS as used here include all public and parastatal organisations and private non-profit institutions, such as universities, that conduct research or work on the development or adaptation of technology, and policies that support agricultural and rural development. If a breed society owns the nucleus herd, then its overall role in the breeding programme would be the traditional role of the nucleus plus its role as a collaborator. Similarly, the overall roles of NARS would be equivalent to the summation of its roles as a collaborator, and policy and planning developer.


NARS = national agricultural research systems, e.g. universities, KARI and its research centres, research stations etc.
Figure 14. Potential key stakeholders in a breeding programme for the Kenyan zebu breeds.

Nucleus herd

The nucleus’ main objective is the improvement of the indigenous cattle. The nucleus should not be engaged in research per se, but should put in place collaborative mechanisms with appropriate stakeholders (e.g. NARS) to ensure that data coming out of the recording system are analysed, interpreted and the results used. Such partnerships will also facilitate identification of emerging researchable issues, which can support the effectiveness of the programme. The nucleus should also be involved in activities directly related to the cattle owners, e.g. extension advice, open days, demonstrations and in identifying with the local community. Performance and pedigree recording, and selection should be the major preoccupation of the nucleus. The nucleus should, through its extension agents and scientists, screen all the cows joining it from the participating herds. Nucleus herds should provide superior genes to the participating herds and encourage farmers to purchase their products through advertisements (e.g. marketing of the breeding stock).

Participating herds (farmers)

Farmers own the animals and have responsibility for day-to-day decisions concerning the animals in their herds, i.e. feeding, health management etc. In an open nucleus system, this group may have the role of providing information on their best animals so that these animals can be introduced into the nucleus. These farmers are clients as well as proprietors of the breeding programme.

Collaborators

This group is important because it has the potential to provide additional human operational and management resources. During the establishment stages, it is this group that could provide additional funding resources.

National agricultural research systems (NARS). These will be required in the early stages of development of a genetic improvement initiative (e.g. to contribute to capacity building) and when this initiative is operational. Qualified personnel to run such an initiative are likely to be found in these systems. Therefore, they are expected to be in charge of the technical support required in the implementation and running of the genetic improvement programme. Their roles could include:

Farmers’ training and extension agents. Farmers’ training centres should train the farmers in aspects of animal production and veterinary sciences, and not just in genetic improvement. Farmers should be aware of what genetic change can achieve and how this can occur. Training of farmers is the responsibility of extension agents who should be able, with the help of researchers, to translate research information into simple terms for the farmer to understand. The extension agent is the contact person for the farmer in relation to improvement of animal production. Experience has shown that the level of management in a farm is positively correlated with the number of times a farmer is in contact with his/her extension agent.

Breed societies. In a developed breeding programme, most of the roles of NARS outlined above are performed by breed societies. In such systems, the nucleus is normally made up of several herds located in different places and breed societies generally co-ordinate the breeding activities between locations. Their other roles, which could also be applicable in the Kenyan situation, include:

Co-operatives. Co-operatives can be farmer organisations when they are 100% owned and run by farmers. Low returns per unit of production, inaccessibility of resources and markets, and ignorance or lack of awareness are some of the problems farmers face. Through co-operatives, farmers create their own infrastructure of marketing and production support services, e.g. services in animal breeding, health care, feed, other inputs and credit facilities.

Consumers. Consumers drive the breeding programme in that they encourage the breeders and producers to focus the programme in ways that reflect the market (consumer) demand. Consumers also influence the breeding traits through their preferences and purchasing power. For example, if consumers prefer meat with less fat and are ready to pay high prices for lean meat, the breeding programmes must be adjusted accordingly to reflect these preferences.

Policy and planning developers

This group should create an enabling environment in responding to consumer and farmer needs. The government, through some of its departments, and with the help of NARS would have to act as a regulatory body by developing animal breeding policies that ensure that the breeding programme is consistent with the overall national goals. Such laws would regulate the activities of each stakeholder by clearly outlining the roles of each. The policies would have to cover a wide area. This group should also provide the broad policy decisions required in planning, implementing and maintaining the operation. It may be important to effectively involve farmers or farmer organisations in making these decisions. While farmers will not have the capacity to understand the technical aspects of the programme, they must be able to obtain practical interpretations associated with certain decision options.

5.5.4 Proposal for a breeding programme in Kenya

A breeding programme should be suited to local infrastructures. In some cases, this may mean compromising the ideal theoretical breeding plan. The following breeding programme is described as a basic model illustrating the possibilities for improvement of the indigenous Kenyan zebu breeds through selective breeding. The most important feature of the breeding programme is its feasibility to do something where previously little or nothing was achieved.

The programme would be located in an area where the Kenyan zebu breeds predominate. As noted in Section 5.4.1, KARI’s RRC at Kiboko in Makueni District could be the nucleus. A two-tier open nucleus breeding scheme supplying young bulls to the participating herds would be assumed. There would be intense recording of performance in the nucleus but none in the field population. Mating would be by natural service both in the nucleus and the participating herds.

Because of the paucity of information, this proposal is based on the following assumptions: (a) that (some sort of) breeding objective for the indigenous Kenyan zebu is developed taking into account improved productivity and conservation of genetic diversity; (b) that economic values of the goal traits are available, and that these are relevant to the production and marketing conditions of the areas where the indigenous Kenya zebu breeds predominate; and (c) that reasonably reliable genetic parameters for the goal traits are available.

The breeding objective should, based on results of the survey (Chapter 3), consider that the breed serves a dual-purpose role producing both meat and milk. This objective reflects the current production and marketing system where milk is paid for on volume alone (not composition) and payment for meat is based on weight, irrespective of the class of cattle. Moreover, the market currently not valued many aspects of carcass quality. The breeding goal traits that need to be considered are lactation milk yield, age at first calving, preweaning daily gain, post-weaning daily gain (to 18 months) and mature live weight.

Cows from the participating village herds that join the nucleus during the foundation stages and thereafter, would be selected using simple procedures that could include milking ability, the age at first calving, size, growth performance, conformation and condition. In some cases, test milking would also be done. The selection of these cows would be by technical experts (e.g. scientists) from the research station assisted by the cattle owner. Cattle owners normally know their animals and can provide the information needed to identify genetically superior animals. The animals transferred to the nucleus would be recorded there during the following year with the remainder of the nucleus herd and re-evaluated. This ensures that all cows in the nucleus are superior to the average of the field population. Permanent environmental effects between herds would be accounted for by adjusting for effects, such as those of management and age of cows. Screening of the field population would include herds in Kitui and Machakos districts. Possibly populations from Kajiado and Taita Taveta districts could be included, but they would need careful screening to avoid inclusion of non-representative animals. The result would be a diverse population, but after several generations of breeding, it is expected that the animals would eventually be more ‘uniform’, reflecting the breeding objective.

A total population of 10,000 cows is envisaged and the size of the nucleus with performance recording would be 10% (1000 cows) of this population. A total of 200 villages located in these districts would participate. Each of these village herds would be expected to release their best cow to the nucleus. With a nucleus size of 1000 cows, progeny testing is not recommended. Therefore, selection in the nucleus would be based on individual performance tests and on performance of relatives. Thus, pedigree recording will be crucial in the nucleus. Progeny testing is feasible in large herds with several hundred cows. In this situation, where AI and semen storage facilities are absent, it would be risky to keep bulls alive while they are being progeny tested, i.e. until their daughters have finished their first lactation. If a breeding programme is set at year 0, the first genetic benefits from progeny testing are not realised until after approximately 10 years. For this reason, pedigree selection is preferred.

In the participating herds, the bulls would be a community property. They would be in the care of a bull keeper who would be remunerated by the farmers through payments for natural matings. In cases where herd size is approximately 40 cows, one young bull would be supplied for natural mating for each three-year period. In such cases, a bull keeper would not be required. Where the herds graze extensively, the bulls would be allowed to run freely with the cows, but each such group of village herds would be treated as a breeding unit. It would be the responsibility of the bull keeper to maintain records of services for payment and parentage. Bulls in natural service would be used for only three years and then replaced with young bulls from the nucleus. The biological and technical parameters are outlined in the following example.

A simple example

Table 19 shows, for a hypothetical example, the breeding goal traits together with their economic values, phenotypic standard deviations, heritabilities and the correlations between them. These parameters are based on the results of Kahi (2000) and, in that sense are not solely hypothetical; however, Kahi’s study was conducted in a production system very different from that under consideration. Therefore, economic values used here might change given differences in the levels of inputs. Even so, some attempt at predicting genetic gain using this information may be instinctive. Selection is on an index based on these traits.

Table 19. Economic values (v), phenotypic standard deviation (p), heritability (h2), genetic correlations (below the diagonal) and phenotypic correlations (above the diagonal) of the breeding goal traits.

Traita

v (KSh)b

sp

hb

Correlations

       

MY

AFC

DG

PDG

LW

MY (kg)

18.9

229

0.12

 

–0.04

0.1

0.11

0.12

AFC (days)

–4.8

118

0.13

0.17

 

–0.25

–0.25

0.15

DG (g/day)

2.8

26

0.21

0.1

–0.25

 

–0.03

0.4

PDG (g/day)

9.1

30

0.26

0.1

–0.25

–0.03

 

0.47

LW (kg)

7

30

0.30

0.03

0.15

0.4

0.47

 
a. MY = lactation milk yield; AFC = age at first calving; DG = preweaning daily gain; PDG = post-weaning daily gain; LW = mature live weight. Repeatability estimate of MY was assumed to be 0.55.
b. KSh = Kenya shilling (US$ 1 = KSh 50 in December 1997).

The nucleus size is 1000 cows, 20% (200 cows) of which are screened from the commercial population. With a mating ratio of 1:40, a population of 1000 cows translates to a total of 25 bulls being required for natural mating. These bulls, from the age of two years, are used for breeding for three years. The generation interval is four years. Assuming a calving rate of 80% and that one-third of calving results in a bull calf that is suitable for breeding, this herd would produce approximately 266 bull calves each year. If 10 bulls are needed each year (i.e. 10/266), this gives a selection intensity (i) of 2.18. For the females, 50% are selected after the first lactation has been completed. This gives a selection intensity of 0.80. Assuming that one-third of the calves are progenies of first calvers (unselected cows), the effective i value equals 0.80 × 2/3 = 0.53. Since the restriction is that herd size should remain constant, culling intensity is maximised. Therefore, 32% of cows are culled due to age, and are replaced with females newly selected from within the nucleus and from the participating herds. For the females in the participating herds, one is selected from each village herd of 45 females (i.e. 1/45). The selection intensity is therefore 2.39. Selection is based on a test-day milk yield, which is assumed to have a heritability estimate of 0.05 (lower than that of lactation milk yield in the nucleus). The generation interval from cows to their offspring is 6 years. Figure 15 shows an outline of the structure of this breeding programme.

As opposed to progeny testing where parents are specifically selected to breed offspring of a given sex, for pedigree selection only two selection pathways, sires to offspring and dams to offspring, are distinguished (Ruane and Smith 1989). However, in an open nucleus breeding scheme, a third selection pathway (that of commercial-born cows to offspring) should also be included. Table 20 shows the information sources for selection in these selection pathways.


Figure 15. Outline of the structure of the breeding programme.

Table 20. The information sources for selection in the three pathways.

Selection pathway

Information source1

Number records

Number calvings

Traits2

Bulls to offspring

Ind

1

 

DG, PDG

 

S

1

 

DG, PDG, LW

 

D

1

1

DG, PDG, MY, AFC

 

DD, SD

1

3

LW, MY, AFC

 

HSS

13

1

MY, AFC

 

HSD

12

1

LW, MY, AFC

Nucleus-born dams to offspring

Ind

1

1

DG, PDG, MY, AFC

 

S

1

 

DG, PDG, LW

 

D

1

2

DG, PDG, MY, AFC

 

DD

1

3

LW, MY, AFC

 

SD

1

3

LW, MY

 

HSS

13

1

MY, AFC

 

HSD

12

1

MY, AFC

Commercial-born dams to offspring

Ind

1

1

Test day milk yield

1. Ind = own performance; S = sire; D = dam; DD = dam’s dam; SD = sire’s dam; HSS = paternal half sib of sire; HSD = paternal half sib of dam.
2. DG = preweaning daily gain; PDG = post-weaning daily gain; LW = mature live weight; MY = milk yield; AFC = age at first calving.

The estimates of annual genetic gain in each breeding goal trait (Table 20) presented in Table 21 are based on the following:

where is predicted genetic gain per year for the kth trait over all selection pathways; i is the selection intensity; rIH is the accuracy of selection; σA is the genetic standard deviation; and  is the summation of generation intervals in ‘l’ selection pathways.

Table 21. Predicted annual genetic gain for the breeding goal traits.

Breeding goal traits

Predicted annual genetic gain

Lactation milk yield (kg)

19.42

Age at first calving (days)

–0.18

Preweaning daily gain (g/day)

1.35

Post-weaning daily gain (g/day)

2.72

Mature live weight (kg)

2.06

It should be noted that because of the deterministic approach, the input parameters (i.e. biological, technical and economic parameters) determined the results completely. Therefore, the potential usefulness of this example is limited by the validity of the assumptions. These results show that with a single nucleus herd of 1000 cows, there can be genetic progress in these traits by simply selecting young bulls and cows, on the basis of pedigree and their individual performance—early growth performance for the bulls and first lactation performance for the females. Due to lower inbreeding and higher selection intensity, opening the nucleus seems to be the most appropriate means of increasing variance in a population, to levels above that in both nucleus and field population. Use is then made of the extra genetic variance by selecting cows born in the field population for use in the nucleus. Since the major questions in establishing breeding and recording programmes are those of return on investments, different breeding programmes need to be compared in relation to the way they influence the accuracy of selection, genetic response, returns, costs and profit.

Apart from improving the animals in the field population, the described breeding programme will bring the participating farmers together and increase their contact with the extension agents. As already mentioned, contact with the extension agents will result in changes in animal management. With the support of the nucleus, participating farmers can come together and form a co-operative. Co-operatives normally work well when the membership is large and where incentives exist. In other words, co-operatives are money-driven. Money generated from the programme through sale of milk, and of culled and breeding animals should be enough to make the breeding programme self-sustaining. With time, these farmers could organise themselves to form a zebu cattle breeder’s society which would then serve to set the breed standards and promote the breed as their own. Breeding programmes based on nucleus herds belonging to NARS should, in the long run, be controlled and owned by farmer organisations, e.g. farmer co-operatives or breed societies.

Any efforts aimed at improving livestock production need to safeguard the functions of livestock at the individual farmer level as well as at the national level. It is important to note that quite often farmers are hesitant and slow in their acceptance of new ideas, as they have developed their own unique ways and methods of operation through experience. Any new ideas should thus have relevance to the farmers’ problems and provide tangible solutions to these. The innovation should, whenever possible, carry enough evidence to suggest potential for success. Most farmers are prepared to believe and adopt change only after seeing the proposed change successfully demonstrated. Answers to constraints to production do not appear to lie in giving isolated attention to individual problems, but rather in a multidisciplinary approach that will have to recognise regional or zonal variations in rural life and even the hidden potential of the indigenous breeds.

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