Breeding programmes for smallholder sheep farming systems: II. Optimization of cooperative village breeding schemes

Review on current status of Bonga, Afar, Menz, and Horro sheep breeds genetic improvement: Breeding program and progress

This working paper reviews the research and development in genetic improvement and breeding strategies of Bonga, Menz, Afar and Horro sheep in Ethiopia. This review aims to provide structured information regarding the Ethiopian indigenous sheep breeds (Bonga, Afar, Menz, and Horro) breeding programs and its progress. Genetic diversity is an essential element for genetic improvement, preserving populations, evaluation and adapting to variable environmental situations. Sustainable breeding techniques and sensible use of indigenous breed have been developed as result of recent research approaches to the conservation of sheep genetic resources. However, there is still growing interest of the government and of farmers in different breeding program to improve indigenous sheep breeds. There is no comprehensive study showing the performance of indigenous sheep breeds (Bonga, Afar, Menz, and Horro) genetic improvement under different breeding program and its progress, both biological and economic, to substantiate the argument on the benefit of different breeding programs for smallholders farmers. Programs for the sheep breeds Menz, Afar, Horro, and Bonga have now been developed at the community level. The idea behind the nucleus breeding program is to develop elite breeding animals by gathering the finest male and female breeding participants from the population in one central location. The first stage in creating a breeding program is defining the breeding goals. Planning breeding programs requires a thorough grasp of the farmers' (beneficiaries') breeding goals and production objectives. Therefore, this review makes it evident that numerous instruments and techniques, including choice experiments, participatory rural assessment procedures, and rating animals from flocks, have been used to define and ascertain the breeding aim of Afar, Horro, Bonga and Menz sheep breeds in Ethiopia.

Production systems and breeding practices of Begaria cattle breed as input for a community-based breeding program

This study aimed to describe the production systems and breeding practices of Begaria cattle breeds as a resource for community-based conservation and breeding program. A semi-structured questionnaire and focus group discussions were employed to identify and describe the breeding practice of the farmer. Three kebeles: Almahal, Fanguso, and Mankush were considered for the study. The data were analyzed using R software. Cattle were kept for a variety of reasons, including milk, breeding, meat, cash, and saving. It was typical throughout the study area to see herd mixing and keeping together (4.7 ± 0.33 herds on average), herd movement during the dry season, and breeding bull sharing (1.9 ± 1.55 shared bulls). During the summer season, cattle rearing in the areas was hindered by feed and water shortages. The breed's major reproduction constraints were abortion (24 %), repeat breeding (19), and calf mortality (14). The primary reason for keeping Begaria cattle was for milk (29 %), cash (26), meat (22), and breeding (0.22). The average age at first calving (AFC), calving interval (CI) and milk yield per day of the breed were 41.5 ± 1.63, 16.0 ± 0.43 months, and 3.2 ± 0.12 L respectively. The average age of breeding bull selection was 3 ± 0.1 years, and it was based on several criteria, including their phenotype, growth, and white coat colour. Based on the current findings, it is recommended that a multi-trait selection program be designed with full stakeholder participation.

Optimization of alternative breeding schemes for the genetic improvement of common Tigray highland sheep in northern Ethiopia

Background

Genetic improvement is one of the major means to enhance the productivity of livestock, and well-designed animal genetic improvement schemes are necessary to achieve genetic gains. The objective of the current study was to design an alternative breeding program to improve the productivity of common Tigray highland sheep. Two village- and two central nucleus-based breeding schemes were simulated and evaluated in terms of genetic gain, bio-economic efficiency and operational feasibility.

Methods

Four breeding schemes were simulated: scheme 1, a one-tier cooperative village-based breeding scheme, scheme 2, a two-tier cooperative village breeding scheme (dispersed village-based nuclei scheme), scheme 3, a central open nucleus-based scheme with 5% nucleus size; and scheme 4, a three-tier breeding schemes (central open nucleus-based linked with multiplier units). Simulation analyses were performed using the ZPLAN computer program, which is based on a deterministic approach to estimate genetic and economic gains in the breeding programs.

Results

Between the two village-based breeding schemes, scheme 2 showed higher genetic gain and economic efficiency in the breeding traits analysed than scheme 1. The central nuclei schemes were more efficient than the village breeding schemes. Scheme 3 was the most efficient with a genetic gain in the breeding objective of US $ 1.03 and a profit of US $ 2.73/ewe/year, but operationally it is also the most difficult to implement as it requires a big central nucleus. A central nucleus linked with the village-based nuclei would be a feasible option to overcome the operational difficulties of the conventional central nucleus schemes. If a village-based breeding program is considered it should be the first step in most low-input systems. In this case, scheme 2 is the most efficient.

Conclusions

With some support from the public sector at the outset and a strong collaboration among the stakeholders including smallholders, scheme 4 could lead to substantial genetic gains in the common Tigray highland sheep breed within its habitat that covers large areas of the Tigray region. Therefore, we recommend a long-term breeding program which should include cross-breeding, genomic selection, updated estimates of genetic and economic values for the common Tigray highland sheep breed.

Three easy fixes for sire use can enhance genetic progress in community-based breeding programmes

We analysed options to optimize the use of sires in sheep and goat community-based breeding programmes (CBBP) for three scenarios occurring under field conditions: premature sale of selection candidates, fixed service periods of selected sires and incomplete sire pedigrees. The first scenario was studied by looking at the outcome of combinations of selection pressures in successive selection stages. A compromise of early sale of sire candidates and genetic progress can be obtained by selecting in two stages, such that selection pressure in the first stage is chosen in terms of achieving an acceptable selection potential after the second stage. Simulations showed the dependency of this compromise on selection accuracies and correlation between selection criteria. For a typical sheep CBBP, only 20% of the top three months weighting male lambs need to be retained to achieve 80% of the potential selection differential on six months weight. For the second scenario, two alternatives to fixed service periods were analysed. When across-age BLUP EBVs are not available, individual sires can be programmed to stay in service according to their initial ranking. In typical sheep, CBBPs genetic progress can be increased by about 9% over response to selection with optimum fixed sire service periods. When BLUP EBVs are available, a simulated retrospective analyses of across-age selection of sires in two current sheep CBBPs increased more than twofold the average breeding values actually observed. Thirdly, we studied the benefit of considering possible sires and their mating probabilities when estimating BLUP breeding values instead of setting such sires as unknown. In a current goat CBBP with up to three possible sires included in the pedigree, the accuracy of breeding values nears the accuracy when sires are known and are higher than accuracies when sires are unknown or when possible sires are ignored.

Community-Based Livestock Breeding: Coordinated Action or Relational Process?

Over the past decade, community-based breeding programs (CBBPs) have been promoted as a viable approach to improving smallholder livelihoods through a systematic livestock breeding. CBBPs aim to initiate systematic breeding at the community level, including an organized animal identification and recording of performance and pedigree data. To ensure the breeding programs' continuity, building capacities, and ownership among participants are essential to the approach. This study's purpose was to understand how CBBPs have evolved in specific institutional settings and which dynamics occur in the course of implementation. We addressed these questions in reflective conversations with six coordinators of a diverse sample of CBBPs: goats (Malawi, Uganda, and Mexico), sheep (Ethiopia), alpaca (Peru), and cattle (Burkina Faso). The interviews and analysis were guided by categories of the multi-level perspective. The respondents considered lack of funding and weak institutionalization as the main constraints on the CBBPs. While the idea of participation and localized ownership was at the center of the programs, linear paradigms of knowledge transfer prevailed. In all cases, the impulse to start a CBBP came from individual researchers, who relied on intermediaries, such as extension agents, for implementation. Personal relations and trust were seen as both a factor in the success and a positive outcome of CBBPs. We conclude that these findings have different implications depending on how rural development is conceptualized: proponents of the innovation systems perspective would call for stakeholders to further align their interests and coordinate their actions. Proponents of process-relational concepts, in contrast, would not consider the CBBP a product but a starting-point for initiators and participants to continuously discover new ways of collaboration and engagement.

Leveraging Available Resources and Stakeholder Involvement for Improved Productivity of African Livestock in the Era of Genomic Breeding

The African continent is home to diverse populations of livestock breeds adapted to harsh environmental conditions with more than 70% under traditional systems of management. Animal productivity is less than optimal in most cases and is faced with numerous challenges including limited access to adequate nutrition and disease management, poor institutional capacities and lack of adequate government policies and funding to develop the livestock sector. Africa is home to about 1.3 billion people and with increasing demand for animal proteins by an ever growing human population, the current state of livestock productivity creates a significant yield gap for animal products. Although a greater section of the population, especially those living in rural areas depend largely on livestock for their livelihoods; the potential of the sector remains underutilized and therefore unable to contribute significantly to economic development and social wellbeing of the people. With current advances in livestock management practices, breeding technologies and health management, and with inclusion of all stakeholders, African livestock populations can be sustainably developed to close the animal protein gap that exists in the continent. In particular, advances in gene technologies, and application of genomic breeding in many Western countries has resulted in tremendous gains in traits like milk production with the potential that, implementation of genomic selection and other improved practices (nutrition, healthcare, etc.) can lead to rapid improvement in traits of economic importance in African livestock populations. The African livestock populations in the context of this review are limited to cattle, goat, pig, poultry, and sheep, which are mainly exploited for meat, milk, and eggs. This review examines the current state of livestock productivity in Africa, the main challenges faced by the sector, the role of various stakeholders and discusses in-depth strategies that can enable the application of genomic technologies for rapid improvement of livestock traits of economic importance.

Genetic diversity and population structure of South African smallholder farmer sheep breeds determined using the OvineSNP50 beadchip

A population structure study was performed in South African ovine populations using the OvineSNP50 beadchip. Blood samples were obtained from 295 sheep of which 172 had been identified as smallholder Dorpers, 4 smallholder White Dorpers, 46 purebred Dorpers, 26 purebred South African Mutton Merinos and 47 purebred Namaqua Afrikaners. Blood from the latter three breeds were obtained from a resource flock maintained on the Nortier research farm. Genetic diversity was estimated using allelic richness (A _r), observed heterozygosity (H _o), expected heterozygosity (H _e) and inbreeding coefficient (F). Population structure analysis was performed using fastSTRUCTURE to determine the breed composition of each genotyped individual. The Namaqua Afrikaner had the lowest H _e of 0.280 ± 0.18 while the H _e of smallholder Dorper, Dorper and South African Mutton Merino did not differ and were 0.364 ± 0.13, 0.332 ± 0.16 and 0.329 ± 0.17, respectively. The average inbreeding coefficient was highest for the pure breeds, Namaqua Afrikaner, Dorper and South African Mutton Merino compared to the average inbreeding coefficient for the smallholder Dorper population. The smallholder Dorper were introgressed with Namaqua Afrikaner, South African Mutton Merino and White Dorpers. Similarly, the smallholder Dorper population was more genetically diverse than the purebred Dorper, South African Mutton Merino and Namaqua Afrikaner from the research farm. The higher genetic diversity among the smallholder sheep may be advantageous for their fitness and can be used to facilitate selective breeding.

Purebreeding of Red Maasai and crossbreeding with Dorper sheep in different environments in Kenya

The aim of this article was to study opportunities for improvement of the indigenous and threatened Red Maasai sheep (RM) in Kenya, by comparing purebreeding with crossbreeding with Dorper sheep (D) as a terminal breed, in two different environments (Env. A and a harsher Env. B), assuming different levels of genotype-by-environment interaction (G × E). Breeding goals differed between environments and breeds. Four scenarios of nucleus breeding schemes were stochastically simulated, with the nucleus in Env. A. Overall, results showed an increase in carcass weight produced per ewe by more than 10% over 15 years. Genetic gain in carcass weight was 0.17 genetic SD/year (0.2 kg/year) across scenarios for RM in the less harsh Env. A. For survival and milk yield, the gain was lower (0.04-0.05 genetic SD/year). With stronger G × E, the gain in the commercial tier for RM in the harsher Env. B became increasingly lower. Selection of females also within the commercial tier gave slightly higher genetic gain. The scenario with purebreeding of RM and a subnucleus in Env. B gave the highest total income and quantity of meat. However, quantity of meat in Env. A increased slightly from having crossbreeding with D, whereas that in Env. B decreased. A simple and well-designed nucleus breeding programme would increase the genetic potential of RM. Crossbreeding of RM with D is not recommended for harsh environmental conditions due to the large breed differences expected in that environment.