Morphological features of indigenous chicken populations of Ethiopia

This study describes the variations in the physical features and the useful attributes of different populations of indigenous chickens. Five populations of chickens in different regions of Ethiopia were studied based on 13 qualitative traits recorded for a total of 1 125 chickens. Additional measurements on quantitative traits (shank length and body weight) were also included. Descriptive statistics (nonparametric and F tests) were used to analyze the data. Each of the study populations possessed multiple variants of plumage colours and other physical features. However, white body plumage is one of the prominent features of Farta chickens and red is predominant in the other populations. Pea comb is the dominant comb type in all regions. Most of the chickens in the high altitude regions have yellow skin. The geographic distribution and frequency of naked neck chickens are generally small, and the available small proportion is found mainly in the low altitude regions. Males in all populations are heavier and taller than the females. Body weights range from 1 411 g (Konso) to 1 700 g (Horro) in adult males and from 1 011 g (Konso) to 1 517 g (Sheka) in females. Most of the morphological traits that were studied showed a very low level of associations with each other

A running breeding program for indigenous chickens in Ethiopia: Evaluation of success

In 2008 a breeding program to increase production level in indigenous chickens was initiated at the Debre Zeit Agricultural Research Center in Ethiopia and is currently producing its 8th generation. Aim of this paper was to evaluate the success of the breeding program. Selection was on own performance for bodyweight at 16 weeks of age (BW16) and for the hens also on cumulative egg number at week 45 of laying (EN45). Heritability for BW16 in the 6th generation (G6) was 0.37, and for EN24 was 0.32. Phenotypic correlation between BW16 and EN24 was 0.36, but genetic correlation was -0.12. Genetic correlations of BW16 with cumulative egg production earlier in the laying series were 0.51 at 8 weeks of laying, decreasing to 0.22 at 16 weeks of laying. The genetic trends were positive for both traits under selection from generation 4 (G4) and G6

Analysis of Alternative Pure-breeding Structures for Sheep in Smallholder and Pastoral Production Circumstances in the Tropics

The key issue in this study was to technically compare, through stochastic simulation, different breeding programmes that vary in the level of interaction between breeders and producers. The breeding structures considered were: (i) a single closed nucleus providing seed-stock to village flocks, (ii) a group of commercial flocks running a co-operative (‘ram circle’) breeding programme with no nucleus, (iii) an interactive two-tier open nucleus breeding scheme, comprising a nucleus and a commercial tier - the best males are used within the nucleus while the remainder migrate to the commercial flocks, with no female migration, and (iv) as scheme iii but with female migration between tiers. For the latter two schemes, 100% of the nucleus animals are distributed over village flocks every 3 years. The nucleus is then replaced by a new batch of selected males and females from the village flocks obtained through ‘interactive cycling screening’, based on ‘picking the best phenotype’ in the commercial flocks. Single trait selection was considered, and based on estimated breeding value, using either best linear unbiased prediction (BLUP) or the individual’s phenotype as a deviation from contemporaries in the same flock, year and season. The results showed that genetic merit increased slightly and inbreeding decreased significantly with increase in nucleus size. For instance, with BLUP selection and trait measurement on both sexes, and first record established at year 2, a nucleus size of 100 dams with 50 dams mated to each sire resulted in genetic merit of 0.118 units and an average inbreeding coefficient of 0.119 while that with 500 dams gave a response of 0.134 with an average inbreeding coefficient of 0.037. Running one closed nucleus had a 6-24% advantage over a ‘ram circle’ in terms of genetic gain. Decreasing the dam to sire ratio was a simple way to avoid inbreeding in breeding schemes of small size, with very little compromise towards genetic gain or even an increase in the longer term. Relative to a two-tier nucleus (scheme i), cyclic screening of commercial animals for use in the nucleus gave an almost optimum genetic response, while the villagers acquired superior breeding stock in return as an incentive to participate in genetic improvement. Participation of farmers offers them a sense of ownership of the breeding programme, and is likely to make it more sustainable in the long-term. This study provides insight into the advantages and disadvantages of designed breeding structures, especially the ‘interactive cyclic’ breeding schemes, which should be useful in deciding breeding programmes to adopt for sheep in developing countries in the tropics. Keywords: Sheep, Breeding Structures, Selection, Tropic

Farm Level Economic Implications of Genetic Selection for Improving Milk Fat Composition

The objective of the study was to assess the farm level economic implications of value-adding genetic selection strategies to improve milk fat composition. Selection based on a quantitative trait (ratio of total saturated to total unsaturated fatty acids in milk) or a known genotype (for the DGAT1 gene) was considered. Technical and economic performance of hypothetical herds were computed by a herd optimization and simulation model. It was assumed that the herds are already bred for the specific milk composition, and the transition period was not considered. Correlated effects of the selection scenarios on milk production, female fertility, and functional longevity traits were accounted for. Results showed that increasing the total unsaturated fatty acids in milk by traditional selection leads to lower net revenue, whereas selection based on DGAT1 genotype results in slightly higher net revenue. Our results, therefore, suggest that genetic selection based on DGAT1 genotype is a more profitable strategy for dairy farmers than selection based on phenotypes for SFA/UFA ratio.dairy cattle, genetic selection, milk composition, farm economics, Livestock Production/Industries,

Characterization and conservation of indigenous sheep genetic resources: A practical framework for developing countries

Livestock characterization projects in developing regions are characterized by a mere physical description of traditionally recognized populations or a purely academic genetic description of populations. However, characterization of livestock resources is meant to serve the purpose of developing conservation and utilization programs. A national characterization project should be geared to the specific national livestock production objectives. Thus there is a need to adopt a more practical characterization approach to assist in the development of national conservation and utilization strategies. This report provides a practical methodological framework suited for characterization and conservation of sheep resources in developing regions. The report highlights current approaches and tools for characterization and conservation of sheep resources and presents a model approach synthesising results of a study on characterization and conservation of sheep resources of Ethiopia. The study is a collaborative project between Wageningen University and the International Livestock Research Institute. The methodological framework can be applied elsewhere in developing countries with similar characterization and conservation objectives. This report largely dwelt on the technical aspects of sheep genetic resource characterization and conservation in developing regions. Operational aspects of setting up national programs for characterization and conservation action may be country specific. However, some general aspects such as institutional setups and breeding policy and strategy formulation could be similar across countries. A proposed scheme for setting up a national livestock characterization and conservation program is presented, taking Ethiopia as a case study

Economic values for traits of meat sheep in medium to high production potential areas of the tropics

Breeding objectives were developed for meat sheep in smallholder production circumstances in the tropics. The traits considered were litter size, lambing frequency, pre-weaning, and post-weaning lamb survival to 12 months, ewe survival, lamb live weight at 12-month, mature ewe live weight, consumable meat, kg of manure DM sold per ewe per year and residual DM feed intake. Three evaluation situations were considered: (i) base with constant number of ewes, (ii) fixed feed resource and (iii) setting feed costs to zero. Sensitivity analysis of economic values to price levels of inputs and meat production was carried out. The fixed feed resource situation appropriately describes smallholder production circumstances. In the base situation, meat production accounted for about 88% of revenue and manure the remaining 12%. Variable costs represented about 95% of the total cost. For the fixed feed resource situation, economic values (US$ per ewe per year) were 12.94 for litter size, 10.18 for lambing frequency, 0.19 for pre-weaning lamb survival, 0.24 for post-weaning lamb survival, 0.36 for ewe survival, 1.02 for 12-month lamb live weight, 0.14 for mature ewe live weight, 0.51 for consumable meat, 0.08 for kg of manure DM sold (per ewe per year) and -0.04 for residual DM feed intake. Litter size and lambing frequency were the most important traits in a breeding objective for smallholder production. Relative to the base situation, setting feed costs to zero had similar results as the situation with restricted feed resource but resulted in larger differences. Sensitivity analysis of economic weights to changes in prices and production circumstances indicated that future economic values for traits might change dependent on levels of output and prices. The exceptions, with regard to changes in meat price are kg of manure DM sold per ewe per year and residual DM feed intake, and with regard to feed costs are consumable meat and kg of manure DM sold per ewe per year. Economic values for 12-month lamb live weight, mature ewe live weight, consumable meat, kg of manure DM sold per ewe per year and residual DM feed intake were not sensitive to changes in management and marketing circumstances. Caution is recommended when the breeding objectives presented here are applied not to disadvantage smallholders in poor climatic years, when farmers are at their most vulnerable situation