Search

In this study, expected genetic progress and economic benefits from implementing three community-based breeding programs for sheep (CBBP) out- and upscaling strategies were investigated. Strategy 1 is to replicate average existing CBBPs, strategy 2 is to increase the number of breeding males produced and disseminated by average CBBPs and strategy 3 is to intensify the use of breeding males with artificial insemination (AI). The strategies were modelled using field and market data from Ethiopian Menz sheep. The data included costs incurred by nucleus farmers to run the breeding program and base farmers to pay for improved rams. Genetic progress in six-month weight and economic benefit in US dollars with a reference planning horizon (H) of 20 years and a discount rate (r) of 0.07 were calculated using gene flow techniques. Genetic progress expected in average existing CBBPs came to 0.11 kg/year and accumulated discounted economic benefit (income/costs) was USD54,290 with a return on investment (income/costs) of USD5.1 per dollar invested. Thus, strategy 1, which replicates ongoing CBBPs, ranked highly beneficial. Strategy 2 was tested with 200 improved rams purchased at 1.1 times their meat market value. Accumulated discounted economic benefit with this strategy resulted in USD133,317 and return on investment was calculated at USD14.1. Cost of improved rams would need to be 2.5 times the current meat market value to make this strategy unprofitable. Strategy 3, taking advantage of AI, was tested in two ways: using fewer rams to increase selection differential in the nucleus of a CBBP (strategy 3a) and increasing the number of ewes in general herds served with improved rams (strategy 3b). Feasible AI programs were modelled allowing for lower conception rates and including all AI costs in the economic analyses. Strategy 3a increased genetic progress of six-month weight from 0.11 to 0.14 kg/year and strategy 3b increased the number of improved lambs from 7290 to 12,474. Therefore, incomes became larger but so did costs, leading to very low or negative benefits. Considering a shorter planning horizon (H = 10) and a larger discount rate (r = 0.12) would reduce benefits and returns to investment but would not change the general finding that out-scaling current CBBPs or upscaling the number of improved males from current CBBPs for dissemination are highly recommendable strategies for livestock development. However, AI, at current conception rates and costs, can only be justified with major subsidies or under specific circumstances.

Awassi dairy sheep farmers in the Middle East are facing high feed costs, particularly during the milk production season, along with large fluctuation in grain and straw prices. Incorporating agro-industrial byproducts into the diet of Awassi dairy sheep can help to balance diets and decrease costs. But it may affect milk quality through changes in the fatty acid profile. Six experimental diets were compared to a control diet in the research station of the International Center for Agricultural Research in the Dry Areas (ICARDA) in Tal Hadya, Syria. Milking Awassi ewes (n = 56) were used to test six experimental diets, in which supplements comprised molasses, sugar beet pulp, or cotton seed cake to a traditional control diet contained barley, wheat bran, and barley straw. Milk samples were collected on a weekly basis from April to June. The daily milk production and fat content were enhanced in diets containing urea-treated wheat straw (P

A meta-analysis of 84 published reports on goats was conducted to calculate weighted and unweighted average direct heritability (ha2), maternal genetic effect (hm2), common environmental effect (c2), repeatability (R), genetic (rg) and phenotypic (rp) correlations for growth, reproduction and milk production traits. Weighted average ha2, hm2, and c2 for growth traits ranged from 0.03 to 0.45, 0.05 to 0.27, and 0.02 to 0.10, respectively. Weighted average ha2 for reproduction and milk production traits ranged from 0.00 to 0.17 and 0.15 to 0.22, respectively. Weighted R for the growth, reproduction, and milk production traits ranged from 0.06 to 0.56, 0.06 to 0.13, and 0.50 to 0.61, respectively. Weighted averages of rp and rg among growth traits ranged from −0.06 to 0.84 and 0.01 to 0.98, respectively. Weighted average rp among milk production traits ranged from 0.18 to 0.94. In most cases average ha2 and rg had higher observed standard deviations compared to the theoretical standard error. The present finding revealed that weighted average ha2, hm2, c2, R, and rg are more reliable for two reasons: estimates of ha2 for some growth traits were more conservative than values from relatively higher number of records and the absence of significant effects of the tested fixed factors on some parameter estimates. However, studies on genetic parameter estimations are required for growth, reproduction, and milk traits in goats.

A structured questionnaire, own-flock ranking experiment, and group discussions were undertaken to assess goat breeding practices and to identify traits of interest for genetic improvement of indigenous goats. Four pastoral villages in Ethiopia, namely, Jarso, Mesoya, Eleweya, and Dharito were selected based on their goat production potential, accessibility, and suitability to implement community-based breeding programs. A survey and flock ranking experiment involving 70 households and 199 goats were used. In flock ranking experiment, goat owners were asked to choose the first three superior and the worst doe within their own flock. They were also asked to provide their reason for ranking the animals. In addition, data on size traits, kid growth, kid survival, reproduction traits, and milk yield were recorded for each doe. Data obtained from questionnaire, flock ranking, and measurements were subjected to both qualitative and quantitative analysis. Large variation was observed between top and last ranked does in most of the traits and price, for example, in body weight (33.6 ± 0.88 vs. 25.2 ± 0.93 kg), doe’s kid survival (92.1 ± 4.01 vs. 59.6 ± 4.48%) and doe’s price (1367 ± 46.5 vs. 833 ± 46.9 (US$1 = 28.4 Ethiopian Birr) Ethiopian Birr). Mobility is practiced with a defined and known pattern; therefore, recruitment of mobile enumerators for data recording would assist in implementation of breeding programs. Breeding objective should emphasize mothering ability (kid growth and survival), milk yield of does, and coat color in all areas. Due to its good correlation with other traits like kid growth and pre-weaning kid survival, considering milk yield alone as selection criteria or giving more weight for milk yield in the breeding program could generate better genetic benefit. Setting-up breeding program should be based on full participation and context of pastoralists.

With the main objective of improving Tajik mohair quantity and quality, frozen semen from eight top performance tested Texan Angora bucks was imported and used on 459 selected local goats from 11 farmers in two insemination seasons. Conception rates in both seasons were very low. Sixty six Texan x Tajik crossbred progeny were compared with 308 contemporary Tajik controls. Early live body weights, mohair quantity and mohair quality data were collected and genotypes compared after correcting for season, farm and sex of progeny, fitting age as a co-variable. Body weights at birth were higher in crossbreds (2.39 vs. 2.19 kg, P

Village- and central nucleus-based schemes were simulated and evaluated for their relative bio-economic efficiencies, using Ethiopia's Menz sheep as example. The schemes were: village-based 2-tier (Scheme-1) and 1-tier (Scheme-2) cooperative village breeding schemes, dispersed village-based nuclei scheme (Scheme-3), conventional 2-tier central nucleus-based scheme (Scheme-4), and schemes linking a central nucleus and village multiplier nuclei with selection in central nucleus (Scheme-5) or in both central and village nuclei (Scheme-6). Among village-based schemes, Scheme-1 gave the highest genetic progress, while Scheme-2 was economically the most efficient with genetic gain in the breeding objective of Birr 5.6 and a profit of Birr 37.2/ewe/year. The central nucleus schemes were more efficient than the village schemes. Scheme-4 was the most efficient with genetic gain in the breeding objective of Birr 13.5 and a profit of Birr 71.2, but is operationally more difficult as it requires a very large central nucleus. The choice between village and central nucleus-based schemes would depend on local conditions (availability of infrastructure, logistics and technical knowhow and support). Linking central nucleus with village-based nuclei (Scheme-6) would be a feasible option to overcome the operational difficulties of the conventional central nucleus scheme. If a village-based breeding program is envisaged as should be the 1st step in most low-input systems, then Scheme-2 is the most efficient. To scale out to an entire Menz breed level, Scheme-3 would be recommended.

A community-based sheep breeding program has been implemented in the highlands of Ethiopia to improve the body weight of Menz sheep. It is important to evaluate the potential consequences of such a breeding strategy on herd dynamics. For this purpose, a dynamic, stochastic herd model was built. The model adopts a system dynamics methodology to study the effect of genetic improvement of body weight on herd dynamics and profitability. The length of the time horizon was 240 months (20 years). The first 120 months served as a baseline scenario, where the fattening of culled breeding rams was practiced. For the second 120 months genetic selection of body weight was introduced considering two scenarios: culled ram and lamb fattening. Results from the model showed a gradual decrease in sheep population size while body weight of the animals improved. The model keeps heavier animals in smaller flocks to match the herd dry matter demand with the available resources. The simulation also demonstrates that breeding for heavier body weight was considerably more profitable than the baseline scenario; and lamb fattening was more profitable than culled ram fattening, as the current practice. Furthermore, voluntary culling may be used to balance herd size with available feed resources. The introduction of a more intensive system that provides more feed resources by resourceful smallholders can be used to achieve higher income without reducing flock size. Further work is however needed to evaluate the model introduced here against field results.

A simulation study was conducted to optimize a cooperative village-based sheep breeding scheme for Menz sheep of Ethiopia. Genetic gains and profits were estimated under nine levels of farmers' participation and three scenarios of controlled breeding achieved in the breeding programme, as well as under three cooperative flock sizes, ewe to ram mating ratios and durations of ram use for breeding. Under fully controlled breeding, that is, when there is no gene flow between participating (P) and non-participating (NP) flocks, profits ranged from Birr 36.9 at 90% of participation to Birr 21.3 at 10% of participation. However, genetic progress was not affected adversely. When there was gene flow from the NP to P flocks, profits declined from Birr 28.6 to Birr -3.7 as participation declined from 90 to 10%. Under the two-way gene flow model (i.e. when P and NP flocks are herded mixed in communal grazing areas), NP flocks benefited from the genetic gain achieved in the P flocks, but the benefits declined sharply when participation declined beyond 60%. Our results indicate that a cooperative breeding group can be established with as low as 600 breeding ewes mated at a ratio of 45 ewes to one ram, and the rams being used for breeding for a period of two years. This study showed that farmer cooperation is crucial to effect genetic improvement under smallholder low-input sheep farming systems.

Mohair quality of Angora goats in the Sogd Province of Tajikistan was assessed in spring and autumn 2007 and 2008 by inspecting and sampling a total of 797 goats of both sexes, different ages and several coat colors from 15 randomly selected flocks. Fiber fineness was assessed visually on the Bradford scale, staple length was measured with a ruler. Midside fleece samples were analyzed with an OFDA instrument to determine average fiber diameter, standard deviation, coefficient of variation (CVFD), comfort factor, fiber curvature and fiber length. On a subset of 153 goats, kemp and med fiber percentage were determined inspecting 300 fibers of each goat with a projection microscope. Mixed model procedures were used to analyze the data. Residuals of the model were used to calculate correlations. The random flock effect was significant for all traits and the fixed sex, age, and color effects were significant for most traits. In spring shearing data, fiber diameter of males was 2.7μm coarser than females and increased with age: 27.3μm (1 year old), 31.3μm (2 years old), 34.6μm (3–5 years old) and 37.0μm (6 years and older). Mohair fiber length ranged 137.3–174.7mm between ages. Six-month-old kid mohair (autumn shearing) was finest (24.4μm) and shortest (95.1mm). White mohair was approximately 3μm coarser than brown and gray mohair. CVFD was not affected by sex and age but related to color with white mohair having a lower CVFD. Comfort factor and visual Bradford count decreased with age. Average med and kemp percentages were 0.88 and 0.34. Almost 20% of goats had 2% or more medullated fibers. The phenotypic correlation between fiber diameter and med percentage was 0.40 and between fiber diameter and kemp percentage −0.08. On average, visual Bradford count underestimated fiber diameter by about 4.1μm. The correlation between fiber diameter and Bradford count was −0.28. Thus, visual assessment of fiber diameter is imprecise and reduction of fiber diameter through selection would therefore require analysis of fleece samples. The correlation between staple length and fiber length was 0.78. Thus, ruler determination of staple length measured on the live animals is a good estimator of fiber length measured on the fleece sample. In comparison with South African mohair, Tajik mohair is not only white, has long fibers, is rather coarse and medullated. Given the high variation between and within flocks in fiber diameter and medullation there is room for culling inferior animals and improve current mohair quality.