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ABSTRACTIn this study, breeding objective traits were identified, and alternative breeding schemes were simulated and evaluated for two goat populations. The traits were as follows: body size, twinning ability and kidding interval (KI) for Arab goats and body size, twinning ability and mothering ability for Oromo goats. The selection criteria were six-month weight (6mw, kg), litter size at birth (LSB), litter size at weaning (LSW) and KI (days). The schemes were as follows: (1) Scheme 1: 2 years of buck use and 10% selection proportion, (2) Scheme 2: 2 years of buck use and 15% selection proportion, (3) Scheme 3: 3 years of buck use and 10% selection proportion, and (4) Scheme 4: 3 years of buck use and 15% selection proportion. The predicted annual genetic gain (PAGG) for 6mw ranged from 0.29 to 0.32 kg for Arab goats while it varied from 0.34 to 0.38 kg for Oromo goats. On the contrary, the PAGGs for LSB and LSW for both populations were considerably small regardless of the different schemes. The economic return (Euro/doe) ranged from 0.99 to 1.15 for Arab goats and from 0.60 to 0.70 for Oromo goats. SCM2 is recommended over other schemes.

ABSTRACTThis study was conducted to investigate the effect of different estrus synchronization protocols followed by artificial insemination on estrus response and the conception rate of Abergelle goats. Three estrus synchronization protocols: (i) the standard protocol associating progestogens, gonadotropins and prostaglandins (P4 + eCG + PGF2α), (ii) single injection of prostaglandin (PGFS), (iii) double injection of prostaglandin (PGFD) were evaluated and compared to a control group that did not receive a hormonal treatment. Estrus behaviour was monitored in all does and those in estrus were inseminated. The estrous response was significantly higher in P4 + eCG + PGF2αdoes than in counterparts in PGFSand PGFDgroups (p < 0.001). Results also revealed an earlier onset of estrus in the PGFD-treated group, a longer duration of estrus for second- and third- parity -does and an earlier onset of estrus in animals having a 3.5 body condition score. Even if the conception rate (CR) was highest when using the PGFDprotocol, the lowest kidding rate (KR) was obtained when using this same treatment. The P4 + eCG + PGF protocol yielded the highest litter size. Farmers’ perception surveys revealed that a higher proportion of goat keepers used a controlled mating system and had culling practices and farmers selected PGFDas a preferred protocol.

Reproductive traits of sheep are under the control of both the environment and genetics. Moreover, most of these traits have low heritability, are sex-limited, and expressed later in the animal’s life, which makes it difficult to quantify in young animals and to apply direct selection to the traits. This calls for the need to identify and include the genetic bases of fertility traits in selection decisions to enhance the performance of fertility traits in sheep breeding programs. Therefore, several polymorphisms in many genes associated with fertility traits have been reported in several sheep breeds worldwide. The bone morphogenetic protein 15 (BMP15), bone morphogenetic protein receptor 1B (BMPR1B), and growth differentiation factor 9 (GDF9) genes are the major fecundity genes investigated in several sheep breeds studied. Polymorphisms on these genes have shown significant associations with fertility traits such as ovulation rate and litter size and have been used in selection programs. However, research findings focusing on candidate genes affecting fertility traits in indigenous sheep breeds from developing countries are lacking. This review has shown that the genes and the polymorphisms on the genes are variable between and within breeds of the sheep explored thus far, which calls for further efforts to examine sheep breeds in developing countries.

ABSTRACTThe study investigated, for fixed time artificially inseminated (AI) Menz ewes in field trials, the reproductive performance of prostaglandin-based treatments simultaneously to the standard ‘P4+eCG’ protocol. A total of 483 Menz ewes were assigned to either the ‘P4+eCG’ protocol, using progesterone impregnated intravaginal sponges in combination with equine chorionic gonadotropin (eCG) injection at sponge withdrawal, or the ‘PGFs’ treatment where sheep received a single injection of prostaglandin or ‘PGF7’ and ‘PGF11’ where ewes were synchronized with 2 injections of prostaglandin 7 or 11 days apart, respectively. AI was implemented with fresh semen at 55 ± 1 h after the end of the hormonal treatment. Conception rate (CR; 60.87 ± 4.2) was highest for PGF11ewes (P < 0.05); PGFsewes had the lowest CR (34.07 ± 4.1). Other factors did not affect variation in CR (P > 0.05). A higher proportion of ewes in the P4+eCG group yielded twins and triplets compared to the 3 prostaglandin-based protocols (P < 0.01). Nevertheless, a higher (P = 0.02) proportion (17.11 ± 4.3) of PGF11ewes yielded twins by comparison to their PGF7counterparts (2.50 ± 2.5). PGF-based protocol with 2 injections 11 days apart, preceded by a careful selection of non-pregnant ewes for cervical fixed-time AI, is a feasible reproductive management for sheep breeding programmes in Ethiopia.

•Elicited goat trait preferences of pastoralists with all-levels and end-point choice experiments.•All-levels design explained pastoralists’ choice behavior better than end-point design.•Drought tolerance, white coat, and disease tolerance are the most preferred traits of bucks and does.•Pastoralists have clear hierarchy for the traits in choosing the next generation of goats.