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To understand the ovarian basis for prolificacy of Bonga sheep, a total of 31 ewes were selected based on litter size (LS) records and divided into two groups: High Prolificacy (HP) (n = 20) with LS ≥ 2 and Low Prolificacy (LP) (n = 11) with LS = 1. At a synchronized estrus, follicular dynamics were determined using transrectal ultrasonography. Plasma estradiol concentrations were also monitored. In total 27 ewes were observed in estrus being 9/11 LP (82%) and 18/20 HP (90%). On the day of estrus (day 0), the mean number of large follicles was higher (p < .05) in HP (1.78 ± 0.19) than in LP (1.0 ± 0.28) ewes. Prior to estrus, more (p < .05) medium follicles were visible for HP compared to LP ewes. Plasma estradiol concentrations were higher in HP compared to LP ewes (18.91 ± 0.41 vs. 14.51 ± 0.65 pg/ml; p < .05) and similarly was ovulation number (2.3 ± 0.15 vs. 1.28 ± 0. 14; p < .05). Higher ovulation rates and litter size in Bonga sheep are evidenced by the previous presence of more large follicles and the existence of co-dominance effects as most likely medium follicles are selected to ovulate., (© 2020 Japanese Society of Animal Science.)

Maximizing the number of offspring born per female is a key functionality trait in commercial- and/or subsistence-oriented livestock enterprises. Although the number of offspring born is closely associated with female fertility and reproductive success, the genetic control of these traits remains poorly understood in sub-Saharan Africa livestock. Using selection signature analysis performed on Ovine HD BeadChip data from the prolific Bonga sheep in Ethiopia, 41 candidate regions under selection were identified. The analysis revealed one strong selection signature on a candidate region on chromosome X spanning BMP15, suggesting this to be the primary candidate prolificacy gene in the breed. The analysis also identified several candidate regions spanning genes not reported before in prolific sheep but underlying fertility and reproduction in other species. The genes associated with female reproduction traits included SPOCK1 (age at first oestrus), GPR173 (mediator of ovarian cyclicity), HB-EGF (signalling early pregnancy success) and SMARCAL1 and HMGN3a (regulate gene expression during embryogenesis). The genes involved in male reproduction were FOXJ1 (sperm function and successful fertilization) and NME5 (spermatogenesis). We also observed genes such as PKD2L2, MAGED1 and KDM3B, which have been associated with diverse fertility traits in both sexes of other species. The results confirm the complexity of the genetic mechanisms underlying reproduction while suggesting that prolificacy in the Bonga sheep, and possibly African indigenous sheep is partly under the control of BMP15 while other genes that enhance male and female fertility are essential for reproductive fitness.

African indigenous sheep are classified as fat-tail, thin-tail and fat-rump hair sheep. The fat-tail are well adapted to dryland environments, but little is known on their genome profiles. We analyzed patterns of genomic variation by genotyping, with the Ovine SNP50K microarray, 394 individuals from five populations of fat-tail sheep from a desert environment in Egypt. Comparative inferences with other East African and western Asia fat-tail and European sheep, reveal at least two phylogeographically distinct genepools of fat-tail sheep in Africa that differ from the European genepool, suggesting separate evolutionary and breeding history. We identified 24 candidate selection sweep regions, spanning 172 potentially novel and known genes, which are enriched with genes underpinning dryland adaptation physiology. In particular, we found selection sweeps spanning genes and/or pathways associated with metabolism; response to stress, ultraviolet radiation, oxidative stress and DNA damage repair; activation of immune response; regulation of reproduction, organ function and development, body size and morphology, skin and hair pigmentation, and keratinization. Our findings provide insights on the complexity of genome architecture regarding dryland stress adaptation in the fat-tail sheep and showcase the indigenous stocks as appropriate genotypes for adaptation planning to sustain livestock production and human livelihoods, under future climates.

The study was conducted to determine feed intake, digestibility, and body weight (BW) change of Washera sheep fed on desho grass and natural pasture hay as a basal diet and supplemented with concentrate mixtures. Twenty-five intact male sheeps with body weight of 19.4 ± 1.89 kg (mean ± SD) were used in randomized complete block design. The dietary treatments were 100% natural pasture hay (NPH) (T1), 75% NPH + 25% desho grass hay (DGH) (T2), 50% NPH + 50% DGH (T3), 25% NPH + 75% DGH (T4), and 100% DGH (T5). Equal amount of concentrate mixture (CM) (300 g DM/day/h) was supplemented in all of the five treatments. The result of laboratory chemical analysis revealed that the CP content of the basal diets increased with increased proportion of desho grass hay inclusion in the treatments at the expense of natural pasture hay. Total DM, OM, CP, NDF, and ADF intake and digestibility was significant (P < 0.05) and in the increasing order of T1 < T2 < T3 < T4 < T5. The average daily body weight gain (ADG) of experimental sheep was significantly (P < 0.05) higher as proportion of desho grass increased from 0 to 100% in the basal diet. The result indicated that desho grass can be used as a basal diet for local sheep with better performance than natural pasture hay-based diets.

Pedigree recording and genetic selection in village flocks of smallholder farmers have been deemed infeasible by researchers and development workers. This is mainly due to the difficulty of sire identification under uncontrolled village breeding practices. A cooperative village sheep-breeding scheme was designed to achieve controlled breeding and implemented for Menz sheep of Ethiopia in 2009. In this paper, we evaluated the reliability of pedigree recording in village flocks by comparing genetic parameters estimated from data sets collected in the cooperative village and in a nucleus flock maintained under controlled breeding. Effectiveness of selection in the cooperative village was evaluated based on trends in breeding values over generations. Heritability estimates for 6-month weight recorded in the village and the nucleus flock were very similar. There was an increasing trend over generations in average estimated breeding values for 6-month weight in the village flocks. These results have a number of implications: the pedigree recorded in the village flocks was reliable; genetic parameters, which have so far been estimated based on nucleus data sets, can be estimated based on village recording; and appreciable genetic improvement could be achieved in village sheep selection programs under low-input smallholder farming systems.

The genetic trends in fitness (inbreeding, fertility and survival) of a closed nucleus flock of Menz sheep under selection during ten years for increased body weight were investigated to evaluate the consequences of selection for body weight on fitness. A mate selection tool was used to optimize in retrospect the actual selection and matings conducted over the project period to assess if the observed genetic gains in body weight could have been achieved with a reduced level of inbreeding. In the actual selection, the genetic trends for yearling weight, fertility of ewes and survival of lambs were 0.81 kg, -0.00026% and 0.016% per generation. The average inbreeding coefficient remained zero for the first few generations and then tended to increase over generations. The genetic gains achieved with the optimized retrospective selection and matings were highly comparable with the observed values, the correlation between the average breeding values of lambs born from the actual and optimized matings over the years being 0.99. However, the level of inbreeding with the optimized mate selections remained zero until late in the years of selection. Our results suggest that an optimal selection strategy that considers both genetic merits and coancestry of mates should be adopted to sustain the Menz sheep breeding program.

Feeding agro-industrial by-products and unconventional forages, rich in potentially anti-nutritional factors, may influence the quality of the raw milk and the dairy products prepared therefrom. The aim of the present study was to determine side-effects on physicochemical properties of milk, yoghurt and cheese of feeding diets where one third were feeds either rich in lipids (tomato pomace and olive cake) or phenols (olive leaves and lentil straw) or electrolytes (Atriplex leaves). The diets, including a control diet, were designed to be isoenergetic and isonitrogenous. They were fed in amounts of 25 kg dry matter/day per head during 50 days to 6×10 multiparous fat-tailed Awassi ewes. Milk samples were analysed for various physicochemical traits and fatty acid composition on days 0, 24, 36 and 48. Three times, milk pooled by group was processed to yoghurt and non-aged farmer-type cheese, which were analysed for their gross and fatty acid composition and texture, and were subjected to sensory evaluation. Feeding olive cake and tomato pomace reduced milk casein, but increased proportions of monounsaturated fatty acids. There were some variations in minerals among test diets but, contrary to expectations, Atriplex did not increase milk sodium. The nutritional composition of yoghurt and cheese was not varied much by the test feeds, except for some changes in fatty acid profile similar to the milk. Yoghurt firmness declined with all test diets, but texture score tended to be lower only for olive cake and leaf diets relative to control. Cheese firmness was increased by feeding the Atriplex leaf and olive cake diets which was also reflected in the texture scores. No off-flavours were reported. Possible reasons for effects on the dairy products are discussed. In conclusion, the feeds investigated had certain effects on the physicochemical properties of dairy products, but these were neither very systematic nor large thus not prohibiting their use in Mediterranean sheep milk production systems.

Community-based breeding programs (CBBPs) have shown, at pilot scale, to be effective and beneficial in achieving genetic progress and in improving livelihoods of smallholder communities. In Ethiopia 134 sheep and goat CBBPs were operational producing their own improved rams and bucks. Based on experience the implementation of further programs is possible with appropriate private and public support. A different challenge is the efficient dissemination of the improved genetics produced in current CBBPs to create population-wide economic impact. We present a framework applied to the Ethiopian Washera sheep breed to meet this challenge. We propose the establishment of a genetic improvement structure that supports a meat commercialization model based on the integration of community-based breeding program cooperatives, client communities and complementary services such as fattening enterprises. We calculated that the recently established 28 community-based breeding programs in the Washera breeding tract can provide genetically improved rams to 22% of the four million head. To reach the whole population 152 additional CBBPs are needed. We simulated the genetic improvements obtainable in the current 28 CBBPs assuming realized genetic progress in CBBPs of a similar breed and calculated the expected additional lamb carcass meat production after 10 years of selection to be 7 tons and the accumulated discounted benefit 327 thousand USD. These benefits could be increased if the CBBPs are linked to client communities by providing them with improved rams: additional meat production would be 138 tons with a value of 3,088 thousand USD. The total meat production of the existingWashera CBBPs was calculated at 152 tons and the joint meat production of CBBPs if integrated with client communities would be 3,495 tons. A full integration model, which includes enterprises purchasing lambs for fattening, can produce up to 4,255 tons of meat. We conclude that Washera CBBPs cooperatives can benefit from a higher level of organization to produce population-wide genetic improvement and economic benefits. Unlike in the dairy and chicken industries, for low input sheep and goat smallholder systems the proposed commercialization model puts breeder cooperatives at the center of the operation. Cooperatives need to be capacitated and supported to become fully functional business ventures. [ABSTRACT FROM AUTHOR]

Background: Ticks are obligate haematophagous ectoparasites considered second to mosquitos as vectors and reservoirs of multiple pathogens of global concern. Individual variation in tick infestation has been reported in indigenous sheep, but its genetic control remains unknown. Results: Here, we report 397 genome-wide signatures of selection overlapping 991 genes from the analysis, using ROH, LR-GWAS, XP-EHH, and FST, of 600 K SNP genotype data from 165 Tunisian sheep showing high and low levels of tick infestations and piroplasm infections. We consider 45 signatures that are detected by consensus results of at least two methods as high-confidence selection regions. These spanned 104 genes which included immune system function genes, solute carriers and chemokine receptor. One region spanned STX5, that has been associated with tick resistance in cattle, implicating it as a prime candidate in sheep. We also observed RAB6B and TF in a high confidence candidate region that has been associated with growth traits suggesting natural selection is enhancing growth and developmental stability under tick challenge. The analysis also revealed fine-scale genome structure indicative of cryptic divergence in Tunisian sheep. Conclusions: Our findings provide a genomic reference that can enhance the understanding of the genetic architecture of tick resistance and cryptic divergence in indigenous African sheep. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In Tunisia, livestock plays an important role in the economy; unfortunately, Tunisian sheep population faces several health challenges. The aim of this trial was to study phenotypic variability of four local sheep breeds and strains to abomasum nematodes infection and to Babesia/Theileria parasites. Faeces, blood and abomasum contents were collected from 310 sheep slaughtered in eight commercial slaughterhouses across North Tunisia. Haematological and biochemical parameters were assessed. DNA was extracted and catch‐all primers were used to detect both Theileria spp. and Babesia spp. DNA. Faecal egg counts (FEC) was quantitatively assessed using simple flotation technique followed by McMaster technique. Male and female worms were collected from all abomasum contents and counted under a stereomicroscope. The percentage of faeces samples positive for GIN's eggs was 30.82%. After worms' recovery, the infection prevalence was estimated to 75.90%. The overall infection prevalence by Babesia spp. and Theileria spp. was 4.21%. The dispersion of observations plots obtained by principal component analysis (PCA) showed two clusters of individuals. The first cluster contains animals having positive Babesia/Theileria PCR, presence of nematodes in the abomasum contents and relatively low total worm count (TWC < 500) expect one animal which was found bearing high TWC (>500). In this same group, with a suspected form of resistance, animals showed normal values of albumin and normal haematological parameters (red blood cell count [RBC], haemoglobin [Hb] and packed cell volume [PCV]). The second cluster represents all the other observations in which subgroups of animals were distinguished on the basis of their potential resistance to abomasum nematodes. Multiple correlations showed significant positive correlations between RBC/Hb, RBC/PCV, PCV/Hb and FEC/TWC. Significant negative correlations were observed between TWC/RBC and TWC/Hb. It is concluded that the phenotypic variability among local sheep breeds is essential for more advanced genetic and genomic studies. [ABSTRACT FROM AUTHOR]

To understand the ovarian basis for prolificacy of Bonga sheep, a total of 31 ewes were selected based on litter size (LS) records and divided into two groups: High Prolificacy (HP) (n = 20) with LS = 2 and Low Prolificacy (LP) (n = 11) with LS = 1. At a synchronized estrus, follicular dynamics were determined using transrectal ultrasonography. Plasma estradiol concentrations were also monitored. In total 27 ewes were observed in estrus being 9/11 LP (82%) and 18/20 HP (90%). On the day of estrus (day 0), the mean number of large follicles was higher (p < .05) in HP (1.78 ± 0.19) than in LP (1.0 ± 0.28) ewes. Prior to estrus, more (p < .05) medium follicles were visible for HP compared to LP ewes. Plasma estradiol concentrations were higher in HP compared to LP ewes (18.91 ± 0.41 vs. 14.51 ± 0.65 pg/ml; p < .05) and similarly was ovulation number (2.3 ± 0.15 vs. 1.28 ± 0. 14; p < .05). Higher ovulation rates and litter size in Bonga sheep are evidenced by the previous presence of more large follicles and the existence of co-dominance effects as most likely medium follicles are selected to ovulate. [ABSTRACT FROM AUTHOR]

Heart girth (HG) bands have been predominantly used in Ethiopia by smallholder farmers, traders and extension workers to estimate liveweight (LW) of livestock. They are produced using recommended and published predictive models from Ethiopia. More recently, some farmers and traders have abandoned the bands due to perceived inaccuracy of LW estimation and reverted to eye-ball estimations. The present study generated a novel algorithm using multiple criteria to develop a robust predictive model for LW estimation of Ethiopian Menz sheep by using HG. Subsequently, recommended models currently in use in Ethiopia were evaluated for accuracy in predicting LW, using data of the present study. Liveweight and HG of 420 Menz sheep were measured. Simple linear model (SLM), Box–Cox (SLM with LW0.75), quadratic and allometric models were used to describe the relationship between LW and HG. Algorithms used to validate the models included data exploration, model construction and model redeployment. Results showed that all models had similar R 2 (≈0.82). All models fitted the criteria of residual analysis and robustness against extreme values. However, only Box–Cox was robust against data redeployment, with 95th percentile of prediction error (PE) less than 10%. Accordingly, a Box–Cox model (LW0.75 = –9.71 + 0.289 (HG)) is robust and can be used to accurately predict LW of Menz sheep. The 95th percentile of PE of existing, recommended models was higher than 10; thus, they cannot be recommended to accurately predict LW of Menz sheep. The present study concludes that an approach based on regressing LW on HG, and then selecting models with the highest R 2, is inadequate to generate accurate and robust prediction models. This highlights the importance of model redeployment to generate accurate prediction models. Calibrated HG bands are suitable alternatives to weighing scales in rural areas of Ethiopia because they are cheaper and not subject to maintenance. Thus, their accuracy and robustness in estimation of LW is vital for sustainable use. Heart girth (HG) bands are suitable alternatives to weighing scales in rural areas of Ethiopia; thus, their accuracy in estimating liveweight (LW) is vital for sustainable use. Regressing LW on HG of Menz sheep, then selecting models with the highest R 2 generates inaccurate prediction models. A novel algorithm using multiple criteria was generated to develop a robust predictive model for LW estimation of Ethiopian Menz sheep by using HG. Model redeployment is crucial to generate accurate prediction models. [ABSTRACT FROM AUTHOR]

• Abortion and neonatal losses were main reproductive problems identified. • Three abortive agents (T. gondii, Chlamydia spp. and C. burnetti) were detected. • Higher seroprevalence of Chlamydia spp. detected in studied flock. Community-based sheep breeding programs (CBBPs) were established in Ethiopia since 2010. Improved rams from CBBPs need to be disseminated. However, there is a risk of transmitting reproductive diseases to other community flocks. To investigate this a cross-sectional study was conducted in 2015/16 to determine serological status of major infectious causes of abortion and associated risk factors in sheep in the highlands of Ethiopia. A total of 120 households from three districts (Bonga, Horro and Menz) were enrolled in the study. Per farm, 3–4 samples of animals aged >2 years were collected. A total of 445 sera were tested for Chlamydia spp., Coxiella burnetti , Toxoplasma, Brucella spp. and Border disease virus. Poison regression was used to model the number of abortions, number of neonatal lost and number of stillbirths in the flocks. A mixed-effects logistic regression model was fitted to identify covariates associated with prevalence of infectious causes of abortion. The study found that 20% [95% CI 12.74, 27.26] of flocks had recent experience of sheep abortion, lamb losses was at 65% [95% CI 56.34,73.65] and still birth at 10% [95% CI 4.55,15.44]. The incidence risk ratio for abortion was higher in larger flocks. Neonatal losses were higher in C. burnetii and Toxoplasma gondii positive flocks, in one of the districts, and in flocks with more than 30 animals. The serological analyses revealed the presence of three abortive infections, while none of the samples tested positive for Brucella spp. or Border disease virus. Of the 120 flocks tested, 107 (89.17%) were positive for Chlamydia spp., 82 (68.33%) for C. burnetii , and 85 (70.83%) for T.gondii. The results highlight the likely contribution of different infectious agents in the reproductive disorders in sheep production in Ethiopia. The high sero-prevalence of infectious agents, especially Chlamydia spp., at both flock and animal level, warrants more in-depth research to attribute reproductive problems to these pathogens. [ABSTRACT FROM AUTHOR]