Prediction of genetic gains for breeding objective traits and designing selection schemes for Washera and Gumuz indigenous sheep

In Ethiopia,there are 32.85 millions of sheep,more than 99 % of which are indigenous.However,the productivity of local sheep under traditional production system is low with high mortality of sheep.There are two ways of improving performance of sheep and goats,namely improving the enviroment of animals and/or improving there genetic potential.The aim of this study was to predict genetic gains of breedingobjective traits and select the best sheep selection scheme for Gumuz andWashera sheep. Body size(six month weight and yearling weight) and litter size were breeding objective traits identified by own flock animal ranking experiment and personal interview. Deterministic approach of ZPLAN computor program is used for modeling input parametres of Gumuz and Washera sheep and simulating breeding plans using gene flow method and selection index procedures. One-tier cooperative sheep breeding scheme were proposed whereby ram exchange between and within villages is the main means of genetic dissimination. Genetic gains predicted for six month weight of Gumuz and Washera sheep were 0.43 and 0.55 kg,respectively. Genetic gains predicted for yearling weight of Gumuz and Washera sheep were 0.55 and 0.60 kg,respectively. Genetic gains predicted for litter size of Gumuz and Washera sheep were 0.08 and 0.09 lambs,respectively. The lower rate of inbreeding, the higher monetary genetic gain for aggregate genotype,higher return to investmnet and higher profit/ewe/year were quality measures of breeding program considered to prefer scheme 4 for both Gumuz and Washera sheep.Hence,for both Gumuz and Washera sheep populations a sheep selection scheme designed with 15 % selection proportion and one year ram use for breeding was recommended. Special emphasis need to be given to yearling weight with higher predicted genetic response and higher percentage return to investment.

Transcriptome Analysis of Neuroendocrine Regulation of Ovine Hypothalamus-Pituitary-Ovary Axis during Ovine Anestrus and the Breeding Season

Most sheep are seasonal estrus, and they breed in autumn when the days get shorter. Seasonal estrus is an important factor that affects the productivity and fertility of sheep. The key point to solve this problem is to explore the regulation mechanism of estrus in sheep. Therefore, in this study, transcriptomic sequencing technology was used to identify differentially expressed mRNAs in the hypothalamus, pituitary and ovary of Small Tail Han sheep (year-round estrus) and tan sheep (seasonal estrus) among luteal, proestrus and estrus stages. There were 256,923,304,156 mRNAs being identified in the hypothalamus, pituitary and ovary, respectively. Functional analysis showed that the photosensor, leucine and isoleucine biosynthesis pathways were enriched significantly. It is speculated that photoperiod may initiate estrus by stimulating the corresponding pathways in hypothalamus. ODC1, PRLH, CRYBB2, SMAD5, OPN1SW, TPH1 are believed to be key genes involved in the estrogen process. In conclusion, this study expanded the database of indigenous sheep breeds, and also provided new candidate genes for future genetic and molecular studies on the seasonal estrus trait in sheep.

Isobaric Tags for Relative and Absolute Quantification-Based Proteomics Reveals Candidate Proteins of Fat Deposition in Chinese Indigenous Sheep With Morphologically Different Tails

Background: Chinese indigenous sheep can be classified into two types according to their tail morphology: fat-rumped and thin-tailed sheep, of which the typical breeds are Altay sheep and Tibetan sheep, respectively.Methods: To identify the differentially expressed proteins (DEPs) underlying the phenotypic differences between tail types, we used isobaric tags for relative and absolute quantification (iTRAQ) combined with multi-dimensional liquid chromatography tandem-mass spectrometry (LC-MS/MS) technology to detect candidate proteins. We then subjected these to a database search and identified the DEPs. Finally, bioinformatics technology was used to carry out Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses.Results: A total of 3,248 proteins were identified, of which 44 were up-regulated and 40 were down-regulated DEPs. Analyzing their GO function terms and KEGG pathways revealed that the functions of these DEPs are mainly binding, catalytic activity, structural molecule activity, molecular function regulator, and transporter activity. Among the genes encoding the DEPs, APOA2, GALK1, ADIPOQ, and NDUFS4 are associated with fat formation and metabolism.Conclusion: The APOA2, GALK1, ADIPOQ, and NDUFS4 genes may be involved in the deposition of fat in the tail of sheep. This study provides a scientific basis for the breeding of thin-tailed sheep.

Whole-Genome SNP Characterisation Provides Insight for Sustainable Use of Local South African Livestock Populations

Local cattle and sheep populations are important for animal production and food security in South Africa. These genetic resources are well adapted to the diverse climatic conditions and hold potential to be utilized in production systems subjected to climate change. The local beef breeds are well integrated into commercial livestock production systems with access to performance recording and genetic evaluations, while local sheep breeds are mainly utilised in smallholder and communal systems. The GeneSeek® Genomic Profiler™ Bovine 150 K SNP genotyping array was used to evaluate the diversity and inbreeding status of four indigenous (Boran, Drakensberger, Nguni, Tuli), two composite (Bonsmara and Beefmaster) and two exotic (SA Hereford and Charolais) beef breeds. The Illumina® Ovine 50 K SNP BeadChip was used to investigate five indigenous (Black Head Persian, Damara, Fat tail, Namaqua Afrikaner, Pedi) and three commercial (Dorper, Dohne Merino and SA Merino) populations. Although ascertainment bias was indicated by the low MAF (the autosome-wide proportion of SNPs with MAF< 0.05 ranged from 6.18 to 9.97% for cattle, and 7.59–13.81% for sheep), moderate genomic diversity was observed (mean Ho ranged from 0.296 to 0.403 for cattle, and 0.327 to 0.367 for sheep). Slightly higher levels of ROH-based inbreeding were calculated for cattle (FROH range: 0.018–0.104), than for sheep populations (FROH range: 0.002–0.031). The abundance of short ROH fragments (mean proportion of <4 Mb fragments: 0.405 for cattle, and 0.794 for sheep) indicated ancient inbreeding in both species. The eight cattle populations were categorized into indicine, taurine or Sanga subspecies based on principal component, model-based clustering and phylogenetic analyses, with high levels of admixture observed within the Drakensberger, Nguni and Tuli breeds. Within the sheep populations, a clear distinction could be seen between the dual-purpose breeds, the meat breed and the indigenous breeds. Despite directional selection practiced in the cattle breeds, genomic diversity was moderate with low inbreeding. The non-commercialized, indigenous sheep populations are more vulnerable with small effective populations. These results emphasise the value of genomic information for effective management to exploit the potential contribution of local genetic cattle and sheep resources in a changing environment.

Qualitative Characters of Indigenous Sheep in Central Brazil: Putting Phenotype into Perspective

For centuries, indigenous sheep have been bred in extensive low-input systems in Midwestern Brazil. The hypothesis of this study was the assumption that phenotypic evaluation of indigenous livestock may drive the establishment of breed standards and official breed recognition, and, therefore, promote more local business opportunities. On the basis of more integrative and participatory theoretical background to applying any decision based on phenotype, we designed this research to determine the most typical and unusual phenotypes of Pantaneiro sheep. Pantaneiro ewes (281 ewes from five conservation units in five counties) were evaluated, bearing in mind both conservation and development. Descriptive statistics were used to classify ewes into typical, intermediate, and unusual phenotypes. Chi-squared tests for association were performed to test if morphological variation in the different sampling sites occurred randomly (p > 0.05) or not (p < 0.05). Some results suggest some sort of diversifying selection pressure, i.e., distinct preferences among keepers. We observed considerable morphologic variation among ewes, but it was straightforward to determine the predominant phenotypes. The study evokes integrative agrobiodiversity by putting phenotypical characterization of indigenous livestock into perspective. Discussions coming from this study may support innovative governance and participative decision-making, allied with strategies that value the socioeconomic, biocultural, and adaptive aspects of indigenous livestock in tropical regions and developing countries. This is a challenge for government, rare-breed keepers, value-chain actors, and civil society.

Morphological variability within the indigenous sheep population of Benin

Knowledge of both the genetic diversity and geographical distribution of animal genetic resources is a prerequisite for their sustainable utilization, improvement and conservation. The present study was undertaken to explore the current morphological variability within the sheep population in Benin as a prelude for their molecular characterization. From November 2018 to February 2020, 25 quantitative linear body measurements and 5 qualitative physical traits were recorded on 1240 adult ewes from the 10 phytogeographic zones that comprise the three vegetation zones of Benin. Fourteen morphological indices were calculated based on the linear body measurements. The collected data were first analyzed using multiple comparisons of least-square means (LSmeans), followed by generalized linear model (GLM) procedures, to explore the relationships among the measured morphometric traits and the 10 phytogeographic zones. Next, the presence of any genetic sub-populations was examined using multivariate analytical methods, including canonical discriminant analysis (CDA) and ascending hierarchical clustering (AHC). Univariate analyses indicated that all quantitative linear body measurements varied significantly (P<0.05) across the phytogeographic zones. The highest values (LSmean± standard error) of withers height (68.3±0.47 cm), sternum height (46.0±0.35 cm), and rump height (68.8±0.47 cm) were recorded in the Mekrou-Pendjari zone, the drier phytogeographic zone in the North, whereas the lowest values, 49.2±0.34, 25.9±0.26, and 52.0±0.35 cm, respectively, were recorded in the Pobe zone in the South. Multivariate analyses revealed the prevalence of four distinct sheep sub-populations in Benin. The sub-population from the South could be assimilated to the short-legged and that from the North to the West African long-legged sheep. The two other sub-populations were intermediate and closer to the crossbreeds or another short-legged sub-breed. The proportion of individuals correctly classified in their group of origin was approximately 74%. These results uncovered a spatial morphological variation in the Beninese sheep population along a South-North phytogeographic gradient.

Discrimination study between the carcass and non-carcass components for interaction between gender, age, and production system in indigenous sheep

The objective of this work was to evaluate the yields, morphometric measures, carcass, and non-carcass components, and carcass regional and tissue composition of an indigenous sheep (Pantaneiro) of different physiological stages (gender, age, system production. Thirty sheep, eleven lambs, nine wethers, and ten cull ewes were used. The lambs were finished in feedlots, the wethers were maintained on pastures and supplementation, and the cull ewes were maintained on an extensive pasture system with mineral salt ad libitum. Slaughter ages were defined to simulate the most representative products and farming systems. Animals were slaughtered and classified as non- castrated lambs, wethers, and cull ewes. The criteria to slaughter lambs and wethers were the body condition, which ranged from 2.5 to 3.0. Cull ewes were slaughtered based on negative pregnancy diagnosis, regardless of their body condition, which ranged from 4.0 to 4.5. All animals were slaughtered after 16-hours of fasting (solids). The ewes presented the greatest fat thickness, differing significantly from the lambs. The morphometric measures were higher in ewes and lambs. The muscle to fat ratio of the animal’s cuts from different physiological stages presented no significant differences. The indigenous Pantaneiro sheep have good potential for meat production regardless of their physiological stages. The ewes stood out, presenting carcasses with good performance considering their potential and longer permanence in the herd due to their reproductive function.

Adaptation and Returns from Improved Indigenous Small Ruminants in Climatically Challenged Smallholder Systems of Kenya

Improved climate-resilient strains of indigenous sheep and goats were introduced in the Nyando basin of western Kenya in 2013. This study evaluated the performance of the breeds five years after their first introduction, and their contribution to household revenues. Red Maasai and Red Maasai x Dorper sheep and Galla goats introduced in Nyando adapted to the environment and retained performance levels exhibited in their original environments. They have been widely adopted by the farmers and are used for upgrading local breeds through crossbreeding, yielding offspring that are 50% heavier than local breeds at one year of age. Costs for producing the small ruminants tend to increase with land size owned, mainly due to higher costs for managing the health of more livestock. The costs of producing goats are significantly higher than for sheep. Revenues accrued from goat milk contribute to 10% of the revenue from goats. The introduced breeds provided a significant productivity lift in the local livestock population, resulting in higher returns to the smallholder farmers. For long-term sustainability of the productivity gains, a community-based selective mating program using reference sire flocks with an overall goal of good growth, adaptability, and milk production should be adopted.