Detection of genomic regions that differentiate from ancestral breeds for milk yield in Indian crossbred cows.

In India, crossbred cows incorporate the high production of dairy breeds and the environmental adaptation of local cattle. Adaptation to different environments and selection in milk production have shaped the genetic differences between and cattle. The aim of this paper was to detect, for milk yield of crossbred cows, quantitative trait loci (QTL) that differentiate from ancestry, as well as QTL that are segregating within the ancestral breeds.

Genomic evaluation of milk yield in a smallholder crossbred dairy production system in India.

Background: India is the largest milk producer globally, with the largest proportion of cattle milk production coming from smallholder farms with an average herd size of less than two milking cows. These cows are mainly undefined multi-generation crosses between exotic dairy breeds and indigenous Indian cattle, with no performance or pedigree recording. Therefore, implementing genetic improvement based on genetic evaluation has not yet been possible.

Genetic diversity and effective population sizes of thirteen Indian cattle breeds.

Background: The genetic structure of a diverse set of 15 Indian indigenous breeds and non-descript indigenous cattle sampled from eight states was examined, based on 777 k single nucleotide polymorphism (SNP) genotypes obtained on 699 animals, with sample sizes ranging from 17 to 140 animals per breed. To date, this is the largest and most detailed assessment of the genetic diversity of Indian cattle breeds.

Results: Admixture analyses revealed that 109 of the indigenous animals analyzed had more than 1% Bos taurus admixture of relatively recent origin.

Inference of Ancestries and Heterozygosity Proportion and Genotype Imputation in West African Cattle Populations.

Several studies have evaluated computational methods that infer the haplotypes from population genotype data in European cattle populations. However, little is known about how well they perform in African indigenous and crossbred populations. This study investigates: (1) global and local ancestry inference; (2) heterozygosity proportion estimation; and (3) genotype imputation in West African indigenous and crossbred cattle populations.

Effect of diet quality and shearing on feed and water intake, in vitro ruminal methane production, and blood parameters of Omani sheep.

The aim of this study was to evaluate the effect of diet and animal shearing on the feed and nutrient intakes, water intake, in vitro ruminal methane production, and blood parameters of Omani sheep. A pens trial was carried out for 16 days each in March and June of 2017 using 20 Omani non-castrated yearling rams selected from the sheep herd in the research station and randomly assigned to four groups with 5 animals per group. Group 1: sheared animals fed a high concentrate (HC) diet, group 2: fleeced animals fed a HC diet, group 3: sheared animals fed a low concentrate (LC) diet, group 4: fleeced animals fed a LC diet.

Detection of genomic regions underlying resistance to gastrointestinal parasites in Australian sheep.

Background: This study aimed at identifying genomic regions that underlie genetic variation of worm egg count, as an indicator trait for parasite resistance in a large population of Australian sheep, which was genotyped with the high-density 600 K Ovine single nucleotide polymorphism array. This study included 7539 sheep from different locations across Australia that underwent a field challenge with mixed gastrointestinal parasite species. Faecal samples were collected and worm egg counts for three strongyle species, i.

Using imputed whole-genome sequence data to improve the accuracy of genomic prediction for parasite resistance in Australian sheep.

Background: This study aimed at (1) comparing the accuracies of genomic prediction for parasite resistance in sheep based on whole-genome sequence (WGS) data to those based on 50k and high-density (HD) single nucleotide polymorphism (SNP) panels; (2) investigating whether the use of variants within quantitative trait loci (QTL) regions that were selected from regional heritability mapping (RHM) in an independent dataset improved the accuracy more than variants selected from genome-wide association studies (GWAS); and (3) comparing the prediction accuracies between variants selected from WGS data to variants selected from the HD SNP panel.

Results: The accuracy of genomic prediction improved marginally from 0.16 ± 0.