Mohsin Ayoub Mir

Corriedale is a globally recognized dual-purpose sheep breed reared for meat and wool production. It was developed by crossing Merino Ewes and Lincoln Rams, combining the fine wool quality of Merin...

We designed a genome-wide high-density SNP array using genetically diverse sheep of the Indian subcontinent. The array includes 627 509 biallelic markers and was validated on 522 individuals from diverse breeds of the Indian peninsula. The average call rate for samples passing quality control was 99.6%, with 96.15% (603 523) markers classified as best and recommended. The high-density SNP array offers dense genomic coverage with an average intermarker distance of 4.6 kb, effectively delineates breed-specific clusters and reveals population stratification, underscoring its utility for genetic analysis, selection, and conservation in sheep. This array addresses the limited representation of Asian and African ovine diversity of the commercially available SNP arrays for sheep. Its applicability across global breeds further supports its value in international ovine genomics.

The present investigation was undertaken to explain the association of SNPs (single nucleotide polymorphisms) in exon 6 and 3′-UTR of OLR 1 gene with milk traits in Sahiwal cattle. Milk traits were observed from 328 Sahiwal cows sired by 64 bulls viz: – First lactation 305 days milk yield (Kg) (FL305MY), Average test day milk yield (Kg) (ATDMY), Average test day fat percentage (%) (ATDFP) and Lactational fat yield (Kg) (LFY). The animal model was used to estimate the breeding values for FL305MY and LFY. The traits ATDMY and ATDFP were corrected for significant non-genetic factors by using LSML-Harvey and subsequently used for association studies. A total of 130 animals for PCR-RFLP and 103 for sequencing were screened through three sets of primers for the presence of polymorphisms in exon 6 and 3′-UTR of the OLR1 gene. The CC genotype of SNP C337A in the 3′-UTR of OLR1 gene had a significant effect (p < 0.01) on ATDFP and LFY. Allele combination CGC had a positive effect (p < 0.05) on ATDFP. Identified SNP C337A and CCGGCC haplotype can be used as potential markers for improving milk yield and composition traits in Sahiwal cattle.

Summary: This study was performed to analyze the morphometric traits and indices in 3000 animals of five registered sheep breeds in the Himalayan region under a multivariate approach. Data were recorded under field conditions with equal coverage of the five breeds, viz., Karnah, Gurez, Poonchi, Bakerwal and Changthangi on body length (BL), height at withers (HW), chest girth (CG), ear length (EL), and tail length (TL). Furthermore, four derived traits (indices) were studied, which included an index of body frame (IBF), an index of thorax development (ITD), a Baron–Crevat index (BCI), and an index of body weight (IBW). Multivariate principal component analysis (PCA) was undertaken on nine morphometric traits. Kaiser’s criterion was used to reduce the number of principal components for further analysis and interpretation. The adequacy of sampling was evaluated using Kaiser–Meyer–Olkin (KMO) test and Bartlett’s test of sphericity. The mean BL ranged from 52.15 (Changthangi) to 71.13 (Gurez). The estimates of HW, CG, EL and TL were highest in Gurez (63.49), Bakerwal (84.82), Bakerwal (7.26), and Karnah (8.18) breeds, respectively. Among the derived traits, the highest IBF was observed in the Gurez breed with an estimate of 112.22. Upon multivariate PCA on the dataset, the first four principal components were able to explain 92.117% of the total variance. The KMO test, Bartlett’s test of sphericity and estimated communalities showed the appropriateness of PCA on the evaluated traits. Four eigenvalues were greater than one and were extracted for further analysis. Morphometric traits were highly correlated, except for EL and TL that showed lower correlation estimates with other traits. The Changthangi population showed the lowest estimates of BL, HW, CG and rectangular body frame. The present study ascertained important morphometric traits/indices that can help in developing selection criteria and formulating sustainable breeding and conservation plans vis-à-vis the unique sheep breeds of the temperate Himalayas.

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The objective of the study was to evaluate the effects of non-genetic factors on reproduction traits viz. age at first semen freezing and age at first semen use of breeding bulls in Sahiwal bulls by fitting least-squares analysis. The information on reproduction traits of 43 Sahiwal breeding bulls belonging to 8 sets of Sahiwal breeding program at Indian Council of Agricultural Research-National Dairy Research Institute (ICAR-NDRI), Karnal (Haryana), India during 27 years (1987-2013) were analyzed using fixed linear model. The information was collected from AI records, reproduction sheets, and bull AI register maintained at different sections of Institute viz. record room of Dairy Cattle Breeding Division (DCB), Cattle Yard, Artificial Breeding Research Centre, ICAR-NDRI, Karnal. The average age at first semen freezing and age at first semen use of Sahiwal breeding bulls was estimated as 3.17±0.01 years and 5.35±0.01 years, with the coefficient of variation 18.93% and 20%, respectively. The overall least-squares mean for age at first semen freezing and age at first semen use was estimated as 3.14±0.09 years and 5.25±0.02 years, respectively, in Sahiwal breeding bulls. Period of freezing/use had significant effects on reproductive traits (p<0.01). Season had no significant effect on any of the traits considered in this study. It can be concluded that management inputs such as nutrition, breeding, and optimum environment should be taken care of to optimize age at first semen freezing and age at first semen use for better utilization of superior germplasm.

The aim of the present investigation was to optimize the age at first use (AAFU) of semen of Murrah breeding bulls, which will help in early selection of bulls under progeny testing program for improving the reproductive performance in the herd. The data on AAFU, conception rate based on first A.I. (CRFAI), overall conception rate (OCR), and birth weight (B.WT) of 57 Murrah bulls during 1993-2014 at NDRI center pertaining to 14 sets of Network Project on Buffalo Improvement at ICAR-National Dairy Research Institute, Karnal, Haryana, India were adjusted for significant environmental influences and subsequently analyzed. Simple and multiple regression models were used for prediction of CRFAI and OCR of Murrah breeding bulls. Comparative evaluation of three developed models (I-III) showed that Model III, having AAFU and B.WT, fulfill the accuracy of model as revealed by high coefficient of determination, low mean sum of squares due to error, low conceptual predictive value, and low Bayesian information criterion. The results revealed that the average predicted CRFAI was highest (39.95%) at 4.5 years of age at first A.I/use. Similarly, average predicted OCR was highest (41.05%) at 4.5 years of age at first A.I/use of Murrah bulls. In organized herd under progeny testing program, Murrah bulls should be used at young age, i.e. prior to 3.5 years, which is expected to result in 5.08% better CRFAI and 1.63% better OCR in comparison to Murrah bulls used after 4.5 years of age.