Effect of non-genetic factors on linear type traits in Karan fries (Bos taurus × Bos indicus) and Sahiwal (Bos indicus) cows in sub-tropical climatic conditions of India.

The focus of present study was to find out the effect of non-genetic factors on linear type traits in Karan Fries and Sahiwal cows reared at an organized farm of northern India. The present study was conducted on Lactating Karan Fries (N = 123) and Sahiwal (N = 133) cows maintained at Livestock Research Center of ICAR- National Dairy Research Institute, Karnal, India during the period of 2017-2019. Total eight udder morphometric traits and seven teat morphometric traits were measured. The linear model including fixed effects of season, parity and stage of lactation was used for the analysis. In Karan Fries cows, linear type traits were significantly affected by parity and stage of lactation, while in Sahiwal cows linear type traits were significantly affected by season, parity and stage of lactation. Udder depth (UD) and udder circumference (UC) were significantly (p < 0.05) affected by season, parity and stage of lactation in Sahiwal cattle, while in Karan Fries cattle udder length (UL) and shortest distance from rear teat ends to floor (SDR) were significantly (p < 0.01) affected by parity and stage of lactation. The results pertaining to present study indicated that season, parity and stages of lactation were important sources of variation for most of linear type traits. Adjustment of data for these effects is necessary to reduce known differences between animals and to obtain reliable estimates of the traits.

Luteinizing hormone beta gene polymorphism and its effect on semen quality traits and luteinizing hormone concentrations in Murrah buffalo bulls.

OBJECTIVE: Present investigation was aimed to study the Single Nucleotide Variants of the luteinizing hormone beta (LHß) gene and to analyze their association with the semen quality (fresh and post-thawed frozen semen) and luteinizing hormone (LH) concentrations in Murrah buffalo bulls. METHODS: Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) and Sanger sequencing method is used to study genetic variability in LHß gene. LH assay was carried out using enzyme-linked immunosorbent assay method. A fixed general linear model was used to analyze association of single nucleotide polymorphism (SNP) of LHß gene with semen quality in 109 and LH concentrations in 80 Murrah bulls. RESULTS: LHß gene was found to be polymorphic. Total six SNPs were identified in LHß gene g C356090A, g C356113T, g A356701G, g G355869A, g G356330C, and g G356606T. Single Stranded Conformational Polymorphism variants of pattern 2 of exon 1+pattern 2 of exon 2+pattern 1 of exon 3 had highly significant (p<0.01) effect on sperm concentration (million/mL), percent mass motility, acrosome integrity and membrane integrity in fresh and frozen semen whereas significant (p<0.05) effect was observed on percent live spermatozoa. SSCP variants of pattern 2 of exon 1+pattern 2 of exon 2+pattern 1 of exon 3 had highly significant (p<0.01) effect on luteinizing hormone concentrations too. CONCLUSION: The observed association between SSCP variants of LHß gene with semen quality parameters and LH concentrations indicated the possibilities of using LHß as a candidate gene for identification of markers for semen quality traits and LH concentrations in Murrah buffaloes.