Bovine milk is important for both veterinary medicine and human nutrition. Understanding the bovine milk proteome at different stages of lactation has therefore broad significance for integrative biology and clinical medicine as well. Indeed, different lactation stages have marked influence on the milk yield, milk constituents, and nourishment of the neonates. We performed a comparative proteome analysis of the bovine milk obtained at different stages of lactation from the Indian indigenous cattle Malnad Gidda (Bos indicus), a widely available breed. The milk differential proteome during the lactation stages in B. indicus has not been investigated to date. Using high-resolution mass spectrometry-based quantitative proteomics of the bovine whey proteins at early, mid, and late lactation stages, we identified a total of 564 proteins, out of which 403 proteins were found to be differentially abundant at different lactation stages. As is expected of any body fluid proteome, 51% of the proteins identified in the milk were found to have signal peptides. Gene ontology analyses were carried out to categorize proteins altered across different lactation stages based on biological process and molecular function, which enabled us to correlate their significance in each lactation stage. We also investigated the potential pathways enriched in different lactation stages using bioinformatics pathway analysis tools. To the best of our knowledge, this study represents the first and largest inventory of milk proteins identified to date for an Indian cattle breed. We believe that the current study broadly informs both veterinary omics research and the emerging field of nutriproteomics during lactation stages.

The identification of genetic polymorphisms in the genes that play a crucial role in regulatiing growth and development of livestock enables us to evaluate the biological similarities and to acquire a better perspective of quantitative traits. The present study was undertaken to characterize genetic variability in the bovine growth hormone receptor (GHR), insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) genes among Bos indicus (Malnad Gidda, Khillar), Bos taurus (Holstein Friesian, Jersey) cattle and Asian water buffalo Bubalus bubalis (Murrah, Surti) using polymerase chain reactionsingle strand conformation polymorphism (PCR-SSCP) analysis. These polymorphisms were confirmed by direct sequencing. The comparative gene sequence analysis in cattle and buffalo breeds revealed 18 single nucleotide polymorphisms (SNPs) across different loci. Eight SNPs were detected in the bovine growth hormone receptor (GHR) gene, of which four were found in the promoter region and four in the exon 4 region. In the IGF-1 gene, two SNPs were observed in the 5ˈUTR, three SNPs in the intron 3 region and two SNPs in the coding region of exon 4. Three SNPs were detected in the exon 2 region of the bovine IGFBP-3 gene. The frequency of rare alleles observed in the present study ranged from 0.04 to 0.16. The present results revealed high levels of genetic variability in the GHR, IGF-1 and IGFBP-3 genes in cattle and buffalo reared in India.

The hypothalamic gonadotropin-releasing hormone receptor (GnRHR) plays an essential physiological role in reproductive function. In this investigation, we studied genetic variation in the entire coding region of GnRHR gene using PCR-SSCP technique in 250 Bos taurus (Holstein Friesian, Jersey) and Bos indicus (Malnad Gidda, Deoni) bulls. The genetic variants in GnRHR gene were determined by PCR-SSCP technique by using 5 sets of primers. SSCP analysis of fragment 1, comprising exon 1, and fragment 3, comprising exon 2, revealed 2 SSCP patterns in all breeds under study, while fragment 2 of exon 1 and fragment 4, comprising exon 3, revealed 3 patterns in Malnad Gidda; Holstein Friesian and Deoni breeds showed 2 SSCP patterns. In Jersey bulls, fragment 4 showed 3 patterns. The fragment 5 comprising exon 3 was monomorphic in all 4 breeds under study. SNPs were confirmed by direct sequencing.

Materials and methods Experimental animals and DNA isolationDeoni cattle are medium-sized dual-purpose Bos indicus cattle found in parts of the Maharashtra, Karnataka, and

Selection of high fertile bulls with the help of marker assisted selection has gained importance in recent years. The low heritability of fertility traits hampers improvement of these traits by conventional selection based on phenotypic records. No information is available on the role of SNPs in KiSS1 gene in cattle on semen quality parameters in bovines. KiSS1 genes code for Kisspeptin, which are essential upstream regulators of neurons secreting gonadotropin-releasing hormone and play crucial role in reproduction.The coding regions along with exon-intron boundaries of KiSS1 gene, was characterized using PCR-SSCP method and direct sequencing. Two genotypes were observed which were represented as SSCP pattern 1 and pattern 2 and found to carry one SNPs (T153C) and one insertion of G at 291_292bp. The bulls with pattern 2 were heterozygous with respect to the transition T153C and pattern1 bulls were homozygous with TT genotype. The transition was predicted to cause amino acid change from Valine to Alanine. The frequency of bulls with pattern1 and pattern 2 were 0.67 and 0.33 in 67 Holstein Friesian bulls and 0.73 and 0.27 in 13 Khillari bulls. The association study of genotypes with semen quality parameters revealed significant association of genotypes with acrosome integrity in fresh semen (P<0.05) and no association with sperm concentration, volume per ejaculate, percent live sperm and Hypo Osmotic Swelling Test (HOST) with higher acrosome integrity in bulls with pattern2. Upon validation of the results in larger population and identifying the exact role of the novel SNP T153C and insertion of G at 291_292bp, they could be incorporated in selection programme for improving fertility in bulls.as markers for acrosome integrity in cattle.