Expression analysis of pro-apoptotic BAX and anti-apoptotic BCL-2 genes in relation to lactation performance in Deoni and Holstein Friesian crossbred cows.

The study was designed with the objective of expression analysis of pro-apoptotic BAX and anti-apoptotic BCL-2 genes on lactation performance in Bos indicus and HF crossbred cows during early lactation. BAX/BCL-2 mRNA expression ratio in HF crossbreds showed a steady increase from 30th day to 90th day, but in Deoni cows the ratio exhibited a different pattern, which increased from day 30 to day 60, decreased on day 75, and then increased on day 90. BAX/BCL-2 expression ratio in Deoni and HF crossbreds were lowest on day 30 and highest on day 90. On contrary, the milk yield was highest on day 30 and lowest on day 90 suggesting BCL-2 gene favors milk production and BAX gene oppose milk production. In comparison to HF crossbreds, Deoni cows exhibited highest BAX/BCL-2 ratio at the end of early lactation, indicating Bos indicus cows were more sensitive to apoptosis than HF crossbreds. Comparison of daily milk yield with BAX/BCL-2 mRNA expression ratio revealed significant negative correlation with a correlation coefficient of -0.98 (P < 0.01) and -0.95 (P < 0.05) in Deoni and HF crossbred cows, respectively. Our study provides new insights into understanding the genetic control of mammary apoptosis between Bos indicus and HF crossbreds.

Differences in milk metabolites in Malnad Gidda (Bos indicus) cows reared under pasture-based feeding system.

The milk and milk products from cows reared under grazing system are believed to be healthier and hence have high demand compared to milk from cows reared in the non-grazing system. However, the effect of grazing on milk metabolites, specifically lipids has not been fully understood. In this study, we used acetonitrile precipitation and methanol:chloroform methods for extracting the milk metabolites followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) run to identify the different metabolites between the milk of grazing and non-grazing early lactating Malnad Gidda cows. Various carbohydrates, amino acids, nucleosides and vitamin derivatives were found to be differentially abundant in grazing cows. A total of 35 metabolites were differentially regulated (fold change above 1.5) between the two groups. Tyrosyl-threonine, histidinyl-cysteine, 1-methyladenine, L-cysteine and selenocysteine showed fold change above 3 in grazing cows. The lipid profile of milk showed a lesser difference between grazing and non-grazing cows as compared to polar metabolites. To the best of our knowledge, this is the largest inventory of milk metabolomics data of an Indian cattle (Bos indicus) breed. We believe that our study would help to emerge a field of Nutri-metabolomics and veterinary omics research.