Heat Stress-induced Changes in Milk Composition and Physiological Responses of Lactating Kankrej Cow during Summer Season as Compared to Thermo-neutral Period

The Kankrej cattle is the heaviest and most priced of the Indian breeds of cattle. It is adapted to the geo-climatic conditions of North Gujarat and Kutch, which is normally hot and dry. It is reared in the district of Banaskantha in the state of Gujarat and also distributed in other parts of India and abroad. The experiment was carried out to study the effect of the summer season on the milk composition and physiological responses in lactating Kankrej cow compared to the thermoneutral period.

For the experiment, total number of 16 clinically healthy Kankrej cows were randomly selected from Livestock Research Station (LRS), Sardar Krushinagar Dantiwada Agricultural University, Banaskantha, Gujarat and categorized into two different groups according to seasons. Physiological responses i.e. respiration rate and rectal temperature were recorded and milk samples were collected from each animal during the summer and thermoneutral period at fortnight intervals. The milk samples were analyzed by using an automated milk analyzer.

The results demonstrate that fat, SNF and density were significantly higher in the summer season. The physiological responses include respiration rate and rectal temperature were found significantly higher during summer than thermoneutral period. Milk protein was significantly higher during the thermo-neutral period as compared to summer.