Shashi Nayyar

Seasonal variation in physiological responses, stress and metabolic-related hormones, and oxidative status of Murrah buffaloes

Abstract Harsh environmental conditions adversely affect the health and productivity of buffaloes. The present study was conducted to investigate the effect of seasonal thermal stress on the physiological responses, oxidative stress and some related hormones in Murrah buffaloes. A significant (p < 0.05) rise was observed in the rectal temperature, respiration rate, pulse rate and superoxide dismutase (SOD) during hot-humid (HH) and hot-dry (HD) seasons compared to thermoneutral (TN) season. Plasma cortisol and malondialdehyde (MDA) levels were low during TN season, intermediate in HD and highest during HH season. Although the levels of plasma triiodothyronine and thyroxine were high during TN season, their levels declined notably during HD and HH seasons. The temperature humidity index had a positive correlation (p < 0.01) with physiological responses, SOD, MDA and plasma cortisol levels. However, it was negatively correlated (p < 0.01) with the concentration of plasma thyroid hormones. The results reveal that buffaloes could cope efficiently with heat stress by reducing the levels of metabolic heat production-related hormones and releasing more antioxidant (SOD). However, they were still showing signs of stress which were reflected by higher levels of cortisol, lipid peroxidation (MDA) and physiological responses. Therefore, promoting health and productivity of buffaloes requires suitable management strategies to alleviate heat stress and provide comfort to them during extreme seasons.

Effect of yea sacc1026 supplementation on feed intake and rumen fermentation in buffalo calves during summer season

The study was carried out with eight apparently healthy male buffalo calves to see the effect of Saccharomyces cerevisae (Yea Sacc1026) supplementation on rumen microbial population and metabolites during summer season. The animals were divided into three groups of four each. Group I (Pre-summer), Group II (summer control) and Group III (summer treatment). Same animals were used in pre-summer and summer control Groups. The animals of Group III were supplemented with Yea Sacc1026 @ 1 bolus (consisting of 25 billion live yeast cells)/animal/d. There was significant (P<0.05) decrease in total bacterial count, total protozoal count, percent entodiniomorphs and A significant increase (P<0.05) in percentage of holotrichs during summer season. The microbial population was higher in Yea Sacc1026 supplemented group as compared to presummer and summer contol groups. However, following supplementation of Yea Sacc1026, there was no significant change in percentage of holotrichs and entodiniomorphs as compared to pre summer and summer control groups. During summer season, there was significant decrease in concentration of total volatile fatty acids and significant increase in levels of ammonia N and total N. The values of above parameters improved with yeast administration. Molar proportion of acetic acid and butyric acid was higher during summer season whereas proportion of propionic acid decreased and these values were restored to normal after Yea Sacc1026 supplementation but butyric acid did not show any change. Hence, supplementation with Yea Sacc1026 could be useful in improving rumen microbial population and optimizing the concentration of rumen metabolites thus ameliorating the adverse affects of summer stress on rumen profile in buffalo calves without affecting feed intake.