Vol. 12, Special Issue 9 (2023)

Author(s):
Sunitha Thomas, Suraj PT, Joseph Mathew, Prasad A, Naicy Thomas, George Sherin K, Pramod S, Sunanda C

Abstract:
A study was conducted to compare the physiological responses of two native goat breeds of Kerala viz. Attappady Black and Malabari goats, when confronted with individual and multiple stresses. A total of 24 animals each, within two years of age, with a body weight of 20-30 kg and almost similar physical parameters were selected and randomly allocated into four treatment groups as heat stress (HS), nutritional stress (NS), combined stress (CS) and Control (C). The NS and C groups were maintained inside the shed and the HS and CS groups were exposed to summer heat by tethering them in an open paddock (11.30 a.m. to 2.30 p.m.) for 28 consecutive days. Feed restriction (40 percent of the control animals) was imposed in the NS and CS groups to impose nutritional stress. Climatological variables (ambient temperature and relative humidity) were monitored hourly during the period. Physiological responses like rectal temperature (RT), pulse rate (PR) and respiration rate (RR) were recorded before and after the stress to assess the variation. Water was provided ad libitum to all the groups. Breed difference was established for all the three parameters. Attappady goats had significantly low RT on days 0, 3, 7 and 14. Treatment had significant effect on RT only on days 14 and 28. PR was significantly (p<0.01) higher in Attappady goats on all days. Treatment groups of both the breeds differed in their pulse rate on day 7, where the heat exposed groups had higher PR than the control animals. Respiration rate was significantly (p<0.01) higher in Attappady goats on days 3 and 7 which later decreased upon chronic stress exposure. Treatment groups of Malabari goats differed in their RR on day 0. No significant effect was observed in Attappady goats.