Seasonal rhythmicity of thermoregulatory physiological responses in fat-rumped sheep under semi-arid tropical environment

ABSTRACT

The immediate response of animals to fluctuations in environmental temperature is an alteration in their physiological responses. For those who failed to cope, their production performance is affected greatly. Fat-rumped sheep is phenotypically different from the commonly available sheep breeds of the semi-arid tropical environment in India. For assessment of thermoregulatory rhythmicity under extreme seasonal variations of the semi-arid tropical region, six adult fat-rumped (Dumba) rams were selected. The study was carried out in the year 2016–2017. All the rams were maintained under stall-feeding condition with a fixed dietary regime. Respiration rate (RR), pulse rate (PR), skin temperature (ST) and rectal temperature (RT) were recorded at morning (08:00 h), and afternoon (14:00 h) in summer (May–June), winter (December–January) and spring (March–April) for six times in each season at 7 days interval. Body weight was taken at the start and end of each season under study. The meteorological data were recorded twice daily at 8:00 h and 14:00 h for the entire study period. The study indicated significant (p < 0.05) variation in RR, PR and ST with respect to season. RT and body weight showed no significant variation among seasons. The result indicated fat-rumped sheep altered their thermoregulatory physiological responses as per the change of season to cope with environmental extremes under semi-arid tropical region.

KEYWORDS:

• Dumba sheep
• respiration rate
• pulse rate
• skin temperature
• rectal temperature
• semi-arid tropics

Acknowledgments

The authors are also highly thankful to Surendra Singh, Ram Raj and Ram Kisan for their technical help during the experiment. The authors thank sincerely The Director, ICAR-CSWRI for providing all necessary facilities for the research work.

Disclosure statement

No potential conflict of interest was reported by the authors.