Long term cyclic heat stress influences physiological responses and blood characteristics in indigenous sheep
Keywords:Blood characteristics, cyclic heat stress, indigenous sheep, physiological responses
The present study was designed to elucidate changes in physiological and blood parameters of indigenous sheep during cyclic heat exposure. Twelve 2-4 year-old sheep with an average body weight of 10.5±0.5 kg were randomly allocated to one of three experimental heat treatments: control (21°C, stall feeding), short term (21°C to 32°C; 32°C for 4 h/d, grazing), and long term (21°C to 32°; 32°C for 8 h/d, grazing).The results have shown that sheep exposed to cyclic heat treatments exhibited higher (P=0.05) rectal temperature, body temperature, and respiratory rate compared to the control group. Cyclic heat treatments significantly decreased heart rate of sheep. There was a sharp reduction in rumination and an increase in time spent by sheep in eating during cyclic heat treatments. Long term heat treatment significantly increased RBC and WBC counts, PCV values, and hemoglobin level than that of the control and short term heat treatments. Similar responses were also observed in plasma glucose, uric acid, aspartate aminotransferase, and blood urea nitrogen levels. These results suggest that short term heat stress is tolerable but long term is physiologically detrimental to them to indigenous sheep.
How to Cite
© Bangladesh Journal of Animal Science.
Authors are required to transfer their copyright to the Bangladesh Journal of Animal Sciences.
All rights reserved. No parts of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without the prior permission of the Bangladesh Journal of Animal Science.