Journal article

Impact of heat stress on the growth performance and retail meat quality of 2nd cross (Poll Dorset x (Border Leicester x Merino)) and Dorper lambs

Minghao Zhang, Robyn D Warner, Frank R Dunshea, Kristy DiGiacomo, Aleena Joy, Archana Abhijith, Richard Osei-Amponsah, David L Hopkins, Minh Ha, Surinder S Chauhan



The present study investigated the impact of heat stress and genetics on lamb growth performance and meat quality. Forty-eight Dorper and 2nd cross [Poll Dorset × (Border Leicester × Merino)] lambs (38--42 kg; 4-5 months old) were allocated to either thermoneutral [TN; 18-21 °C, 45-55% relative humidity (RH)], or heat stress (HS; 28 °C-38 °C, 40-60% RH) conditions in a 2 × 2 factorial design for 2 weeks. Compared with 2nd cross, Dorper lambs had a lower respiration rate (RR) and rectal temperature (RT), and exhibited less decline in body weight under HS. 2nd cross lambs showed a higher body weight gain than Dorpers under TN conditions. HS increased a* and chroma of the Longissimus thoracis e..

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Funding Acknowledgements

Authors would like to acknowledge Faculty of Veterinary and Agricultural Sciences, The University of Melbourne and Lindsay and Alice Gamble trust fund for providing top up scholarship to Minghao Zhang and start up fund to Dr. Surinder Singh Chauhan to conduct this research.