Impact of heat stress on the growth performance and retail meat quality of 2nd cross (Poll Dorset × (Border Leicester × 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

doi:10.1016/j.meatsci.2021.108581

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

Meat Sci. 2021 Nov:181:108581. doi: 10.1016/j.meatsci.2021.108581. Epub 2021 May 29.

Authors

Affiliations

¹ School of Agriculture and Food, The University of Melbourne, Parkville, VIC 3010, Australia.
² School of Agriculture and Food, The University of Melbourne, Parkville, VIC 3010, Australia; Faculty of Biological Sciences, The University of Leeds, Leeds LS2 9JT, United Kingdom.
³ School of Agriculture and Food, The University of Melbourne, Parkville, VIC 3010, Australia; Department of Animal Science, University of Ghana, Legon, Ghana.
⁴ Centre for Red Meat and Sheep Development, NSW Department of Primary Industries, Cowra, NSW 2794, Australia.
⁵ School of Agriculture and Food, The University of Melbourne, Parkville, VIC 3010, Australia. Electronic address: ss.chauhan@unimelb.edu.au.

PMID: 34098379
DOI: 10.1016/j.meatsci.2021.108581

Abstract

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 et lumborum (LTL) from 2nd cross lambs over 10 days of display, but had no impact on Dorper LTL. In conclusion, Dorpers showed higher heat tolerance compared with 2nd cross lambs during the 2 weeks HS.

Keywords: Growth performance; Heat stress; Lamb meat; Retail display.

MeSH terms

Animals
Body Temperature
Color
Heat Stress Disorders / genetics
Heat Stress Disorders / physiopathology
Heat Stress Disorders / veterinary*
Muscle, Skeletal
Red Meat / analysis*
Respiratory Rate
Sheep
Sheep Diseases / genetics
Sheep Diseases / physiopathology*
Sheep, Domestic / genetics
Sheep, Domestic / growth & development*
Weight Gain