Impacts of seasonal ambient temperature and humidity on meat quality characteristics of sheep and beef longissimus thoracis muscles

The effects of seasonal temperature and humidity on meat quality characteristics sheep (12 months age) beef cattle (24 were investigated. Samples longissimus thoracis (500 g) muscle randomly collected from 96 48 between November 2018 October 2019. All the samples kept in chiller at 4-5ºC for h. over a 12-month period this was divided into two seasons based ambient relative Basrah region. Theses named: Cool Season (November to March with average 23.0±1.54ºC 59.0±1.75% humidity) Hot (April 40.5±1.77ºC 53.5±5.98 humidity). ultimate pH (pHu), expressed juice, cooking losses, shear force, sarcomere length, myofibrillar fragmentation index colour lightness (L*), redness (a*), yellowness (b*) parameters determined. effect season Longissimus both species found be significant (P<0.05). hot had significantly (P<0.05) higher pHu values, longer lower force values than during cool season. Sheep muscles group darker that those cold group, L*, a* b* measurements. present findings indicated (>40ºC) leads heat stress cattle, which increased influenced other related properties. These will assist producers improve by slaughtering livestock early hours day. has also an impact animal welfare.