This study utilised 2877 lambs. Plasma indicators of acute and chronic stress were quantified and analysed for their association with meat quality and carcass yield traits.
Production factors had the largest impact on indicators reflecting acute stress, feed deprivation, dehydration, muscle activity and damage, the majority of which were elevated above normal range.
Phenotypically leaner lambs also demonstrated greater fat metabolism and lower rates of glycogen turnover. Loin ultimate pH demonstrated a positive association with levels of plasma glucose and lactate, indicating that acute stress has an impact on glycogen turnover and ultimate pH in lamb.
Feed deprivation beyond 36 hours had a negative impact on ultimate pH of the M. Semitendinosus in Merino lambs and caused a 3% reduction in carcass weight.
Further work is required to understand methods of mitigating acute stress in order to minimise high ultimate pH and reduced tenderness.
In addition, it has been demonstrated that Merino genotypes have a significantly higher fat turnover in response to feed deprivation and stress, and indicates that shorter duration of curfew and lairage may be beneficial in minimise carcass losses and meat quality.