The effect of seasonal heat stress on rigor development and the incidence of pale, exudative turkey meat

Abstract

Heat stress is one of the prominent ante-mortem stressors that elicits pale, soft, and exudative meat characteristics in stress-susceptible pigs. Industry reports of exudative turkey meat increase in the early summer with the onset of prolonged high temperatures. To study the effect of seasonal heat exposure on turkeys, 122 17-wk-old Nicholas tom turkeys were subjected in January either to growth temperatures of 16/24 C (night/day) (control) or to elevated temperatures of 32/38 C (night/day) (heat-stressed, HS). Turkeys were processed at 21 wk of age in a manner simulating commercial conditions. Pectoralis muscle samples were taken at 15 min (prechill), 2 h (postchill), and 24 h and analyzed for R-value, pH, and color. At 2 h, the remaining intact Pectoralis muscle was harvested, aged on ice for 23 h, and analyzed for drip loss and cook loss. Percentage mortality and carcass weights were not significantly different between treatments. By 15 min post-mortem, the HS birds exhibited a faster pH decline and had higher R-values that persisted through 24 h. The HS birds were also paler in color and exhibited increased drip loss and cook loss when compared to controls; however, expressible moisture was not different between treatments. In addition, the HS birds had a higher frequency of abnormal birds than controls when birds were grouped as normal (L* < 53) or abnormal (L* > 53).

Carcass and meat quality traits of chickens fed diets concurrently supplemented with vitamins C and E under constant heat stress

“…This reduction is necessary for the conversion of muscle into meat (Dransfield and Sosnicki, 1999;Lehninger et al, 2008). Chronic exposure to high ambient temperatures, as occurred in the present study, may have lead to an exhaustion of muscle glycogen reserves in vivo, resulting in meat with higher pH (Mckee and Sams, 1997;Dai et al, 2012). Acute heat stress, in contrast, has been associated with faster postmortem pH decline and lower pH (Debut et al, 2003).…”

Effects of heat conditioning and dietary ascorbic acid supplementation on growth performance, carcass and meat quality characteristics in heat-stressed broilers

“…The pH value is a direct reflection of muscle acid content, and affects shear force, water holding capacity and color of meat (9,14,36). It has been reported that seasonal heat stress accelerates post mortem metabolism and biochemical changes in the muscle, which produces a faster pH decline, lower ultimate pH and higher lightness in turkey meat (27). In this study, it was also observed that heat stress significantly decreased initial and ultimate pH values measured on breast and thigh meat (P<0.05).…”

Different rates of glycolysis affect glycolytic activities and protein properties in turkey breast muscle

“…In North America, over 5% to 30% of turkey breast muscles are detected as PSE-like meat (Barbut, 1993) and its incidence seems to increase (Chiang et al, 2004). However, in most of the studies carried out on poultry, PSElike meats often showed lower ultimate pH than normal meat (Barbut, 1993;McKee and Sams, 1997). Even if the alterations of PSE turkey meat are very similar to those observed in pork, the environmental and/or genetic origin has not yet been proven in poultry (Chiang et al, 2004).…”