Assessment of interactions between glutamine and glucose on meat quality, AMPK, and glutamine concentrations in pectoralis major meat of broilers under acute heat stress

Romney-cross ewe lambs (n = 27) were subjected to controlled environmental conditions to induce acute heat stress. The goals of the study were to: (1) determine appropriate physiological indicators of acute heat stress, (2) determine threshold rectal temperatures (Tr) for catecholamine and cortisol release, (3) determine effects on meat quality, and (4) assess the effect of dehydration on the above measures. There were 3 treatments: control (ambient temperature and humidity), heat stress (33°C, and 85-100% humidity), and heat stress combined with water deprivation. The duration of the treatment period was 12 h. Respiration rate (Rf) and rectal temperature (Tr) were highly correlated with increasing temperature humidity index (THI) (r > 0.75, P < 0.001), whereas heart rate was less responsive to THI (r = 0.30, P < 0.05). The welfare of these lambs was at risk at Tr greater than 40.5°C, a point at which respiration rate was maximal and unable to prevent further increases in Tr. Plasma cortisol concentrations were increased in heat-stressed lambs after Tr reached approximately 40.7°C. Plasma catecholamines were only elevated in lambs when Tr was greater than 42°C. The majority of lambs subjected to heat stress had a Tr less than 42°C, and there were no significant effects on meat quality. Despite exhibiting increases in plasma protein concentrations, there were no indications that dehydrated lambs were under additional stress during heat challenge in comparison with hydrated lambs.

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Acute Heat Stress-Induced Alterations in Blood Acid-Base Status and Skeletal Muscle Membrane Integrity in Broiler Chickens at Two Ages: Implications for Meat Quality

Poultry Science ◽

10.1093/ps/80.4.418 ◽

2001 ◽

Vol 80 (4) ◽

pp. 418-425 ◽

Cited By ~ 182

Author(s):

D.A. Sandercock ◽

R.R. Hunter ◽

G.R. Nute ◽

M.A. Mitchell ◽

P.M. Hocking

Keyword(s):

Skeletal Muscle ◽

Heat Stress ◽

Meat Quality ◽

Broiler Chickens ◽

Membrane Integrity ◽

Muscle Membrane ◽

Acid Base ◽

Acute Heat Stress ◽

Acid Base Status

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Effects of Dietary Supplementation with Epigallocatechin Gallate on Meat Quality and Muscle Antioxidant Capacity of Broilers Subjected to Acute Heat Stress

Animals ◽

10.3390/ani11113296 ◽

2021 ◽

Vol 11 (11) ◽

pp. 3296

Author(s):

Fei Zhao ◽

Xiaocheng Wang ◽

Yang Li ◽

Xingyong Chen ◽

Zhaoyu Geng ◽

...

Keyword(s):

Lactic Acid ◽

Heat Stress ◽

Antioxidant Capacity ◽

Meat Quality ◽

Free Group ◽

Mrna Level ◽

Drip Loss ◽

Mrna Levels ◽

Sod Activity ◽

Acute Heat Stress

This study evaluated epigallocatechin gallate’s (EGCG’s, 400 mg/kg) effect on meat quality and muscle antioxidant status of broilers under acute heat stress (AHS). A total of 144 21-day-old male Huainan partridge chickens were randomly allocated to the EGCG-free group (12 replicates) and the EGCG group (6 replicates). On day 94, the EGCG-free group was divided into the control group (CON) and the AHS group, and then AHS group and EGCG group (identified as AHS + EGCG group) were treated with AHS (33 ± 1 °C for 12 h). AHS increased (p < 0.05) L*24h, drip loss, muscle lactic acid, malondialdehyde (MDA) contents, and kelch-like ECH-associated protein 1 (Keap1) mRNA level, and decreased (p < 0.05) eviscerated percentage, pH24h, a*, muscle total superoxide dismutase (T-SOD) activity, the ratio of T-SOD/MDA and glutathione peroxidase /MDA, glycogen content, and nuclear factor erythroid 2-related 2 (Nrf2), catalase (CAT), NAD(P)H/quinone dehydrogenase 1 (NQO1) mRNA levels. The AHS + EGCG group exhibited lower (p < 0.05) L*24h, drip loss, muscle lactic acid, MDA contents and Keap1 mRNA level, and greater (p < 0.05) eviscerated percentage, pH24h, a*, muscle T-SOD activity, the ratio of T-SOD/MDA, Nrf2, and NQO1 mRNA levels compared with the AHS group. In conclusion, EGCG protects against AHS-impaired meat quality by improving muscle antioxidant capacity, which seems to be associated with the activation of the Nrf2 signaling pathway.

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