Effects of dietary supplemental methionine source and betaine replacement on the growth performance and activity of mitochondrial respiratory chain enzymes in normal and heat‐stressed broiler chickens

Abstract

This study aimed to evaluate the effects of dietary supplemental methionine (Met) source and betaine (Bet) replacement for Met on performance and activity of mitochondrial respiratory chain enzymes (MRCEs) in normal and heat‐stressed broiler chickens. Total of 1,200‐day‐old Ross 308 chicks were allocated to two houses, each consisted of 12 treatments, five replicates of 10 birds each with 2 × 2×3 × 2 (temperature × Met source × Met level × Bet, respectively) split‐plot factorial arrangement. Met level in the basal diets was 70% requirements (Req) that was increased to the requirement or 130% by supplemental dl‐ or l‐Met. Bet was or was not substituted at the rate of 30% supplemental dl‐ or l‐Met. Feed conversion ratio (FCR) in chicks fed 70% l‐Met was lower than those fed 70% dl‐Met diet during 1–10 days (p = 0.04). Broilers fed diets containing requirement or 130% Met, regardless of its source, showed higher weight gain (WG) than those received 70% Met diet during 11–42 days (p < 0.001). Feed intake (FI) of broilers fed 130% Met diet was decreased compared to other two groups during 11–42 days (p < 0.05). One hundred thirty percent Met requirement diet resulted in lower FCR comparing to other two groups during 11–42 days (p < 0.001). Heat‐stressed birds grew less than those under normal condition (p < 0.05). Broilers fed Req Met diet under normal temperature exhibited higher activities of complexes (Cox) I and III (p < 0.05). Cox I activity in heat‐stressed birds fed Bet + diet was similar to those fed Bet‐diet under normal temperature (p = 0.046). It is concluded that performance and the activities of Cox I and III were increased as the level of Met increased. Bet replacement for 30% supplemental Met resulted in similar consequences comparing to non‐Bet replacement diets on performance, but increased the activity of Cox III. l‐Met was effective than dl‐Met at the cellular level. High ambient temperature depressed performance and MRCE activity.

Impacts of dietary supplementation with nano-iron and methionine on growth, blood chemistry, liver biomarkers, and tissue histology of heat-stressed broiler chickens

“…Also, methionine is an essential factor in heat stress resistance. It is a glutathione precursor; it relives reactive oxygen species (ROS); therefore, supplementation of methionine can contribute to the antioxidant status of poultry (Sahebi Ala et al 2019 ). Methionine can be gained through diet; therefore, much or less Met consumption can result in DNA methylation shift (Niculescu and Zeisel 2002 ), which may, in turn, support genomic insecurity (Arai and Kanai 2010 ).…”

Betaine Supplementation May Improve Heat Tolerance: Potential Mechanisms in Humans

“…As core temperature is a key indicator of exercise-associated GI disturbances [ 77 , 78 , 85 , 86 ], if betaine can attenuate the rise in core temperature during exercise in the heat, endotoxemia and thereby heat-related injuries may be preventable. The majority of this work has been performed in animal models (i.e., chickens, cows, ducks, goats, poultry, and sheep) with most demonstrating betaine to effectively combat thermal stress [ 84 , 87 , 88 , 89 ].…”

“…Additionally, betaine supplementation may play an indirect role in managing heat stress through alterations in cellular metabolism and blood chemistry. Several researchers have demonstrated that broiler chickens without betaine supplementation experienced a reduction in mitochondrial function when exposed to heat stress [ 87 , 93 ]. However, betaine supplementation successfully attenuated this loss, restoring function to thermoneutral levels [ 87 ].…”

“…Several researchers have demonstrated that broiler chickens without betaine supplementation experienced a reduction in mitochondrial function when exposed to heat stress [ 87 , 93 ]. However, betaine supplementation successfully attenuated this loss, restoring function to thermoneutral levels [ 87 ]. Although the exact mechanism is unclear, mitochondrial function may be improved due to decreased osmotic stress and thereby decreased reactive oxygen species formation [ 80 , 94 ].…”

“…It is important to highlight that the studies demonstrating improved heat tolerance in animal models supplemented with betaine chronically in the feed or the water supply [ 84 , 87 , 88 , 89 , 91 , 99 , 100 ]. This strategy provides a daily dose of betaine, thereby loading the compound within the body.…”