Protein expression in pectoral skeletal muscle of chickens as influenced by dietary methionine

Abstract

Effects of dietary methionine (Met) on pectoralis muscle development and the effect that Met as a nutritional substrate has on protein expression of skeletal muscle cells of pectoralis muscle of chickens were evaluated in this study. Broiler chickens received a common pretest diet up to 21 d of age and were subsequently fed either a low (LM) or high Met (HM) diet (0.41 vs. 0.51% of diet) from 21 to 42 d of age. Dietary deficiency was shown in vivo judging by the depression in breast meat weight and yield when broilers were fed the LM diet. Global protein expression was analyzed by quantitative high-performance liquid chromatography nanospray ionization tandem mass spectrometry. Up- and downregulated proteins were analyzed via Ingenuity Pathways Analysis to identify the metabolic pathways affected. Four canonical pathways related to muscle development were identified as being differentially regulated between LM- and HM-fed chickens. These pathways included the citrate cycle and calcium, actin cytoskeleton, and clathrin-mediated endocytosis signaling. The HM diet may have allowed for increased muscle growth by an increased availability of nutrients to muscle cells. Although the Met supplementation was associated with enhanced breast muscle growth, contraction fiber concentrations in muscles decreased and were associated with a lower calcium transportation rate and sensitivity and with a lower energy supply. It is further suggested that increased muscle protein deposition, that was induced by Met supplementation, may have been largely due to sarcoplasmic rather myofibrillar hypertrophy.

Effects of dietary lysine and methionine supplementation on Ross 708 male broilers from 21 to 42 days of age (II): breast meat quality

“…Previous research [1] indicated that an increase in dietary methionine (Met) from 0.41% (8% higher than the 0.38% as recommended by NRC [2]) to 0.51% (34% higher than the NRC…”

“…Therefore, dietary Met supplementation induces lower relative myofibrillar protein solubility, which may improve breast meat tenderness. In addition, Zhai et al (2012) [1] reported that Met supplementation may lead to greater nutrient absorption into muscle cells. This may affect breast meat nutrient composition.…”

“…Global protein expression indicated that even though Met supplementation enhanced breast muscle growth, contractile proteins (including F-actin and myosin) in the muscle were down-regulated. Muscle growth may be caused by two types of hypertrophy: myofibrillar hypertrophy (an increase in contractile proteins) and sarcoplasmic hypertrophy (an increase in a semifluid interfibrillar substance that lacks contractile proteins) [1]. The different types of hypertrophy may result in variability in meat quality [3][4][5].…”

Bioavailability of liquid methionine hydroxy analogue-free acid relative to DL-methionine in broilers

“…Methionine-induced alterations of metabolic pathways controlling lipogenesis may also be involved (Takahashi and Akiba, 1995). Zhai et al (2012) muscle protein deposition might have been due to sarcoplasmic rather than myofi brillar hypertrophy. Because of the diminishing returns pattern observed in all the response criteria studied, exponential model by Littell et al (1997) was used to estimate the bioavailability of MHA-FA relative to DLM.…”

“…VII show that, in comparison with equimolar levels of DLM, the MHA-FA availability was lower in all cases, the greatest diff erence being found in carcass and breast meat yields. The sensitivity of both absolute and relative breast meat yield to dietary methionine levels has been demonstrated in many studies (Schutte and Pack, 1995;Zhai et al, 2012). Also, it has been shown that the optimal levels of SAA (as well as lysine) for breast meat deposition are higher than for body weight gain (Bartov and Plavnik, 1998).…”