Effects of diet-induced differences in growth rate on metabolic, histological, and meat-quality properties of 2 muscles in male chickens of 2 distinct broiler breeds

摘要: This paper, the second from a comprehensive study, describes effects of varying growth rate by feeding at different planes nutrition with constant ME:CP ratio on muscle characteristics and meat quality in 2 distinct broiler breeds male chickens (Arbor Acres, commercial line; Beijing-You, Chinese nonimproved line). Experimental diets, differing average 2% CP, were formulated high-, medium-, or low-nutrient densities for 3 growing phases. Male hatchlings (216 each breed) randomly assigned to 6 pens 12 birds treatment. Altered histological fibers, early postmortem metabolism, investigated pectoralis major biceps femoris. At their market age, Arbor Acres broilers had significantly higher concentrations plasma protein lipid metabolites, ratios white red intermediate pH, L* b* values, lower glucose muscle-fiber diameter, contents energy stores, a* value, drip loss, shear force than values found Beijing-You (P < 0.01). Higher nutrient density increased size decreased glycogen reserve, reduced extent acidification chickens, while accelerating transformation intermediate-to-white enhancing hastening decrease pH 0.05). In breed, most variables (e.g., force, color) consistent biochemical changes caused strategy. Together, dietary can influence as result altered initial metabolic muscle. Many responses diet are breed tissue dependent chickens.