Maternal low-protein diets influence sex-specific growth performance, meat quality, and intestinal morphology of broiler offspring.

This study was conducted to elucidate the effects of the maternal low-protein diet on growth performance, meat quality, and intestinal morphology in broiler offspring by sex. Three hundred 10-week-old Tianfu broiler breeders were randomly allotted to 2 dietary treatments: normal protein (NP) or low CP diets (LP), and fed these diets for 24 weeks. Diets were isocaloric across three phase, with LP diets containing 30 g/kg less CP than NP diets [phase 1 (10 to 18 wk): 150 vs 120 g/kg; phase 2 and 3 (19 to 21 wk; 22 to 33 wk): 160 vs 130 g/kg]. Employing a 2 × 2 factorial design (maternal diet:NP/LP; offspring sex), 364 one-day-old chicks (7 replicates of 13 birds each) were fed standard diets for 84 days. Results showed that maternal low-protein diet did not effect offspring growth performance (final body weight, average daily gain, feed conversion ratio; P > 0.05). However, it reduced the initial body weight of all broiler offspring (P < 0.01). In males, maternal low-protein diet did not effect slaughter performance (P > 0.05); increased thymus index and breast shear force (P < 0.05); and reduced breast muscle fiber cross-sectional area and diameter (P < 0.01), and the jejunal crypt depth (P < 0.05). In females, unlike males, it did not effect immune organ index, breast meat quality, or breast muscle fiber characteristics (P > 0.05); increased semi-eviscerated and eviscerated rate (P < 0.05); and reduced jejunal villus height (P < 0.05). Furthermore, compared to the NP, it reduced nitrogen intake by 21.97% and nitrogen excretion by 15.56% in male offspring. In conclusion, maternal low-protein diets exerted sex-specific effects on broiler physiology without compromising overall growth performance.