Dietary energy levels affect productivity, meat quality, blood variables, energy efficiency and welfare indicators in broilers under welfare rearing conditions

Numerous studies have explored the welfare rearing conditions of broilers; however, studies on the level of metabolisable energy (ME) in feed, which is a key factor in broiler growth, are lacking. Accordingly, this study investigated the appropriate ME levels for broilers under welfare rearing environments. A total of 980 one-day-old male chickens (Ross 308) were allocated to each group according to the environment and dietary ME as follows: conventional environment fed a standard ME program (conventional control; CC), welfare environment with a standard ME (welfare control; WC) and welfare groups with 200 kcal/kg lower (WL200), 100 kcal/kg lower (WL100), 100 kcal/kg higher (WH100) and 200 kcal/kg higher (WH200) than standard ME. The experiment lasted 5 weeks. The productivity, meat quality, blood and intestinal characteristics, nutrient digestibility and welfare indicators were analysed, whose results are as follows: WH200 had the highest body weight and low feed conversion ratio, whereas CC had the lowest feed intake (p