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

Abstract

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 < 0.001). The WL200 treatment resulted in a low pH, high cooking loss and lightness (L*) of breast meat (p < 0.001). Total cholesterol, triglyceride and corticosterone levels increased in the CC group (p < 0.01). Notably, The WH200 treatment improved gut properties, nutrient digestibility and footpad condition (p < 0.01). Therefore, it is inferred that an appropriate high-ME feed supply can effectively improve broiler productivity, nutritional efficiency and welfare in a welfare rearing environment.

Keywords

• broiler
• dietary energy
• performance
• energy utilisation
• welfare indicator