Effects of metabolizable energy and balanced protein on egg production, quality, and components of Lohmann Brown laying hens

Abstract

SUMMARY A 4 × 3 factorial experiment with 4 dietary ME levels (2,400, 2,550, 2,700, and 2,850 kcal/ kg) and 3 CP levels (14.5, 16.0, and 17.5%) was conducted to determine the effects of ME and CP on egg production (EP) performance, egg quality, and egg components of laying hens. The protein ingredients were composed of soybean meal (36.5%), cottonseed meal (36.5%), and canola meal (27.0%). A total of 900 commercial Lohmann Brown pullets, 26 wk of age, were randomly assigned into 12 treatments (5 replicates with 15 birds per replicate). Feed and water were provided ad libitum throughout the experiment (12 wk). The optimum intake of ME and CP for maximum egg production, egg mass (EM), and feed conversion ratio (FCR) was calculated. There was an interaction between ME and CP on EP, EM, and FCR (P < 0.001). By response surface analysis, the ranges of estimated optimum ME and CP intake were 325.7 to 331.7 kcal/d (2,591 to 2,683 kcal/kg) and 19.5 to 20.7 g/d (15.58 to 16.64%), respectively, for optimum EP, EM, and FCR. The highest EP and EM were observed with 16% CP (21.13 g/d) and 2,400 kcal/kg of ME (316.95 kcal/d) in the diet. Diets with high CP (17.5%) and low energy (2,400 kcal/kg) exhibited the poorest EP (71.58%), EM (42.15 g/d), egg shell quality (0.289 mm), and broken egg ratio (0.25%). Thus, moderate ME and high balanced protein are very important for optimizing the FCR, EP, and EM of Lohmann Brown laying hens.