High-protein maize in dietsfor broilers

摘要

The nutritional performance of three highproteinmaize hybrids was compared with conventionalmaize in a 42-day feeding trial inbroilers. The following experimental dietswere compared: i) control diet (CTR) containingconventional maize; ii) diet containinghybrid IPM1; iii) diet containing hybrid IPM2;iv) diet containing hybrid IPM3. The diets wereoffered to male broilers (Hubbard Ultra-Yield;120 birds per treatment) in 3 phases: starter,grower and finisher. All the diets were isonitrogenousand iso-energetic. The IPM2 andIPM3 diets (containing maize grains with thehighest protein and essential and non-essentialamino acid contents) resulted in a higherfinal weight in broilers (2622 and 2632 g,respectively, versus IPM1 and CTR diets;P<0.05), a higher average daily gain (60.8 and61.4 g/d, respectively, versus IPM1 and CTRdiets; P<0.05) and better feed to gain ratios(1.70 and 1.69, respectively, versus the CTRdiet; P<0.05) throughout the experimentalperiod. The nutritional characteristics of thedifferent maize varieties were also evaluatedusing a 9-day digestibility trial in male rats (6rats per treatment). Higher percentages ofnitrogen retention were obtained from theIPM2 (54.02%) and IPM3 (53.51%) diets comparedwith the CTR (44.20%) and IPM1(41.87%) diets (P<0.05). These results suggesta greater amino acid availability in thediets based on high-protein maize varieties.Therefore, high-protein maize can profitablybe included in broiler diets with the advantageof reducing the use of imported protein sources (such as soybean meal) because of itshigher protein content and consequently, providingsavings on feed costs.