Feeding program with different dietary crude protein and metabolizable energy levels, for broilers

Two trials were conducted to evaluate four different nutritional plans with different energy (ME) and protein (CP) levels, nominated PN1 (highest levels), PN2 (medium), PN3 (low) and PN4 (lowest) in starter, grower and finisher periods of broiler raising. The performance, carcass and parts yield and economic analyses were evaluated in male (Trial 1) and female (Trial 2) broilers. The experimental design consisted of four treatments and four replicates with 880 chickens, randomized into 16 floor pens (55 birds/ pen). When necessary, Tukey test was used to compare difference among means. The results showed that the increase of nutrients of diets improved the performance of 1-39-day-old male broilers and 1-46-day-old females. The different nutritional plan did not affect the carcass yield of male and female birds. Nevertheless, broilers fed with high protein and energy levels (PN1 and PN2) showed better breast yield. No significant differences among treatments were observed for carcass and part yields. The greatest economic return in kg of weight male broilers was obtained when low protein and energy was used. However, for carcass and part yields of male broilers, PN2 group presented the greatest economic return. Independently of the product sold, female broiler fed PN3 showed better economic return.