Impact of Different Levels of Crude Protein on Production Performance and Meat Quality in Broiler Selected for Slow Growth

The production performance and meat quality of the slow-growing hybrid Hubbard JA757 were monitored under conditions diets differentiated by crude protein content. A total 1200 as-hatched day-old chickens equally randomly allotted into two treatments (T-1 T-2), with six replicates provided for each treatment (100 chickens/replicate). T-1 received standard (according to Company recommendations), those in T-2 fed supplemented (+0.5% CP growing phase +1.0% finishing phase). At end investigations (age 56 days), performed better than growth traits (+2.72% body weight; +2.77% daily gain; −0.34% mortality; −4.15% feed conversion ratio); slaughtering (+0.66% dressed yield; +1.10% breast +1.25% thigh weight); (+0.55% dry matter muscles +1.52% muscles) (p > 0.05). Statistically significant differences < 0.05) occurred between weight, weight gain, ratio due 0.5% supplementation during 15–28 day age period, justifying usefulness increasing throughout grower diet only not period.