THE INFLUENCE OF FEED PROTEIN AND ENERGY LEVEL ON THE GROWTH AND SLAUGHTER PERFORMANCES AT "HUBBARD F15" BROILER CHICKENS

Adela Marcu, I. Vacaru-Opriş, A. Marcu, Maria Nicula, D. Dronca, B. Kelciov

Abstract
In this paper was studied the influence of feed energy-protein level on the growth performance (average daily gain, feed conversion), slaughtering efficiency and participation of the cutting parts in the whole carcasses structure at "HUBBARD F15" hybrid slaughtered at 42 days old. The two groups (control group-Lc and experimental group-Lexp) were given feed mixed with different level of energy and protein (Lc-standard hybrid, Lexp-higher by 10% compared to standard hybrid). In the growth period for each group were made weighings at: 1, 7, 14, 21, 28, 35 and 42 days. After slaughter, at 30 carcasses from each group (15 females and 15 males) was determined the slaughtering efficiency and participation of the cutting parts in the whole carcass structure. For analysis of variance were used Anova and Mann Whitney tests. At the end of the growing period, at Lexp group average body weight was with 6.50% higher compared to Lc group, but the situation is reversed for the feed conversion index. Slaughtering efficiency had higher values at Lexp compared to Lc, registering a decrease from 1.70% up to 1.92% after 24 hours of refrigeration. For participation of the cutting parts in the whole carcass structure at Lexp group were registered the highest values for breast and thighs and at the Lc group for the wings, shanks and other parts (head, neck, back and legs). At the Lexp group the feed with higher protein-energy level had positive influence on the growth and slaughter performances.

Key words: average daily gain, feed conversion index, hybrid, slaughtering