Effect of protease and duration of fattening period on dressing percentage of roiler chickens

Abstract

This study evaluates the effect of different crude protein levels in broiler diets supplemented with 0.2% and 0.3% protease enzyme (Ronozyme Pro Act) on dressed carcass weight and dressing percentage during two fattening periods (49 and 63 days). The fast-growing strain Cobb 500 was used. At the end of the fattening trial i.e. at 49 and 63 days, 10 male and 10 female birds were randomly sacrificed from each experimental group to determine body weights and conventionally dressed, ready-to-roast and ready-to-grill carcass weights. The data obtained were used to calculate the dressing percentages of the differently dressed carcasses. Results indicated that carcass weights and dressing percentages were not affected by diet (P>0.05), but also showed that the increase in the length of the fattening period by two weeks (from 7 to 9 weeks) led to increased carcass weights, while dressing percentages decreased (P (lt) 0.05).

U radu su prikazani efekti različitih nivoa sirovih proteina u hrani za tovne piliće, uz dodatak enzima proteaze (Ronozyme Pro Act) u količini 0,2% i 0,3% na masu i randmane obrađenih trupova pri različitom trajanju tova (49 i 63 dana). U ogledu je korišćen brzorastući tovni hibrid Cobb 500. Na kraju oglednih perioda, 49 i 63. dana, odabrano je slučajnim izborom po 10 muških i 10 ženskih pilića iz svake eksperimentalne grupe i izmerena je masa grla pre klanja, masa klasično obrađenog trupa, trupa spremno za pečenje i trupa spremno za roštilj. Na osnovu ovih podataka izračunat je randman različito obrađenih trupova pilića. Dobijeni rezultati ukazuju da mase i randmani trupova nisu bili pod uticajem ispitivanih obroka (P>0,05), ali i da su se sa produžavanjem trajanja tova za 2 nedelje (sa 7. na 9 nedelja) povećale mase trupova, uz istovremeno smanjivanje randmana obrađenih trupova (P (lt) 0,05).