Effect of stocking density on growth performance and carcass characteristics of broilers grown to 3 kg under antibiotic free conditions

Authors: Olanrewaju, Hammed; Magee, Christopher; Collier, Stephanie; Purswell, Joseph - Jody

Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Consumers assumed that stocking density (SD) to be one of the most crucial factors that influence animal welfare, but livestock producers in other hand assumed that any improvements in the area of animal welfare will have a negative impact on farm profitability. With increasing movement away from antibiotics as growth promoters coupled with increasing market weights and manipulations of SD, modification of traditional methods of housing management and environmental control is necessary to maintain or enhance production efficiency. Hence, this study examined the main effects of SD of broiler chickens fed antibiotic free (ABF) diets on growth performance and carcass characteristics of broilers grown to 3 kg. Results show that body weight and body weight gain, live weight and carcass weights were not affected by stocking density. Also, mortality was not affected by stocking density. However, feed intake and feed conversion ratio for the starter period were affected at lower stocking density, but were not different for the remainder of the flock. In conclusion, stocking densities up to 42 kg/m2 with appropriate environmental management has little effect on overall production efficiency and processing yield in ABF broilers.

Technical Abstract: Lower stocking densities may play a significant role in minimizing difficulties such as necrotic enteritis when reducing or eliminating antimicrobials (antibiotic free; ABF) in poultry diets. This study investigated the effects of stocking densities on growth performance and carcass characteristics of broilers grown to 3 kg fed antibiotic free diets. A total of 888 1-d- old Ross x Ross 708 chicks were randomly distributed into 24 pens. The treatments were four stocking densities including 29, 33, 39, and 42 kg of BW/m2; each treatment was represented by six replicates. Treatments were blocked within the room to account for any variations in room conditions and treatment assignments were randomized within each block. Used bedding was obtained from commercial farms to simulate commercial conditions. Feed and water provided ad libitum. Birds were fed antibiotic free (ABF) diets and provided a three phase-feeding program (Starter: 0-15 d, Grower: 15-28 d, and Finisher: 29-42 d). Birds and feed were weighed on 1, 15, 28, and 42 d of age to measure growth performance. On d 43, 10 (five males and five females) birds from each pen were processed to determine weights and yields. The BW and BW gain, live weight and carcass weights were not affected by stocking density. Mortality was not affected by stocking density. However, FI and FCR for the starter period were significantly elevated (P < 0.001 and P < 0.001, respectively) at lower stocking densities, but were not different for the remainder of the flock. In conclusion, stocking densities up to 42 kg/m2 with appropriate environmental management has little effect on overall production efficiency and processing yield in ABF broilers.