Impacts of stocking density on the performance and welfare of broiler chickens.

摘要

The current study was performed to investigate the influence of different stocking density rates on the performance, thermophysiological measurements as well as blood parameters of 0 to 30 d of age female Ross broiler. A total of 96 chicks were randomly distributed in a randomized complete block design among 12 cages. Three stocking density rates were applied; low (28.0 kg/m2), medium (37.0 kg/m2) and high (40.0 kg/m2). Results revealed that cumulative body weight gain (BWG) and feed intake (FI) were influenced (P<0.01) by the rate of stocking density, while no effect (P>0.05) were observed for broilers mortalitycorrected feed conversion ratio (FCR). Higher BWG (P<0.01) and FI (P<0.05) were reported for low and medium density rates broilers in comparison to the high density rate broilers. Overall means of body temperature as well as head, neck, wing, body and shank surface temperatures have displayed (P<0.05) higher values in medium and high density rates broilers compared to the low density rate broilers. Furthermore, increasing the stocking density from 28 to 40 kg/m2 induced a state of hemodilution in higher density rate broilers, which might explain the noticeable decrease in packed cell volume (PCV). Meanwhile, an increase in serum aspartate aminotransferase (AST) was observed in the higher density group, which might indicate hepatocellular injures. It can be concluded that increasing the stocking density rate from 28 to 40 kg of BW/m2 had evident impingement effects on the performance of broiler chicken and could jeopardize their welfare.