동물복지를 고려한 점등시간이 육계 병아리의 성장 능력 및 혈액 성상에 미치는 영향

Abstract

This study was conducted to investigate the effect of three different photoperiods on growth performance, blood properties, and stress indicators in broiler chicks between 1-7 days after hatching. Two hundred and fifty-two 1-day-old male broiler chicks (57.0±0.12 g) were divided into three treatments, with 4 replicates per treatment and 22 birds per replicate subjected to three different photoperiods of 24L, 22L/2D and 18L/6D. A light-emitting diode bulb served as the light source, with an illuminance of 30 lx. As an experimental diet, a commercial feed based on a corn-soybean meal, with 22% CP and 3,150 kcal/kg ME diet, and water were fed <i>ad libitum</i>. Body weight gain, feed conversion ratio, and liver weight ratio showed a statistically significant difference between the 18L/6D and 24L treatments (<i>P</i>&lt;0.05), but with no significant difference between the 22L/2D treatment and either the 24L or 18L/6D treatment. The breast meat ratio was 5.59% in the 18L/6D treatment group, which was lower than that of other treatment groups (<i>P</i>&lt;0.05). The triglyceride levels were highest (<i>P</i>&lt;0.05) in the 18L/6D treatment among treatments, but alanine aminotransferase levels were significantly higher (<i>P</i>&lt;0.05) in the 22L/2D treatment than in the 24L treatment. Levels of cytokines, i.e., Interleukin-6 and Tumor Necrosis Factor-α did not show a significant difference among the treatments, but corticosterone content was significantly higher (<i>P</i>&lt;0.05) in the 24L treatment than in the 18L/6D treatment. In conclusion, 22 hours of lighting is appropriate between 1~7 days after hatching, considering growth performance and the overall health of broiler chicks.