Poultry Production Department, Faculty of Agriculture, Assiut University, Assiut, 71515, Egypt.
Animal and Poultry Production Department, Faculty of Technology and Development, Zagazig University, Zagazig, 44511, Egypt.
Int J Biometeorol. 2020 Aug;64(8):1295-1303. doi: 10.1007/s00484-020-01906-z. Epub 2020 Apr 6.
Lighting regimes are possibly used as a strategy to improve rabbit production in tropical regions; on this background, this study was conducted to assess the possible role of different light (L):dark (D) regimes in improving growing New Zealand white rabbit's performance. Sixty-four growing rabbits were randomly divided into four groups. Rabbits of the first group (C) were exposed to 12 h of light (from 10.00 to 22.00 h). Rabbits of the second group (T1) were exposed to 12 h of light (from 22.00 to 10.00 h). The third group (T2) was exposed to 8 h of light (from 10.00 to 18.00 h), while the fourth group (T3) was exposed to 8 h of light (from 22.00 to 06.00 h). Temperature-humidity index values ranged between 27.00 and 28.87, indicating exposure of growing rabbits to very severe heat stress. Body weight (BW), body weight gain (BWG), feed consumption (FC), feed conversion ratio (FCR), carcass traits, blood parameters, and some physiological (rectum temperature, respiration rate) and health aspects (morbidity, mortality, and health risks %) were investigated. Rabbits of T1 showed the highest (P < 0.05) averages of BW and BWG in comparison with their counterparts. There were no significant differences in FC; however, rabbits of T1 had the lowest value of FCR at marketing. The percentages of dressed carcass, liver, and kidney in T1 and T3 were the highest. Non-significant changes were observed among the groups in most of the metabolic and hematology parameters of blood, except for ALT and N/L ratio. Further, rabbits of T1 showed the lowest rectal temperature and respiration rate in comparison with their counterparts. Conclusively, the utilization of photoperiod of afternoon program for over a short period of time in rabbitry brought in beneficial effects on growth performance and other productive and physiological parameters of growing rabbits.
光照制度可能被用作提高热带地区家兔生产性能的策略;在此背景下,本研究旨在评估不同光照(L):黑暗(D)制度在提高新西兰白兔生长性能方面的可能作用。将 64 只生长兔随机分为四组。第一组(C)的兔子暴露在 12 小时的光线下(从 10.00 到 22.00 小时)。第二组(T1)的兔子暴露在 12 小时的光线下(从 22.00 到 10.00 小时)。第三组(T2)暴露在 8 小时的光线下(从 10.00 到 18.00 小时),而第四组(T3)暴露在 8 小时的光线下(从 22.00 到 06.00 小时)。温湿度指数值在 27.00 到 28.87 之间,表明生长兔暴露在非常严重的热应激下。体重(BW)、体重增重(BWG)、饲料消耗(FC)、饲料转化率(FCR)、胴体性状、血液参数以及一些生理(直肠温度、呼吸率)和健康方面(发病率、死亡率和健康风险%)进行了研究。与对照组相比,T1 组的兔子表现出最高的 BW 和 BWG 平均值(P<0.05)。FC 没有显著差异;然而,T1 组的兔子在上市时的 FCR 值最低。T1 和 T3 组的胴体、肝脏和肾脏的比例最高。各组血液中大多数代谢和血液参数没有显著变化,除了 ALT 和 N/L 比值。此外,与对照组相比,T1 组的兔子直肠温度和呼吸率最低。综上所述,在兔舍中短时间内利用下午的光周期对生长兔的生长性能和其他生产性能和生理参数产生了有益的影响。