Linhoss John, Purswell Joseph, Magee Christopher, Chesser Daniel
Department of Agricultural and Biological Engineering, Mississippi State University, Mississippi State, MS, USA.
USDA ARS Poultry Research Unit, Mississippi State, MS, USA.
Poult Sci. 2021 Mar;100(3):100929. doi: 10.1016/j.psj.2020.11.080. Epub 2020 Dec 17.
Crop fill rates are measured as an indirect means of assessing management during the brooding phase. Primary breeder guidelines indicate that 95% of the chicks assessed should present a crop that is full, soft, and rounded after 24 h, which indicates chicks have successfully located feed and water. Crop fill progression has received little attention in the scientific literature and is primarily discussed in trade literature, and thus, the dynamic nature of crop fill progression has not been previously characterized. This study examined the role of 2 market weight stocking density treatments (29.3 kg/m and 43.9 kg/m) on performance and crop fill of broilers grown to 14 d. Crop fill progression was observed at 2, 4, 8, 12, 24, and 48 h after placement and tracked BW of birds that presented empty crops at 24 h; chicks with empty crops were identified to track postplacement BW. Stocking density had no significant effect on bird performance or crop fill. At 24 h, 86% of birds in this study had full, soft, and rounded crops, while only 3% of birds had crops that were devoid of food or water at 24 h. BW for birds with empty crops was significantly lower at 7 d (P = 0.006) but not at 14 d (P = 0.535). The data herein indicate that crop fill rates of 95% or higher at 24 h may be difficult to achieve in typical commercial broiler settings. In addition, assessing crop fill may be a useful tool to diagnose conspicuous management problems during brooding, but it does not appear to be a direct predictor of early performance.
嗉囊充盈率是衡量育雏期管理情况的一种间接方法。原种鸡饲养指南指出，在24小时后，经评估95%的雏鸡嗉囊应饱满、柔软且呈圆形，这表明雏鸡已成功找到饲料和水。嗉囊充盈过程在科学文献中很少受到关注，主要在行业文献中讨论，因此，嗉囊充盈过程的动态特性此前尚未得到描述。本研究考察了两种市场体重饲养密度处理（29.3千克/平方米和43.9千克/平方米）对饲养至14日龄肉鸡的生产性能和嗉囊充盈情况的影响。在雏鸡入舍后2、4、8、12、24和48小时观察嗉囊充盈过程，并跟踪24小时嗉囊为空的鸡的体重；识别出嗉囊为空的雏鸡以跟踪入舍后的体重。饲养密度对鸡的生产性能或嗉囊充盈情况没有显著影响。在24小时时，本研究中86%的鸡嗉囊饱满、柔软且呈圆形，而在24小时时只有3%的鸡嗉囊没有食物或水。嗉囊为空的鸡在7日龄时体重显著较低（P = 0.006），但在14日龄时没有显著差异（P = 0.535）。本文数据表明，在典型的商业肉鸡养殖环境中，24小时时嗉囊充盈率达到95%或更高可能难以实现。此外，评估嗉囊充盈情况可能是诊断育雏期明显管理问题的有用工具，但它似乎不是早期生产性能的直接预测指标。
