Animal Breeding and Genomics, Wageningen University & Research, 6700 AH Wageningen, The Netherlands; Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, 3508 TD Utrecht, The Netherlands.
School of Natural and Environmental Sciences, Newcastle University, NE1 7RU, Newcastle upon Tyne, United Kingdom.
Poult Sci. 2022 Oct;101(10):102086. doi: 10.1016/j.psj.2022.102086. Epub 2022 Jul 30.
Fast-growing broilers are relatively inactive and this is thought to be a result of selection for high growth rates. This reduced activity level is considered a major cause of leg weakness and associated leg health problems. Increased activity, especially early in life, is suggested to have positive effects on leg health, but the relationship between early activity and growth is unclear. A clearer understanding of the relationship between activity early in life and body weight gain could help determine how selecting on increased early activity could affect body weight gain in broilers. Here, a radio frequency identification (RFID) tracking system was implemented to record daily individual broiler activity throughout life, in 5 production rounds. As mean activity levels alone do not capture the variation in activity over time, multiple (dynamic) descriptors of activity were determined based on the individual birds' daily distances moved, focusing on the period from 0 to 15 days old. The mean, skewness, root mean square error (RMSE), autocorrelation, and entropy of (deviations in) activity were determined at the individual level, as well as the average daily gain (ADG). Relationships between activity descriptors and ADG were determined for 318 birds. Both when combining the data from the different production rounds and when taking production round and start weight into account, a negative relationship between ADG and RMSE was observed, indicating that birds that were more variable in their activity levels had a lower ADG. However, the activity descriptors, in combination with recording round and start weight, explained only a small part (8%) of the variation in ADG. Therefore, it is recommended for future research to also record other factors affecting ADG (e.g., type of feed provided and feed intake) and to model growth curves. Overall, this study suggests that increasing early activity does not necessarily negatively affect body weight gain. This could contribute to improved broiler health and welfare if selecting for increased activity has the expected positive effects on leg health.
快速生长的肉鸡相对不活跃，这被认为是选择高生长率的结果。这种活动水平的降低被认为是腿部虚弱和相关腿部健康问题的主要原因。增加活动量，尤其是在生命早期，被认为对腿部健康有积极影响，但早期活动与生长之间的关系尚不清楚。更清楚地了解生命早期活动与体重增加之间的关系，可以帮助确定选择增加早期活动如何影响肉鸡的体重增加。在这里，实施了射频识别（RFID）跟踪系统，以在 5 个生产轮次中记录整个生命过程中每只肉鸡的日常个体活动。由于平均活动水平本身并不能捕捉到随时间变化的活动变化，因此根据个体鸟类每天移动的距离确定了多个（动态）活动描述符，重点关注 0 至 15 天的时期。在个体水平上确定了（偏差的）活动的平均值、偏度、均方根误差（RMSE）、自相关和熵，以及平均日增重（ADG）。确定了 318 只鸟的活动描述符与 ADG 之间的关系。当组合不同生产轮次的数据时，以及当考虑生产轮次和起始体重时，都观察到 ADG 与 RMSE 之间呈负相关，这表明活动水平变化较大的鸟类 ADG 较低。然而，活动描述符，结合记录轮次和起始体重，仅解释了 ADG 变化的一小部分（8％）。因此，建议未来的研究还记录影响 ADG 的其他因素（例如，提供的饲料类型和饲料摄入量）并建立生长曲线模型。总体而言，这项研究表明，增加早期活动不一定会对体重增加产生负面影响。如果选择增加活动量对腿部健康有预期的积极影响，这可能有助于改善肉鸡的健康和福利。
