Research Department, Hatchtech BV, Veenendaal, the Netherlands; Adaptation Physiology Group, Department of Animal Sciences, Wageningen University and Research, Wageningen, the Netherlands.
Adaptation Physiology Group, Department of Animal Sciences, Wageningen University and Research, Wageningen, the Netherlands.
Poult Sci. 2022 Oct;101(10):102088. doi: 10.1016/j.psj.2022.102088. Epub 2022 Aug 3.
Early life experiences are known to be of great importance for later life. For instance, exposure to stress during early life can increase fearfulness at later age. In broilers, delayed feeding after hatch may cause metabolic stress. Besides, delayed feeding after hatch may affect neonatal broiler development and thermogenesis and consequently preferred ambient temperature. Moreover, these effects of feeding strategy may be dependent on late incubation temperature. To study this, eggs (n = 1,338) from a 54-wk-old Ross broiler breeder flock were incubated at 37.8°C (control) or 36.7°C (lower) eggshell temperature (EST) during late incubation (≥ embryonic d 17). At hatch, two feeding strategies were applied (direct access (early feeding) or 51 to 54 h delayed access (delayed feeding)). Broilers (n = 960) were equally divided over 32 pens and grown for 3 wk. Stress was assessed by determination of corticosterone in blood at 0 h, 48 h, 96 h and d 21 after hatch. Fearfulness was assessed by tonic immobility at d 13. Temperature preference was assessed at d 2 and d 12. Broiler development was determined at 0 h, 48 h, and 96 h after hatch. There was no EST × feeding strategy interaction for any parameter (P ≥ 0.07). Early feeding resulted in a 2.5× lower plasma corticosterone concentration at 48 h (P < 0.01) and a 2.2°C and 2.0°C lower preference temperature for d 2 and d 12 respectively (P = 0.01) compared to delayed feeding. Tonic immobility was not affected. In conclusion, early feeding reduces exposure to stress in the short term and stimulates thermoregulatory ability of broilers in the longer term.
早期生活经历对后期生活非常重要。例如，早期生活中的压力暴露会增加后期的恐惧。在肉鸡中，孵化后延迟进食可能会导致代谢应激。此外，孵化后延迟进食可能会影响新生肉鸡的发育和体温调节，进而影响其偏好的环境温度。此外，这些饲养策略的影响可能取决于后期孵化温度。为了研究这一点，来自 54 周龄罗斯肉鸡种鸡群的鸡蛋（n=1338）在后期孵化（≥胚胎第 17 天）期间在 37.8°C（对照）或 36.7°C（较低）蛋壳温度（EST）下孵化。孵化时，应用了两种饲养策略（直接进食（早期进食）或 51 至 54 小时延迟进食（延迟进食））。肉鸡（n=960）平均分为 32 个围栏，并饲养 3 周。通过在孵化后 0 小时、48 小时、96 小时和第 21 天测定血液中的皮质酮来评估应激。通过在第 13 天进行强直不动性评估来评估恐惧。在第 2 天和第 12 天评估温度偏好。在孵化后 0 小时、48 小时和 96 小时测定肉鸡的发育情况。对于任何参数，EST×饲养策略相互作用均无差异（P≥0.07）。与延迟进食相比，早期进食使 48 小时时血浆皮质酮浓度降低 2.5 倍（P<0.01），第 2 天和第 12 天的偏好温度分别降低 2.2°C 和 2.0°C（P=0.01）。强直不动性不受影响。总之，早期进食可在短期内减少应激暴露，并在长期内刺激肉鸡的体温调节能力。
