ABSTRACT

1. Broiler chicks are frequently deprived of food up to 72 h due to uneven hatching rates, management procedures and transportation to farms. Little is known about the effect of delayed feeding due to extended hatching times on the early neonatal development of the caeca. Therefore, the objective of this study was to investigate the developmental changes and effects of a 48-h delay in feed access immediately post-hatch (PH) on the caeca.

2. After hatch, birds (Ross 708) were randomly divided into two treatment groups (n = 6 battery pen/treatment). One group (early fed; EF) received feed and water immediately after hatch, while the second group (late fed; LF) had access to water but had delayed access to feed for 48 h. Contents averaging across all regions of the caeca were collected for mRNA expression as well as for histological analysis at −48, 0, 4 h PH and then at 1, 2, 3, 4, 6, 8, 10, 12 and 14 days PH.

3. Expression of MCT-1 (a nutrient transporter), Cox7A2 (related to mitochondrial function) IgA, pIgR, and ChIL-8 (immune function) genes was affected by delayed access to feed that was dependent by the time PH. Expression of immune and gut barrier function-related genes (LEAP2 and MUC2, respectively) was increased in LF group. There was no effect of feed delay on expression of genes related to mitochondrial functions in the caeca, although developmental changes were observed (ATP5F1B, Cox4|1). Caecal mucus and muscle thickness were affected by delayed access to feed during caeca development.

4. The data suggested a limited effect of delayed feed access PH on the developmental changes in caecal functions. However, the caeca seemed to be relatively resistant to delayed access to feed early PH, with only a few genes affected.

摘要

1. 由于孵化率、管理程序和运往农场的不均匀，肉鸡经常被剥夺食物长达 72 小时。关于由于孵化时间延长而导致的延迟喂养对盲肠早期新生儿发育的影响知之甚少。因此，本研究的目的是调查在孵化后 (PH) 立即延迟 48 小时采食对盲肠的发育变化和影响。

2. 孵化后，鸟类 (Ross 708) 被随机分成两个处理组（n = 6 个电池栏/处理）。一组（早期喂食；EF）在孵化后立即喂食和饮水，而第二组（后期喂食；LF）可以喂水，但延迟喂食 48 小时。收集盲肠所有区域的平均含量，用于mRNA表达以及在 -48、0、4 小时 PH 和然后在 1、2、3、4、6、8、10、12 和 14 天 PH 的组织学分析.

3. MCT-1（一种营养转运蛋白）、Cox7A2（与线粒体功能相关）IgA、pIgR 和 ChIL-8（免疫功能）基因的表达受到延迟获取饲料的影响，这取决于时间 PH。LF组免疫和肠道屏障功能相关基因（分别为LEAP2和MUC2）的表达增加。尽管观察到发育变化（ATP5F1B，Cox4|1），但进食延迟对盲肠中线粒体功能相关基因的表达没有影响。盲肠发育过程中延迟获得饲料会影响盲肠粘液和肌肉厚度。

4. 数据表明延迟喂食 PH 对盲肠功能发育变化的影响有限。然而，盲肠似乎对延迟获取早期 PH 的饲料具有相对抵抗力，只有少数基因受到影响。