Abstract:
The objective of this study was to investigate the effect of feeding behavior on feed intake and body weight in growing layers and the underlying mechanisms, thereby providing a scientific foundation for optimal feeding practices in growing layers\' management. A total of 144 Hy-line brown growing layers of 10 wk old and similar body weight, were divided into 3 treatment groups with different feeding frequency and equal cumulative daily feeding amount: the once-a-day feeding group (F1) was fed at 9:00 am every day, with feeding amount of 150 g/layer; the twice-a-day feeding group (F2) were fed at 9:00 am and 13:00 pm every day, with each feeding amount of 75 g/layer; the 4 times-a-day feeding group (F4) were fed at 9:00 am, 11:00 am, 13:00 pm, and 15:00 pm every day, with each feeding amount of 37.5 g/layer. Pre-experiment lasted for 1 wk and formal experiment lasted for 8 wk. The results indicated that the daily feed intake and body weight were decreased (P < 0.05) while feed conversion ratio was not affected (P > 0.05) as daily feeding times increased. The glandular stomach proportion was significantly increased in twice-a-day feeding group, while liver proportion and ileum length were significantly increased in 4 times-feeding group (P < 0.05). Additionally, 4 times-feeding daily resulted in a significant elevation of blood glucose levels, which may have suppressed feed intake (P < 0.05). In 4 times-feeding group, the plasma triglyceride levels increased as feeding times, accompanied by a notable up-regulation in the mRNA level of appetite-suppressing gene, hypothalamic pro-opiomelanocortin (POMC) and glandular stomach ghrelin. This modulation effectively suppressed the subsequent feed intake and body weight. Therefore, 4 times feeding daily is recommended in growing layers\' management, because it reduced the feed cost without affecting the feed conversion efficiency.
摘要:
本研究的目的是研究摄食行为对生长层采食量和体重的影响及其潜在机制,从而为生长层管理中的最佳饲喂实践提供科学依据。总共144层Hy线棕色生长层,10周龄,体重相似,分为3个不同饲喂频率和每日累积饲喂量相等的治疗组:每天一次的饲喂组(F1)每天上午9:00饲喂,饲喂量为150克/层;每天两次喂养组(F2)每天上午9:00和下午13:00喂养,每次喂食量为75g/层;每天4次喂食组(F4)在上午9:00喂食,上午11点,13:00pm,每天下午15点,每次投料量为37.5克/层。预实验持续1周,正式实验持续8周。结果表明,随着日饲喂次数的增加,日采食量和体重下降(P<0.05),饲料转化率不受影响(P>0.05)。每天两次喂养组的腺胃比例显着增加,4次喂养组肝脏比例和回肠长度显著增加(P<0.05)。此外,每天喂食4次导致血糖水平显着升高,这可能抑制了采食量(P<0.05)。在4次喂养组中,血浆甘油三酯水平随着进食时间的增加而增加,伴随着食欲抑制基因mRNA水平的显著上调,下丘脑前阿片黑皮质素(POMC)和腺胃ghrelin。这种调节有效地抑制了随后的饲料摄入量和体重。因此,建议在生长层管理中每天喂食4次,因为它在不影响饲料转化效率的情况下降低了饲料成本。