Fueled by consumer preference for natural and antibiotic-free products, phytogenics have become the fastest growing segment of the animal feed additives. Yet, their modes of action are not fully understood. This study was undertaken to determine the effect of 5 phytogenics (3 feed- and 2 water-supplements) on the growth performance of commercial broilers, and their potential underlying molecular mechanisms. Day-old male Cobb 500 chicks (n = 576) were randomly assigned into 48 pens consisting of 6 treatments (Control; AVHGP; SCP; BHGP; AVSSL; SG) in a complete randomized design (12 birds/pen, 8 pens/treatment, 96 birds/treatment). Chicks had ad libitum access to feed and water. Individual body weight (BW) was recorded weekly and feed intake was measured daily. Core body temperatures were continuously recorded using thermo-loggers. At d 35, hypothalamic tissues were excised from the thermo-logger-equipped chickens (n = 8 birds/treatment) to determine the expression of feeding-related neuropeptides. Both feed (AVHGP, SCP, BHGP) and water-supplemented (AVSSL, SG) phytogenics significantly improved feed efficiency (FE) compared to the control birds. This higher FE was achieved via a reduction in core body temperature and improvement of market BW, without changes in feed intake in broilers supplemented with phytogenic water additives as compared to the control group. Broilers fed dietary phytogenics, however, attained higher feed efficiency via a reduction in feed intake while maintaining similar BW as the control group. At the molecular levels, the effects of the phytogenic water additives seemed to be mediated by the activation of the hypothalamic AgRP-ORX-mTOR-S6k1 and inhibition of CRH pathways. The effect of the phytogenic feed additives appeared to be exerted through the activation of AdipoQ, STAT3, AMPK, and MC1R pathways. This is the first report describing the likely central mechanisms through which phytogenic additives improve the growth performance and feed efficiency in broilers.

中文翻译：

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植物源性饲料和水添加剂通过调节（an）促食欲下丘脑神经肽表达提高肉鸡的饲料效率

在消费者对天然和无抗生素产品的偏好的推动下，植物源已成为动物饲料添加剂中增长最快的部分。然而，他们的行动方式尚未完全了解。本研究旨在确定 5 种植物源性物质（3 种饲料补充剂和 2 种水分补充剂）对商品肉鸡生长性能的影响及其潜在的潜在分子机制。日龄雄性 Cobb 500 雏鸡（n = 576）被随机分配到 48 个围栏，由 6 个处理（对照；AVHGP；SCP；BHGP；AVSSL；SG）组成，完全随机设计（12 只鸡/围栏，8 个围栏/处理） , 96 只鸡/处理）。小鸡可以随意获取饲料和水。每周记录个体体重（BW），每天测量采食量。使用热记录仪连续记录核心体温。在第 35 天，从配备热记录仪的鸡（n = 8 只鸡/处理）中切除下丘脑组织以确定与喂养相关的神经肽的表达。与对照鸡相比，饲料（AVHGP、SCP、BHGP）和水补充剂（AVSSL、SG）植物源显着提高了饲料效率（FE）。这种较高的 FE 是通过降低核心体温和改善市场 BW 实现的，与对照组相比，补充植物性水添加剂的肉鸡的采食量没有变化。然而，饲喂植物性饲料的肉鸡通过减少采食量获得更高的饲料效率，同时保持与对照组相似的体重。在分子水平上，植物源水添加剂的作用似乎是由下丘脑 AgRP-ORX-mTOR-S6k1 的激活和 CRH 通路的抑制介导的。植物性饲料添加剂的作用似乎是通过激活 AdipoQ、STAT3、AMPK 和 MC1R 途径发挥的。这是第一份描述植物性添加剂提高肉鸡生长性能和饲料效率的可能核心机制的报告。