Ahmadipour Behnam, Naeini Shahabodin Zafari, Sharifi Mohammadreza, Khajali Fariborz
Department of Animal Science, Shahrekord University, Shahrekord, 88186-34141, Iran.
J Poult Sci. 2018;55(1):60-64. doi: 10.2141/jpsa.0170044. Epub 2017 Sep 25.
Guanidinoacetic acid (GAA) has been shown to spare arginine (ARG) requirements in chickens. ARG plays a critical role in enhancing growth and preventing right ventricular hypertrophy (RVH) in broiler chickens subjected to hypobaric hypoxia. However, ARG is not available as a feed grade supplement in the market. Therefore, we evaluated the effects of commercially available GAA supplement as an alternative on growth performance and RVH in broilers raised at high altitude (2100 m). Five graded levels of GAA ranging from 0 (control) to 2 g/kg were provided in isoenergetic and isonitrogenous diets to broilers (Ross 308) from day 1 to 42, post-hatch. Results indicated that responses to GAA were nonlinear and attained plateau values within the studied range of GAA supply. While weight gain and feed intake were unaffected by GAA supply, feed conversion ratio was improved by GAA supplementation up to 1.5 g/kg. Similar trends were observed for the proportions in the liver and heart, as well as hematocrit. GAA supplementation at 1 and 1.5 g/kg resulted in reduced abdominal fat deposition as well as a decline in right-tototal ventricular weight ratio (RV:TV, an index of RVH). A significant (<0.05) increase in serum nitric oxide concentration was observed at 1 and 1.5 g/kg GAA supplementation. However, GAA supply led to lower serum malondialdehyde and uric acid levels than in the control. In conclusion, GAA supplementation up to 1.5 g/kg had the potential to improve growth performance and RVH response. Meanwhile, GAA supply beyond 1.5 g/kg could deteriorate these responses.
胍基乙酸（GAA）已被证明可节省鸡对精氨酸（ARG）的需求。精氨酸在提高生长性能和预防低压低氧环境下肉鸡的右心室肥大（RVH）方面起着关键作用。然而，市场上没有饲料级的精氨酸补充剂。因此，我们评估了市售的GAA补充剂作为替代品对高海拔（2100米）饲养的肉鸡生长性能和RVH的影响。从孵化后第1天到第42天，给肉鸡（罗斯308）提供等能量和等氮的日粮，其中GAA有五个分级水平，范围从0（对照）到2克/千克。结果表明，对GAA的反应是非线性的，并且在研究的GAA供应范围内达到了平稳值。虽然体重增加和采食量不受GAA供应的影响，但补充GAA至1.5克/千克可提高饲料转化率。在肝脏和心脏的比例以及血细胞比容方面也观察到了类似的趋势。补充1克/千克和1.5克/千克的GAA可减少腹部脂肪沉积，并降低右心室与总心室重量比（RV:TV，RVH的一个指标）。补充1克/千克和1.5克/千克的GAA时，血清一氧化氮浓度显著（<0.05）升高。然而，与对照组相比，GAA供应导致血清丙二醛和尿酸水平降低。总之，补充高达1.5克/千克的GAA有可能改善生长性能和RVH反应。同时，超过1.5克/千克的GAA供应可能会使这些反应恶化。
