Department of Poultry Science, The University of Georgia, Athens 30602.
Phibro Animal Health Corporation, Teaneck, NJ 07666.
Poult Sci. 2017 Jun 1;96(6):1615-1622. doi: 10.3382/ps/pew475.
A series of 4 floor pen studies was conducted to evaluate the effects of environmental temperature modification on nicarbazin (NIC) responses in broiler chickens raised to 28 d of age. Birds were reared at either standard temperatures (recommended by the primary breeder for ages zero to 28 d) or at 3°C below this level. From placement to 28 d, birds were provided feeds containing zero, 100, or 125 ppm NIC, comprising a 2 × 3 factorial arrangement in each test. Two of the trials were conducted in the presence of an imposed coccidial challenge and 2 were conducted in healthy animals. At 18 and 28 d of age, performance was recorded; cloacal temperatures were measured at 7, 14, 21, and 26 days. Mortality data were collected daily and coccidial lesions were scored at 6 d post challenge. Results of these studies revealed that NIC improved coccidial lesion scores regardless of environmental temperature. In the absence of coccidial challenge, NIC depressed performance, but reductions in environmental temperature diminished the magnitude of these responses. Under conditions of coccidial challenge, NIC significantly improved body weight gains in both temperature environments. Compared to standard temperature conditions, lower environmental temperatures exerted a positive effect on feed conversion rates of NIC-fed broilers. Birds reared in the low temperature environment exhibited lower cloacal temperatures than standard environment groups throughout the test period. Irrespective of coccidial challenge, lower environmental temperatures significantly reduced nicarbazin mortality compared to standard temperature groups, resulting in a significant nicarbazin x temperature interaction. This finding indicates that temperature modification is a practical method for minimizing mortality over the course of 28-day nicarbazin usage.
进行了一系列 4 地板房研究，以评估环境温度调节对饲养至 28 日龄肉鸡的尼卡巴嗪（NIC）反应的影响。鸟类在标准温度（主要饲养员推荐的 0 至 28 日龄温度）或低于此水平 3°C 的温度下饲养。从放置到 28 日龄，给鸟类提供含有 0、100 或 125 ppm NIC 的饲料，每个测试均采用 2×3 因子设计。两次试验在实施球虫挑战的情况下进行，两次试验在健康动物中进行。在 18 和 28 日龄时记录性能；在 7、14、21 和 26 天测量肛门温度。每天收集死亡率数据，并在挑战后 6 天对球虫病变进行评分。这些研究的结果表明，无论环境温度如何，NIC 均可改善球虫病变评分。在没有球虫挑战的情况下，NIC 会降低性能，但降低环境温度会减少这些反应的幅度。在球虫挑战的情况下，NIC 可显著改善两种温度环境下肉鸡的体重增加。与标准温度条件相比，较低的环境温度对 NIC 喂养肉鸡的饲料转化率产生了积极影响。在整个试验期间，在低温环境中饲养的鸟类的肛门温度低于标准环境组。无论是否存在球虫挑战，与标准温度组相比，较低的环境温度都会显著降低 NIC 的死亡率，从而导致 NIC×温度的显著相互作用。这一发现表明，温度调节是在 28 天 NIC 使用过程中最小化死亡率的实用方法。
