USDA, Agricultural Research Service, Poultry Research Unit, Mississippi State, MS 39762-5367, United States of America.
Poult Sci. 2019 Mar 1;98(3):1075-1082. doi: 10.3382/ps/pey466.
We evaluated the influence of light sources and photoperiod on blood physiological variables in four trials. In each trial, 720 1-d-old Ross × Ross 708 chicks were randomly distributed into 12 environmentally controlled rooms (30 males/30 females/room). The experimental design was a 4 × 3 factorial treatments consisting of four light sources [incandescent (ICD, standard), compact fluorescent, neutral light emitting diode, and cool poultry-specific-filtered LED] and three photoperiods [long/continuous (23L:1D), regular/intermittent (2L:2D), and short/non-intermittent (8L:16D)] from d8-d56 at 50% relative humidity. Birds were fed the same diet, while feed and water were provided ad libitum. Blood samples were collected from the brachial wing vein on d 14, 28, 42, and 56 of age and analyzed immediately. Light sources had significant (P ≤ 0.05) effects on body weight (BW), and some of the selected blood physiological indices except Hb, Hct, Ca2+ angap, glucose, and corticosterone. Also, the photoperiods had significant (P ≤ 0.05) effects on BW and most of the selected blood physiological indices except HCO3-, angap, glucose, corticosterone, and T4. However, all these changes were still within the normal acid-base homeostasis and physiological ranges of this species. Acid-base regulation during the short photoperiod exposure had not deteriorated despite higher pCO2 that consequently decreased blood pH, due to a respiratory acidosis. Plasma corticosterone and glucose concentrations were not affected by treatments, suggesting an absence of physiological stress. It was concluded that the three LED light bulbs evaluated could be suitable for replacement of ICD along with the regular/intermittent photoperiod. Commercial poultry facilities can thereby reduce energy costs and optimize production efficiency without compromising the welfare of broilers grown to heavy weights (>3 kg).
我们在四项试验中评估了光源和光周期对血液生理变量的影响。在每项试验中，将 720 只 1 日龄的罗斯 308 公鸡和母鸡随机分配到 12 个环境控制房间（每间 30 只鸡，雄性和雌性各半）。试验设计为 4×3 因子处理，包括四种光源[白炽（ICD，标准）、紧凑型荧光灯、中性发光二极管和冷却家禽专用过滤 LED]和三种光周期[长/连续（23L：1D）、常规/间歇（2L：2D）和短/非间歇（8L：16D）]，从第 8 天到第 56 天，湿度为 50%。所有鸟类均饲喂相同的日粮，自由采食和饮水。在第 14、28、42 和 56 天龄时，从臂翅静脉采集血液样本并立即进行分析。光源对体重（BW）和部分血液生理指标（除 Hb、Hct、Ca2+ angap、葡萄糖和皮质酮外）有显著影响（P≤0.05）。光周期对 BW 和大多数血液生理指标（除 HCO3-、angap、葡萄糖、皮质酮和 T4 外）有显著影响（P≤0.05）。然而，所有这些变化仍在该物种正常酸碱平衡和生理范围内。尽管较高的 pCO2 导致血液 pH 值降低，产生呼吸性酸中毒，但短光周期暴露期间的酸碱调节并未恶化。处理对血浆皮质酮和葡萄糖浓度没有影响，表明没有发生生理应激。结论是，评估的三种 LED 灯泡可以与常规/间歇光周期一起替代 ICD。商业家禽养殖场可以降低能源成本并优化生产效率，而不会损害体重达到（>3kg）较重的肉鸡的福利。
