Feed Science Institute, College of Animal Science, Zhejiang University, Hangzhou, China.
Poult Sci. 2018 Jan 1;97(1):110-117. doi: 10.3382/ps/pex260.
This study was conducted to evaluate the effect of in ovo feeding of cationic amino acids on hatchability, hatch weights, and organ developments in pigeon squabs. Two experiments were conducted in this study. Eggs in Exp. 1 were subjected to modification of in ovo feeding in pigeons. Optimal time was determined by checking amniotic fluid volume, and suitable length was confirmed through ink injection. Results showed that the optimum time of in ovo feeding was on d 13 of embryonic development, and the suitable injected length was 20 mm to reach the amniotic cavity of the embryo. Eggs in Exp. 2 were transferred to access in ovo feeding of cationic amino acids. A total of 75 fertile pigeon eggs was randomly distributed into 5 treatments of 15 replicate eggs. Treatments in Exp. 2 consisted of non-injected controls (Control), a sterile buffered solution (0.75% saline), or a cationic amino acid mixture (> 98.5% purity crystalline L-arginine, > 98% purity crystalline L-lysine, and > 98.5% purity L-histidine) containing 0.1, 1, or 10% concentration (Conc.), which were relative to their total content in the eggs, respectively. The crystalline amino acids were dissolved in 200 μL buffered solution prior to in ovo feeding. After hatching, hatch weight (HW) and organ weight (OW) of the squabs were measured immediately. In ovo feeding of cationic amino acids increased the proportions of yolk-free hatch weight to hatch weight (YFHW/HW) (quadratic P = 0.01), and those of OW to YFHW including the heart (quadratic P = 0.01), kidney (quadratic P < 0.01), and liver (quadratic P = 0.02) compared to the control group, and the levels of those ratios were maximized in the 1% Conc group. Also, a proportion of small intestine weight to YFHW improved (linear P = 0.02, quadratic P = 0.05) after in ovo feeding. The organ weight of the head, leg, heart, lung, kidney, proventriculus, pancreas, liver, and small intestine correlated with YFHW positively (0.4 < correlation coefficient < 0.8, P < 0.05). In conclusion, cationic amino acids injection into amnion can improve the embryonic development, which may be mediated by the increment of relative organ weight.
本研究旨在评估在鸽子胚中添加阳离子氨基酸对孵化率、孵化体重和器官发育的影响。本研究进行了两项实验。实验 1 中的鸡蛋接受了鸽子胚中添加阳离子氨基酸的改良。通过检查羊水体积确定最佳时间，并通过墨水注射确认合适的注射长度。结果表明，最佳的胚中添加时间是胚胎发育的第 13 天，合适的注射长度为 20 毫米，以到达胚胎的羊膜腔。实验 2 中的鸡蛋被转移到胚中添加阳离子氨基酸。总共 75 个有活力的鸽子蛋被随机分配到 5 个处理组，每个处理组 15 个重复蛋。实验 2 中的处理组包括未注射对照组（Control）、无菌缓冲液（0.75%盐水）或含有 0.1%、1%或 10%浓度（Conc.）的阳离子氨基酸混合物（>98.5%纯度结晶 L-精氨酸、>98%纯度结晶 L-赖氨酸和>98.5%纯度 L-组氨酸），分别相对于它们在鸡蛋中的总含量。晶体氨基酸在胚中添加之前溶解在 200μL 缓冲液中。孵化后，立即测量雏鸽的孵化体重（HW）和器官重量（OW）。与对照组相比，胚中添加阳离子氨基酸增加了蛋黄无孵化体重与孵化体重的比例（YFHW/HW）（二次 P = 0.01），以及包括心脏（二次 P = 0.01）、肾脏（二次 P <0.01）和肝脏（二次 P = 0.02）在内的 OW 与 YFHW 的比例，并且在 1%Conc 组中这些比例达到最高。此外，胚中添加后小肠重量与 YFHW 的比例提高（线性 P = 0.02，二次 P = 0.05）。头部、腿部、心脏、肺、肾脏、前胃、胰腺、肝脏和小肠的器官重量与 YFHW 呈正相关（0.4 < 相关系数 < 0.8，P <0.05）。综上所述，将阳离子氨基酸注入羊膜可以改善胚胎发育，这可能是通过相对器官重量的增加来介导的。
