Xin Qian, Wang Minghui, Jiao Hongchao, Zhao Jingpeng, Li Haifang, Wang Xiaojuan, Lin Hai
College of Animal Science and Techonology, Shandong Key Lab for Animal Biotechnology and Disease Control, Taian, Shandong 271018, China.
College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China.
Poult Sci. 2021 Jul;100(7):101098. doi: 10.1016/j.psj.2021.101098. Epub 2021 Mar 11.
Calcium (Ca) and phosphorus (P) transporters are responsible for their absorption and transport in small intestine and kidney, contributing to eggshell formation. The light-dark cycle is a primary cue in the reproduction of laying hen. In this study, we investigated the effect of different light-dark programs on eggshell quality and the expression of genes related to Ca and P transportation in laying hens. Seventy-two 56-week-old laying hens were randomly divided into two groups and reared at 16-h light and 8-h dark (control) or 9-h light and 15-h dark regime (long dark phase, LDP). The expressions of calcium transporter calbindin-D28k (CaBP-D28k), plasma membrane Ca ATPase 1b (PMCA1b), and phosphorus transporter NaPi-IIb (NPt2b) and NaPi-IIa (NPt2a) were measured in the small intestine, kidney, and eggshell gland. The results showed that feed intake (P < 0.001) and egg weight (P = 0.05) were decreased by LDP treatment. Compared with control, the eggshell hardness was increased (P = 0.011) by LDP treatment, but the eggshell thickness and the percentage of eggshell were not changed. The Ca and P contents in eggshell were increased by LDP treatment. During the scotophase, LDP-hens showed higher serum Ca (P = 0.0056) and P levels (P = 0.079) but lower alkaline phosphatase (ALP) activity than that of control hens. In the duodenum, the relative higher expression of CaBP-D28k and PMCA1b in scotophase compared to photophase was masked by LDP treatment. The expression of CaBP-D28k and osteopontin (OPN) in the eggshell gland were increased by LDP treatment, compared to control hens. In the jejunum, the protein expression levels of CaBP-D28k and PMCA1b decreased during photophase in LDP-hens. The result indicates that the increased blood Ca and P concentration during scotophase by LPD treatment is beneficial to the deposition of Ca and P in the eggshell. The result offers an alternative strategy for managing laying hens with poor eggshell quality.
钙（Ca）和磷（P）转运蛋白负责它们在小肠和肾脏中的吸收与转运，对蛋壳形成有重要作用。明暗循环是蛋鸡繁殖的主要信号。在本研究中，我们调查了不同明暗程序对蛋鸡蛋壳质量以及与钙磷转运相关基因表达的影响。72只56周龄蛋鸡被随机分为两组，分别饲养在16小时光照和8小时黑暗（对照组）或9小时光照和15小时黑暗（长黑暗期，LDP）环境中。测定了小肠、肾脏和蛋壳腺中钙转运蛋白钙结合蛋白-D28k（CaBP-D28k）、质膜钙ATP酶1b（PMCA1b）以及磷转运蛋白钠磷协同转运蛋白-IIb（NPt2b）和钠磷协同转运蛋白-IIa（NPt2a）基因的表达。结果显示，LDP处理使采食量（P < 0.001）和蛋重（P = 0.05）降低。与对照组相比，LDP处理使蛋壳硬度增加（P = 0.011），但蛋壳厚度和蛋壳比例未改变。LDP处理使蛋壳中的钙和磷含量增加。在暗期，LDP组蛋鸡血清钙（P = 0.0056）和磷水平（P = 0.079）高于对照组，但碱性磷酸酶（ALP）活性低于对照组。在十二指肠中，LDP处理掩盖了暗期相较于光期CaBP-D28k和PMCA1b相对较高的表达。与对照组相比，LDP处理使蛋壳腺中CaBP-D28k和骨桥蛋白（OPN）的表达增加。在空肠中，LDP组蛋鸡光期CaBP-D28k和PMCA1b的蛋白表达水平下降。结果表明，LPD处理使暗期血钙和血磷浓度升高，有利于蛋壳中钙和磷的沉积。该结果为管理蛋壳质量差的蛋鸡提供了一种替代策略。
