Wu Lihua, Wang Xiaona, Lv Xianliang, He Lei, Qu Hongxia, Shi Chuanxin, Zhang Liao, Zhang Jinliang, Wang Zhixiang, Han Jincheng
College of Animal Science and Technology, Henan Agricultural University, Zhengzhou 450046, Henan, China.
Department of Animal Science, College of Life Science, Shangqiu Normal University, Shangqiu 476000, Henan, China.
J Poult Sci. 2022 Apr 25;59(2):129-136. doi: 10.2141/jpsa.0210019.
1,25-Dihydroxycholecalciferol (1,25-(OH)-D) is the final active product of vitamin D. This study aimed to investigate the effects of 1,25-(OH)-D on growth performance, bone development, and calcium (Ca) transporter gene expression levels in the small intestine of broiler chickens. On the day of hatching, 140 female Ross 308 broilers were randomly allotted into two treatments with five replicates (14 birds per replicate). Two levels of 1,25-(OH)-D (0 and 1.25 µg/kg) were added to the basal diet without vitamin D. Results showed that the addition of 1.25 µg/kg 1,25-(OH)-D increased the average daily feed intake and the average daily gain and decreased the feed conversion ratio and mortality in 1- to 19-day-old broiler chickens compared with the basal diet without vitamin D (<0.05). 1,25-(OH)-D also enhanced the length, weight, ash weight, and the percentage contents of ash, Ca, and P in the tibia and femur of broilers (<0.05). The mRNA expression levels of the Ca-binding protein (CaBP-D28k) in the duodenum, jejunum, and ileum of 19-day-old broilers increased to 88.1-, 109.1-, and 2.7-fold, respectively, after adding 1,25-(OH)-D (<0.05). The mRNA expression levels of the plasma membrane Ca ATPase 1b (PMCAlb) in the duodenum and the sodium (Na)/ Ca exchanger 1 (NCX1) in the duodenum and the jejunum were also enhanced to 1.57-2.86 times with the addition of 1,25-(OH)-D (<0.05). In contrast, the mRNA expression levels of PMCA1b and NCX1 in the ileum and that of vitamin D receptor (VDR) in the small intestine were not affected by 1,25-(OH)-D (>0.05). These data indicate that 1,25-(OH)-D upregulated Ca transporter gene transcription and promoted Ca absorption in the small intestine, especially in the proximal intestine (duodenum and jejunum), thereby improving growth performance and bone mineralization in broiler chickens.
1,25 - 二羟基胆钙化醇（1,25-(OH)-D）是维生素D的最终活性产物。本研究旨在探讨1,25-(OH)-D对肉鸡生长性能、骨骼发育以及小肠中钙（Ca）转运蛋白基因表达水平的影响。在孵化当天，将140只罗斯308雌性肉鸡随机分为两个处理组，每组五个重复（每个重复14只鸡）。在不含维生素D的基础日粮中添加两种水平的1,25-(OH)-D（0和1.25μg/kg）。结果表明，与不含维生素D的基础日粮相比，添加1.25μg/kg 1,25-(OH)-D可提高1至19日龄肉鸡的平均日采食量和平均日增重，并降低料重比和死亡率（<0.05）。1,25-(OH)-D还增加了肉鸡胫骨和股骨的长度、重量、灰分重量以及灰分、钙和磷的百分比含量（<0.05）。添加1,25-(OH)-D后，19日龄肉鸡十二指肠、空肠和回肠中钙结合蛋白（CaBP-D28k）的mRNA表达水平分别提高到88.1倍、109.1倍和2.7倍（<0.05）。添加1,25-(OH)-D后，十二指肠中质膜钙ATP酶1b（PMCAlb）以及十二指肠和空肠中钠（Na）/钙交换蛋白1（NCX1）的mRNA表达水平也提高到1.57至2.86倍（<0.05）。相比之下，回肠中PMCA1b和NCX1的mRNA表达水平以及小肠中维生素D受体（VDR）的mRNA表达水平不受1,25-(OH)-D的影响（>0.05）。这些数据表明，1,25-(OH)-D上调了钙转运蛋白基因的转录，并促进了小肠尤其是近端小肠（十二指肠和空肠）中的钙吸收，从而改善了肉鸡的生长性能和骨骼矿化。
