Intestinal segment and vitamin D3 concentration affect gene expression levels of calcium and phosphorus transporters in broiler chickens

Jincheng Han¹^,²^,^*, Lihua Wu¹^,²^,³, Xianliang Lv¹^,²^,³, Mengyuan Liu¹^,²^,³, Yan Zhang¹^,²^,³, Lei He¹^,²^,⁴, Junfang Hao¹^,², Li Xi¹^,²^,^**, Hongxia Qu¹^,², Chuanxin Shi¹^,², Zhiqiang Li¹^,², Zhixiang Wang³, Fei Tang⁵, Yingying Qiao⁶

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¹Shangqiu Normal University, Shangqiu 476000, China.

²Henan Engineering Research Center of Green Feed Additive Development and Application, Shangqiu 476000, China.

³Henan Agricultural University, Zhengzhou 450001, China.

⁴Henan Normal University, Xinxiang 453007, China.

⁵Shandong Haineng Bioengineering Co., Ltd., Rizhao 276800, China.

⁶Sumy National Agrarian University, Sumy 19500, Ukraine.

^**Corresponding Author: Jincheng Han, Shangqiu Normal University, Shangqiu 476000, China. Henan Engineering Research Center of Green Feed Additive Development and Application, Shangqiu 476000, China. E-mail: j.c.han@hotmail.com.

^**Corresponding Author: Li Xi, Shangqiu Normal University, Shangqiu 476000, China. Henan Engineering Research Center of Green Feed Additive Development and Application, Shangqiu 476000, China. E-mail: xili_0808@163.com.

© Copyright 2022 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Two experiments were conducted in this research. Experiment 1 investigated the spatial expression characteristics of calcium (Ca) and phosphorus (P) transporters in the duodenum, jejunum, and ileum of 21-day-old broilers provided with adequate nutrient feed. Experiment 2 evaluated the effects of dietary vitamin D3 (VD3) concentration (0, 125, 250, 500, 1000, and 2000 IU/kg) on growth performance, bone development, and gene expression levels of intestinal Ca and P transporters in 1–21-day-old broilers provided with the negative control diet without supplemental VD3. Results in experiment 1 showed that the mRNA levels of calcium-binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), plasma membrane calcium ATPase 1b (PMCA1b), and IIb sodium-phosphate cotransporter (NaPi-IIb) were the highest in the broiler duodenum. By contrast, the mRNA levels of inorganic phosphate transporter 1 (PiT-1) and 2 (PiT-2) were the highest in the ileum. Results in experiment 2 showed that adding 125 IU/kg VD3 increased body weight gain (BWG), feed intake (FI), bone weight, and percentage and weight of Ca and P in the tibia and femur of 1–21-day-old broilers compared with the negative control diet (<italic>p</italic> < 0.05). The rise in dietary VD3 levels from 125 to 1000 IU/kg further increased the BWG, FI, and weights of the bone, ash, Ca, and P (<italic>p</italic> < 0.05). No difference in growth rate and leg bone quality was noted in the broilers provided with 1000 and 2000 IU/kg VD3 (<italic>p</italic> > 0.05). Supplementation with 125–2000 IU/kg VD3 increased the mRNA abundances of intestinal Ca and P transporters to varying degrees. The mRNA level of CaBP-D28k increased by 536, 1161, and 28 folds in the duodenum, jejunum, and ileum, respectively, after adding 1000 IU/kg VD3. The mRNA levels of other Ca and P transporters (PMCA1b, NCX1, NaPi-IIb, PiT-1, and PiT-2) increased by 0.57–1.74 folds by adding 1000–2000 IU/kg VD3. These data suggest that intestinal Ca and P transporters are mainly expressed in the duodenum of broilers. Moreover, the addition of VD3 stimulates the two mineral transporter transcription in broiler intestines.

Keywords: Vitamin D3; Broiler chicken; CaBP-D28k; PMCA1b; NaPi-IIb; PiT-1