1,25-Dihydroxycholecalciferol Improved the Growth Performance and Upregulated the Calcium Transporter Gene Expression Levels in the Small Intestine of Broiler Chickens

Abstract

contributed equally to this work. 1,25-Dihydroxycholecalciferol (1,25-(OH)2-D3) is the final active product of vitamin D. This study aimed to investigate the effects of 1,25-(OH)2-D3 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)2-D3 (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)2-D3 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 (P < 0.05). 1,25-(OH)2-D3 also enhanced the length, weight, ash weight, and the percentage contents of ash, Ca, and P in the tibia and femur of broilers (P < 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)2-D3 (P < 0.05). The mRNA expression levels of the plasma membrane Catransporting 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)2-D3 (P < 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)2-D3 (P > 0.05). These data indicate that 1,25-(OH)2-D3 upregulated Ca transporter gene transcription and promoted Ca 2+ absorption in the small intestine, especially in the proximal intestine (duodenum and jejunum), thereby improving growth performance and bone mineralization in broiler chickens.

Performance and bone health of broilers reared under artificial lighting and supplemented with different levels of vitamin D3

“…The potential of using reduced dietary vitamin D levels for healthy birds reared in a completely closed environment without performance and bone health impairment was previously described (Leyva-Jimenez et al, 2019;Tizziani et al, 2019). Vitamin D 3 improves performance by causing an increase in Ca and P absorption in the duodenum (Wasserman and Taylor, 1966;Han et al, 2018;Wu et al, 2022). In its active form, the 1,25-hydroxicholecalciferol bonds to its specific enterocyte intranuclear receptor (VDR) leading to an increased gene expression of calcium-active transporters at the apical membrane of the enterocyte (Han et al, 2018).…”

Serum bone remodeling parameters and transcriptome profiling reveal abnormal bone metabolism associated with keel bone fractures in laying hens

“…Furthermore, 25-OHD 3 and 1,25-(OH) 2 D 3 , two important metabolites of vitamin D 3 , play significant roles in modulating Ca and P absorption and metabolism in the intestinal tract and improving bone health and growth performance of animals ( Kakhki et al, 2019 ). In laying hens and broilers, the supplementation of dietary 25-OHD 3 or 1,25-(OH) 2 D 3 as a nutritional component can enhance bone strength and eggshell quality ( Kakhki et al, 2019 ; Wu et al, 2022 ). This study showed that FK birds decreased Ca, P, and 25-OHD 3 concentrations in serum samples compared to NK layers, suggesting that reduced Ca, P, and 25-OHD 3 levels in the blood circulation might be associated with decreased keel bone mass and quality by inhibiting the mineralization of keel bone and increasing the fragility of keel bone in laying hens.…”