Feeding 25-hydroxycholecalciferol improves gilt reproductive performance and fetal vitamin D status1
J ANIM SCI June 4, 2012 jas.2011-5023
J. D. Coffey*, E. A. Hines*, J.D. Starkey*,2, C. W. Starkey* and T. K. Chung†
*Department of Animal and Food Sciences, Texas Tech University, Lubbock, TX 79409
†DSM Nutritional Products Asia Pacific, 2 Havelock Road, #04-01, Singapore 059763
?2 Corresponding author: jessica.starkey at ttu.edu
Little information is available regarding the effects of vitamin D and its metabolites on reproduction in swine. To investigate the effects of feeding the circulating metabolite of vitamin D, 25-hydroxycholecalciferol (25OHD3, Hy· D, DSM Nutritional Products, Basel, Switzerland) on maternal and fetal circulating 25OHD3 concentration and gilt reproductive performance, a total of 40 PIC Camborough-22 gilts (BW on d -6 = 138 kg) in 4 replicates were randomly assigned to 1 of 2 corn-soybean meal-based diets.
The control diet (CTL) was formulated to contain 2,500 IU D3/kg diet, while the experimental diet (25OHD3) was formulated to contain 500 IU D3/kg diet + 50 µg 25OHD3/kg diet.
Gilts were fed 2.7 kg of their assigned diet once daily beginning 43 d before breeding. Gilt BW were measured on gestational d -6 and d 90. Gilts were artificially inseminated with PIC 337-G semen 12 h and 24 h after showing signs of estrus. Blood samples were collected from the jugular vein on gestational d – 43, – 13, 46, and 89 for analysis of circulating 25OHD3 plasma concentration and overall vitamin D status of the gilts. At gestational d 90 ± 1, gilts were harvested and reproductive tracts were removed. Fetal weight, sex, crown-to-rump length (CRL), as well as the number of mummified fetuses were recorded. As expected, circulating plasma concentrations of 25OHD3 were not different among treatment groups at d -43 (CTL = 53.8 ng/mL, 25OHD3 = 57.4 ng/mL; P = 0.66).
However, gilts fed 25OHD3 had greater (P < 0.001) circulating plasma concentrations of 25OHD3 on d -13 (89.7 vs. 56.7 ng/mL), d 46 (95.8 vs. 55.7 ng/mL), and d 89 (92.8 vs. 58.2 ng/mL) of gestation compared to CTL-fed gilts.
Circulating 25OHD3 was also greater in fetuses from 25OHD3-fed gilts on d 90 (P < 0.001).
A 23% increase in pregnancy rate was observed in 25OHD3-fed gilts compared to CTL (78% vs. 55%, respectively; P = 0.21). Maternal BW gain (without conceptus), number of mummified fetuses, mean fetal weight, and mean fetal CRL were similar among treatments (P > 0.05).
However, litter size was larger (CTL. =10.2;25OHD3=12.7; P =0.04) in 25OHD3-fed gilt compared with CTL-fed gilts.
Notably, mean fetal weight was not decreased in 25OHD3-fed gilts as frequently occurs when litter size is increased . Overall , feeding 25OHD3 to first-service gilts before and during gestation improved both maternal and fetal vitamin D status and improved maternal reproductive performance.
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