Improvement of maternal vitamin D status with 25-hydroxycholecalciferol positively impacts porcine fetal skeletal muscle development and myoblast activity.

There is little information available regarding the influence of maternal vitamin D status on fetal skeletal muscle development. Therefore, we investigated the effect of improved vitamin D status resulting from 25-hydroxycholecalciferol (25OHD3) supplementation of dams on fetal skeletal muscle developmental characteristics and myoblast activity using Camborough 22 gilts (n = 40) randomly assigned to 1 of 2 corn-soybean meal-based diets. The control diet (CTL) contained 2,500 IU cholecalciferol (D3)/kg diet, whereas the experimental diet contained 500 IU D3/kg diet plus 50 µg 25OHD3/kg diet. Gilts were fed 2.7 kg of their assigned diet once daily beginning 43 d before breeding through d 90 of gestation. On gestational d 90 (± 1), fetal LM and semitendinosus muscle samples were collected for analysis of developmental characteristics and myoblast activity, respectively. No treatment difference was observed in fetal LM cross-sectional area (P = 0.25). Fetuses from 25OHD3-supplemented gilts had more LM fibers (P = 0.04) that tended to be smaller in cross-sectional area compared with CTL fetuses (P = 0.11). A numerical increase in the total number of Pax7+ myoblasts was also observed in fetuses from 25OHD3-supplemented gilts (P = 0.12). Myoblasts derived from the muscles of fetuses from 25OHD3-fed dams displayed an extended proliferative phase in culture compared with those from fetuses of dams fed only D3 (P < 0.0001). The combination of additional muscle fibers and Pax7+ myoblasts with prolonged proliferative capacity could enhance the postnatal skeletal muscle growth potential of fetuses from 25OHD3-supplemented gilts. These data highlight the importance of maternal vitamin D status on the development of fetal skeletal muscle.

Feeding 25-hydroxycholecalciferol improves gilt reproductive performance and fetal vitamin D status.

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, ROVIMIX 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, and 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 with 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 with 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 gilts 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.

Transient neonatal diabetes mellitus in half sisters. A sequel.

This is a sequel to a previous report of two half sisters with transient neonatal diabetes mellitus. In 1970, the same syndrome developed in a third half sibling, a boy, born of the same father by his third wife. It followed essentially the same neonatal clinical course as that of his two half sisters. The firstborn sibling, aged 19 years, is reported to be free of signs and symptoms of diabetes; the third born was clinically well with no glycosuria at 9 years 3 months of age, and was reported to be in good health at 11 years of age. In 1978, at age 15 years diabetic ketoacidosis and coma developed in the second-born sister and she has had insulin-dependent diabetes since that time. These cases present a unique genetic pattern and, to our knowledge, there have been no reports of cases of transient neonatal diabetes becoming full-blown type I insulin-dependent diabetes mellitus later in life.