Table 7.
Whole Longissimus lumborum and muscle fiber characteristics of pigs at weaning from sows fed vitamin D3 alone or in combination with 25(OH)D31
| Diet2 | |||||
|---|---|---|---|---|---|
| 1,500 IU D3 | 500 IU D3 and 25 μg 25(OH)D3 |
1,500 IU D3 and 50 μg 25(OH)D3 |
SEM | Probability, P < | |
| Pigs, n | 11 | 12 | 12 | --- | --- |
| Live birth weight, kg | 1.46 | 1.43 | 1.28 | 0.091 | 0.323 |
| Live weaning weight, kg | 5.82 | 5.64 | 5.24 | 0.276 | 0.334 |
| Whole muscle CSA, mm 2 | 656 | 604 | 541 | 57.3 | 0.360 |
| All fiber characteristics3 | |||||
| Number4 | 754,550 | 753,211 | 684,633 | 66,665 | 0.657 |
| CSA, μm2 | 563 | 565 | 505 | 45.6 | 0.553 |
| Myonuclei5 | 1.59 | 1.48 | 1.38 | 0.380 | 0.916 |
| Satellite cells5 | 0.12 | 0.11 | 0.12 | 0.105 | 0.999 |
| Fiber type characteristics6 | |||||
| Type I | |||||
| Number7 | 91,248 | 93,984 | 79,139 | 9,894 | 0.468 |
| Distribution,8 % | 12.2 | 12.7 | 11.6 | 0.83 | 0.646 |
| CSA, μm2 | 434 | 393 | 416 | 21.5 | 0.384 |
| Type IIA | |||||
| Number7 | 117,943 | 132,715 | 119,140 | 12,253 | 0.616 |
| Distribution,8 % | 15.7 | 17.7 | 17.9 | 0.81 | 0.129 |
| CSA, μm2 | 401 | 360 | 345 | 26.1 | 0.291 |
| Type IIX | |||||
| Number7 | 200,114 | 206,098 | 175,679 | 23,920 | 0.584 |
| Distribution,8 % | 26.8 | 26.3 | 24.6 | 1.42 | 0.498 |
| CSA, μm2 | 539 | 532 | 469 | 37.2 | 0.329 |
| Type IIB | |||||
| Number7 | 345,264 | 320,416 | 310,674 | 29,229 | 0.658 |
| Distribution,8 % | 45.7 | 42.9 | 45.8 | 1.44 | 0.256 |
| CSA, μm2 | 671 | 727 | 613 | 74.4 | 0.537 |
1A total of 69 sows (DNA Line 200 × 400) and their progeny over three consecutive farrowing groups were used to determine if feeding a combination of vitamin D3 and 25(OH)D3 influences neonatal and sow performance and vitamin D status, muscle fiber morphometrics, and subsequent growth performance of the piglets. Thirty-five piglets were sacrificed at weaning.
2Three maternal dietary treatments were fed from artificial insemination until weaning on day 21 of lactation. Vitamin D3 (Rovimix D3-500, DSM Nutrition Products, Parsippany, NJ) and/or 25(OH)D3 (Hy-D Premix 137.5 mg/kg, DSM Nutritional Products, Parsippany, NJ) were used to achieve desired vitamin D3 concentrations for each treatment.
3Overall fiber characteristics independent of fiber type.
4Total number of muscle fibers was determined by the number of photomicrograph frames in the whole muscle CSA multiplied by the average number of fibers in a frame.
5Myonuclei and satellite cells are expressed as number per fiber.
6Fibers that stained exclusively positive for BA-D5, SC-71, and BF-F3 were labeled type I, type IIA, and type IIB, respectively. Fibers that stained positive for both SC-71 and B-FF3 were labeled as type IIX fibers.
7Total number of a specific fiber isoform was determined by the number of photomicrograph frames in the whole muscle CSA multiplied by the average number of the specific fiber isoform in a frame.
8Distribution was calculated by the number of the specific fiber divided by the overall total fibers multiplied by 100%.