This study was performed to evaluate the effects of dietary vitamin levels on
physiological responses, blood profiles, and reproductive performance in
gestating sows. A total of 52 F1 multiparous sows (Yorkshire × Landrace) with an
average body weight of 223.5 ± 31.7 kg, an average parity of 6.4 ± 2.7, and an
average backfat thickness of 18.5 ± 4.9 mm were divided into four treatment
groups considering body weight, backfat thickness, and parity in a completely
randomized design with 13 replicates. The treatments were 100% (V1), 300% (V3),
600% (V6) and 900% (V9) of the National Research Council (NRC) Nutrient
Requirements of Swine. The gestation diet was formulated based on
corn-soybean meal (SBM) and contained 3,265 kcal of metabolizable energy (ME)/kg
and 12.00% crude protein. During the lactation period, all sows were fed the
same commercial lactation diet. There was no significant difference in body
weight of gestating sows. However backfat thickness tended to increase when
higher levels of vitamins were provided to gestating sows (p
< 0.10). When high levels of dietary vitamins were provided, the body
weight change of lactating sows increased (p < 0.01).
When sows were fed higher levels of vitamins, the feed intake of lactating sows
tended to decrease (p = 0.06). There were no treatment
differences in the number of total born, born alive, stillbirth piglets, or the
body weight of piglets according to different dietary vitamin level. As dietary
vitamin level increased, the serum concentration of 25(OH)D3 in sows
at 90 days of gestation linearly increased (p < 0.01).
Furthermore, the serum vitamin E level of gestating sows was linearly increased
with increasing dietary vitamin level (p < 0.05). The
current NRC vitamin requirements are sufficient for gestating sows and higher
levels of vitamins in the gestation diet did not show any beneficial effects for
gestating and lactating sows.