Abstract
This research aimed at assessing the impact of continuous supplementation of 25-hydroxycholecalciferol (25(OH)D3) to diets fed during gestation and lactation on sow reproductive performance and on productivity of the offspring. Thirty-two Large White × [Large White × Landrace] sows were inseminated with semen from a terminal sire (PIC 337) and stratified into two blocks based on monthly production groups, with an average parity of 2.2 ± 1.69 and a body weight of 161.3 ± 25.40 kg at service. Sows were randomly assigned to either a control diet without 25(OH)D3 or a diet containing 50 µg of 25(OH)D3. Standard farm management practices were applied, and treatments were maintained throughout gestation (115.8 ± 1.43 days) and lactation (19.6 ± 4.63 days). At weaning, 300 pigs (average weight 4.9 ± 1.63 kg and 19.6 ± 4.63 days of age) were allotted to 28 pens with an average of 10.7 ± 0.46 pigs per pen, balanced by sex. Weaned pigs from control sows were assigned to control diets during the post-weaning period without 25(OH)D3, and weaned pigs from sows fed the diet containing 25(OH)D3 were assigned to diets after weaning that contained 50 µg/kg of 25(OH)D3. Key performance indicators including average daily feed intake (ADFI), average daily gain (ADG), and gain:feed (G:F) were measured over a 53-day period, using a four-phase feeding program: Phase 1 (7 days), Phase 2 (7 days), Phase 3 (14 days), and Phase 4 (25 days). Diets were formulated to meet nutritional requirements within each phase. Diets fed to both treatments contained a vitamin premix that provided 1,200 international units of vitamin D3 per kilogram finished diet. Data were analyzed by T-test using PROC GLM in SAS (SAS Inst. Inc., Cary, NC, USA). Results indicated that supplementation of 25(OH)D3 during gestation and lactation did not affect sow productivity or pig weight at weaning. However, inclusion of 25(OH)D3 in diets for weaned pigs reduced ADFI (P < 0.02) and increased G:F (P < 0.01), whereas no difference in ADG was observed (Table 1). In conclusion, continuous supplementation of 25(OH)D3 to sow diets during gestation and lactation did not influence reproductive performance, but inclusion of 25(OH)D3 in diets for weaned pigs improved G:F after weaning, which indicates that pigs fed a diet containing 25(OH)D3 may be better able to handle the weaning stress.
