PSIII-14 - Supplementation of 25(OH)D₃ in sow diets and its effect on post-weaning pigs productivity

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.