191. Effects of Maternal Zinc Supplementation Strategies During Gestation on Farrowing Characteristics, Colostrum Total Solids, and Serum Biochemical Profiles in Sows and Their Newborn Piglets.

Abstract The objective of this study was to evaluate the effects of maternal dietary zinc (Zn) supplementation strategies during gestation on farrowing characteristics, colostrum total solids, and serum biochemical profiles of sows and their newborn piglets. Four hundred seventeen PIC Camborough® sows were assigned to three Zn supplementation strategies using zinc oxide (ZnO) as source: low Zn from breeding to farrowing (LZn114; 250 mg Zn/d), high Zn from d80 of gestation to farrowing (HZn34; 850 mg Zn/d), and high Zn from breeding to farrowing (HZn114; 850 mg Zn/d). All sows were weighed at d112 ± 1 of gestation and at weaning (d21 ± 1 of lactation), and backfat thickness and caliper score were measured at d108 ± 3 of gestation. A subset of 30 sows (10 per treatment) with similar parity and caliper score 13-15 throughout gestation was selected for sampling and litter performance evaluation. Blood was collected from these sows at 108 ± 2 d of gestation and 6.5 ± 2 d after weaning. Blood samples were also collected from the umbilical cords of piglets born to these sows and pooled per litter. Serum biochemical profile measured in sows and piglets included glucose, cholesterol, triglycerides, total protein, albumin, creatinine, urea, alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). Among the selected sows, farrowing was individually monitored to record piglet birth interval, farrowing duration, oxytocin use, and obstetric interventions. Colostrum total soluble solids were determined in samples collected from all teats of these sows within 12 h of the onset of farrowing. A mixed-model analysis of variance was performed according to a randomized block design, including treatment as a fixed effect and sow as a random effect (P ≤ 0.05; trends at P ≤ 0.10), followed by Tukey’s test for multiple comparisons. Maternal body condition (pre-farrowing and at weaning) and serum biochemical profile (pre-farrowing) were not affected by treatments (P ≥ 0.147). Farrowing characteristics and reproductive performance were not affected by treatments (P ≥ 0.546). However, colostrum total soluble solids tended to be higher in HZn114 than in LZn114 sows (26.74 vs. 24.44%; +9.4%; P = 0.085), whereas HZn34 had intermediate values (24.87%). At birth, piglets from HZn114 sows tended to have lower AST (−49.9%; P = 0.080) and ALT (−36.7%; P = 0.067) compared with LZn114, with intermediate values for HZn34. At weaning (Table 1), HZn114 sows had lower ALT concentrations (−31.4%; P = 0.022) than LZn114 and tended to have lower ALP (−39.7%; P = 0.094), with intermediate values for HZn34. In conclusion, high dietary Zn supplementation to sows throughout gestation (HZn114) tended to increase colostrum soluble solids and reduced indicators of hepatic cellular stress in sows at weaning and cellular stress in piglets at birth. For image description, please refer to the figure legend and surrounding text.