PSVII-9 The Impact of Increasing Dietary Manganese on the Reproductive Performance of Sows. (12th April 2022) - Edmunds, Clint E
Abstract: The objective of this study was to determine the effect of dietary manganese (ProPath Mn, Zinpro Corporation) on the reproductive performance of sows. Sows (N = 39; 231 ± 8 kg) were randomly assigned to 1 of three dietary levels of Mn (CON: 0 ppm Mn; PRO20: 20 ppm Mn; PRO40: 40 ppm Mn). Experimental treatments were initiated at breeding and continued through 2 parities. Sows were blocked by parity within each farrowing group and dietary treatments were represented within each block. Data were analyzed as a randomized complete block design using the MIXED procedure of SAS with diet as a fixed effect and block as a random effect. Dietary treatment did not affect sow body weights ( P > 0.10). Lactation feed intake was increased in PRO20 sows compared with CON and PRO40 sows ( P < 0.05). PRO20 and PRO40 sows farrowed heavier piglets (CON 1.23 kg; PRO20 1.57 kg; PRO40 1.40 kg; P = 0.001) with improved average daily gain to weaning (CON 213 g/day; PRO20 237 g/day; 220 g/day; P < 0.05), compared with CON sows. Milk fat content (average from d 7 and 14 of lactation) was reduced in PRO20 (5.5%) and PRO40 sows (6.1%; P < 0.05) compared with CON sows (7.8%), possibly due to increased milk demand from the piglets. There were no significant differences in milk mineral concentrations during lactation or piglet tissue Mn-superoxide dismutase (MnSOD) activity at weaning ( P > 0.10). On day 3 of lactation, prolactin concentrations were similar across treatments ( P > 0.10), whereas progesterone concentrations tended to differ in response to Mn level (CON 23.70 ng/mL; PRO20 26.15 ng/mL; PRO40 22.10 ng/ml; P = 0.09). Supplementary dietary Mn throughout 2 gestation and lactation cycles led to increased birth weights and pre-weaning growth of piglets.