The objective of this study was to determine the effect of dietary manganese on the reproductive performance of sows. Sows (n = 39; 231 ± 8 kg) were randomly assigned to one of three dietary levels of supplemented Mn (CON: 0 ppm Mn; PRO20: 20 ppm Mn; PRO40: 40 ppm Mn). The experimental treatments were initiated at breeding and continued through two parities. The sows were blocked by parity within each farrowing group. The 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. The lactation feed intake increased in the PRO20 sows compared to the CON and PRO40 sows (p < 0.05). The PRO20 and PRO40 sows farrowed piglets with improved average daily gain from birth to weaning (CON 214 g/day; PRO20 237 g/day; 220 g/day; p < 0.05) compared to the CON sows. The milk fat content was lower in the PRO20 (5.5%) and PRO40 sows (6.1%; p < 0.05) compared to the CON sows (7.8%), possibly due to increased milk demand. Supplementary dietary Mn throughout two gestation and lactation cycles led to improved birth weights and pre-weaning growth of piglets.

The objective of this study was to determine the impact of varying dietary manganese and selenium concentrations, antioxidant cofactors, on the growth performance and fecal microbial populations of nursery pigs. The piglets (N = 120) were blocked by weight (5.22 ± 0.7 kg) and sex. The pens (n = 5/treatment) within a block were randomly assigned to diets in a 2 × 3 factorial design to examine the effects of Se (0.1 and 0.3 mg/kg added Se) and Mn (0, 12, and 24 mg/kg added Mn) and were fed in three phases (P1 = d 1–7, P2 = d 8–21, P3 = d 22–35). The pigs and orts were weighed weekly. Fecal samples were collected d 0 and 35 for 16S rRNA bacterial gene sequencing and VFA analysis. The data were analyzed as factorial via GLM in SAS. There was a linear response (p < 0.05) in overall ADG across dietary Mn. Supplementing 24 mg/kg Mn tended to decrease (p < 0.10) the relative abundance of many bacteria possessing pathogenic traits relative to Mn controls. Meanwhile, increasing Mn concentration tended to foster the growth of bacteria correlated with gut health and improved growth (p < 0.10). The data from this study provide preliminary evidence on the positive effects of manganese on growth and gut health of nursery pigs.

The objective of this study was to determine the effect of altering dietary levels of manganese and selenium on growth performance and MnSOD specific activity. Weaned piglets were blocked by weight (n = 216; 5.21 ± 1.17 kg; 21 ± 3 d) and sex (2 barrows and 2 gilts/pen). Pens within a block were randomly assigned to dietary treatments in a factorial design with main effects of Se (0.1 and 0.3 ppm) and Mn (0, 12, and 24 ppm). Diets (n = 9 pens/treatment) were fed in three phases (P1 = d 1–7, P2 = d 7–21, P3 = d 21–35). Pigs and orts were weighed weekly and pigs were bled on d 0, 7, 21, and 35 for analysis of specific activity of red blood cell MnSOD. Data were analyzed as 2x3 factorial design via SAS PROC GLM. There were no Se effects or Mn x Se interactions observed. There was a linear increase (P < 0.05) in overall ADG (397, 424, and 438 g day^-1pig^-1 for 0, 12, 24 ppm Mn, respectively). There was a linear trend (P < 0.1) in overall ADFI (557, 560, 592 g day^-1pig^-1 for 0, 12, 24 ppm Mn, respectively). Feed efficiency (d 0–35) across increasing Mn levels were 0.71, 0.76, 0.74 (P > 0.1). MnSOD activity in RBC increased from d 0–7, peaked on d 7 and decreased to d 35. On d 7, diets with 12 and 0 ppm Mn had significantly increased (P < 0.05) MnSOD activity (0.91 and 0.87 IU mg^-1 protein, respectively) compared to diets with 24 ppm Mn (0.67 IU mg^-1 protein). The dietary treatment that best maintained MnSOD activity was 0.3 ppm Se and 12 ppm Mn supplemented, while ADG was maximized in the diet with 0.3 ppm Se and 24 ppm Mn supplementation.

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.