Effects of Dietary Valine Chelated Zinc Supplementation on Growth Performance, Antioxidant Capacity, Immunity, and Intestine Health in Weaned Piglets

Abstract

This study was conducted to investigate the effects of dietary valine chelated zinc (ZnVal) supplementation on growth performance, antioxidant capacity, immunity, and intestine health in weaned piglets. A total of 240 healthy 35-day-old weaned piglets (Duroc × Landrace × Yorkshire, average weight 10.70 ± 0.14 kg) were randomly divided into five groups with six replicate pens and eight piglets per pen. Dietary treatments were a corn–soybean meal basal diet supplemented with 0, 25, 50, 75, and 100 mg/kg ZnVal, respectively. The experiment lasted for 28 days. Results showed that average daily gain (ADG) was increased (P < 0.05) by ZnVal with 75–100 mg/kg supplementation on days 15–28 and with 50–100 mg/kg supplementation on days 1–28. Supplementation of 25–100 mg/kg ZnVal reduced (P < 0.01) the diarrhea rate of weaned piglets on days 1 to 14 and 1 to 28. Dietary supplementation with 25–100 mg/kg ZnVal increased (P < 0.05) copper/zinc-superoxide dismutase (Cu/Zn-SOD) and decreased malonaldehyde (MDA) activities in the serum on day 14 and 28. Supplementation of 25–100 mg/kg ZnVal increased (P < 0.05) glutathione peroxidase (GSH-Px) activity in serum on day 14. Additionally, the supplementation of 75 mg/kg ZnVal significantly increased the activity of superoxide dismutase (SOD) and Cu/Zn-SOD in the liver (P < 0.05). Furthermore, the supplementation of 25–100 mg/kg ZnVal significantly increased the total antioxidant capacity (T-AOC) in the liver (P < 0.05). Higher (P < 0.05) concentrations of IgG in the serum were measured from piglets supplemented with 75–100 mg/kg ZnVal on day 14 and dietary supplementation with 25–100 mg/kg ZnVal increased the level of immunoglobulin G (IgG) in serum on day 28 (P < 0.05). In addition, higher (P < 0.05) concentrations of immunoglobulin A (IgA) in the duodenum and ileum were measured from piglets supplemented with 75 mg/kg ZnVal and the supplementation of 25–100 mg/kg ZnVal also showed a higher (P < 0.05) concentration of immunoglobulin G (IgG) in duodenum. Supplementation of 50–100 mg/kg ZnVal increased the villus height and villus height/crypt depth of jejunum (P < 0.05). Moreover, dietary supplementation with 75–100 mg/kg ZnVal showed a higher (P < 0.05) concentration of zinc in the liver and supplementation of 50–100 mg/kg ZnVal increased (P < 0.05) the concentration of zinc in the heart, spleen, and kidney. In conclusion, the present research showed that supplementation of ZnVal improves growth performance by increasing antioxidant capacity and immunity and regulating intestinal morphology and the optimal inclusion level of ZnVal was 65~80 mg/kg.

The Effect of Sodium Alginate-Coated Nano-Zinc Oxide on the Growth Performance, Serum Indexes and Fecal Microbial Structure of Weaned Piglets

“…MDA, one of the final products of polyunsaturated fatty acid peroxidation, is the most commonly known product, whose levels can directly reflect the lipid oxidative injury and can be regarded as a reliable marker of antioxidant status [ 28 , 31 ]. Previous studies have reported that different Zn sources (different concentrations) increased the activities of SOD, GPx and T-AOC and reduced the level of MDA, and further influenced the antioxidant status of piglets [ 15 , 18 , 25 , 27 , 32 ]. In line with the previous literature, our results also showed that ZnO and saZnO supplementation significantly increased the activity of T-AOC.…”

“…Liu et al [ 17 ] reported that hydrolysable tannins (HT) + ZnO supplementation significantly improve the levels of IgM and IgA in serum compared with the CON group. Peng et al [ 34 ] and Zhang et al [ 32 ] showed that porous ZnO and valine-chelated Zn (ZnVal) increased serum IgG. Another study also indicated that ZnO and nano-ZnO increased the serum concentration of IgA and decreased the concentration of IgM, but had no impact on IgG [ 35 ].…”

“…The major Zn-containing enzymes, ALP and Cu/Zn-SOD, were regarded as biological indicators to evaluate the status of Zn in piglets [ 21 , 27 , 36 ]. Many studies have reported that different Zn resources pronouncedly increase the activities of ALP [ 14 , 21 , 34 ] and Cu/Zn-SOD [ 32 ]. In line with previous findings, saZnO and ZnO supplementation significantly increased the activity of serum ALP, while only saZnO markedly increased the level of Cu/Zn-SOD compared with the CON group, indicating a higher bioavailability of saZnO.…”