The purpose of this study was to investigate the effects of zinc glycinate (Gly-Zn) on growth performance, serum biochemical index, intestinal morphology, and hepatic metallothionein (MT) mRNA expression in the liver of yellow feather broilers. A total of 540 18-day-old yellow feather broilers were randomly divided into three groups: control group (basal diet), ZnSO4 group (basal diet plus 60 mg Zn/kg from ZnSO4), and Gly-Zn group (basal diet plus 60 mg Zn/kg from zinc glycinate). Each treatment group had 6 replicates with 30 birds in each replicate. The experiment lasted for 42 days (18 to 59 days of age). The results showed that Gly-Zn supplementation significantly improved the average daily gain (ADG) and average daily feed intake (ADFI) of broilers during 18 to 39 days of age compared with that in the control group (P < 0.05) but not different from the ZnSO4 group. The Gly-Zn group had higher glutathione peroxidase (GSH-Px) (P < 0.05) and lower malondialdehyde (MDA) concentrations than the broilers in the control and ZnSO4 group. It was also observed that zinc content in the tibia of Gly-Zn group broilers was higher than the control and ZnSO4 group (P < 0.05). The results of intestinal morphology parameters showed that the Gly-Zn group significantly increased the villus height in duodenum and jejunum (P < 0.05) and decreased crypt depth in duodenum and ileum compared to the control group. However, there were no significant differences between the Gly-Zn group and ZnSO4 group in duodenum and ileum regarding intestinal morphology parameters. The Gly-Zn group significantly increased mRNA expression of MT in the liver than both control and ZnSO4 groups (P < 0.05). Collectively, the results indicated that supplementing 60 mg Zn/kg through zinc glycinate improved growth performance and serum indexes as well as intestinal morphology of yellow feather broilers. It also regulates MT gene expression more effectively than the ZnSO4 group at the transcriptional level.

No abstract

This study aimed to investigate the effects of niacin on growth performance, intestinal morphology, intestinal mucosal immunity, and colonic microbiota in weaned piglets. A total of 96 weaned piglets (Duroc × (Landrace × Yorkshire), 21-d old, 6.65 ± 0.02 kg body weight (BW)) were randomly allocated into 3 treatment groups (8 replicate pens per treatment, each pen containing 4 males; n = 32/treatment) for 14 d. Piglets were fed a control diet (CON) or the CON diet supplemented with 20.4 mg/kg niacin (NA) or an antagonist for the niacin receptor GPR109A (MPN). The results showed that NA or MPN had no effect on ADG, ADFI, G/F or diarrhea incidence compared with the CON diet. However, compared with piglets in the NA group, piglets in the MPN group had lower ADG (p = 0.042) and G/F (p = 0.055). In comparison with the control and MPN group, niacin supplementation increased the villus height and the ratio of villus height to crypt depth (p < 0.05), while decreasing the crypt depth in the duodenum (p < 0.05). Proteomics analysis of cytokines showed that niacin supplementation increased the expression of duodenal transforming growth factor-β (TGF-β), jejunal interleukin-10 (IL-10) and ileal interleukin-6 (IL-6) (p < 0.05), and reduced the expression of ileal interleukin-8 (IL-8) (p < 0.05) compared with the control diet. Piglets in the MPN group had significantly increased expression of ileal IL-6, and jejunal IL-8 and interleukin-1β (IL-1β) (p < 0.05) compared with those in the control group. Piglets in the MPN group had lower jejunal IL-10 level and higher jejunal IL-8 level than those in the NA group (p < 0.05). The mRNA abundance of duodenal IL-8 and ileal granulocyte-macrophage colony-stimulating factor (GM-CSF) genes were increased (p < 0.05), and that of ileal IL-10 transcript was decreased (p < 0.05) in the MPN group compared with both the control and NA groups. Additionally, niacin increased the relative abundance of Dorea in the colon as compared with the control and MPN group (p < 0.05), while decreasing that of Peptococcus compared with the control group (p < 0.05) and increasing that of Lactobacillus compared with MPN supplementation (p < 0.05). Collectively, the results indicated that niacin supplementation efficiently ensured intestinal morphology and attenuated intestinal inflammation of weaned piglets. The protective effects of niacin on gut health may be associated with increased Lactobacillus and Dorea abundance and butyrate content and decreased abundances of Peptococcus.