Search

This study was to determine the effects of dietary Zn-methionine (Zn-Met) supplementation on the laying performance, egg quality, antioxidant capacity, and serum parameters of laying hens. Jingh ong-1 strain laying hens (n = 720, 49 wk of age) were randomly assigned to 6 treatments with 6 replications of 20 birds. The control was fed a basal diet supplemented with 80 mg of Zn/kg as Zn sulphate of diet and the 5 groups were fed a basal diet supplemented with 20, 40, 60, 80, and 100 mg of Zn/kg as Zn-Met of diet for 10 wk, respectively. At the terminal experiment, there were significant differences between control and 80 mg/kg Zn-Met group in feed intake (P < 0.05) and feed conversion ratio (FCR) (P < 0.01). Egg weight (P < 0.05) and albumen height (P < 0.01) reduced and were not significantly influenced by supplemental 80 mg/kg Zn-Met group until being stored 15 d as compared to the control. Zn-Met group in 100 mg/kg significantly increased haugh unit (P < 0.05) as compared to the control. The activity of MDA in serum had a linear decrease in 20 to 100 mg/kg Zn-Met. The activity of CAT in liver and GSH-Px in serum had quadratic effects in response to the Zn-Met treatments. Compared to the control, 60 mg/kg Zn-Met group increased the T-AOC, GSH-Px activity in serum (P < 0.01), and the T-AOC (P < 0.05), CuZnSOD (P < 0.01), GSH-Px (P < 0.01) activity in liver. Compared with the control, the concentration of serum ionic Ca in 80, 100 mg/kg Zn-Met treatments reduced (P < 0.01) significantly while the activity of serum alkaline phosphatase (AKP) increased in the Zn-Met groups of 40, 60, and 80 mg/kg (P < 0.01), and 100 mg/kg (P < 0.05). In conclusion, dietary Zn-Met supplementation at 60 to 80 mg/kg had more positive effects on performance, egg quality, and antioxidant capacity in laying hens as compared to 80 mg/kg ZnSO4., (© 2018 Poultry Science Association Inc.)

This experiment was conducted to evaluate the effects of dietary supplementation with Clostridium butyricum on laying performance, egg quality, serum parameters, and cecal microflora of laying hens in the late phase of production. Jinghong-1 strain laying hens (n = 960; 48 wk of age) were randomly allocated to 5 treatment groups with 6 replicates of 32 hens. Hens were fed with basal diet (control) and basal diet supplemented with 2.5 × 104 (CB1), 5 × 104 (CB2), 1 × 105 (CB3), and 2 × 105 (CB4) cfu/g C. butyricum for 10 wk. The results showed that egg production, egg mass, and eggshell strength increased quadratically as supplemental C. butyricum increased, and these responses were maximized in the CB2 group (P < 0.05). Compared with the control group, the addition of C. butyricum resulted in quadratic effects on serum total protein, uric acid, calcium, complement component C3 and catalase concentrations, and these responses were maximized or minimized in the CB2 group (P < 0.05). Linear and quadratic increases were observed in serum IgM, total superoxide dismutase, and glutathione peroxidase concentrations, and these responses were maximized in CB2 or CB3 group (P < 0.05). The addition of C. butyricum in the CB2 group resulted in linearly increasing levels of serum IgG concentration as compared with the control group (P < 0.05). Spleen index increased (P < 0.05) in the CB2 group. Hens fed with C. butyricum reduced (P > 0.05) the population of E. coli, while Bifidobacterium counts increased quadratically and maximized in the CB2 group (P < 0.05). In conclusion, the results indicated that dietary supplementation with C. butyricum (5 × 104 or 1 × 105 cfu/g) could improve laying performance and egg quality by promoting immune function, enhancing antioxidative capacity, and benefiting the cecal microflora of laying hens in the late phase of production., (© 2018 Poultry Science Association Inc.)

This study was conducted to investigate the effects of dietary manganese-methionine (Mn-Met) supplementation on the egg quality of laying hens. A total of 480 Jinghong-1 strain layers aged 53 wk were divided into 5 groups with 6 replicates of 16 layers. Birds in the control group were fed a diet supplemented with 60 mg Mn/kg in the form of MnSO4; the birds in other 4 experimental groups were fed a diet supplemented with 20, 40, 60, and 80 mg Mn/kg as Mn-Met, respectively. Dietary Mn-Met treatments significantly affected (P < 0.05) the albumen height, yolk color, and Haugh unit compared to those of the control diet. The Mn contents in the eggshell increased (P < 0.01) significantly by increasing the Mn-Met supplementation, whereas Mn content in eggshell was triple that in the yolk or albumen. Compared with the 60 mg/kg Mn-Met group, the transverse surface in the control group had (P < 0.01) a greater width of mammillary cones, and there were obvious cracks on the outer surface in the control. There was no difference (P > 0.05) in the eggshell gland (ESG) in the expression of calbindin-D28k (CaBP-D28k) mRNA in response to any diet treatment. In conclusion, dietary Mn-Met supplementation increased internal egg quality and the ultrastructure of the eggshell. Compared to the control, 60 mg/kg Mn-Met treatment resulted in improving egg quality, and 20 mg/kg Mn-Met treatment had similar effects the control treatment had on the egg quality. This indicates that the inorganic Mn can be replaced by the lower concentration of Mn-Met., (© 2017 Poultry Science Association Inc.)