RESUMO
OBJECTIVE: TLRI 211-1 is a novel Bacillus subtilis strain. This experiment was to investigate dietary supplementation of TLRI 211-1 on laying performance, egg quality and blood characteristics of layers. METHODS: One hundred and twenty 65-wk-old Leghorn layers were divided into four treatment groups for 8 weeks experiment. Each treatment had three replicates. The basal diet was formulated as control group with crude protein 17% and metabolizable energy 2,850 kcal/kg and supplemented with TLRI 211-1 0.1%, 0.3%, and commercial Bacillus amyloliquefaciens 0.1% as treatment 2, 3 and 4 groups, respectively. Both TLRI 211-1 and commercial Bacillus amyloliquefaciens were adjusted to contain 1×109 colony-forming unit (CFU)/mL (g), hence the 0.1% supplemental level was 1×109 CFU/kg. RESULTS: The results showed that TLRI 211-1 0.3% and commercial B. amyloliquefaciens groups had higher weight gain than the other groups; TLRI 211-1 0.1% group had better feed to eggs conversion ratio than the control and commercial B. amyloliquefaciens groups (p<0.05). Bacillus subtilis supplementation increased yolk weight (p<0.05). In egg quality during storage, TLRI 211-1 0.1% had higher breaking strength than the control group at the second week of storage (p<0.05). At the third week of storage, TLRI 211-1 0.3% had higher Haugh unit (p<0.05). Hens fed diets supplemented with TLRI 211-1 0.3% significantly decreased blood triglyceride levels and increased blood calcium levels (p< 0.05). TLRI 211-1 0.3% group had lower H2S (p<0.05) and hence had less unpleasant odor in excreta of hens. CONCLUSION: In conclusion, supplementation with 0.1% TLRI 211-1 can significantly improve feed to eggs conversion ratio. TLRI 211-1 supplementation also can maintain eggs at their optimum quality level during storage. The study showed that B. subtilis TLRI 211-1 can be used as feed additives for improving egg production performance and egg quality.
RESUMO
The effects of maternal vitamin E supplementation on the antioxidant status of chicks were investigated. Female breeder chicks were fed corn-soybean growing diets without supplemental vitamin E for a 17-wk developmental period. After 17 wk, the birds were randomly assigned to 5 treatments and fed corn-soybean diets supplemented with 0, 40, 80, 120, and 160 mg/kg vitamin E (all-rac-alpha-tocopherol acetate), respectively. Blood samples were collected and pullets were artificially inseminated at 35 wk of age. Eggs laid beginning on d 2 after insemination were placed in an incubator. At the time of hatching, 12 chicks from each treatment were randomly sampled and killed. Livers and brains of chicks were collected for the subsequent evaluation of antioxidant status. Plasma vitamin E concentrations increased linearly (P < 0.001; r = 0.997) with the increase in supplemental vitamin E, but those in egg yolk reached a plateau at 120 mg/kg supplemental vitamin E. The malondialdehyde (MDA) concentration, an indicator of lipid peroxidation, of chick brain decreased linearly (P < 0.01; r = -0.909) with the increase in supplemental vitamin E. Pullets given 160 mg/kg supplemental vitamin E had lower plasma MDA concentrations than those given 0 mg/kg (P < 0.05). Similar results were found for the reactive oxygen species levels, an indicator of oxidative stress, of chick brain and liver. For antioxidant enzymes, chicks of pullets given 120 mg/kg supplemental vitamin E had higher (P < 0.05) activities of liver catalase than those given 0-80 mg/kg. Chicks of pullets given 160 mg/kg supplemental vitamin E had higher (P < 0.05) activities of brain superoxide dismutase than those given 0-40 mg/kg. These results indicated that maternal supplementation with high levels of vitamin E (120-160 mg/kg) enhances antioxidant capability and depresses oxidative stress in chicks.