To evaluate the effects of different combinations of probiotics on performance, egg quality, and immune response of layer hens, a trial was carried out with 1,800 white feather layer hens of the Lohmann variety. The experiment was conducted by using a completely randomized design with 9 treatments, 4 replicates, and 50 hens in each replicate. Compared with the control group, group F, which added a composition of heat-inactivated Lactobacillus salivarius(CB) and Bacillus subtilis to the diets of layer hens, caused highly significant (P < 0.05) increases in egg production, daily egg yield, damaged egg ratio, combined with a significant (P < 0.05) decrease in feed conversion and damaged egg ratio. Group G, adding a combination of inactivated Lactobacillus salivarius and sodium butyrate, resulted in a significant increase (P < 0.05) in daily egg yield, feed conversion, damaged egg ratio and Haugh unit. Meanwhile, groups D and H had significantly decreased feed conversion (P < 0.05), and groups B, H, and I had a significantly decreased damaged egg ratio. In serum levels, no significant difference was observed except a significant decrease (P < 0.05) in total cholesterol (groups D, E, and G) and low-density lipoprotein cholesterol (group E and G) and a significant increase (P < 0.05) in total cholesterol (groups D, E, and G) compared with group A. According to the hemagglutination inhibition test, the antibody titer of antibody against the avian influenza virus was significantly (P < 0.05) higher in most treated groups such as groups B, C, E, G, and I after d 15 fed to layers with probiotics and groups B, C, D, E, F, G, and H after d 45 compared with the control group. No significant difference was observed in the antibody titer against the Newcastle disease virus at d 15, but significantly (P < 0.05) higher at d 45 in groups F and G. These results demonstrate that several combinations of probiotics used in this experiment have a positive impact on the performance, egg quality, and immune response of layer hens, and the following work will continue to focus on these groups.

An experiment was conducted to evaluate the effects of one alpha-hydroxycholecalciferol (1α-OH D3) on growth performance, tibia quality, and skin and meat color in broilers fed calcium (Ca)- and phosphorus (P)-deficient corn-soybean meal diets. A total of 288 male Ross broilers, at 21 days of age, were randomly assigned to three treatments with eight cages per treatment. Three levels of 1α-OH D3 (0, 5, and 10 μg/kg) were added to a basal diet (0.50% Ca, 0.13% non-phytate phosphorus (NPP), and 0.35% total phosphorus (tP)) without vitamin D3. As a result of this study, the addition of 1α-OH D3 increased body weight gain (p<0.001), feed intake (p = 0.007), feed efficiency (p<0.001), tibia weight (p = 0.002), length (p<0.001), breaking-strength (p = 0.012), ash (p<0.001), Ca (p<0.001), and P content (p = 0.004). Dietary 1α-OH D3 enhanced breast meat yellowness (p = 0.015) and the length and weight of the small intestine of the broilers. Moreover, 1α-OH D3 decreased serum Ca concentration (p = 0.074) and breast meat redness (p = 0.010). These results indicate that the 1α-OH D3 improves growth, tibia quality, and meat color in broilers fed Ca- and P-deficient corn-soybean meal diets.