The aim of this study was to evaluate the effects of dietary levels of xylanase on production performance, egg quality, nutrient digestibility, and excreta microbiota shedding of laying hens in a 12-week trial. Two-hundred-forty Hy-Line brown laying hens (44 wk old) were distributed according to a randomized block experimental design into one of 4 dietary treatments with 10 replicates of 6 birds each. The 4 dietary treatments were corn-soybean-meal-wheat-based diets supplemented with 0, 225, 450, or 900 U/kg xylanase. Daily feed intake, egg production, egg weight, egg mass, feed conversion ratio, and damaged egg rate showed no significant response to increasing xylanase supplementation during any phase (P > 0.05). No significant responses were observed for apparent total tract digestibility of dry matter, nitrogen, or gross energy (P > 0.05). A significant linear increase to increasing xylanase supplementation was seen for lactic acid bacteria numbers, although coliforms and Salmonella counts were not affected. Increasing the dietary xylanase resulted in a significant linear increase in eggshell thickness in wk 3, 6, 9, and 12 (P < 0.05). In addition, a significant linear increase occurred for Haugh unit and albumen height in wk 12 (P < 0.05). In summary, the inclusion of xylanase in corn-soybean-meal-wheat-based diets increased eggshell thickness, Haugh unit, albumen height, and excreta lactic acid bacteria count but had no effect on production performance or nutrient digestibility.

The objective of the study was to determine the effects of mixer of protected feed additives (MFA) on growth performance, blood metabolites, fecal microflora counts, and immune responses in growing pigs. A total of 150 pigs [(Landrace×Yorkshire)×Duroc] with an initial body weight (BW) of 25.61 ± 0.01 kg were used in a 4-week feeding trial. Pigs were allotted to one of five diet groups (basal diet supplemented with 0%, 0.35%, 0.75%, 1.50%, or 3.0% of MFA with 6 replicates per group and 5 pigs/replicate). Inclusion of MFA tended (P=0.085) to results in a linear increase in BW at week 4 and overall average daily gain (ADG, P=0.064). However, MFA inclusion had no effect on average daily feed intake or gain:feed ratio during the entire experiment period. When 3% MFA was added to the diet, reduction was observed for cortisol level (P=0.032) and low-density lipoprotein cholesterol (P=0.008) at 4 weeks after dietary treatments. The inclusion of MFA had positive effects on fecal score at week 3 and 4 (P=0.068, 0.023, respectively) and the count of Lactobacillus was increased at the end of week 1 and 4 (P=0.099, 0.014, respectively), whereas for E. coli decreased at the end of week 1 and 4 (P=0.043, 0.067, respectively). Type O antibody titres against foot-and-mouth disease virus (FMDV) in growing pigs fed diet supplemented with MFA (1.5%) was significantly (P=0.008) higher than other dietary treatment groups. In conclusion, inclusion of MFA in growing pigs diet may improve ADG, beneficial fecal microflora counts and FMDV type O antibody titre after vaccination and reduced cortisol level, LDL/C and incidences of diarrhoea.