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Necrotic enteritis (NE) is a common poultry disease that significantly affects the profitability of commercial broiler production. Traditionally, antibiotic feed supplements are administered to poultry to combat the negative effects of NE. However, due to the ban on growth-promoting antibiotics in the European Union, increasing concern for antibiotic resistance, and demand for drug residue free poultry products, alternative approaches are necessary to maximize broiler performance against NE. A study was conducted to determine the efficacy of feeding Bacillus subtilis (QST 713) spores in broilers using an NE-induced challenge condition. High and low concentrations of B. subtilis (QST 713) spores (1 × 106 and 1 × 105 cfu/g of feed) in broiler feeds were used to identify the appropriate dose to overcome the adverse effects of NE. A treatment group supplemented with bacitracin methyl disalicylate (BMD) at a therapeutic level (50 g/t) was included to compare the efficacy of B. subtilis to a conventionally used antibiotic. Based on these results, NE was successfully induced in the nonmedicated broiler chickens orally inoculated with coccidial oocyst and Clostridium perfringens. Relative to the nonchallenged group, birds infected with NE with no medication showed a significantly (P < 0.05) decreased BW gain, increased FCR, increased NE lesion score, and increased NE mortality. Supplementation of B. subtilis at 1 × 106 cfu/g of feed and BMD mitigated the negative effects of NE in all production parameters and measures of NE infection. No significant differences (P > 0.05) were observed between NE-challenged birds fed with high dose of B. subtilis (QST 713) and those birds supplemented with BMD. Low dose supplementation (1 × 105 cfu/g of feed) of B. subtilis (QST 713) increased NE mortality (P < 0.05) relative to high dose supplementation. Overall, based on these data, adequate supplementation of B. subtilis (QST 713) could serve as an alternative approach in controlling NE infection in broilers without continuously depending on antibiotics during their growing period.

The absorption of folic acid in the intestine is the major factor that determines the level of folate in the bloodstream and eventually the amount of folate that is transferred into eggs. Antinutritive constituents of cereal grains, such as nonstarch polysaccharide, can potentially influence the absorption of nutrients, including folate. Two studies were designed to determine whether the types of cereals and enzyme supplementation in laying hen diets could affect folate content in chicken eggs. In the first study, 96 Bovan White hens (n = 12/diet) received a corn-, wheat-, barley-, or barley + ß-glucanase-based ration, containing 0 or 4 mg/kg of diet of crystalline folic acid for 21 d. Response criteria included production parameters and egg folate measurements. In the second study, 120 Hy-Line CV20 laying hens (n = 12/diet) received a 25% rye-wheat ration containing 0, 0.5, 1.0, 2.0, or 4 mg of crystalline folic acid/kg of feed with or without supplementation of a ß-glucanase and xylanase enzyme cocktail (2,000 units/kg of diet) for six 7-d periods. Production parameters, including in vivo viscosity of jejunal digesta and egg folate content, were measured. In the first study, the type of cereal in the diet significantly (P < 0.05) influenced total egg folate content. Hens fed the corn-based diet had significantly higher total egg folate content than those fed the wheat-based diet (37.2 vs. 28.1 µg/egg). However, the egg folate content did not differ between hens fed the corn- and barley-based diets (37.2 vs. 30.4 µg/egg). Consequently, supplementation of ß-glucanase enzyme to the barley-based diet did not affect total egg folate content. In the second study, the addition of enzyme to the 25% rye- and wheat-based diet had no significant (P > 0.05) effect on egg folate content. The production performance of the laying hens in both studies was also not affected by the type of cereal and enzyme supplementation. Overall, we conclude that the type of dietary cereal may influence the deposition of folate in eggs; however, dietary supplementation of enzyme does not influence egg folate concentration.

Supplementing laying hen diets with folic acid at 4 mg/kg of diet for 3 wk led to the production of folate-enriched eggs with an approximately 3-fold increase in egg folate concentration relative to a regular commercial egg. However, because long-term consistency in folate deposition is important for successful folate enrichment of natural foods such as eggs, 2 studies were designed to determine the level of folic acid required to maximize egg folate content and consistency throughout the entire cycle of egg production. In study 1, Hy-Line W36 and W98 laying hens (n = 156/treatment) received a barley-based diet containing 0 and 4 mg/kg of folic acid, whereas in study 2, a total of 1,248 Hy-Line CV20 laying hens (n = 416/treatment) received a barley-based ration supplemented with folic acid at 0, 2, or 4 mg/kg of diet. Both studies lasted for eleven 28-d periods. Response criteria included production parameters, egg quality measurements, and measures of egg folate content. Results of both long-term production studies support the use of 4 mg of folic acid/kg of diet as the recommended level of folic acid supplementation in terms of maximizing egg folate concentration over time. This is supported by the higher egg folate content and more consistent egg folate deposition at 4 mg of folic acid/kg of diet as compared with 0 and 2 mg of folic acid/kg of diet. Hy-Line W98, a strain of hens selected for large egg mass, benefited more from increased dietary folic acid in terms of increased egg production than did Hy-Line W36 and CV20 hens, strains selected for better egg efficiency and livability. Sensitivity and responsiveness to increasing dietary folic acid concentration in terms of egg folate content were, however, similar for all strains. In conclusion, eggs of laying hens were consistently enriched with folate by dietary supplementation with 4 mg of folic acid/kg of diet throughout the production cycle.