Effect of amino acid formulation and dietary direct-fed microbial supplementation on egg production and egg characteristics in laying hens

An experiment was conducted to determine whether direct-fed microbial supplementation could alleviate a marginal amino acid (AA) deficiency in Hyline 36 laying hens from 33 to 44 wk of age. The experiment was a 2 x 4 factorial design with or without a commercial direct-fed microbial (Primilac; 1.36 kg/1,000 kg) and 4 levels of AA formulation. Egg characteristics (yolk, albumen, or shell proportions and yolk or albumen solids) were not affected by diet. Primilac supplementation had no effect on egg production or egg mass. However, Primilac supplementation reduced feed intake-to-egg mass ratio by 2.4 and 3.4% from 33 to 36 wk and 41 to 44 wk, respectively. Total eggs laid and egg mass were greatest when at least 14.4 g of CP, 804 mg of Lys, 382 mg of Met, 601 mg of TSAA, 502 mg of Thr, and 609 mg of lie were consumed per hen per day from 33 to 44 wk of age. In conclusion, Primilac supplementation was not able to completely alleviate a marginal AA deficiency in laying hens but did improve feed intake-to-egg mass ratios during 8 wk of the 12-wk study.