PRODUCTION VARIABLES AND NUTRIENT RETENTION IN SINGLE COMB WHITE LEGHORN LAYING PULLETS FED DIETS SUPPLEMENTED WITH DIRECT-FED MICROBIALS

Two experiments were carried out for six and seven 28-d periods, respe ctively, with DeKalb XL Single Comb White Leghorn laying pullets to as certain the effect of feeding 1,100 mg Lactobacillus (Lacto)/kg diet ( ppm) and 2,200 ppm Lacto diets, and the supplementation of these diets with 1 and 3% fat, on layer performance and nitrogen, calcium, and ph osphorus retention. The dietary treatments were corn-soybean meal (C-S ) control, C-S plus condensed cane molasses solubles (CCMS)-1,100 ppm Lacto (4.4 x 10(7) cfu/mg Lacto), and C-S plus CCMS-2,200 ppm Lacto (8 .8 x 10(7) cfu/mg Lacto) without fat (Experiment 1) and without and wi th 1 and 3% supplemental fat to each Lacto level (Experiment 2). In bo th experiments, layers fed the 1,100 ppm Lacto diets had better (P<.05 ) hen-day production, daily feed consumption, egg mass, egg weight, eg g size, and feed conversion than layers fed diets without Lacto. Egg m ass, interior egg quality, and feed conversion (Experiment 1), mean bo dy weight gains, and nitrogen, calcium, and phosphorus retention (Expe riment 2) were further improved (P<.05) with feeding 2,200 ppm Lacto d iets. Feeding Lacto diets with 1% fat provided (P<.05) larger eggs and better (P<.05) nitrogen and phosphorus retention, whereas 3% fat decr eased (P<.05) feed consumption and nutrient retention and improved (P< .05) feed conversion and body weight gain. Positive correlations betwe en Lacto diets and nitrogen and calcium retentions, daily feed consump tion, and egg size were observed. Feeding 1,100 ppm Lacto diets to lay ers stimulated appetite and improved egg production, egg mass, egg wei ght, egg size, and feed conversion. Addition of fat to Lacto diets red uced daily feed consumption and provided better feed conversion, egg m asses, egg sizes, body weight gains, and nutrient retentions.