PHYTASE ACTIVITY, PHOSPHORUS AND CALCIUM RETENTION, AND PERFORMANCE OF SINGLE COMB WHITE LEGHORN LAYERS FED DIETS CONTAINING 2 LEVELS OF AVAILABLE PHOSPHORUS AND SUPPLEMENTED WITH DIRECT-FED MICROBIALS

The presence of phytase activities in condensed cane molasses solubles (CCMS) and CCMS-Lactobacillus (Lacto) were determined. Single Comb Wh ite Leghorn layers were fed .25 and .45% available P (AP) diets supple mented with CCMS and CCMS-Lacto for nine 28-d periods to determine phy tase activities of the gastrointestinal (GI) tract contents and intest ine, liver, and pancreatic tissues, the GI tract pH, the P and Ca rete ntion, and layer performance. Six dietary treatments were corn-soybean (C-S) control, C-S + CCMS, and C-S + CCMS-1,100 mg Lacto/kg diet (ppm )[4.4 x 10(7) cfu/mg Lacto] each with .25 and .45% AP. The CCMS were u sed as a carrier for the Lacto, and the CCMS and CCMS-Lacto premix wer e incorporated at 2% of the diets. Phytase activity was much higher in CCMS-Lacto premix than in CCMS. Phytase activities of the crop conten ts were higher with the CCMS-Lacto diets regardless of the AP level. I ntestinal phytase activity was higher with the .45% AP CCMS-Lacto diet than the unsupplemented .45% AP diets. Lactobacillus supplementation did not stimulate phytase activities in the intestinal contents or liv er and pancreatic tissues. The pH of the crop and intestinal contents were much lower for the Lacto-fed layers than the layers fed unsupplem ented diets regardless of dietary AP levels. No differences in Ca rete ntions were observed with Lacto supplementation regardless of the diet ary AP levels. However, higher P retentions were observed with the Lac to supplementation in the .25% AP diet. Layers fed .25 and .45% AP Lac to-supplemented diets had lower hen-day egg production, poorer feed co nversion value, consumed slightly more feed, produced less egg mass, a nd laid larger eggs than the layers fed .25 and .45% AP unsupplemented diets. Lacto supplementation to .25% AP diet produced eggs with highe r specific gravity than the unsupplemented .45% AP diet, but not diffe rent from unsupplemented .25% AP diet. Layers fed the .25% AP diets ha d lower BW gains than layers fed the .45% AP diets regardless of Lacto supplementation. Phytase activity was present in the Lacto source, an d the presence of phytase and Lacto supplementation to a .25% AP diet improved P retention in layers.