Phytase Activity, Phosphorus and Calcium Retention, and Performance of Single Comb White Leghorn Layers Fed Diets Containing Two Levels of Available Phosphorus and Supplemented with Direct-Fed Microbials

Abstract

The presence of phytase activities in condensed cane molasses solubles (CCMS) and CCMS-Lactobacillus (Lacto) were determined. Single Comb White Leghorn layers were fed .25 and .45% available P (AP) diets supplemented with CCMS and CCMS-Lacto for nine 28-d periods to determine phytase activities of the gastrointestinal (GI) tract contents and intestine, liver, and pancreatic tissues, the GI tract pH, the P and Ca retention, 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 × 107 cfu/mg Lacto] each with .25 and .45% AP. The CCMS were used as a carrier for the Lacto, and the CCMS and CCMS-Lacto premix were incorporated at 2% of the diets.Phytase activity was much higher in CCMS-Lacto premix than in CCMS. Phytase activities of the crop contents were higher with the CCMS-Lacto diets regardless of the AP level. Intestinal 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 liver and pancreatic tissues. The pH of the crop and intestinal contents were much lower for the Lacto-fed layers than the layers fed unsupplemented diets regardless of dietary AP levels. No differences in Ca retentions were observed with Lacto supplementation regardless of the dietary AP levels. However, higher P retentions were observed with the Lacto supplementation in the .25% AP diet. Layers fed .25 and .45% AP Lacto-supplemented diets had lower hen-day egg production, poorer feed conversion value, consumed slightly more feed, produced less egg mass, and laid larger eggs than the layers fed .25 and .45% AP unsupplemented diets. Lacto supplementation to .25% AP diet produced eggs with higher specific gravity than the unsupplemented .45% AP diet, but not different from unsupplemented .25% AP diet. Layers fed the .25% AP diets had lower BW gains than layers fed the .45% AP diets regardless of Lacto supplementation. Phytase activity was present in the Lacto source, and the presence of phytase and Lacto supplementation to a .25% AP diet improved P retention in layers.