Feeding native laying hens diets containing palm kernel meal with or without enzyme supplementations. 2. Excreta nitrogen, ammonia, and microbial counts

Abstract

SUMMARY Previously, we reported that feeding native Indonesian laying hens a diet containing up to 30% palm kernel meal (PKM) resulted in comparable egg production to that of hens fed a corn-soybean meal (control) diet regardless of enzyme supplementation. In the present paper, we focus on the effect of the PKM diet on nitrogen excretion, ammonia (NH3) volatilization, as well as microbial counts. One-hundred and eighty 48-wk-old local hens were allotted to 180 cages (1 bird/cage) in a curtain-sided house. Twelve diets were assigned randomly to 15 cages each. The diets were a factorial combination of 3 levels of PKM (0, 15, and 30%), 2 concentrations of a fiber-degrading enzyme [0 and 15 units β-glucanase (major enzyme) activity/kg of diet; Ronozyme VP, DSM Nutritional Products Inc., Basel, Switzerland], and 2 concentrations of phytase + protease mixture [0 and 2,000 units of phytase (Ronozyme NP) + 12,500 units of protease (Ronozyme ProAct) activity/kg of diet; both products of DSM Nutritional Products Inc.]. Diets were isocaloric (2,758 kcal of ME/kg) and contained 17.5 to 18.4% CP and were fed for 10 wk. At 4 wk, excreta DM (but not N) increased as dietary PKM concentrations increased (19.44 vs. 21.98 vs. 23.02% for 0, 15, and 30% PKM, respectively; P ≤ 0.005). However, there were no effects of enzyme supplementations on excreta DM or N. Decreases in excreta NH3 of 36 to 47% (P ≤ 0.0001) associated with PKM concentration or of 11 to 18% (P ≤ 0.05) associated with the use of fiber degrading enzyme were observed. Although phytase + protease supplementation did not show a significant effect on NH3 reduction, interaction effects of enzymes with PKM on NH3 were observed. Moreover, increasing PKM to 30% resulted in increased Lactobacillus spp. and reduced coliform/Escherichia coli counts (P ≤ 0.005), and lower (P ≤ 0.05) excreta pH. Interaction effects between PKM and individual enzymes used on Lactobacillus spp. or between PKM and both enzymes on coliform/E. coli were observed.