Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca: Veterinary Medicine (Nov 2024)

Nitrogen Balance and Uric Acid Excretion in Lohmann-Brown Hens Fed Diets with Different Crude Protein and Metabolizable Energy Levels

  • Mădălina CIOARIC (DEGENARO),
  • Rosalie BĂLĂCEANU,
  • Andrei Tudor KACENCO,
  • Ivona ZĂBAVĂ,
  • Ilinca IOZON,
  • Nicolae DOJANĂ

DOI
https://doi.org/10.15835/10.15835/buasvmcn-vm:2024.0008
Journal volume & issue
Vol. 81, no. 2
pp. 1 – 7

Abstract

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This study aimed to determine the effect of dietary metabolizable energy (ME) and crude protein (CP) levels on nitrogen excretion and laying performance in laying hens. Four groups of 20-week-old Lohmann hens were fed different ME and CP level diets, expressed as higher (H) or lower (L) versus control: group HME/HCP (2,820 kcal ME/16.7% CP), group HME/LCP (2,820 kcal/14.8% CP), group LME/HCP (2,690 kcal/16.7% CP) and group LME/LCP (2,690 kcal/14.8% CP). The control group was fed a commercial diet (2,754 kcal/15.5% CP). Experimental feeding lasted 12 weeks. Egg production was significantly improved (P=0,015) in HME/HCP group. Feed conversion ratio was significantly lower (P=0.013) in HCP groups versus control). The amount of uric acid excreted by HCP groups was 40% higher versus LCP groups (P=0.000) and excreted uric nitrogen was 24.2% higher in HCP versus LCP groups (P=0.001). HCP groups excreted 0.43 g/cap./day more nitrogen versus LCP groups (P=0.001). HCP groups retained 0.21 g/egg mass/day more nitrogen versus LCP groups. ME-supplements did not significantly modify the amount of nitrogen excretion. In conclusion, the tested CP diet supplementations increase faecal nitrogen excretion and egg-retained nitrogen in layers. Effect on laying performances depends of CP level and CP/ME ratio in the diet.

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