NUTRITIONAL AND BIOLOGICAL METHODS OF NITROGEN EMISSION REDUCTION ON PRODUCTION PERFORMANCE OF GUINEAFOWL

Reducing crude protein (CP) level in the feed without altering the amino acid contents by supplementing synthetic amino acids to reduce nitrogen excretion, adding ofexogenous protease enzyme infeed to improve nitrogen utilization and treating litter with the culture ofMethylomonas methanica (MM) to prevent methane emission from litter are the proven methods in commercial poultry production, especially in broiler farming to protect the environment. However, the efficacy of these nitrogen emission reduction strategies on the performance and economics of guinea fowl in intensive production has not been studied adequately. Therefore, a biological experiment was conducted with high protein (HP) diets with (Tl) or without (T2) fish meal (FM) and low protein (LP) diets added with exogenous protease enzyme with (T3) or without (T4) FM. The levels of critical amino acids in all the feed were balanced with the supplementation of synthetic amino acids. These treatments contained six replicates of each with 15-day-old keets. At the start of ninth week, the litter of three replicates from each treatment was sprayed with MM culture additionally, forming four more treatment groups, from T5 to T8 respectively. The results of the study indicated that replacing FM with plant protein sources did not affect body weight. The overall trend revealed that the reduction of CP by 2% had a negative (P<0.05) impact on body weight; while, the addition of protease in feed had no notable effect. The feed consumption was not affected by the withdrawal of FM or reducing CP level by 2% ordietary protease supplementation or MM litter treatment. The feed efficiency was negatively impacted (P<0.05) by withdrawal ofFMin high and low protein diets; -while, feed efficiency -was not improved by protease supplementation in LP diets. The level of CP or -withdrawal FM or protease enzyme supplementation in the ration did not affect livability. The MM litter treatment did not affect gro-wth rate, feed consumption, feed efficiency and livability of guinea fowls. The results indicated that the benefit-cost ratio could be improved in guinea fowls by using low CP feed.