Dietary Manipulation Of Crude Protein and Amino Acids for Reduced Ammonia Emission from Broiler Litter

Five sequential broiler flocks were raised on the same litter to evaluate the efficacy of dietary manipulation on ammonia and other gaseous emissions, broiler litter total ammoniacal nitrogen (TAN), litter pH and moisture content, and broiler chicken performance. Dietary treatments consisted of four levels of crude protein (CP): a conventional High CP diet (Hi), a very Low CP diet (Low) with supplemental essential amino acids (EAA), and two intermediate CP diets (M-Hi and M-Low) obtained by mixing the High and Low CP diets in a 2:1 and 1:2 ratio, respectively. Results indicate that a reduced CP diet with supplemental EAA may achieve satisfactory bird performance. Over five flocks raised on the same litter, pens for birds on the Hi CP diet exhibited significantly greater equilibrium NH ₃ gas, despite negligible NH ₃ during two flocks when litter became dry. Mean litter pH ranged from 6.9 to 8.8 over all treatments. Consistently through all flocks, the Hi CP treatment had the highest pH while the Low CP diet had the lowest pH. This study has demonstrated that lower CP diets can be used to control waste N and equilibrium NH ₃ gas. This has implications for improving the house environment quality, bird comfort and control of costs associated with excess N waste in broiler litter.