Submitted to: Animal Production Systems and the Environment
Publication Type: Proceedings
Publication Acceptance Date: 10/3/2001
Publication Date: 10/3/2001
Citation: Sistani, K.R., Rowe, D.E., McGowen, S.L., Brink, G.E., Miles, D.M. 2001. Impact of drying method, rearing temperature, and dietary phosphorus level on broiler manure nutrient composition. Proceedings International Symposium addressing Animal Production and the Environment, October 3-5,2001, Research Triangle Park, North Carolina. Interpretive Summary: The interaction and relationship between dietary phosphorus level, environmental rearing temperature, pre-chemical analysis handling of manure and nutrient composition of broiler manure are important problems that need to be investigated. For example, research has shown that high ambient temperature may reduce broiler feed intake and reduce retention of phosphorus and other minerals. This study attempted to address these issues. Results indicated that fresh manure samples should be used for nitrogen determination. Nitrogen loss of more than 20% could happen as a result of drying regardless of drying method. The diet phosphorus concentration had a significant impact on broiler manure phosphorus content. The effect of rearing temperature on manure nutrient content was inconsistent.
Technical Abstract: Proper sample preparation and optimization of the techniques for manure chemical analyses are the keys to the determination of precise manure rates for land application. This study was conducted to determine: 1) the impact of pre-analysis drying methods, 2) the effect of dietary P concentration on broiler manure P content, and 3) the effect of bird-rearing temperature (RT) on broiler manure nutrient composition. Four drying methods, air drying (AD), freeze drying (FD), oven drying at 65 deg.C (OD65), and oven drying at 105 deg.C (OD105) were evaluated on broiler manure generated at 16, 21, and 26 deg.C. The results were compared with analysis of the fresh broiler manure with no drying (ND). All drying treatments resulted in highly significant N loss (21-27%) compared to ND at all RT. However, there were no significant differences in total N loss among the four drying methods examined in this experiment. There was significant loss of NH4-N with OD105 for all RT. The greatest loss of P,Ca,Mg,K,Fe,Mn, and Zn were observed with FD. The diet P concentration did not affect the broiler manure total N content. However, a significant decrease in total N occurred at all P levels due to drying when compared with fresh manure analysis. The diet P level had significant effect on total P and water-extractable P. We recommend fresh broiler manure analysis for the determination of total N and NH4-N after a proper mixing to obtain a homogeneous paste. For analyses of P,Ca,Mg,K,Fe,Mn, and Zn of the broiler manure, ND, AD, and OD65 generaly resulted in lower reduction of these nutrients.