Effects of drying method and rearing temperature on broiler manure nutrient content

There is no universally accepted method for preparing poultry manure sample s prior to chemical analysis for nutrient content. Proper sample preparatio n and optimization of the techniques for manure chemical analyses are the k eys to the determination of precise rates for land application to crops and pastures. This study was conducted to determine the effect of bird-rearing temperature (RT) and pre-analysis drying methods on broiler manure nutrien t content. Four drying methods, air drying (AD), freeze drying (FD), oven d rying at 65 degreesC (OD65), and oven drying at 105 degreesC (OD105) were e valuated on manure of birds grown at 16, 21, and 26 degreesC. The results w ere compared with analysis of the fresh broiler manure with no drying (ND), All drying treatments resulted in highly significant nitrogen (N) loss (21 %-27%) compared to ND at all rearing temperatures. However, there were no s ignificant differences in total N loss among the four drying methods examin ed in this experiment. There was significant loss of NH4-N with OD105 for a ll RT, but no pattern was observed among other drying methods and RT with r egard to NH4-N and organic N. The effect of drying methods on broiler manur e nutrient content followed the same trend for all the rearing temperatures . The greatest loss of phosphorus (P), calcium (Ca), magnesium (Mg), potass ium (K), iron (Fe), manganese (Mn), and zinc (Zn) were observed with freeze drying. We recommend fresh broiler manure analysis for the determination o f total N and NH4-N after a proper mixing to obtain a homogeneous paste. Fo r analyses of P, Ca, Mg, K, Fe, Mn. and Zn in the broiler manure, ND. AD, a nd OD65 generally resulted in lower reduction of these nutrients.