Genetic variation in nitrogen and phosphorus content in broiler excreta

The nutrient content in the soil surrounding the poultry farms has increased as a result of the high content of nitrogen (N) and phosphorus (P) in the poultry excreta. The current study aimed to propose a strategy to reduce the N and P content in the excreta by genetic selection in broilers for efficient nutrient utilization. The traits measured were the percentage of N in the excreta (PNE) and the percentage of P in the excreta (PPE), on a dry matter basis. Individual 24-hr excreta samples were collected from 6 wk old birds. Excreta samples were collected from birds of two distinct genetic lines raised in a commercial breeding farm. Analysis of excreta samples collected during the first period (197 bird samples belonging to 15 sire families) and second period (278 birds belonging to 25 sire families) suggested a heritability of 0.08, 0.16 for PNE and 0, 0.20 for PPE, respectively. Phenotypic and genetic correlations between the measured traits from the two lines were very low; however, phenotypic correlation analysis of PNE and PPE with other traits of commercial interest showed some favorable as well as neutral associations. The results suggest that genetic selection of birds for PNE and PPE could improve the environment and the market value of the birds.