Abstract :
Experiments have been carried out to study the changes in the values of total nitrogen (N), in vitro digestible crude protein (IVDCP), in vitro apparent organic matter digestibility (IVOMD), in vitro digestible energy (IVDE), crude fibre (CF) and cell-wall constituents (NDF, ADF, ADL) for laying-hens excreta under the effects of: (1) two types of drying: (a) drying at 175°C for 10 minutes (D1); (b) drying at 55°C for 5 days (D2). (2) different doses of gamma irradiation [0, 10, 50, 100, 150 kilogray (kGy)]. The results indicated that there was a significant (P < 0.05) decrease in values of NDF and ADF (by 7%), CF and IVDCP (by 13%), and N (by 16%), and a significant increase in the values of IVOMD (by 12%) and IVDE (by 630 kJ/kg DM) as a result of drying (D1) in comparison with drying (D2). A significant (P < 0.05) decrease was observed in the values of NDF and ADF (by 6%), CF (by 12%) and a significant increase in the values of IVOMD (by 13%) and IVDE (by 980 kJ/kg DM) as a result of gamma irradiation treatment (100 kGy) in comparison to the control sample. There was no significant difference between doses (100 kGy and 150 kGy). Gamma irradiation had no effect on N, ADL and IVDCP values. Combined treatment (D1 + 100 kGy) resulted in a better effect in reducing the concentrations of CF, NDF and ADF and in increasing the values of IVOMD and IVDE.
