MVSc

The effects of different levels of protease supplementation viz., 0.02 and 0.04 per cent in low protein layer ration of Japanese quails on their production performance and economic feasibility was evaluated using one hundred and sixty laying birds for a period of twenty weeks. The birds were divided into four dietary treatment groups, viz., standard quail layer ration (T0), low protein quail layer ration (T1), low protein quail layer ration with 0.02 per cent protease (T2), and low protein quail layer ration with 0.04 per cent protease (T3). The standard quail layer ration was formulated as per the recommendations for laying Japanese quails by the Central Avian Research Institute, Izatnagar. It contained 22 per cent crude protein (CP) and 2650 kcal/kg of metabolisable energy. The low protein quail layer ration was formulated with a low percentage of crude protein (CP 18%) and same level of metabolisable energy as the standard layer ration. The body weight gain during the entire experimental period was highest for the birds fed 0.02 percent of protease compared to other treatment groups. But analysis of data revealed no significant difference between treatments. Age at sexual maturity and 50 per cent production were not at all influenced by enzyme supplementation statistically. Numerically the birds fed 0.04 per cent enzyme reached age at sexual maturity and 50 per cent production earlier. A numerical improvement was noticed in total egg production, over all hen day and hen housed egg number and overall hen housed and hen day egg production per cent in the birds fed 0.02 per cent protease with low protein layer ration compared to the non supplemented group. Egg weight and egg quality characteristics such as shape, albumen and yolk indices, internal quality unit (IQU) and shell thickness were not affected by enzyme treatment. Feed intake per bird per day and feed efficiency were not significantly influenced by the supplementation of enzyme. Only the serum protein values of standard quail layer ration was statistically more than the other groups. However the enzyme treatment had no effect on the serum protein values of low protein groups. The retention per cent of nitrogen was highest for the groups of birds fed low protein layer rations and lowest for those fed standard protein layer ration. The retention of nitrogen was unaffected by the enzyme treatment. The mortality was not affected by the enzyme treatment. The analysis of economics indicated least cost per egg for the birds fed 0.02 per cent enzyme (T2). The birds fed standard layer ration performed better than low protein groups without or with two levels of protease.