PhD

A study was conducted in the Department of Poultry Science, College of Veterinary and Animal Sciences, Kerala Agricultural University to find out the effect of supplementation of a multi enzyme preparation ‘Polyzyme’ on the production performance of indigenous layer ducks. Diets containing 8 and 12 per cent CF and the high fibre diet supplemented with Polyzyme were fed to ducks from 20 to 56 weeks of age under cage system of rearing. Foraging ducks procured from three different regions of Kerala namely Kuttanad, Palakkad and Thrissur were utilized to evaluate the nutritional and physiological status of foraging ducks in Kerala.
Two hundred, 18 weeks old indigenous layer ducks were housed in cages at the rate of two ducks per cage. They were divided in to five groups viz., T1, T2, T3, T4 and T5 consisting of 40 ducks in each treatment group having four replicates with 10 ducks in each replicate. The control group T1 was allotted with 8 per cent CF diet. The diets with 12 per cent CF, T2, T3, T4 and T5 were supplemented with polyzyme levels at Zero, 0.06, 0.12 and 0.18 per cent respectively. All the diets contained 18 per cent CP and 2550 kcal ME/kg diet.
Nutritional and physiological status of foraging ducks was assessed by collecting crop, body fat and blood samples from 10 ducks each from three regions namely Kuttanad, palakkad and Thrissur. The nutrient availability in the crop contents of the ducks was estimated. The crop contents and fat were screened for pesticide residues using Gas Chromatography. Hemoglobin, plasma total protein, lipids and cholesterol were analyzed to assess the physiological status of the foraging ducks and that under cage system of rearing.
The mean body weight of indigenous layer ducks ranged from 1532.50 to 1663.0 g at 20 weeks, 1649.75 to 1682.25 g at 40 weeks and 1647.00 to 1799.25 g at 52 weeks of age with significant difference (P<0.01) between the lowest and highest groups only at 52 weeks of age.
The cumulative Duck housed egg number during 21 to 56 weeks of age was highest (141.98) in 0.06 per cent enzyme supplemented group (T3) and lowest (108.68) in 8 per cent crude fibre diet group (T1) and the DHN in all the 12 per cent CF dietary groups were significantly higher than that of control group (P<0.05). The mean percent Duck housed production was highest (56.34) in 0.06 per cent enzyme diet group and lowest (43.12) in 8 per cent CF diet group during 21 to 56 weeks period. The highest weekly egg production per cent (83.29) was recorded in 0.06 per cent enzyme dietary group at 35 weeks of age.
The overall mean egg weight for 21 to 56 weeks of age was significantly higher in all enzyme supplemented dietary groups than that of control group (P<0.05). The total egg mass per duck during 23 to 56 weeks was ranged from 7.22 to 9.67 kg showing the highest egg mass in 0.06 per cent enzyme supplemented group and the lowest in control group.
The overall mean daily feed consumption per duck for 21 to 56 weeks period ranged from 145.33 to 163.72 g and significantly higher in all diets contained 12 per cent CF and the mean cumulative feed intake was ranged from 36.63 to 41.26 kg with an overall mean value of 40.16 kg.
Feed Conversion Ratio (FCR) per dozen eggs for 25 to 56 week period was numerically better (3.41) in 0.06 per cent enzyme supplemented group.
Physiological profile of indigenous layer ducks indicated that hemoglobin values ranged from 11.84 to 12.86 g/dl at 20th week, 12.86 to 13.72 g/dl at 40th week and 12.96 to 13.83 g/dl at 52nd week among the five treatment groups. Results of the plasma biochemical analysis revealed that total protein values did not differ significantly either at 20, 40 or 52 weeks of age among the groups. The mean values at 20, 40 and 52 weeks of age were 4.24, 4.95 and 4.87 g/dl respectively. Plasma Cholesterol values at 20 weeks ranged from 181.83 to 207.33 mg/dl among groups. The corresponding values at 40 weeks ranged from 179.85 to 185.75 mg/dl and at 52 weeks from 162.02 to 167.80 mg/dl. The plasma total lipid values at 20, 40 and 52 weeks of age ranged from 595.90 to 638.86, 683.42 to 716.30 and 785.22 to 826.35 mg/dl respectively.
Per cent digestibility of protein, fat and fibre fractions namely Neutral detergent fibre and Acid detergent fibre were numerically higher in enzyme supplemented groups compared to other groups.
The moisture content of the meat from indigenous layer ducks at 56 weeks of age ranged from 73.38 to 75.96 per cent among the experimental groups and foraging ducks. Crude protein value ranged from 17.03 to 18.81, fat from 2.73 to 4.82 and total ash from 2.18 to 3.88 per cent.
The livability was 100 per cent in experimental groups T3 and T4 and 97.5 per cent each in the other three groups.
The chemical composition of the crop contents collected from foraging ducks indicated that moisture content ranged from 41.0 to 53.0 per cent, crude protein 10.2 to 17.5, ether extract 1.87 to 3.7, crude fibre 11.3 to 19.8 and total ash 9.5 to 17.0 per cent.
The mean hemoglobin and plasma biochemical values of foraging ducks between 38 to 44 weeks of age were within the normal range and were comparable with that of ducks in intensive system.
The organochlorine residue estimated in the crop content and fat of foraging ducks from three regions of Kerala namely Kuttanad, Palakkad and Thrissur indicated that the residues detected in the samples were below the Maximum Residue Level of OC compounds in poultry. The combined residue level of all organochlorine compounds in the crop content of foraging ducks from Kuttanad, Palakkad and Thrissur were 0.0018, 0.0152 and 0.0033 ppm respectively. The combined residue in the fat of foraging ducks were higher than those values observed in crop contents at Kuttanad, Palakkad and Thrissur region and were 0.0117, 0.0419 and 0.0077 ppm respectively.
Based on the present study it was concluded that 12 per cent crude fibre can be included advantageously in the diet of indigenous layer ducks. Supplementation of 0.06 per cent polyzyme in 12 per cent fibre diet will help to enhance the production performance of indigenous layer ducks.
Results from the studies on foraging ducks revealed that nutrient availability from foraging fields are widely variable. Physiological parameters in respect of hemoglobin, plasma total protein, lipids and cholesterol in foraging ducks are comparable to that under intensive system of management. Organochlorine residues in the crop content and fat of foraging ducks from Kuttanad, Palakkad and Thrissur are below the Maximum Residue Levels of the compounds in poultry.