Effect of variation in nutrient density on production performance and serum biochemical parameters of Rhode Island Red laying hens

Abstract

The effect of variation in nutrient density of diets on production performance, egg quality and serum biochemical parameters of Rhode Island Red (RIR) laying hens was studied. A total of 96, RIR laying hens (28wk) were randomly distributed into three treatment groups with four replicates in each group with 8 birds in each replicates. These birds were reared in dip litter system under uniform management conditions throughout the experimental period (26-34 wk = 8 wks). A standard diet (control diet) containing 2600 kcal/kg ME, 16% CP, 0.7% lysine and 0.35% methionine was formulated. Subsequently, two other diets were formulated where in the above nutrients were either increased or decreased by 5%.A measured quantity of each diet was fed to one of the treatment groups for a period of eight wks to study their performance. Reducing the nutrient density by 5% resulted in negative growth and the layers lost body weight by 44.70g. The laying hens fed diet with 5% higher nutrient density gained highest weight of 72.21g which was significantly higher compared to the other two groups. Reducing the nutrient density by 5% resulted in reduced egg production, low egg mass output and poor feed efficiency compared to control. On the other hand increasing the nutrient density by 5% did not elicit any beneficial effects on these parameter compared to the control diet. None of the of the egg quality parameters (% albumen, % yolk, % eggshell, shell thickness and Haugh unit score) were significantly influenced due to variation in nutrient density in diets. Reducing the nutrient density of the diet by 5% significantly decreased the protein concentration in serum. However, no difference in serum protein concentration could be observed due to increase in nutrient density by 5% as compared to control. The concentration of uric acid in serum was lowest in the dietary groups in which nutrient density was reduced by 5%. Increasing the nutrient density by 5% significantly increased the uric acid concentration in serum of laying hens as compared to either control or low nutrient density diet. Thus it may be concluded that the diet containing 2600 kcal/ME per kg diet, 16.0% CP, 0.70 % lysine and 0.35% methionine could be adequate in maintaining optimum performance in RIR laying hens.