Effects of Supplemental Papain on Egg Production and Quality, Serum and Liver Traits of Laying Hens

This study investigated the effects of papain supplementation on egg production and quality, serum and liver traits of laying hens. Sixty 75-week-old white Leghorn laying hens were randomly assigned into control (base diet), supplemental 0.14g/kg feed (low dose) and 0.28g/kg feed (high dose) papain groups. Experimental results from the two-month study indicated that the feed intake of the high-dose papain group was significantly higher than that of the control group (P < 0.05). The papain supplementation groups showed significantly reduced liver cholesterol (P < 0.05); the high-dose group also showed reduced serum cholesterol (P < 0.05). Glutamate pyruvate transaminase (GPT) activity in the papain supplementation groups was lower than in the control group (P < 0.05). The papain supplementation groups showed increased serum total protein and IgG levels (P < 0.05), with the high-dose papain group also showing an enhanced serum total globulin percentage (P < 0.05). The study results indicated that supplemental high-dose (0.28g/kg feed) papain in old laying hens has positive effects on their health.