Comparison of different papaya forms on the growth performance, immune response, antioxidative capacity, and caecal microbiota of Japanese Quails

Abstract

Papaya is a sparsely branched tree and grows in many tropical and subtropical areas. Herein, this study compared the effects of papaya at 0.75 % as seeds meal (PSM), leaves meal (PLM), latex powder (PLP), or a mixture of them (PMIX) on the performances of Japanese quails. Two hundred unsexed Japanese quail (1st week-old) with an initial body weight of 21.08 ± 0.32 g were allocated into five experimental groups in cages with free access to water and test diets. Birds fed diets enriched with PSM, PLM, PLP, or PMIX for 55 weeks. The results showed that quail groups fed on papaya diets exhibited improved (P < 0.05) final weight, weight gain (WG), and feed conversion ratio (FCR) than the control. Dietary PLP or PMIX resulted in a remarkable WG enhancement, while PMIX reduced the FCR (P < 0.05). Activities of digestive enzymes (amylase, trypsin, and chymotrypsin) were enhanced (P < 0.05) with dietary papaya, especially in birds fed on PLP. Quails fed on PLM, PLP, or PMIX diets had reduced albumin/globulin ratio (A/G), triglycerides, total cholesterol, and low-density lipoprotein levels. At the same time, the level of high-density lipoprotein and the activity of aspartate aminotransferase increased (P < 0.001) by dietary PLP and PMIX. Moreover, higher total antioxidant capacity, superoxide dismutase, and lower malondialdehyde were recorded with papaya supplements than with the control. A similar trend was recorded for immunoglobulin G and M (IgG and IgM), phagocyte activity, and phagocyte index. Interestingly, low caecal harmful microbiota populations were observed in birds treated with papaya. In conclusion, the dietary inclusion of different papaya parts (leaves, seed, latex, and their mixture) can improve the productive performance, immunity, antioxidant indices, intestinal enzymes, and decline intestinal pathogens of growing Japanese quails.