Growth performance, carcass characteristics and haemato-biochemical indices of broiler chickens fed sub-optimal protein diets with or without papaya enzyme

Abstract

Two dietary protein levels (standard and sub-optimal) were supplemented with or without papaya enzyme (PE) so as to ascertain the effect on growth performance, carcass characteristics and blood parameters of broiler chickens. Four experimental diets each were formulated during the starter (1-28d) and finisher (29-49d) phases. Starter diets A and B contained 23 and 20% CP respectively while at the finisher phase, they contained 20% and 18%CP respectively. Papaya enzyme (PE) was added as diets C and D. A total of 120 day-old Arbor Acre chicks were randomly allocated to the four dietary treatments comprising of three replicates each in a completely randomized design. Daily Feed Intake (DFI) and Daily Weight Gain (DWG) were measured while Feed to Gain Ratio (FGR) was estimated. At day 49, twelve birds per treatment were slaughtered in order to measure carcass cut-up parts (thigh, breast, neck, wing, back, drumstick and abdominal fat), and selected organs were weighed and expressed relative to live weight. Data collected were subjected to analysis of variance in a 2 × 2 factorial arrangement and treatment means separated using Duncan Multiple Range Test. Results showed that broiler chickens fed sub-optimal protein levels and supplemented with PE (20/18%CP) gave comparable response like those on standard diet (23/20%CP). Performance parameters were not significantly (P>0.05) influenced except feed intake at the starter phase. Marginal improvements were recorded for PE supplemented diets at the starter phase compared to those without PE. Carcass and organ weights were not influenced by protein or inclusion of PE. Abdominal fat pad was higher in diets with high protein. The PCV, Hb, RBC, MCHC and ALT values were higher with the use of PE while the interaction revealed that there were significant (p<0.05) differences, which did not follow any definite pattern. In conclusion, papaya enzyme improved performance of broiler chickens on the sub optimal protein diet.

Keywords: Carcass, Papaya enzyme, Performance, Poultry