Performance, Carcass Characteristics, Cardio-Pulmonary Morphometry, Gut-Morphology, Fatty Acid Profile and Humoral Immunity of Commercial Broiler Birds Fed Diet Supplemented with Blended Fish Protein

Abstract

A 35-day trial was conducted to explore if different sources of dietary proteins at varying levels of metabolizable energy had any effect on the average daily feed intake (ADFI), average daily gain (ADG), feed efficiency (FE), carcass characteristics, cardio-pulmonary morphometry, gut morphology, profile of unsaturated fatty acid (UFA), saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA) and humoral immunity of the broiler birds. Total 288 Ross-308 day old male broiler birds were randomly distributed in four dietary treatment groups in a 2×2 factorial arrangement (Two different sources of proteins, i.e., plant and animal with two different levels of metabolizable energy, i.e., low and high). Each treatment had nine replicates containing eight birds per pen. Results indicated that, the supplementation of blended fish protein substantially increased (p<0.001) the final body weight and decreased (p<0.001) the ADFI at 1-14 d, 15-35 d and 1-35 d compared with plant protein. The ADG increased at 1-14 d (p<0.001), 15-35 d (p<0.05) and 1-35 d (p<0.05) and the FE improved (p<0.001) at 1-14 d, 15-35 d and 1-35 d. Similarly, the high energy diet significantly increased (p<0.001) the final body weight and decreased the ADFI at 1-14 d (p<0.001), 15-35 d (p<0.05) and 1-35 d (p<0.05) compared with low energy diet. The ADG increased (p<0.001) and the FE improved at 1-14 d, 15-35 d and 1-35 d. The animal protein increased the thigh weight (p<0.01), the neck weight (p<0.05) and the ratio (p<0.001) of ∑UFA:∑SFA and ∑PUFA:∑MUFA in the breast muscles of the broiler birds. The GLM identified no interaction effect (p>0.05) of energy and protein on the ADFI, ADG, FE, cardio-pulmonary morphometry and humoral immunity of the broiler birds against Newcastle and Infectious Bronchitis diseases. The RV:TV remained within standard range indicating no symptoms of cardiac dysfunctions. It was concluded that the fishmeal supplemented high energy diet improved weight gain, feed efficiency and meat quality of broiler by increasing ∑ω-3 and ∑ω-7 fatty acids as well as the ratio of ∑ω-3:∑ω-6, ∑UFA:∑SFA and ∑PUFA:∑MUFA in the breast muscles of the broiler birds.