Growth analysis of broilers fed by diets containing different oils

Abstract

Objective of this study is to evaluate growth pattern of boilers fed diets containing different oils. Data for this study were obtained from an experiment involving 160 unsexed one day old chicks of Ross 308 cross randomly allocated to four dietary treatments (n=40) with five replicates in each of them (eight birds per replicate) over 42 days. Feeding experimental diets was introduced in the last 21 days. Composition of experimental diets (C, D1, D2 i D3) was the same, containing different levels of added oils. Control diet contained 6% of sunflower oil. D1, D2 and D3 diets contained added oils in the following combinations: 1% fish oil + 2% linseed oil + 3% rapeseed oil (D1), 1.5% fish oil + 1.5% linseed oil + 3% rapeseed oil (D2) and 2% fish oil + 1% linseed oil + 3% rapeseed oil (D3). All diets were isoenergetic and contained 0.015% vitamin E. Gompertz model fits the data obtained from weekly weighing of birds. The model indicated high accuracy with the determination coefficient of over 99.9%. Predicted mature weight of birds, initial specific growth rate per week, rate of exponential decay of the initial specific growth rate, age of birds at inflection point, weight at the inflection point, and maximum weight gain at inflection point for each dietary treatment were subjected to one-way variance analysis. A positive effect of dietary omega-3 fatty acids on most of examined growing curve parameters has been established.