Energy and ether extract digestibility of commercially available lipids fed to broilers

Abstract

Energy is an expensive component of diets with lipids providing a concentrated energy source to meet these needs; in addition, supplementary lipids affect milling efficiency and diet palatability. Because of the increased use of lipids as feedstocks in renewable energy production, typical fats and oils are becoming more limited and costly to the livestock industry necessitating the need to source and understand the caloric values of alternative lipids. The experiments reported herein determined the caloric value of typical and non-typical fats when supplemented to growing broilers and compared these empirical values to values predicted by commonly used equations. Thirteen sources of lipids consisting of an animal-vegetable fat blend, poultry fat, 3 soybean oils, 3 distillers corn oils, palm oil, acidulated canola-soybean oil soapstock, acidulated palm oil-soybean oil soapstock, flaxseed oil, and canola oil were evaluated. Differences in the determined nitrogen corrected apparent metabolizable energy (kcal/kg) were observed among the lipids tested (animal-vegetable fat blend, 7,671; poultry fat, 7,984; 3 soybean oils, 8,118, 7,535, and 8,767; 3 distillers corn oils, 8,205, 7,990, and 9,364; palm oil, 7,408; acidulated canola-soybean oil soapstock, 8,056;, acidulated palm oil-soybean oil soapstock, 7,685; flaxseed oil, 8,588; and canola oil, 7,854) and the use of a commonly used prediction equation did not adequately estimate the caloric value compared with the empirical values. Data presented also shows the difficulty of determining and predicting energy values of lipids when used at low inclusion levels.