**3.4 Soy oil**

Soy oil has found many food uses due to its excellent nutritional qualities, widespread availability, economic value and wide-use functionality. Soy oil is a highly concentrated source of feed energy. Its caloric value is the major reason for its increased use.

Gaiotto et al. (2000) evaluated performance of broilers fed diets containing 4% supplemental fat from the sources: soybean oil (SOY4), beef tallow (TAL4), acidulated soapstock (SOAP4), mixtures 2%:2% (SOAP2/TAL2), (SOAP2/SOY2) and (SOY2/TAL2), and confirmed the superiority of soybean oil relative to the other fat sources fed to broiler and demonstrated that the quality of acidulated soapstock and beef tallow may be improved when used in 1:1 mixtures with soybean oil.

For laying hens Costa et al. (2008) evaluated soy and canola oil, and they observed better results for those characteristics were obtained as soybean oil increased. However, the egg mass conversion was negatively influenced by increase of canola oil. The addition of soybean oil promoted better performance as compared to canola oil.

For swine, Mascarenhas et al. (2002) evaluated the effects from two lipid sources (soybean oil and coconut oil) on performance from 60 to 100 kg boars and they observed that diets with coconut oil as lipidic source showed the best results of weight gain.
