Evaluating the performance, carcass traits and conjugated linoleic acid content in muscle and adipose tissues of Black Bengal goats fed soybean oil and sunflower oil

Abstract

An experiment was conducted to investigate the feeding of soybean oil (SOY) and sunflower oil (SUN) on performance, carcass traits and fatty acid (FA) composition, including conjugated linoleic acids (CLA) in meat of Black Bengal goats. Eighteen growing goats (initial body weight (BW) of 11.1±0.49kg and 9–12 months of age) were equally allotted into 3 groups (control, SOY and SUN) in a randomized complete block design (blocked according to initial BW). Goats were fed concentrate mixtures with similar nitrogen and calculated metabolizable energy content with added vegetable oils (SOY or SUN) at 45g/kg dietary dry matter or without oil (control), and berseem hay (60:40). A metabolic trial was conducted after 105 days of feeding, and carcass traits and fatty acid composition of longissimus dorsi muscle and subcutaneous adipose tissues were determined at 122 days of feeding. Oil supplementation did not affect (P>0.05) average daily gains and feed intake in goats. Digestibilities of nutrients except ether extract (EE), and intake, excretion and balance of nitrogen were also similar (P>0.05) among dietary treatments. Digestibility of EE in goats receiving both plant oils was higher (P<0.01) than control. Feeding of oils did not affect (P>0.05) carcass traits, and percentages of protein, fat and ash in muscle. While supplementing oils did not change (P>0.05) the proportion of total saturated FA, they lowered several medium-chain FA in muscle and adipose tissues. However, the proportion of total polyunsaturated FA (PUFA; P<0.001) and CLA cis-9, trans-11 (P<0.001) in these tissues were highest in SUN, followed by SOY, and control. Oils had no effect (P>0.05) on concentrations of serum glucose, cholesterol and protein, but increased (P<0.05) serum triglyceride concentration compared with control. In conclusion, feeding of SOY and SUN at a concentration of 45g/kg of total diets did not affect digestibility and performance, but increased the PUFA and CLA content in muscle and adipose tissues in Black Bengal goats with the greatest effect noted for SUN.