Longissimus muscle fatty acid profile of crossbred Boer goat kids fed diets containing crude glycerin
Crude glycerin is a co-product of biodiesel production with a high concentration of glycerol. Due to the high production of biodiesel, there is a wide availability of crude glycerin and it is becoming an interesting ingredient for animal nutrition. Most studies focus on the sheep as small ruminants, while limited research exists evaluating crude glycerin in the diet of goat kids. Twenty crossbred Boer goat kids (20.8 ± 2.9 kg of BW at slaughter) were used in a randomized complete block design to determine the effect of partial replacement of corn by crude glycerin on Longissimus muscle fatty acid profile. Kids were penned individually for 51 d and fed an isonitrogenous (14.0 ± 0.2 % CP, DM basis) diet composed of 70% concentrate and 30% forage (Coastcross Bermudagrass hay). Increasing levels of crude glycerin (80.0% glycerol, DM basis) were 0, 4, 8 or 12% corresponding to the experimental diets G0, G4, G8 and G12, respectively. Total lipids of muscles were extracted, esterified and methylated. Methyl esters were separated by gas chromatography (VARIAN 430-GC, California, USA) using a 60 m capillary column. Orthogonal polynomials for treatment responses were determined by linear, quadratic, and cubic effects. Effects were declared significant at P < 0.05, and trends are discussed between P > 0.05 and P < 0.10. Linear decrease (P < 0.05) for linoleic acid (3.57, 2.84, 3.76 and 2.33) and w6:w3 ratio (10.61, 9.71, 7.26 and 7.18 for G0, G4, G8 and G12, respectively) were observed with crude glycerin inclusion. The proportion of capric and eicosanoic acids tended (P = 0.06) to increase linearly. Saturated, Monounsaturated and Polyunsaturated fatty acids were not affected by treatments. In conclusion, the partial replacement of corn by crude glycerin cause a little effect on meat fatty acid profile.
Keywords: co-product, meat, quality