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FATTY ACID PROFILEsOF LONGISSIMUS DORSI FROM NELORE CATTLE ON PASTURE SUPPLEMENTED WITH CRUDE GLYCERIN AND WHOLE COTTONSEED
There is interest in the composition of fatty acids (FA) in beef for reduction of short-chain FA, with increment of medium-chain and omega-3 FA, by their anticarcinogenic and immune-stimulatory effects. Nutritional strategies to improve meat quality should be studied to possibility better meat FA profile in this products. The aim of this experiment was to evaluate whole cottonseed and crude glycerin association in multiple supplements for 50 Nelore cattle in the fattening phase at Brachiaria brizantha pastures on longisssimus dorse FA profile. Animals were supplemented with 4 kg/d (21% of crude protein). The experiment was performed in a 2 x 2 factorial design (two levels of crude glycerin (0 and 15%) and two levels of whole cottonseed (0 and 25%). Orthogonal contrasts were used to evaluated the effect of crude glycerine, whole cottonseed and the interaction, adopting 0.05 to the critical level of probability. Inclusion of whole cottonseed reduced the quantity of hypercholesterolemic FA: C14:C19 (p= 0.049), C16:0 (p= 0.038), C16:C19 (p= 0.006) and C17:0 (p= 0.028). However, inclusion of crude glycerin increased C17:0 (p= 0.002) and C17:1 (p= 0.003). The cottonseed promoted an increase in the concentration of C18:0 (p< 0.001) possibly due to extensive biohydrogenation of isomers C18:1, C18:2 and C18:3 (p< 0.001). The glycerin promoted an increase in C18:2C9t11 conjugated linoleic acid (p= 0.046) due to reduction in lipolysis of FA in the rumen, with limited biohydrogenation. The C20:1 (p= 0.02) was reduced by feeding of cottonseed, due to the low concentration of this fatty acid in the ingredient. There was no influence of the inclusion of glycerin and/or cottonseed on the total of saturated FA, monounsaturated or polyunsaturated FA, as well as their relations (p>0.05). The supply of glycerin and whole cottonseed modify the FA profile, because of ruminal biohydrogenation modulation by glycerine, for healthy meat production.
Keywords: meat quality, supplementation, stearic acid.