Ácido linoléico conjugado e perfil de ácidos graxos no músculo e na capa de gordura de novilhos bubalinos alimentados com diferentes fontes de lipídios

Abstract

Avaliaram-se o teor de ácido linoléico conjugado (CLA) e o perfil de ácidos graxos no músculo e na capa de gordura de novilhos bubalinos alimentados com diferentes fontes de lipídios. Utilizaram-se 12 animais castrados, da raça Murrah, com peso vivo de 306±8kg, submetidos aos tratamentos sem lipídeo adicional, grão de soja e óleo de soja, confinados durante 84 dias. Após o abate a carcaça foi resfriada a 5ºC, durante 24 horas. Foi feita secção entre a nona e a 11ª costelas da meia carcaça direita, de onde se separou músculo e capa de gordura, analisadas as concentrações de CLA e de ácidos graxos, por cromatografia gasosa. O fornecimento de óleo de soja resultou em maior concentração de CLA no músculo e na capa de gordura, e a adição de óleo de soja menores concentrações de ácidos graxos saturados, principalmente os ácidos mirístico e palmítico. Os animais que receberam a dieta com grão de soja integral também apresentaram menor teor de CLA e redução nas concentrações de mirístico e palmítico. Esses efeitos foram observados somente na capa de gordura e em menor intensidade.

Meat characteristics of Nellore steers fed whole cottonseed

“…For example, in the experiment of Mir et al (2004), the concentration of conjugated linoleic acid of cattle meat was quadruplicated after animals received with sunflower. A similar result was observed with the inclusion of soybean oil in the diet that increased the content of conjugated linoleic acid in the meat (Oliveira et al, 2008). The percentage of conjugated linoleic acid of cattle meat was increased with the addition of frying oil to the diet (Nelson et al, 2008).…”

“…This can be explained by the slow release of triglycerides in the grain, which allowed normal ruminal biohydrogenation by microorganisms. Oliveira et al (2008), when increasing the lipid content of ration through the addition of whole soybean grain, did not observe the increase of conjugated linoleic acid concentration. However, the addition of 15% of sunflower seed in the diet of finishing sheep increased the percentage of conjugated linoleic acid in the meat (Bolte et al, 2002), suggesting that cottonseed and soybean grain in the rumen may have a different behavior from sunflower seed.…”

“…Silva et al (2009) Silva et al (2009) verified that the concentration of C 24:1 , C 20:1 , C 20:3 and C 22:2 acids were not altered by the lipid-rich diet. Oliveira et al (2008) observed an increase in the percentage of C 20:4 in the meat from buffalo fed soybean. There was no difference (P>0.05) among the treatments for the percentage of evaluated isomers of octadecadenoic acid (C 18:2 ) e.g.…”

“…The results indicate that cottonseed also keeps a favorable biohydrogenation route to C 18:1 trans 10 -trans 11 accumulation as the main fatty acid C 18:1 trans in the rumen. The content of C 18:1 acid in buffalo meat was not modified by the inclusion of soybean in the diet but there was an increase of vaccenic acid concentration (Oliveira et al, 2008). Mir et al (2008) obtained a reduction of C 18:1 cis 9 and C 18:1 cis 11 concentration.…”

“…During the breaking process of double bonds and consequent hydrogen addition, there is the formation of intermediate compounds, among them the conjugated linoleic acid (Jenkins & McGuire, 2006). Because unsaturated fatty acids are completely and rapidly available in the rumen, it is possible to state that the capacity of microorganisms to completely saturate the volume of linoleic acids may have been exceeded, making intermediate fatty acids from biohydrogenation reactions go to the intestines; that caused the increase of conjugated linoleic acid concentration (Oliveira et al, 2008).…”