Influence of Fish Oil Supplementation on the Concentration of Conjugated Linoleic Acid (CLA) and Omega 6 and 3 in Buffalo Milk Exequiel Maria PATIÑO a* , Maria Alicia JUDIS b , Marcial SANCHEZ NEGRETTE a , Jose Feliciano CEDRES a , Gladys Isabel REBAK a , Ana Maria ROMERO b , Mirtha Marina DOVAL b and Gustavo Angel CRUDELI a a Facultad de Ciencias Veterinarias, Universidad Nacional del Nordeste (UNNE), Sargento Cabral 2139, Corrientes (3400), Argentina b Departamento de Ciencias Básicas y Aplicadas. Universidad Nacional del Chaco Austral (UNCAus). Presidencia Roque Sáenz Peña, Chaco, Argentina *Corresponding email: exepa@vet.unne.edu.ar ABSTRACT The aim of this research work was to investigate the influence of fish oil supplementation on the concentration of conjugated linoleic acid (CLA) and omega 6 and 3 in samples of buffalo milk. A total of 24 female buffaloes separated at random into three groups were fed for 49 days with: natural pasture (group I), supplemented with 70 ml of fish oil (group II) and 140ml of fish oil (group III). In the experiment the concentration of CLA showed differences (P<0.05) among the three groups, with a maximum of 7.14 mg/g fat in group II. No significant differences were found in omega-6 among the three groups. The highest value of 3.82 mg/g fat corresponded to group I, whicht had not been supplemented with fish oil. Significant differences were observed in omega 3 (P<0.05) in groups II and III with respect to group I. The highest average value of 2.42mg/g fat was obtained in group III. The closest relationship omega 6/3 (1.37:1) was observed in group III. As a result, the diets of groups II and III, which included fish oil, increased significantly the content of CLA and omega 3 with reductions in levels of omega 6. Keywords: Bubalus bubalis, CLA, fish oil, milk, omega 6 and 3 INTRODUCTION The CLA is the term used to describe one or more positional and geometric isomers of linoleic acid (cis-9, cis-12, octadecadienoic acid) that contains double conjugated bonds. Such bonds are usually found in positions 9 and 11, or 10 and 12. They can be cis or trans configuration. The CLA biologically active form would be represented by the isomer cis-9, trans-11 CLA (also called rumenic acid), representing 80 to 90% of total CLA in milk fat (Belury, 2002). It has been shown that CLA inhibits the carcinogenesis onset in skin tumors, in tumors of the stomach and in mammary gland tumors, all of them induced experimentally with different carcinogens in mice (Ha et al., 1990, Ip et al., 1994). Hypocholesterolemic properties have been demonstrated in pilot studies with hamsters fed with a hypercholesterolemic diet and supplemented with CLA. This experiment showed a significant reduction in total cholesterol, LDL-cholesterol and triglycerides (Nicolosi et al., 1993). Hypocholesterolemic properties were also 351 Buffalo Bulletin 2013 Vol.32 (Special Issue 1): 351-354 Accepted April 10, 2013; Online November 11, 2013.