Effect of feeding soybean, linseed oil and different forms of tocopherol on the redox and immune profiles of turkey hens

Copyright resides with the authors in terms of the Creative Commons Attribution 2.5 South African Licence. See: http://creativecommons.org/licenses/by/2.5/za Condition of use: The user may copy, distribute, transmit and adapt the work, but must recognise the authors and the South African Journal of Animal Science. ______________________________________________________________________________________ Abstract The aim of the study was to analyse whether, and to what extent, the use of RRR-d-α-tocopherol in diets containing oil rich in linoleic or linolenic acid (soybean or linseed oil, respectively) would make it possible to halve the dosage of this antioxidant with respect to α-tocopherol without negatively affecting the redox and immune status of turkey hens. The experiment was carried out on 480 turkey hens, type BIG 6, which were divided into four groups. Birds in Group I (control) received soybean oil and synthetic dl-alphatocopherol acetate in their feed mixture. Group II received soybean oil and natural RRR-d-alpha-tocopherol. Birds in Group III received linseed oil and synthetic tocopherol, whereas those in Group IV had linseed oil and natural tocopherol. At the end of the ninth, eleventh and fifteenth weeks of life, blood was sampled from their brachial veins for analyses. Haematological, immunological and proand antioxidative parameters were measured. The application of linseed oil had a minor effect on the immune and antioxidative systems of the turkey hens. The study showed that the addition of the natural form of RRR-d-alpha-tocopherol with soybean and linseed oils stimulated the mechanisms of the antioxidative defence system more effectively than dlalpha-tocopherol acetate addition with these oils. It may be possible to use the natural form of tocopherol in diets rich in linoleic and linolenic acid (soybean/linseed oil) without detrimental effect on redox and immune status of turkey hens. However, the commonly used tocopherol acetate, despite the higher dosage, is cheaper. Thus, from an economic point of view, the use of linseed oil with the synthetic form of vitamin E is worth recommending. ______________________________________________________________________________________