EN
The aim of the study was to analyse whether and to what degree the use of RRR-d-α-tocopherol in diets containing an oil rich in linoleic or linolenic acid (soyabean or linseed oil, respectively) would make it possible to halve the dosage of this antioxidant with respect to that of α-tocopherol without negatively affecting the metabolic status and rearing performance of slaughter turkey hens. A study was performed on 480 one-week-old turkey hens reared until the 16th week of life. The hens in groups I and II received soyabean oil, in groups III and IV linseed oil in feed mixture. The birds in groups I and III received dl-α-tocopherol acetate, whereas those in groups II and IV RRR-d-α-tocopherol. The body weight gain and feed intake were monitored. Selected haematological and biochemical parameters were estimated in blood. The linseed oil was found to improve production effects and carcass traits in turkey hens. It may also contribute to stimulation of erythropoiesis. It should be emphasized, however, that it may overburden the organism, as indicated by the increased activity of liver enzymes. It is possible to use the natural form of tocopherol in diets rich in linoleic and linolenic acid (soyabean/linseed oil) without detrimental effect on metabolic status and rearing performance in turkey hens. Nonetheless, the commonly used tocopherol acetate, despite the higher dosage, is cheaper and has similar effects. Thus, from an economic point of view, the use of linseed oil with the synthetic form of vitamin E can be recommended.