Phytase and vitamin E in the feed of growing pigs: 2. Influence on carcass characteristics, meat and fat quality

Abstract

Lipid oxidation is one of the the major causes of deterioration in the quality of meat and meat products. In addition to its nutrition value, meat has other aesthetic attributes, including its attractive sensory properties and therefore, lipid oxidation in meat and adipose tissue is undesirable. It can be reduced by the addition of antioxidants to feeds.Vitamin E functions is a lipid‐soluble antioxidant in the cell membranes. One of the most potent forms is α‐tocopherol. It is capable of quenching free radicals and thus protects susceptible cellular structures, especially polyunsaturated fatty acids in cell membranes, against oxidation and subsequent breakdown to potentially harmful, chemically reactive products (Packer and Fuchs 1993). Vitamin E supplementation above the physiological demand enhances the vitamin E concentration in tissue samples, milk and eggs (Leonhardt et al. 1997). Furthermore a positive effect on the various quality criteria of products of animal origin such as shelf life, colour, taste, etc. can be realized to meet the expectations of consumers (Asghar et al. 1991b; King et al. 1995).In another article it was demonstrated that supplementing diets with phytase had a positive effect on the digestibility of minerals such as phosphorus, calcium, iron and zinc (Gebert et al. 1999). The results indicated that dietary fat digestibility was significantly decreased due to the phytase supplementation. In addition, the α‐tocopherol digestibility had a tendency to be impaired in the phytase‐ or vitamin E (200 p.p.m. α‐tocopheryl acetate)‐supplemented diets, indicating that the released minerals of the phytic acid complex could act as bi‐ and trivalent cations and might damage those nutrients which are susceptible to oxidation (mainly polyunsaturated fatty acids) or could use up the antioxidative vitamins in the digesta.Therefore it was of interest to investigate the effect of phytase and vitamin E (α‐tocopheryl acetate) supplementation in pig diets on the carcass characteristics as well as meat and fat quality, mainly with respect to stability against oxidative destruction.