Influence of organic and conventional pasture management on the beta-carotene, retinol and alpha-tocopherol status of steers

In recent years there has been an increasing trend in the UK to develop low input (organic) systems for the production of agricultural commodities such as meat, milk and milk products, grains, vegetables and fruits. This trend is driven by a combination of consumer demand, environmental concerns and premium payments for such produce. There is also a consumer presumption that produce obtained ‘organically’ and animals reared under organic regimes are more natural and thus ‘better’ than products produced using more intensive systems. In the case of cattle there is evidence (Younie and Halliday, unpublished data) that animals grazed on ‘organic’ pasture perform less well and tend to be less healthy than their counterparts fed conventionally. To maintain ‘organic’ status essential micronutrients such as vitamins and minerals cannot be supplied from synthetic mineral and vitamin premixes. It is well documented that the fat soluble vitamins and their precursors are important factors in maintaining the nutritional and immune status of animals as well as the storage properties of meat. (Bendich, 1989, 1991, Ranken, 1989). The purpose of the work was to assess the fat soluble vitamin status of extensive and intensive pastures and the effect of grazing these on the blood levels in steers.