Vitamin E and Linolenic Acid Content of Hay as Related to Different Drying Conditions

Abstract

During the harvesting season of 1964 the contents of vitamin E and linolenic acid were determined in 3 different grass species, viz. timothy grass, red clover, and tufted hair grass. The influence on the 2 components in timothy grass of stage of development, harvesting methods, and climatic factors was studied. In timothy grass having reached the flowering stage the tocopherol content was 108 [gamma]/g and the linolenic acid content of its fat 49.1% as compared to 52 [gamma] /g and 21.8%, respectively, in a late stage of development. The losses of vitamin E in timothy grass hay, dried on hay poles, were remarkable even under favorable weather conditions, whereas the fatty acid composition of the fat remained largely unchanged. In cocked hay a decrease in vitamin E content could be demonstrated as early as within 10 days, in spite of favorable drying conditions, whereas the linolenic acid content did not decrease until later, following a change towards rainy weather. In hay, dried as a swath, there occurred a rapid decrease in both vitamin E and linolenic acid content even under favorable weather conditions. The rate of vitamin E destruction was greatest (nearly 60% within 4 days) in hay, dried as a swath and artificially moistened. Studies were made also on changes in iodine value and degree of oxidation of the hay as related to different methods for haymaking.