Studies of the composition of sainfoin

Abstract

1. Studies were made of the composition of Giant sainfoin cut successively at different stages of growth in two seasons under contrasting conditions of weather and soil.2. Cuts were taken at preflowering, early- and full-flowering stages of growth. Yields of both fresh material and dry matter substantiated the usual farming practice of taking two cuts at full flower in one season, and indicate that cutting sainfoin before it comes into bloom has a seriously depressing effect on productivity.3. Like most green fodder crops, sainfoin has a lower content of crude protein and nitrogen-free extractives, and a higher content of crude fibre as the plant increases in maturity. The mineral content is somewhat variable, and in particular the potassium content appears to reflect the status of this element in the soil.4. The ratio of leaf dry matter to total dry matter of the plant decreases with advancing maturity. The leaf composition is fairly constant, irrespective of stage of growth, number of cuts and season, the fibre content being remarkably constant in contrast with that of stem, where it increases with advancing maturity. Leaf is richer than stem in crude protein, ether extract and total mineral matter, particularly calcium. Thus changes which do occur in the composition of the plant are due to variations in stem composition and leaf-stem ratio.5. Analyses of sainfoin hay, made under both experimental and commercial conditions, are discussed, and the range of variation in the main constituents of thirty-five commercial samples is commented upon.6. The present investigations into the composition of sainfoin, both as green fodder and as hay, show figures that differ appreciably from those derived from earlier German work. Examination of the data available for the nutritive value of fresh and conserved sainfoin reveal anomalies which suggest that such data are not typical of the crop as grown in this country, and also suggest the need for more modern data.