Effect of Stage of Maturity and Storage on Qual- Ity, Quantity, and Nutritive Value of South Dakota

I N much of the Northern Great Plains area native grasses are of paramount importance to livestock production and hays from these grasses constitute the chief roughage harvested to maintain livestock when grazing will not support them. Tonnage of prairie hay harvested in South Dakota in 1948 and 1949, a total of 4,492,000 tons, was twice as great as the harvested tonnage of all tame hays combined. A common practice in harvesting prairie hay has been to arrange haying operations to interfere least with other summer work. In following such practice, many stockmen have done the bulk of their haying from late September until winter weather interfered. Many ranchers believe that any loss in quality by late harvesting is offset by a greater yield per acre. A need was seen to test representative native hays to determine the effect of stage of maturity on feeding value and digestibility of such hays and to study the nutritive value of hay stacked under range conditions and stored over a period of years. Since droughts often prevent the production of hay for harvest, the successful stockman must harvest enough hay during productive years to carry over the dry years. Work done at other stations indicates that hay harvested late in the season has lost much of the nutritive value that could have been obtained if the hay had been harvested at an earlier date. Hopper and Nesbitt (1930) reported that both stage of maturity and grass species influenced chemical composition and nutritive value of hays and grasses. Declines in chemical composition and/or nutritive value as stage of maturity in grasses advanced were noted by Burkitt (1940), Sotola (1941), Patton and Gieseker (1942), Patton (1943), McCall, Clark, and Patton (1943), McMillen et al. (1943), Crampton and Jackson (1944), and Baker et al. (1947).