The composition and nutritive value of hay grown in the east of Scotland and the influence of late applications of nitrogenous fertilizers

Abstract

In a previous communication from this department (Smith & Comrie, 1948) analyses of Lothians' seedshay for the years 1945-7 were reported. The results indicated an average protein content much lower than the figures commonly quoted for seeds-hay and gave cause for concern over the tendency to overestimate its food value. During the years 1948-51 further information was obtained for both seeds-hay and meadow hay grown in the east of Scotland and the effects of late top-dressings of nitrogenous fertilizers were also examined. Lewis (1939Lewis ( , 1941 had shown that applications of ammonium sulphate, sodium nitrate or 'Nitrochalk', applied even as late as 7 days before mowing, could produce significant increases in the protein content of hay, and it seemed likely that with hay of so low a protein content as that usually found in the Lothians, the response to late treatment with nitrogenous fertilizers would be most marked. No information was then available concerning the influence of such fertilizer treatment on the digestibility of hay, so adequate samples of both treated and untreated hays were collected for feeding tests with sheep. Shortly after the commencement of these experiments Ferguson (1948) reported the results of digestibility trials carried out in 1945 and 1946 with hays untreated and treated with late applications of ammonium sulphate or 'Nitrochalk'; the protein in the treated hays was found to be more digestible than that in the control hays, but the digestibilities of the other nutrient fractions did not appear to be affected by the treatments. The two untreated hays examined by Ferguson contained 9-67 and 10-36% protein in the dry matter and so were quite unlike the Lothians' seeds-hays, most of which Smith & Comrie (1948) found to contain less than 7% protein. Further work with low protein hays typical of those found in the Lothians was therefore clearly necessary. EXPERIMENTALIn 1948 experiments were carried out at six different centres, field strips being treated and replicate samples of treated hay and of adjacent untreated hay being taken for analysis. The fertilizers were broadcast at times varying from 9 to 24 days before • Present address: The University, Glasgow, W. 2.mowing. When the hay was ready for loading, samples of treated and iintreated material were taken for the digestibility tests with sheep. A similar procedure was followed at six centres in 1949, but in addition a 4 x 4 Latin square layout was adopted at one centre near to Edinburgh (Balerno) in order to obtain information on crop yields and on the percentage recovery of the nitrogen applied. In 1950 and 1951 only Latin square or random block experiments were carried out, and as these involved a great deal of attention the work was confined to three centres close to Edinburgh.Digestibility trials were made with half-brod wethers, each sample of hay being fed to two sheep, and the faeces collected over a period of 12 days. Although the experiments were not designed specifically to measure the utilization of the digested pr...

The effect of root feeding on the intake and production of dairy cows

“…and D.C.P. values were calculated from the chemical analyses together with the digestibility coefficients for Scottish hays (Moon, 1954), silage (McDonald & Purves, 1956), concentrates and roots (Woodman, 1954) and Kellner's constants. The total nitrogen content of the fodder-beet and, to a lesser extent, the silage, included large amounts of non-protein nitrogen, that of the fodder-beet accounting for 71 % of the total nitrogen and that of the silage for 29%.…”

The effect on milk composition of feeding spring grass to cows

“…Weekly analyses of all three feeds varied so little that a final composite sample, representative of each feed for the whole experiment, was made and analysed in the detail shown in Table. 1. The nutritive value of the hay was estimated from Moon's (12) recent studies of Scottish hays and those of the beet pulp and concentrate were calculated from Woodman's (13) tables, basing the value for the concentrate on the D.C.P. and S.E.…”

The effect of level of concentrate feeding before and after calving on the production of dairy cows

“…The hay was made from somewhat more mature herbage cut at the early flowering stage and consisted largely of Italian ryegrass with a little perennial ryegrass. The starch equivalent and digestible crudeprotein content of the concentrate mixture were calculated from Evans (1960), and the hay and silage values from Moon (1954) and McDonald & Purves (1956) respectively.…”