Grassland Cum Animal Research

Manawatu Times, Volume 63, Issue 80, 5 April 1938, Page 10

Grassland Cum Animal Research

(By P. D. Sears, Assistant Agrostologist.) For the past three seasons the Grasslands Division has, in collaboration with the Dairy Research Institute and the Fields Division of the Department of Agriculture, been investigating the problem of feed flavours in cream. This trouble, which is ranked as a major problem in the Waikato, show r s up in the spring and early summer months, and work has already shown it to be the result of flush of growth of the clovers in the sward. Detailed observations on pastures are taken in the Waikato district and at the substation at the Ruakura Farm, while collaborative work with the Dairy Research Institute on a portion of the Dairy Farm of Massey College has been instituted at Palmerston North. On this farm, provision is made for grazing cows continuously on pastures of known botanical composition, while also there is a stall feeding baru for continual indoor husbandry of six animals. Pure stands of red clover, white clover, subterranean clover, suckling clover, perennial ryegrass, Italian ryegrass, cocksfoot, lucerne, vernal and Lotus, etc., have been established and fed in a pure or a mixed state. Detailed chemical and botanical records are kept of all feed ingested, while the Dairy Research staff I vc graded and carried out chemical and bacteriological tests on all creams from the cows. Out of this work has come much valuable information on the nutrition of the milking cow, and it has demonstrated the great value of testing out the various species anl mixtures under controlled and yet practical conditions. The trials have shown that white clover, subterranean clover and broad red clover all produce taint in cream, while perennial ryegrass and Italian ryegrass do not exert any influence on flavour. Ou the much debated question of the relative flavour intensities of subterranean clover and white clover, the -decision is that subterranean clover causes most flavour iu its early flush of growth, while white clover, remaining luscious, causes flavour late: on.

The importance of the time elapsing between consumption of tainting foodstuffs and milking well recognised. In this connection data relating to the quantity of fodder eaten at various times throughout the day by stall cows was collected. The consumption of feed between midnight and morninng milking time was very low and the cream produced in the morning was free from taint. On the other hand, relatively heavy consumption of tainting foods at mid-day intensified taint in the evening cream, while lower consumption at this period and again prior to milking, reduced it

When the grazing animals were moved from non-tainting (ryegrass) to tainting (ryegrass and clover) pasture within four hours of milking time, a pronounced taint was observed in their cream; conversely taint war: nearly eliminated when the animals were moved at this time from tainting to nontainting or very bare pastures. The work of establishing, managing and analysing these stands of pure and mixed swards to previously determined standards, is one which requires an application of all forms of management and manurial practices. Before any pasture is fed to the herd, either indoors under stall conditions, or outside by grazing, a detailed botanical analysis is made, and, if necessary, any adjustment is made by adding to or subtracting from the various species comprising the feed. Previous botanical estimations give one a lead as to what management and fertilising programme to adopt in order to attain the required composition and condition of the sward. This detailed analysis is carried out by the field staff and by trained girls working in the laboratory. Over the last twelve months (in addition to eye

estimations and point analyses in the field) approximately 80'"' samples have

been dissected in the laboratory. These separations take from one to one and a half hours and call for d ; ssecting a mown or plucked sample c * mired herbage into each npecies. The difficulty of the work is not apparent until one realises that the sample consists of only leaves or portions of such aud each must be accurately known and separated.

Detailed records of each cow’s consumption are kept and it is possible at any date to tell how much of any specific grass or clover or weed that has been actually consumed between any two hours during the day. By working with these figures andthe results from the Dairy Research Institute, valuable correlations have been made relating to both feed flavours and nutrition problems. In addition, trials are being conducted to find out the relative palatability of pedigree and other ryegrasses, and also on the growth rates of clover and grasses. By the use of such information it is hoped to follow up in much greater detail the fundamental question of the nutritional and economic value of pasture species when grown under pasture conditions.