FEED FLAVOURS

Wairarapa Times-Age, 13 April 1938, Page 3

FEED FLAVOURS

RESULTS OF INVESTIGATIONS. DETAILED ANALYSIS MADE OF GRASSES. 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, states Mr P. D. Sears, Assistant Agrostrologist. This trouble, which is ranked as a major problem in the Waikato, shows up in the spring and early summer months, and work has already shown it to be the result of the flush of growth of the clovers in the sward. Detailed observations on pastures are taken in the Waikato district and at the sub-station 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 barn 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 mixed state. Detailed chemical and botanical records are kept of all feed ingested, while the Dairy Research staff have 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 and mixtures under controlled and yet practical conditions. The trials have shown that white clover, subterranean clovei' and broad red clover all produce taint in cream, while perennial

exert any influence on flavour. On the much debated question of the relative flavour intensities of subterannean clover, the decision that subterranean clover causes most flavour in its early flush of growth, while white clover, remaining luscious, causes flavour later on .

The importance of the time elapsing between the consumption of tainting foodstuffs and milking is 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 morning 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 Mods at midday 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 was nearly eliminated when the animals were moved at this time from tainting to non-tainting or very bare pastures. PROGRAMME. The work of establishing, managing and analysing these stands of pure an'i 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 substracting from the various species comprising the feed. Previous botanical estimations give one a lead as to what management and fertilising programme to adopt 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 i approximately 800 samples have been dissected in the laboratory. These separations take from one to one and a-half hours, and call for dissecting a mown or plucked sample of mixed herbage into each species. The difficulty of the work is not apparent until one realises that the sample consists of only leaves or portions of such, and 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 and the 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 pedigrees 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.