TAINT IN BUTTER.

Manawatu Standard, Volume LVIII, Issue 177, 27 June 1938, Page 4

TAINT IN BUTTER.

FEED FLAVOUR EFFECTS. ADDRESS BY PROFESSOR RIDDET .! The problem of feed flavours in butter was referred to by Professor W. Riddet, director of the Da.iry Research Institute at Massey College, in the course of an address, to the Rational Dairy Association’s conference at New Plymouth. j '“Butter companies,” Professor Riddet said, “experience considerable difficulty in avoiding feed flavours. For years, both factories and farmers complained that, although , they were . taking great care in the production of their cream and in the manufacture of their butter, they could not avoid certain objectionable flavours at par- ' ficular periods of the year, especially during the spring months. What was i Specially aggravating to the farmer was the fact that, as he improved his production by approved methods of 'farm improvement, the intensity of taint in cream produced bv his cows ( tended to increase. It was thought by some—now shown to be an erroneous Opinion —that the off flavour was due to contamination of the cream supply with undesirable types of bacteria; view was held' beca'use the affected

cream was produced on farms where no common taint-producing weeds were v predominating. Tlifmks to the co-opera-’'tion in the early, /stages of the research work of certain factories in the ' Waikato, where the .taint' was most

widely experienced,, it was shown .through the collaboration of the Dairy '■Research Institute and the Plant Research Bureau' that the characteristic feed taint could not be attributed to insanitary methods of milk production. It was concluded from observations made on pastures by Mr Bruce Levy, Director of the Grasslands Division of the Plant Research Bureau, and from correlations between the clover content of these pastures and the intensity of ‘feediness’ in the cream, that the characteristic taint was primarily due to leguminous pasture plants. i “This survey,” the professor continued, “indicated that several clover species were probably responsible, in particular suckling' plover, subterranean clover arid white clover. ■ . Contrary to commonly expressed opinions, tlje'topdressing of pasture did not necessarily make the condition worse. Top dressing certainly encouraged the growth, of clovers early in the season, and made the taint appear earlier in the year in cream from topdressed than from untreated pastures pbnt the untreated pastures produced just as much taint —indeed in most cases a stronger taint rather later in the seaeon, as the poorer quality leguminous plants, headed by suckling clover, started to grow. It was shown that, rather than increase clover taint, the topdres6ing of the land in the course of time decreased it, because it first increased the growh of clovers which in turn encouraged the growth of grasses and as more stock was carried on the land, resulting in greater consolidation of the soil, the sole of grass improved and the clover percentage of the pasture tended slowly to decrease. Thus as the state of fertility of the land was raised by tondressing, the t&int was kept in check. V CONCLUSIONS DRAWN.

“It was observed in these investigations that cream produced at the evening milking was more highly Tainted than that produced at the morning milking. Mr Levy concluded from observations of the grazing habits of cows at pasture that this was due to the animals feeding immediately before the evening milking, but not feeding during the dark hours of the night- prior to the morning milking. Art extensive and intensive series of experiments was in the meanwhile instituted at Massey College under the joint auspices of the Dairy Research Institute and the Plant Research Bureau. One lot of animals was grazed on specially seeded pastures consisting of .ryegrass, and ryegrass apd. white clover, respectively, whilst another lot were kept continuously in a cow-shed

where they were fed definite grasses and clovers and mixtures, of these in definite proportions. These details first, of all confirmed the belief that various clover species were definitely responsible for the characteristic taint in cream and they confirmed tlie other observation that. ingestion of these within four hours of milking/intensified the taint of the cream at that milking- It was. shown that the clover species tainted cream in the following descending order: Suckling clover, subterranean clover, white clover, and red clover. Even small amounts of suckling clover caused the taint when by chance present in the grazing pastures. Later work .showed that tne taint varied with the season of the year, being most intense in the , late spring months and least troublesome in the fate summer. It is not yet clear frdm the investigations whether this is due to the clover growing more rapidly in the .spring months than 1 later in the year, or to the clover being consumed in an earlier stage of growth. The bulk of evidence suggests that it is the rate of growth rather than the stage of growth that is the important matter.

SOLUTIONS TO PROBLEM. “Working on the observation that the ingestion of clover within ' four hours of milking causes taint, cows in full milk were removed from tainting pastures and kept on comparatively bare pastures prior to milking. This practice was effective in keeping taint in check and did not result in any drop in production. This, then, is one solution of the problem. -It has the disadvantage, however, that it entails some work in moving: Cows from one pasture to another miring the . day, and it is .also open to tiro objection that in the period- of peak pasture production frequently there are no hare- paddocks on a farm. To . #jyercome this difficulty Mr Marryat, of the Fields Division, of the Department of Agriculture, working at Ruakura, experimented with different methods ■of grazing pastures in order to control the percentage of clover jn pastures in the. spring months. Incidentally, it should be explained that prior to this the Fields Division' had with the wholehearted support of its director, Mr Tcnnent, given considerable help in the work. Mr Marryat demongtated that the clovers in pastures could be kept in check and the grasses encouraged by preventing the pastures from being grazed bare in the autumn, winter and early spring. He showed that, by judicious spelling of pastures and the rotation of grazing, it is possible to maintain the production of grass on each field and indeed increase it, and at the same time keep feed taint ill check. This principle naturally needs special adaptation to each farm, but it is surely within the range of most farmers to apply general principle in farming practice.” Professor Riddet said that complementary to the work on methods oi avoiding the incidence of feed taint, a considerable number of manufacturing experiments had been carried out with a view to determining whether clover taints can be removed from cream by manufacturing processes. It had been shown quite clearly that the deodptbsation of cream subsequent to pasteurisation removed the greater part of these feed taints. Butter made from deodorised cream was comparatively froe 'from feed flavour and, provided that the treatment of tlie cicam was properly carried out, the butter was quite good commercially. “The deodorisation process,” he continued, jn the case of our experiments, was carried out in a New Zealand-made machine. The treatment in this machine has been shown, to lia.ve no injurious effects upon the flavour of untainted cream butter, but, in our experimental work, it slightly increased fat losses and reduced slightly the time taken lip in working the butter. It must bo recognised that, although the deodorisation of cream is a very effective means of reducing the intensity of ‘feediness’ in butter, nc efforts should

bo spared to improve pastures whereby taint will he<at least minimised if it cannot be eradicated. The taint referred to in clover has been shown to be identical with that in lucerne. It is, however, different from that experienced when certain weed plants, such as land cress and pennyroyal, are ingested, and it does not necessarily follow that the processing methods which prove successful in the case of clover taint will be equally successful in the case of other types of taint. Nevertheless, it is believed that the work carried out by the various organisations mentioned above has been effective in providing a way of overcoming clover taint. The work is now being carried to the wider issue of makng a close examination of file influence of different pasture species and soil types upon the composition and flavour of milk and cream,” lie concluded.