STOCK FEEDING.

Waikato Times, Volume 109, Issue 18347, 5 June 1931, Page 3

STOCK FEEDING.

IMPORTANT RESEARCH. aamm MINERALS INCREASE GROWTH. MILK AND FLEECE YIELDS. (From a Special Correspondent). LONDON, May 1. Remarkable increases in the yield of milk and wool, and in the growth rate of lambs, obtained both by small amounts of minerals to stock and by using mineral fertilisers, are recorded in a report just published by the Economic Advisory Council on “The Mineral Content of Natural Pastures.’’

The results of these experlbents, which were carried out during the last two years in Kenya, apply equally to wide areas of natural pastures in South Africa, Australia, New Zealand, Rhodesia and other parts of the Empire. . . Minerals, it is now known, are found in pastures as well as in mines. Scientists have shown that a deficiency of minerals in the herbage causes serious diseases and lowers vitality in stock. These experiments prove that the addition of ininera.s will increase the yield and improve the health of animals grazmg on pastures where ttic deficiency is not so marked as to cause disease.

Power of Common Salt. An Empire-wide scheme for tackling the mineral deficiencies problems was launched in 1926, centred at the Rowett Research Institute m Aberdeen, and the Empire Marketing Board met the costs by grants totalling £25,000. In 1928 the Kenya Government handed over their experimental stock farm at Naivasln for the Investigation described In the report. It was carried out co-ope-ratively by Rowett Institute scientists working In Kenya and by -Kenya agricultural and veterinary officers. Valuable work within the scope of the scheme 'has been done In Australia, New Zealand and Rhodesia. The pioneer research, which made possible this Empirewide investigation, was largely carried out at Onderstepoort in South Africa. The whole enquiry is, therefore, a remarkable example of Empire learn w'ork. The Kenya tests show that common salt alone, used as a fertiliser, increased the yield of the most deficient pastures by 25 per cent. Nitrogen and phosphates actually raised the vield of herbage by 400 per cent. Grazing animals showed, a definite preference for the fertilised plots. “Eat More Minerals.” Direct feeding of minerals to the animals has equally remarkable results. A mineral supplement increased the milk yield of dairy cows by 30 per cent., speeded up the rate of growth of iambs by 10 per cent., and added 10 per cent., on to tho Reece weight of sheep. Four centres in Kenya—Nalvasha, .Moio, Nakuru and the At'hi Plains — were selected for experiments. In general, all pastures were deficient in sodium and chlorine (the constituents of common salt) compared with good British pastures, and all except Naivasha were also low in phosphorus. At Moio the deficiency in phosphorus was as great as in parts of South Africa, where it causes disease in cattle. The feeding of minerals to dairy cows had such a good effect on the cow’s health that an animal receiving minerals could he told at a glance even at a distance, by its sleek and glossy coat and its condition from the "control” cows with their staring coats and thin, anaemic look. / Stronger Calves. The calves of the mineral-fed group were considerably larger and stronger at birth. The mixture used consisted of two-thirds bone meal, onemird salt, and a trace of potassium iuu.de. Each cow'was given about ioz per gallon of milk. aheep received the same mixture, ilio quantity of the wool was inj. cased witnout any apparent loss of i... uiiy. Tnis is an important point, ,'e.eause in Australia it has been round ...,ut where pastures are improved by using phosphatic manures, the weight or the lleeoe is increased but, at the same time, the quality deteriorates Feeding experiments carried out in Hie rich pastures of Navaisha gave no significant increase In the growth of lambs or the yield of milk. It is only on poor pastures that mineral supplements give marked results. Yield of Pastures Doubled. Dr. J. B. Orr, Director of the Rowett Institute, believes that there aro vast areas throughout Africa, Australia and other parts of the Empire where the yield of tho animals grazing over them could be very greatly increased by the large-scale application of these Kenya results: It nas even been stated that a combination of fertilisers, mineral supplements, ami improved pedigree grasses could double the carrying capacity of the Empire’s grasslands. Each part of the Empire, of course, has a different aspect of the question to grapple with. 'Dr. Orr’s team has shown that mineral deficiencies arc, broadly speaking, of two kinds. Where hot, dry weather brings droughts, as in parts of Kenya, South Africa and Australia, phosphorus is the missing element, whereas in areas of high rainfall such as Scotland and tho Falkland Islands the shortage is generally of calcium. In Kenya soils, the report says, “phosphorus appears to be the limiting factor for the growth of good pasture.” The application of phosphorus not only increases the hulk of the pastures, hut tends to keep them green and succulent in times of drought. Australian and New Zoaland Work.

Recent work at the Waite Institute In Australia has shown that the transpiration of plants (he., the evaporation of water from the !ca\ r s) is "■rcater on phosphorus-poor sc .s than on tlioso rich in tins clement. This suggests that phosphatic fertilisers would actually tend to conserve moisture in times of drought. The story of “Nakuruilis’,, a wasting disease of cattle grazing In the Nakuru district of Kenya, is told In lids report. Iron salts, which make up for the lack of iron In the Nakuru district grazing, have been found to prevent the disease altogether. A very similar disease, "bush-sickness,” which occurs in New Zealand was discovered in .1918 by New Zealand workers to be due to lack of iion and is being largely eliminated in the same way.