COPPER FOR PASTURES

Press, Volume LXXXVII, Issue 26396, 14 April 1951, Page 5

COPPER FOR PASTURES

Reply To Officials

MR W. B. TROTTER’S COMMENTS The opinions oh top-dressing pastures with copper, given at a meeting in Christchurch. recently by 'Dr. L J. Cunningham, Dr. J. F. Filmer. and Mr A. C. S- Wright, broke little new ground, and Mr W. B. Trotter, who has been a leading advocate for the use of copper sulphate in certain conditions, comments on these opinions in a letter printed below.

It was most unfortunatethat so few farmers turned up to the meeting, possibly because few of. them knew about it, , but it is doubly unfortunate that Mr Trotter was not there to take part in the discussion. Farmers all over the country have taken a deep interest in the experiences of Mr Trotter, and a large number have spent, and are spending, money on many other trace elements for top-dressing pasture as well as on bluestone. Most farmers at present can spare some money for experimental work, but there has been a strong demand from individual farmers ana from farmers’ organisations for carefully controlled scientific research into the results Mr Trotter has reported from time to time. It is most sincerely to be hoped that Dr. Cunningham and Dr. Filmer, Mr Wright, and other Government scientists, will be at the Lincoln Sheepfarmers’ meetirfg to.be held at Lincoln College on May 30, 31, and June 1, when Mr Trotter will present a paptr on his experiences. The event would give an ideal opportunity for full discussion of a subject which is verv much in the minds of farmers. Mr’Trotter writes:— “Farmers in Canterbury have been warned on many occasions by departmental officers of the dangers arising from the use of bluestone as a topdressing. After over two years we have the official opinion as stated by Mr Wright and Dr. Cunningham. It is significant that Mr Wright says ‘Application may be dangerous.’ The -use of the word ‘may’ proves that Mr . Wright does not know whether it is dangerous or not, and this is certainly a modification of the strict warnings which have been issued to farmers from time to time. ’ Copper Hills “Mr Wright should take a trip to the copper hills in Australia. He can easily prove or disprove his theory there. He will find bluestone lying on the surfape of the ground, and also that the best wool and sheep in Australia are grown there. There is a degree of copper poisoning adjacent to the copper mills through dust from the mills. “Dr. Cunningham told me in conversation that as a scientist he. is required to be exact, yet I do not think he said anything which cannot be completely answered. He states first that anyone who used copper on soil which was not known to be deficient was wasting money. Well on this property no copper deficiency is known. I sowed one ton of bluestone costing £6O and had an increase in production of 70 per cent., representing a return of approximately £4OOO. I do not think it was a waste of money. “As regards the questionnaire issued to 229 farmers in the Fairlie district my thanks are due to the farmers who did not answer. I told local farmers at that time that the statistics asked for by Mr Armstrong would be used as an argument to atiemot to discredit my experiments. We all know that, through the big increase in the use of lime and super in ■ Fairlie district, stock has increased, wool has increased, and lambs have increased. My reason for advising farmers not to answer the questionnaire was that it Was not likely that the answers would reveal that the increase had been obtained at the expense of stock health, as proved bv the huge increase irt the use of stock remedies (something like 2000 per cent.). This information was vital to obtain a true picture of the position. "Dr Cunningham has sttid that I claimed that the use of copper has reduced nauasites. This is not correct. I have said, and I repeat it, that the use of copper has made my stock immune from worm attack. The action which I took was not against worm: but rather to strengthen the red cells in the bloodstream of the animals. Having accomplished this I find that worm is powerless to attack. I removed the cause and so did not need to bother with cures. “I have claimed that extra copper made possible increased rate of growth in lambs. Dr. Cunningham has gone to some of the best country in New Zealand (there are not very many fembs which kill at 601 b or better in New Zealand) to see if this is so. These lambs are so good that most farmers in the country would be most interested to know just what they were fed on—what pasture analysis revealed, what pasture species were present and so on. • Light Lambs ‘He ?® e , ms t 0 J hink that the fact that Jo tambs in my draft of January 12, 1950, had a greater copper count than the heavier lambs disproves my claun. The answer is quite simple. Of the lambs yarded, 87 , per cent ere , n A ra tJ e< t to the works. Of the 1200 September lambs, average a S e I 1 days, 1154 were marked, of which not less than 154 were twin lambs. Of the October lambs yarded, 292, average age 94 days, 184 were marked. The smaller lambs are the twin lambs, so Dr. Cunningham then selected six large lambs and six twin lambs at the same age. The copper count in a liver represents the amount of copper which is in storage. There is no copper in milk, so nature provides each lamb with a quantity copper J n J he , liver ‘ wh ich mqst suffice until the lamb starts grazing. Lonper is an integral part of bone and is also a catalyst whereby the lamb utilises the iron in the liver to form the red cells in the blood. These lambs then started grazing about the same time and the intake of copper should be equal. However, the single lambs made much more rapid growth than the twins and in building a bigger frame naturally used more copper. The limiting factor m the growth of the twin lambs is quite obviously the milk supply which would only be about half that obtained by the single. The single lamb which had made such rapid growth could hardly be expected to have as high a copper count as the small twin. "I have been asked to give a paper on this subject at the Farmers’ Conference to be held at Lincoln College at the end of May, so I will reserve further comments till then. May I conclude by sincerely thanking North Canterbury Federated Farmers for • support and for their persistence m being instrumental in at long last obtaining this official statement.”