STOCK DISEASE

New Zealand Herald, Volume LXXIV, Issue 22851, 5 October 1937, Page 12

STOCK DISEASE

LOSSES IN WAIKATO-i

RESEARCHES BY DEPARTMENT:

MINERAL UNBALANCE IN FEED

STATEMENT BY THE MINISTER

[>)Y TELEGRAPH PRESS ASSOCIATION] WELLINGTON. Monday

Reports of a mysterious disease causing heavy losses among dairy cows in the Waikato were brought to 'the notice of the Minister of Agriculture, the Hon. W. Lee Martin, to-day. The Minister stated that the trouble had been reported upon by the Department of Agriculture and he gave a resume o£ the position according to present veterinary knowledge. He added that wlierever farmprs had any cases of milk fever which did not show the ordinary typical symptoms they should get in touch with the local officers of the department at the earliest possible moment and instruction about how th<» cows should be handled would be immediately given.

"For a number of years past, particularly ill the Waikato, but not c-on-fined to that district, there lias been mortality among newly-calved cows in the months of July, August and September, due to three diseases, sometimes occurring separately and sometimes in combination," said the Minister. "These three diseases are milk fever, grass staggers, and paralysis. After calving all these diseases are present in various dairying countries and have been existent for many'years in New Zealand, but are tending to become widespread, and this year hare been particularly severe. Symptoms and Treatment "If the autumn .has been one of good growth, so that cows are in good condition prior to the winter, and then there is a s'.harp drop in the plane of nutrition and then a rapid upward trend, milk fever is often troublesome but where typical it can generally be successfully and easily treated. When, however, such cases are complicated', either with grass staggers or particularly with post-partum paralysis, miik fever treatment alone is not successful, and severe mortality may take place.

"Considerable attention has been given to these - diseases by veterinary officers, in association with laboratory officers from Wallaceville. Blood analyses have shown that in cows goinjdown just after calving there is very low blood calcium, while in those cows showing staggers and fits some days or weeks after calving the magnesium of the blood is considerably lowered. In the third condition, known technically as acetonaemia, in which cows tend to become paralysed, prior nutritional history results in the liver being loaded with fat. making it unable to function properly. Consequently partially broken down fat bodies circulate in the blood.

Combination of Conditions

"Tests were made on a number of cows this season by departmental veterinarians and it was found that the animals were showing a combination of acetonaemia and milk fever," continued Mr. Lee Martin. "The" treatment for milk fever frequently' brought a cow out of a coma, but she was unable to regain her feet. When molasses in quantity was given immediately, the cow regained consciousness. Beneficial results were sometimes experienced, but many fanners did not recognise the combination of conditions and, consequently, lost cows, a proportion of which might have been saved had the correct curative treatment been adopted. "A predisposing factor in the occurrence of milk fever is a mineral unbalance in feed conditions. Pasture may tend, particularly in winter and early springtime, to be unbalanced so far as lime and phosphorus are concerned, being high in the latter mineral and low in the former. This condition tqnds to bind the lime and magnesium, so that is is not readily available for the cow during the particular stress period when milk secretion commences. Balancing the Diet "Prevention obviously must be based on giving of more caicium and magnesium or els« lowering the phosphate in the food. The latter is not practicable. Therefore, increasing the feeding o? calcium and magnesium well alfead of calving is necessary. Such a course is regularly advised by the department, lime to be given in water troughs or in the form of licks, while dolomite, which contains salts of magnesium, or Epsom salts, are used in the lick, hay or ensilage to give the requisite quantity of magnesium. "Such methods have proved fairlysatisfactory in control when acetonaemic conditions are not also present. When, however, acetonaemia appears in combination with milk fever further treatment with sugar is required to help burn the fat, and molasses is prescribed in quantity. Acetonaemic conditions are due entirelv -to prior nutritional history and when these occur and milk fever develops as well, treatment is far more precarious where either condition occurs Further Research &■ "It is essential that further research work 011 the nutritional aspects of all three diseases should be carried out in order to define exactly the feeding procedure that is practicable as a means of prevention," concluded the Minister. "In this, adequate and balanced mineral provision and readily-available carbohydrates must form the framework. A careful survey of nutritional conditions occurring on farms where the troubles have been present is being carried out and an extensive campaign for the adoption of preventive measures by farmers is planned. "As is the case with most" nutritional diseases, certain cows are more prone to be.affected than others. None of the conditions is, of course, infectious. Real and effective control lies along the line of feeding management.