CURATIVE TREATMENT OF BUSH SICKNESS BY IRON SALTS.

New Zealand Journal of Agriculture, Volume XVIII, Issue 4, 21 April 1919, Page 193

CURATIVE TREATMENT OF BUSH SICKNESS BY IRON SALTS.

By

C. J. REAKES,

D.V.Sc., M.R.C.V.S., Director-General of Agriculture;

and B. C. ASTON, F.1.C., Chemist to the Department.

ONE branch of experimental work at the Mamaku Farm has been the administration to stock of medicinal compounds—supplied in the form of brick-licks, which the animals voluntarily con-

sume, and drenches, given by hand or in the drinking-water —all of which contain elements known or suspected to be deficient in the soil of the area under investigation. It is, of course, not intended to suggest that drenching of stock with any remedy, however cheap or efficient, would be a practical remedy for bush sickness. The aim of drenching experiments is merely to obtain quick confirmation, on a few typical animals, of ideas formed from laboratory experience dealing with a subject of which so little is known that it may be regarded as situated on the borderland of knowledge.

Previous articles in this Journal and records in the Annual Report of the Department* have shown that while phosphate top-dressings as

a class are the best io produce a good palatable pasture, with a great general improvement in quality and quantity, this alone will not on the badly affected country keep the animals grazed on the pasture healthy, nor will it enable them to rear healthy offspring. But the dressing of pastures by phosphates does enable animals to be grazed and kept in health for a much longer period than if no such dressing was practised. 4 If, however, in addition to grazing on phosphatedressed pasture cattleyare drenched for a period with syrup of phosphate of iron when they show signs of going off in condition they ,may be brought round from time to time and thereby be kept healthy.

The question, then, arises whether this good effect of the syrup of phosphate of iron is due to the phosphate or to the iron. An extended experiment in which cattle were supplied .with superphosphate dissolved in drinking-water showed that the animals could not be kept healthy by this means longer than a year on untreated pasture, while in another experiment on treated pasture it was found that phosphate of iron gave a much better result than superphosphate. (Annual Report, 1916-17, p. 12.) ■ .

The direction which the curative experiments have therefore taken during the past year has been towards finding a substitute for syrup of phosphate of iron which will give the same good results but which does not contain phosphate. In this success has been achieved. The compound most experimented with has been the double citrate of iron and ammonium (the Ferri Ammon. Cit. of the pharmacist). It will be seen that this contains no phosphate, and yet, as the following experiments show, it is quicker and therefore more efficacious even than the syrup of phosphate of iron in bringing back a sick beast to health when grazed on good - conditioned pasture which has been dressed with phosphate.

One of the cows, “-.Mary,” originally bred on the farm, was going off in condition with bush sickness,' and was drenched with iron and ammonium citrate (Howards and Son's Ferri et Ammon. Citras, P.B.), 10 oz. of the crystallized salt in 1 gallon of water, 2 oz. of the solution being given night and morning. The animal showed signs of improvement within a month. The treatment was continued for three'months, and she was then put on to other pasture with , other cows which had merely access to iron-chloride brick-lick. In January last this cow was in excellent condition.

Another cow, “ Jane,” who was born on the farm, was a wreck with bush sickness on nth May, 1918, but when dosed similarly with Ferri Ammon. Cit. quickly recovered, and was in good condition in October.

A calf showing signs of bush sickness was drenched with Ferri Ammon. Cit. (1 oz. of the same solution night and morning) at beginning of June up till 9th September, and made a complete recovery.

A yearling was early in July placed on the Ferri Ammon. Cit. treatment, getting 2 oz. of the solution night and morning. Progress was slow at first, but after improving continuously from 20th July it was, early in December, taken off the citrate and put on to lactate of iron, when it commenced to decline.

In addition to the iron-ammonium citrate, tartrated iron was tried as an alternative.

“Torpedo,” a thin old cow, very low in condition and suffering from bush sickness, had had access to ferrous - sulphate salt brick for some time, which she took but did not improve on. She was accordingly put on to pasture similar to that of the other stock which had received citrate of iron and ammonium, but in this case the preparation used (io oz. to the gallon) was made up of tartrate of iron and potassium — tartaratum, P.B. (Howards’ and Tyrer’s)— 2 oz. of this solution being given night and morning for two months. The treatment pulled her round considerably, and in December she was so far advanced that' the treatment was discontinued. This is the only experiment to be recorded with tartrate of iron and potassium, but so far as it goes it indicates that this salt may be expected to prove

efficacious

The fact that one or two organic salts of iron have shown excellent results does not imply, however, that others would be equally efficacious. The lactate of 'iron (ferrous lactate) has been experimented with at some length. This iron salt has been found successful in treatment of anaemia or chlorosis in human patients by Parisian medical men, and supplies of lactic acid are available as a waste by-product in the tanning industry. In experiments with cattle the ferrous lactate, given either as a drench or as a lick in brick form made up with plaster-of-paris and common salt, has proved disappointing. Animals invariably scour badly under its administration, and although they take the lick containing the lactate greedily' up to the last there appears to be some reason why they are not able to assimilate satisfactorily this form of iron salt. Probably the lactic acid . is an unsuitable acid to administer to ruminants.

Inorganic iron preparations have been tried to a considerable extent both as licks, drenches, and medicated drinking-water. With licks the best results have been obtained from what is termed the “ B ” lick, which contains iron in the form of ferric chloride (see fig. i). The drawback to the lick is that a certain proportion of animals (about one-third) either take none at all or take it in such small amounts that no beneficial results are obtained. The other form of iron tried in brick form was ferrous sulphate, which, has not given such good results as the chloride brick. Although both of these compounds give satisfaction up to a certain stage, they must be considered as only supplemental to the other treatment, which is truly curative.

The composition of the “ B ” lick is as follows : Ferric chloride, 4jper cent. ; calcium hydrate, io per cent. ; sodium chloride, 20 per cent. ; calcium sulphate and water, 66 per cent.

Ferric chloride supplied as a medicated drinking-water has proved only a temporary alleviative. Ferric phosphate has given slightly better results, but there is considerable difficulty of getting stock to take the medicated water when there are pools of rain-water from which they prefer to drink.

The calves raised on the farm, mentioned in the 1916-17 Annual Report (p. 13) as doing so well on a treatment which included calcium

phosphate, iron sulphate, salt, and sugar, mixed in the skim-milk on which they were fed, all did well and throve up till May (see fig. 2), when they were put out on to grass and commenced to go off in condition. But the fact that nine out of twelve calves were reared to the age of nine months in a season when the mortality among calves in the district was exceptionally high and most settlers lost all their calves is no doubt attributable to the medicinal treatment.

SUMMARY.

Summarizing the results of the medicinal experiments to date, it would appear that of the inorganic preparations while either the administration of (a) phosphates or (&) iron compounds to cattle on phos-phate-dressed pasture may enable them to be kept healthy for a much longer period than otherwise would be possible, it is only by drenching with a syrup-of-iron phosphate that animals may be kept healthy indefinitely or cured of bush sickness. Of organic compounds it is certain that the double citrate of iron and ammonium is a quicker cure for bush sickness than the syrup-of-iron phosphate. It is probable that other organic salts of iron would be similarly successful.

Note.—The experiments at Mamaku dealt with in the foregoing notes were under the supervision of Mr. W. T. Collins, M.R.C.V.S., Veterinarian, Hamilton, the animals being in charge of Mr. R. A. Jackson, Farm Overseer. Mr. R. Alexander, Inspector of Stock, Hamilton, superintended the purchase of necessary animals from time to time. Each of these officers by his keen assistance has contributed in no small degree to the success of the experiments.

* For articles and reports on bush sickness see Journal for November, 1911, August, 1912, April, 1913, June, 1913, February, 1914, November, 1915, October, 1916; and the Annual Report for 1915-16 (pages 3 and 36), 1916-17 (pages 12 and 39), and 1917-18 (pages 7 and 35). Articles on “Pumice Soils” are to be found in the Journal for May, 1912, August, 1913, October, 1917, and November, 1918.