Weight responses to copper therapy in cattle.

Abstract

'Weight Responses to Copper Therapy in Cattle ' By L. E. DONALDSON* Copper deficiency in cattle has been reported in Queensland by Harvey (1952)) Sutherland (1952)) Chester, Marriott, and Harvey (1957)) Alexander and Harvey (1957). However, significant increases in growth rate have not been recorded following copper therapy in cattle affected with copper deficiency. Copper deficiency was suspected in beef cattle on a property south of Townsville, because of poor growth rate of animals in the age group nine months to two years. In June, 1958, and November, 1958, liver samples were collected by biopsy for copper analysis from five animals. Results were:November, 1958 June, 1958 13 p.p.m. 13 p.p.m. Average . . . 2-42 p.p.m. 7-23 p.p.m. Range These results' were' regarded as indicative of an inadequate copper status and an investigation to evaluate responses to copper therapy was initiated. Ninety cattle, nine to thirteen months of age, were divided at random into four groups with comparable ra.tios of males and females. Two, groups remained as untreated controls. Animals of the third group received 400 m,gm. copper glycinate (120 mgm. copper) by intramuscular injection into the semi-tendinosis muscle. Animals of the fourth group were treated with 20 c.cs. of 2.5% solution of copper sulphate (125 mgm. copper) by intramuscular injection. The animals received the above treatments on the 3rd November, 1958, the 5th January, 1959, and the 8th April, 1959, and all were weighed on the same dates. At the commencement of the trial dry *conditions prevailed, no rainfall having been recorded for approximately five months. Good rains fell on the 16th December and subsequent dates and from that period until the conclusion of the trial, green feed was abundant. The data on liveweight performance of the animals are presented in Table I and II:l TABLE I Weight Gains - 3/U/58 to 5/l/59 Group sex No. of Animals Mean Initial Weight (ibs.) Mean Gain (Ibs.1 Treatment Means t lbs. 1 Control I Control 2 Glycinate Sulphate Steers Heifers Steers Heifers Steers Heifers Steers Heifers IO 7 10 9 IO 9 8 9 361 362 385 375 376 377 397 392 15 23 18 29 44 49 30 36 18 2 5 24 2 5 46 k 5 35 & 5 * Department of Agriculture and Stoc k, Townsville, Queensland. * Adjusted for differences in initial weights, regression co-efficient -0.08 lb. per lb. *+ Sulphate > Control 1 at 5:/, level of probability. *** Glycinate > both controls at 1 y0 level of probability. 167 TABLE II Weight Gains - 3/11/58 to 8/4/59 Group Sex No. of Animals Mean Initial Weight (Ibs.1 Mean Gain (Ibs.1 Treatment Means 1 Ibs. 1 Control 1 Control 2 Glycinate Sulphate Steers Heifers Steers Heifers Steers Heifers Steers Heifers 8 4 8 6 10 8 7 7 355 347 396 374 376 380 387 397 174 159 168 172 197 198 180 168 166 2 9 171 t 9 198 * 8 176 k 9 There are no significant differences among treatments. * Adjusted for differences in initial weights, regression co-efficient -0.10 lb. per lb. The results indicate that a response to copper therapy was obtained during the period when dry conditions prevailed. At this time grazing was concentrated on drying swamps in which para grass (Brachiaria mutica) and salt water couch (Sporobolus virginicus) were the main pasture constituents. After rains in December cattle grazed on sandy ridges where rat-tail grass (Sporobolus poiretii), couch grass (Cynodon dactylon), crowsfoot (Eleusine indica), and Townsville lucerne (Stylosanthes sundaica) were the major species. At the commencement of the trial cattle had been grazing for some months on the drying swamps. It is assumed that bodily reserves of copper had been depleted by this stage and that the weight response resulted from restoration of adequate copper levels by therapy. Failure to obtain a response during the period when adequate green keed was available suggests that animals could select a diet with adequate levels of available copper from the greater range of pasture species on the sandy ridges. Following this pilot trial a more intensive investigation is now in progress to evaluate effects of therapy with copper and/or cobalt over a complete twelve month period. ACKNOWLEDGEMENTS The author acknowledges the assistance of Dr. J. M. Harvey for ,chemical analysis and of Mr. A. W. Beattie for statistical analysis of the data. REFERENCES Harvey, J. M. (1952)-Aust. Vet. J. 28 : 209-15. Sutherland, D. N. (1952)-Aust. Vet. J. 28 : 204-8. Chester, R. D., Marriott, S. M., and Harvey, J. M. (1957)-Qd. J. Agric. Sci. 14: I-22. Alexander, G. I., and Harvey, J. M. (1957)-Qd. 3. Agric. Sci. 14: 23-8. DISCUSSION Dr. E. A. Campbell (Qld.) asked the level of copper in the pasture and soil. Answer .-The paragrass had a low copper status, 5.5 p.p.m. 168 R. J. Moir (W.A.) asked if the sulphate situation had been studied in the pastures. Answer.-No. Dr. J. Harvey (Qld.) had checked copper, sulphate, and molybdenum levels. The) sulphate level was greater than 0.2 gms. % and ranged up to 0.31 or 0.4 gms % in Queensland. It would appear that the data reported are the result of a Mo.-induced copper deficiency. G, Osborne (Qld.) asked which injection route was considered preferable. Answer--Subcutaneous was preferred. Intramuscular injections with copper sulphate may cause carcase damage though copper glycinate may be better. Intravenous injections were too slow for commercial conditions. Professor N. T. M. Yeat ` (N.E.) asked for information on the es clinical symptom S l of copper deficiency in th .e field. Answer.-There is insufficient information on this subject. There is a bleaching and harshness of the coat in areas known to be deficient in copper, but this is no,t necessarily critical or diagnostic. Scouring certainly occurs when the condition is advanced and the animal is close to death. In other cases it may not occur in animals with only 5 p.p.m. copper in the liver. There does not appear to be an effect on reproduction. H. J. Lee (S.A.) agreed that copper deficiency was in need of redefinition. Diagnosis in Queensland had been based on copper levels in liver and blood but these conventional criteria have not been accompanied by signs, of deficiency, nor have animals responded to copper therapy. This seems to be the first case of a response to copper therapy in Queensland. The situation in southern Australia with sheep is similar. 169