Dehorning of Cattle

New Zealand Journal of Agriculture, Volume 84, Issue 4, 15 April 1952, Page 297

Dehorning of Cattle

By

D. W. CALDWELL,

Veterinarian, Department of Agriculture, Hamilton

LjORNS add nothing to the value of cattle for the purposes for which they are kept ■ • on New Zealand farms; on the other hand, they cause damage and indirectly are responsible for loss of production in milking herds. This article discusses various methods of dehorning and also suggests that long-term breeding programmes could give polled breeds for all purposes.’

CATTLE are one of the oldest species of domesticated animals used by mankind. Records of domesticated cattle for work and production of meat, hides, and milk go back to the earliest written history. It seems strange that any breed of cattle for whatever purpose they are kept, except as draught animals where horns can be useful, should have retained their —weapons of defence and offence and quite useless to domesticated animals; worse than useless, because they can be the-cause of great economic loss and danger to other cattle and to their attendants. It is even more amazing that where dehorning is practised, the male is often deliberately left horned and a potential danger to his owner or any other person coming in contact with him. Bulls are notoriously unreliable and tragedies due to goring are common in the cattle-raising areas of the world. Retained to Enhance Appearance Many owners of commercial herds dehorn their cattle as a routine practice, but stud breeders usually favour the retention of horns and one seldom sees a dehorned animal in the show ring. Breeders claim that an excellent specimen of a breed type has its appearance enhanced by correctly shaped horns, but it is reasonable to suppose that this fashion could be altered and that in a short time the polled or dehorned animal would be equally attractive and a horned beast would become something of a freak. Cattle are reared and kept to produce meat or milk and neither of these points has anything to do with horns. Ayrshire cattle, to take a good example, are renowned for their ability to produce milk, but it is because of the capacity and excellence of their udders combined with a high efficiency in converting pasture to milk, certainly not because of their formidable horns.

Every year a heavy loss is caused by horn injuries inflicted among cattle and there is a less spectacular but equally heavy loss of production due to bullying and disturbances in herds at pasture, at water troughs, and in yards waiting to be milked. Disturbance is often more serious when cattle are break grazed with an electric fence and a herd eats forward concentrated on a

long, narrow strip of grass. Bullying cows without horns will cause trouble, but there is no risk of their causing serious injury to other cattle, dehorned herd is quieter in the ya T d ’ is quickly bailed up and milkeo, and is handled With less risk of personal injury. Polled or dehorned cattle travel well, do not injure each other in trucks, are easier to handle, and arrive at saleyards or slaughter- . houses in better condition without wounds or bruises inflicted by horns, The standards of the stud breeder and the show ring should be on a business footing. If dehorned or polled cattle are economically a sounder proposition than horned cattle, a change should be just as desirable in.the show rm g as in the milking shed or drafting P en - . It has been said that dehorning ls painful ,^° n r .adult animals, but any pain. inflicted is fleeting and less distressing than the often prolonged and repeated pain caused by ripping and gouging from horns. c(| in T erament Change in Temperament ’ , - , „ J he removal of horns from a group °£ animals brings about marked changes m temperament. What may b ? called the - social order is com--lalterad Pugnacious cattle which ruled others by their ability to wound or frighten find when they no longer nave horns that a more peaceI" attitude is necessary and often they become markedly docile. A dehorned herd like a flock of sheep, will g^az ® steadily with hardly a head llf ted from the ground and . when reP le l e will lie down and ruminate contentedly. Such behaviour assists considerably to improve the production of a herd. A vicious bull will often be,come amazingly amenable after he has been dehorned. It would surely be better to breed cattle without horns than to submit

them to mutilation after birth. Though New Zealand farmers are noted for their progressive outlook, many herds still contain horned cattle, which are potentially dangerous and are responsible for loss in income. There are two ways of producing a polled strain of a horned breed. The first is by breeding from the polled mutations which appear from time to time in animals of a pure horned breed, an example of this being the modern strain of polled Herefords bred in the U.S.A., where new registrations of purebred polled Herefords are now over 30,000 per year. The other method is by crossing horned cattle with a polled breed, when all the progeny of this first cross will be polled and the general appearance and commercial qualities will be intermediate between the two breeds. If polled progeny are mated back to the horned breed for several generations 50 per cent, at the fifth cross will be born polled and will be nearly 100 per cent, true in conformation and production to the original horned breed. When polled animals have the desirable characteristics they can then be mated together, and then if breeding is based on the Mendelian laws of inheritance and only animals which breed true to the polled characteristics are selected, a purebred polled strain with all the desirable qualities of the original horned breed can be built up. Dehorning An understanding of the composition of the parts involved is necessary to appreciate what dehorning entails. The horn itself is a hollow core of keratin, a material similar to hair, covering and growing from a core of bone which is rough on the surface, is covered with horn-producing cells, and has a plentiful blood supply running through it. The horn core is hollow and communicates with the frontal sinuses of the skull (see diagram at left). The nervous supply to the horn emerges from the skull through a hole above the eye, runs along just below a ridge of bone under the skin, and divides at the base of the horn. The arterial blood supply comes up from the region of the throat. To do dehorning satisfactorily and to prevent the regrowth of deformed and unsightly horn stubs it is necessary to remove all horn-producing tissue, which means in practice that a ring of hair-bearing skin about jin. thick has

to ,be . removed with the horn itself when » dehorning is carried out. In animals at birth and until they are 3 months old the horn is only a bud with a . solid core and does not communicate with the frontal sinuses. The ideal time to remove the horn-producing tissue is when animals are from 7 to 10/ days old; little pain is inflicted, there is no infection of sinuses and pus formation, and no ugly high poll is left as in dehorned adults. Young Animals The methods used for animals a few days old are: — • ■ 1. The cautery or hot iron, which may be electrically heated or heated in a fire. 2. Chemicals, usually caustics. 3. Mechanical methods such as a gouge or. curved knife. The cautery or debudding iron is ideal. It consists of ah electrically heated copper instrument of the shape shown in the. diagram on this page or a fire-heated iron of the same shape. The iron should be heated to a cherry red and applied over the horn bud and moved back and forth until a coppercoloured ring of tissue shows right round the horn bud. This destroys the circulation to the developing horn and the bud eventually drops off. There is no wound, no infection, a poll of pleasing appearance, and, most essential, no horn growth. Chemicals: Caustic soda or caustic potash are chemicals commonly used for destroying horn buds. A ring of petroleum jelly is smeared on the hair round the horn bud and the caustic stick applied to the bud until it bleeds slightly. Calves must be protected from rain for some days, as rain will carry the caustic down the cheeks or into the eyes, causing irritation and sometimes blindness. Another chemical used is a flexible paint made of antimony trichloride (28 per cent.), salicylic acid (7 per cent.), and flexible collodion (65 per cent.). The hair round the bud is clipped, the horn bud cleaned with methylated spirit, and the paint brushed on and allowed to harden. If the paint is used on an animal more than a week old, the tip of the horn bud should be cut off before the paint is applied.

Mechanical methods are seldom employed in New Zealand. They involve the use of a curved knife or a double, cup-shaped pincer arrangement for removing the horn bud complete with a ring of hair. This method is painful and often unsatisfactory and leaves a wound which may become infected. Adult Cattle Dehorning in adult cattle can be carried out with a guillotine designed for the purpose, a saw, a flexible wire with handles, or rubber rings. Of the various methods the properly designed guillotine, which is massive and strong and has a ratchet or multiple joint designed to aid the operator, is best if a large number of adult cattle require to be dehorned simultaneously. The horn can be removed cleanly and quickly, but great care

must be taken to prevent injury to the bones of the skull adjoining the base of the horn through applying weight and leverage on the heavy guillotine and through the struggling of the animal. Use of a local anaesthetic greatly lessens the pain of the operation and therefore reduces risk of injury through resistance of the animal. Sawing is done with a butcher’s saw with coarse teeth, such as is used for cutting bone, but is slower and the animal may become unruly if not properly anaesthetised. An electric rotary saw has been designed for dehorning and has been used to some extent. It is quicker than the hand saw, but slower than the guillotine. The flexible wire method was used principally to avoid bleeding, but requires practice and is too slow. Rubber rings are unsatisfactory for dehorning, though some farmers claim excellent removals. They may slip upward and press on the horn itself with . ''little or no effect.

Their action is slow

and must cause

some continued

pain to the animal. Such prolonged discomfort will lower-. milk yield for some time following the application of the rings. Variation in the diameter of the horns to be removed results in variable pressures from the rings and results are therefore uncertain. Whatever method is used it is essential that the horn and a ring of hair be removed quickly and cleanly, that bleeding be prevented as much as possible, and that adequate restraint

is available. A local or general anaesthetic prevents pain and reduces greatly risk of interference with production. Blood is often sprayed over a wide area when horns are removed, but bleeding is seldom dangerous and usually stops spontaneously. It can be prevented best by applying a tourniquet of strong string such as binder twine round the poll and both horns with two connecting strings to tighten up from front to rear over the poll between the horns. The tourniquet must be cut and removed after a few hours. Tourniquets are commonly used for dairy cattle, but not for run stock, which are more difficult to yard and bail up in a race or dehorning pen. With run cattle applications of a thin layer of cottonwool carrying a dusting of sulphanilamide powder should be made to the area from which horns are removed. This will clot the bleeding vessels in a short time and only in exceptional circumstances should further attention be necessary. Alternatively an animal could be restrained in a bail, a tourniquet applied as for dairy cattle, and the beast kept in the yards for an hour or two and released after removal of the cord.

Dehorning bails, either temporary or permanent, are best for restraining animals. 'They are designed for handling animals about the head while they are held firmly. Every farm carrying cattle should be equipped with a dehorning bail, which is useful for a number of operations other than dehorning. General or local anaesthesia is used commonly by veterinary surgeons when dehorning adult animals. In Great Britain it is illegal to dehorn cattle over 1 month old without administering an anaesthetic. Local anaesthesia by blocking the appropriate nerve with a suitable injection is very effective and is used frequently. Consideration should be given by all farmers, particularly cattle breeders, to the desirability of breeding polled cattle for all purposes. Meantime debudding of calves in the first 14 days of their life is the best method of dealing with horned cattle. However, where adults must be dehorned use of a guillotine, a local anaesthetic, and a tourniquet is the ideal method.