Replacements for Town Supply Dairy Herds

New Zealand Journal of Agriculture, Volume 84, Issue 4, 15 April 1952, Page 305

Replacements for Town Supply Dairy Herds

By

I. G. WATT,

Veterinarian, Department of Agriculture, Auckland

THE dairyman on town supply is always faced with the problem of maintaining his "quota" the quantity of milk he has contracted to supply throughout the year. Replacements to town supply herds as required are essential and in this article some practical methods of keeping an adequate reserve of cattle for such herds are discussed.

NOW that compulsory tuberculin testing has been introduced for these herds it is more important than ever that a supply of healthy cows is available to replace milkers culled irom herds on town supply. With this system of farming there is on the average a larger wastage factor than in creamery herds, and it has long been a matter of great concern among town supply farmers that the cows they have to buy may be someone elses culls. Many mature dairy cows sold in local sales are there because they have been failures in another herd. Temporary sterility, mastitis, black pox, bad temper, and low production are common reasons for a farmer’s culling from his own herd, so why should it not be the same for his neighbour? Thus some cows are passed from herd to herd with a loss everywhere the animals are introduced. ■nr , j , Much of this loss is due to the farmers themselves. If they would send the cull cows to the works instead of to the local sales, much of the loss due to unsound cows circulatmg among the herds would be avoided, This would be hard on farmers who like to fatten a few boners, but it would prevent unsound animals returning to dairy herds. „ . , x „ Buying mature cows from an unknown source leads eventually to trouble in the herd. Many of the cows may be cases of latent tuberculosis, which could develop to infect the whole herd; others may be carriers of

trichomoniasis, the cause of “temporary sterility”, or may introduce contagious abortion or the less serious vaginitis. They may not be noticed until too late; a mature cow without a full history may be as dangerous a source of infection as a scrub bull picked up at a local sale. Empty cows are particularly dangerous. The owner of a small herd may be forced to buy cows at the drop, as the area of his farm will not allow him to carry non-producing animals. On some of these farms no dry stock at all are kept. The way to overcome this difficulty would be to buy from dispersal sales, but autumn calvers present a problem. However, those herds are quite few, relatively, and the majority of town suppliers could safeguard the health of their herds by avoiding the mature cows and replacing as necessary either by buying heifers or by rearing their own calves. Buying heifers close to calving naturally has its risks, as their capabilities are unknown; in any case, the yield will be lower than that of cows for a season or two, but heifers are generally much freer from disease than adult cattle, since they have not been exposed to infection so long, and this is an important factor in maintaining the health of the herd. The obtaining of suitable heifers will be discussed later. There are, then, two possibilities for the progressive town supply farmer—he can either buy heifers or rear calves. Calves can be derived from the herd itself or bought very young from suit-

able breeders. The latter method would appeal before the herd was built up to an efficient level of production, and the calves introduced would, in time, be a most valuable addition to the herd. • The advantages of rearing calves are obvious and are being appreciated more and more by town supply dairymen.

The “backing” of both sire and dam can be knownnot only the amount of butterfat, but, more important to this branch of the industry, the amount of milk of reasonable test given over a long lactation by a healthy cow which breeds regularly. The temperament of the dam is known and a quiet, amiable, easily milked cow is the ideal town supply animal. In tuberculin-tested herds and all town supply herds will be tested eventuallythere would V be no possible chance of introducing tuberculosis. Calves could be vaccinated against contagious abortion also and the risk of “slipping” practically eliminated. The use of good bulls would be warranted, and the indiscriminate buying of scrub bulls at sales eliminated. These bulls are often the means of spreading genital tract infections from herd to herd. Further, the progeny of the better type of cow in the herd would not be wasted in the bobby calf pen. There must be thousands of calves of excellent possibilities on the dams’ side sent to the works each year. Rearing of heifer calves from the best cows in each herd would save this waste and at the same time the whole herd would be graded up so that in a very few years there would emerge a herd of which any owner would be proud. Interest taken in stock bred and reared by himself gives the farmer a sense of achievement. Sharemilking contracts which forbid rearing of young stock are to be strongly condemned. Methods of Rearing If the rearing of calves is discussed on economic grounds and the immediate cash outlay and returns balanced, it is extremely difficult to say whether rearing calves pays or does not pay.

Costs of rearing have been estimated from £0 per head on a Jersey stud farm to £2 10s. on a grade farm where proven sires have been used for years and where the herd average is in the vicinity of 4501 b. of butterfat, with a target of 3001 b. before Christmas. There are, however, many factors, already mentioned, which must be taken into consideration. It would obviously be difficult to assess the loss which might be caused if a “storm” of “slips” due to contagious abortion occurred in a herd or if a bought-in animal infected the remainder with trichomoniasis. A farmer’s rearing of his own replacements must be assessed as an insurance policy against introduced disease as well as a method of obtaining milkers for the herd. There is a choice of several methods of rearing calves for town supply farms; for example, they may be bucket fed at home, reared on nurse cows, or sent to a creamery supplier to rear until weaning. Each method has its adherents and the advantages or otherwise will be discussed. The methods of feeding calves on the farm are set out in Department of Agricultore Bulletin No. 228, so that m this discussion only special points will be raised. p Bucket Feeding On town supply farms bucket feeding means that after the initial 3 weeks or so on whole milk the breeder has the alternative of conturning with whole milk or of changing on to substitutes such as skimmed milk powder, buttermilk powder, meal, etc. Whole milk is expensive, espedaily when paid for at town milk winter prices, so that it is essential that the most economical method is used. The new-born calf to develop normally must receive colostrum or first milk, which is laxative and also contains many protective substances, Subsequently the calf should be fed

on whole milk, for calves under 2 weeks old must receive whole milk, whatever they are to receive after that age. For some time there will be a certain amount of milk available which cannot be used for human consumption, as it is illegal to use milk or town supply until the cow has been calved for 4 days, and as the cows calve over a period, no saleable milk need be used in some cases, The quantity fed should be carefully measured—a quart for the second day, preferably divided over three feeds, and then gradually increased so that after a week the calf will be receiving between 2 and 3 quarts daily. Of course, larger calves will require more food than small Jersey calves, As cows wiR be calving over a period, there will be colostrum which s no t needed for the new-born calves, r was formerly considered very risky | o give colostrum to calves over a wee o i d because of the laxative effect, which might cause scouring, Some recent work overseas, however, has shown that colostrum can be used y itself, if broken down with waterone third of water to two thirds of colostrum feeding older calves, This means that any colostrum in excess of what is required for the new calves could be mixed with the calf feeding milk and thus not be wasted. Further, as this substance is rich in vitamin A, the usual calf milk would be fortified by adding quantities of this valuable protective vitamin. In order to conserve milk the Department of Agriculture Animal Research Station, Ruakura, has investigated methods of early weaning and f be general recommendation has been made that 50 to 60 gallons of whole milk are adequate if fed over 8 weeks, the calves then being weaned on to good pasture and rotationally grazed, Undersized calves should, for safety, be given a further 2 weeks’ milk feeding. This is still expensive using milk at winter prices, and in an endeavour

to ascertain how things were working out in practice the writer visited ordinary commercial town supply herds where breeding replacements was accepted as the usual practice. All these farmers were convinced that rearing calves was economic and in all cases whole milk alone was used up to 2 weeks, this being mainly milk unsuitable for human consumption. After this period a change was made during a further 2 weeks on to a substitute such as skimmed milk powder, dried buttermilk powder, mother liquor (a by-product of the milk sugar industry), straight meal, etc. Dried buttermilk was most popular and reared excellent calves. The quantity generally used was about lib. mixed with a gallon of water, the mixture being stirred vigorously. First-quality buttermilk powder is considered essential. The cost of this method of feeding was estimated at about 2s. per calf per day, which is not excessive. Animals reared on dried buttermilk powder on one farm produced up to 3581 b. of fat as 2-year-olds for a total cost of whole milk and buttermilk of £2 10s. per calf. Some farmers prefer calf meal. On one farm visited excellent calves were reared during the expensive milk period by feeding whole milk for the first 2 weeks and then breaking the calves over the next fortnight on to a diet of meal and water. The meal used was a proprietary product and the total cost of meal for six calves was just under £5. This was much less than the cost of raising them on milk at 2s. per gallon. Meal feeding was continued up to 8 weeks, but the time varied, depending on the quality of the pasture available and on the size of the calves, which when seen were thriving and quite up to others of the same age in size and vigour. Bucket feeding has its dangers. More calves are killed by overfeeding than under-feeding. Overfeeding from the bucket is the most likely cause of serious scouring among calves. Not only is food being wasted when calves are scouring, but simple scours can cause deaths rapidly if neglected. Bulletin No. 228 deals with scouring fairly fully, but some additional information may be helpful, especially on some farms where scouring appears to occur each year despite efforts of the farmer to maintain cleanliness. Feeding calves from the bucket may be dangerous because the calf may bolt too large a quantity of milkoften cold. In natural feeding, when the calf takes small quantities of milk as required and well diluted with saliva, the curd formed in the stomach is soft; under conditions on most dairy farms the curd may be formed into a hard mass which is digested by the animal only with great difficulty. Particularly is this so where hightesting milk is used. This opens the way for bacteria, and “white scours” or “blood scours” may occur very easily. Much of the blood scours is due to coccidia and unfortunately a calf paddock may become infected with coccidia and cause trouble each year. Prevention is better than cure, and milk should be diluted with water and fed warm. This will help to maintain normal conditions, more especially if the calves are not restricted to one paddock, but are moved around from

an early age. If scouring occurs, sulpha drugs given under veterinary direction may be very useful; for blood scours a veterinarian will prescribe suitable treatment. A simple device has been patented by a farmer at Karaka, Auckland, by which calves are fed by suction through a rubber teat. It is rather astonishing that more breeders do not make use of this idea, as a much more natural feeding action is obtained and scouring is therefore less likely to occur.

Nurse Cows

Some very successful town suppliers have used nurse cows to rear calves, up to eight calves having been reared on one cow during one season. Naturally this is hard on the cow, but the method offers the easiest way to rear calves when fresh skimmed milk is not available.

Here again caution must be exercised. Nurse cows should be tuberculin tested before being used for calf feeding. As the cows are run with the calves, away from the main herd, risk of reinfection with tuberculosis during the feeding period is remote, but each season these cows should be tested as a precaution.

Congenital tuberculosis in calves is comparatively rare in New Zealand. This has been investigated by postmortem examination during meat inspection on many thousands of bobby calves in meatworks. However, tuberculosis may be rapidly acquired if tuberculous animals are used as nurse cows, particularly if the udders are infected. Heifers reared on nurse cows should be trained after weaning to go through the bails, as they are liable to be very difficult animals to break in later if they are not handled early. Some farmers do not wish to go to the trouble of rearing their own calves. It is possible in many cases for them to make arrangements with a creamery supplier to take a certain number of calves to rear until weaning. Here again there is the chance of the calves becoming infected with tuberculosis through drinking infected milk. This can be a very real risk in certain areas. As the suggestion that the owner should have his whole herd tuberculin tested before rearing the calves might not be very welcome, with the high price of cows at present, the alternative would be to have the calves tuberculin tested before they are brought home after weaning. A general idea of the infective possibilities of the milk could also be gained from the killing sheets of pigs if any are slaughtered on the owner’s account, and, in addition, a herd with a history of cows condemned clinically for tuberculosis should be avoided. One farmer who had his calves reared as described stated that the cost was £5 10s. per head, the calves being returned healthy and fit by the new year.

. Whatever method of feeding milk is adopted, the most critical time for young animals is after weaning. Rotational grazing in the best of pasture is essential. Calves can be used to top paddocks effectively and even quite young animals will graze steadily over the tops of well-grown pasture without taking much from the cows which follow them.

More especially in the warmer areas, worm parasites must be avoided, particularly Haemcmchus contortus, the large stomach worm, and regular phenothiazine drenches given, except under the most ideal conditions, when drenching may not be warranted. Rearing Yearlings An additional problem confronts the average town supply farmer who stocks up to the limit and does not have grass to spare for young stock. At the same time he wishes to rear his own replacements and add interest to farming. This is where interested bodies should take a hand. It should be possible without undue difficulty to arrange a scheme whereby suitable graziers could take weaned calves for a reasonable fee, rear them on the more extensive properties until they are well in calf, and then return them to the owner. A variation of this scheme would be for certain dairy farmers ,to ' contract to supply “marked” heifers to a rearer who could buy them for a satisfactory price and subsequently sell them to town supply farmers. Some dairy farmers already supply an annual quota of heifers to town suppliers, and this system is capable of wide extension. Hit-or-miss methods are of little use. Agreements would have to be made and a guarantee given to supply and take a regular number of heifers whichever system is to be used. In spring, when grazing is plentiful, many people are willing to graze a few heifers to keep down the feed, but such a scheme would be of little use if the heifers had to be taken back in summer or autumn when feed becomes short.

This article envisages a wider development whereby calves would be taken and carried for a definite period so that heifers calving when required could be supplied. For example, in the Auckland town supply area the majority of such heifers would be required to calve in early autumn. Therefore, calves kept would be autumn calves where possible. Since these heifers could be tested for tuberculosis and inoculated against blackleg and contagious abortion, their value as replacements would be great, especially as they would be coming in during autumn. On a national basis, there is a chailenge to the whole dairy industry. Quite apart from replacements to town milk herds, farmers should realise that New Zealand can no longer afford the annual loss of calves from aboveaverage cows to the bobby calf pools. Nor can she afford the continued use of scrub bulls and cull cows in any branch of dairy farming. Breed societies, particularly those concerned with milk-producing breeds, could profitably interest themselves in this field, as the potential market both tor heifers and for herd sires is very great indeed, with no possibility of saturation of the market. The demand for marked calves will increase as breeding becomes general throughout town supply herds and the present wasteful buying and selling methods are abandoned. Marked calves are at least a sign that the breeder is herd testing and thus give some indication that the calves are from dams well up to average production. . On a fully organised basis artificial insemination in town supply . a remg would enable proven sires in the milkproducmg breeds to be used to better advantage.