How to Rear Calves on Milk Substitutes

New Zealand Journal of Agriculture, Volume 99, Issue 2, 15 August 1959, Page 141

How to Rear Calves on Milk Substitutes

Ruakura Farmers’ Conference Told

MILK by-products offer the best hope for very early replacement of whole milk in calf rearing. Buttermilk powder, which has an appreciable amount of fat and is usually cheaper than skim milk powder, is being increasingly used by farmers. The importance of fitting changes of diet to the calf's stage of development was stressed by Professor I. L. Campbell, Head of the Dairy Husbandry Department, Massey Agricultural College, in a paper to the Ruakura Farmers' Conference in June, in which he discussed trials with the feeding of buttermilk powders to calves. An adaptation of his address follows.

IN some respects feeding dairy cows is simpler than feeding animals of many other species. With the help of micro-organisms in its rumen, the cow manufactures some of the vitamins it needs, notably B complex vitamins like B x , B, and 812.B 12 . The cow is able to utilise cellulose quite well, a thing we humans and the pig cannot do at all well. It can convert some simple nitrogen compounds to useful protein something we humans cannot do either —and it can utilise a wide variety of carbohydrates such as the various sugars and starches that are found in plant material. Tire newly born calf can do none of these things. Its rumen is not developed to handle bulky fibrous feeds. It lacks the teeming population of micro-organisms which attack cellulose, convert non-protein nitrogen to useful protein, and produce vitamins. It has not yet developed the capacity to . produce . all the enzymes necessary to break down the wide variety of carbohydrates found in the feed of more mature animals.

The answer to the newly born calf’s problem is milk, a food which is almost completely digestible, contains proteins of high biological value, and is normally adequate in vitamins and minerals for the first few weeks of the calf’s life. It provides as a source of energy a carbohydrate, lactose, which the calf is already equipped to utilise. Calf's Rapid Early Development The calf’s development proceeds rapidly over the first few weeks of its life. From its surroundings—pasture, soil, hay, bedding—it picks up bacteria and other micro-organisms which establish themselves in the rumen. During its first or second week it samples grass, and perhaps hay, and by the > third week it is grazing appreciably. The rumen expands and the microorganisms flourish. The calf develops the capacity -to digest carbohydrates other than lactose, in particular starch, moderately well by about one month of age. This development is hastened

by the early introduction of non-milk feeds. For example, the rumen at birth weighs only about a third of the total weight of the four stomachs. At the end of the second month, in calves given access to pasture, .it has increased to half the total weight of the stomachs. Its absorbing surfaces are developed by the presence of the products of the fermentation of fibrous foodstuffs. ■ However, we must not rush this process of food substitution. If we try to introduce too much of these new foods too early, too much undigested material may pass to the small and large intestines where undesirable fermentation by bacteria causes upsets, scouring, and ill-thrift or worse. This is what almost invariably happens if we try to replace milk by a starchy meal too early and too quickly, say at two to three weeks. When this happens the only thing to do is to start from the beginning again. Stop feeding for 24 hours, but give warm water or lime water; give a laxative to help move out the offending material, and some appropriate antibiotic or sulpha drug to restrict the bacterial activity in the gut. Then start feeding diluted whole milk, working back to normal strength and quantities over a few days. If, then, we wish to reduce the quantity of whole milk used in calf rearing, we must use replacement foods which are appropriate to the stage of development of the calf at the time of substitution. Use of Pasture We in New Zealand have exploited the. use of pasture as a milk substitute

perhaps to a greater extent than farmers of any other dairying country. Under our conditions pasture can be entirely substituted for milk for well grown calves between six and 10 weeks of age. By this time the calf’s intake from grazing is adequate and it is digesting the pasture as well as a mature animal, provided the pasture is leafy and clean. Rotational grazing seems the best means of ensuring this. Incidentally, new devices which have come on the market in the last year or so which provide a means by which calves can suck their milk from a large can have been found by some farmers to facilitate the adoption of rotational grazing at an early stage. If we try to substitute an all-pasture diet for milk too early, say at two, three, or four weeks of age, we get an ill-thrifty, pot-bellied calf, if it lives at all. The digestive system has been stretched to accommodate the bulky feed, but not enough of it can be digested and utilised to provide the nutrients necessary for good growth. Starchy Grains and Meals From birth some time elapses before a calf can make good use of starchy foodstuffs. But by about the third or fourth week this capacity is developed in most calves sufficiently to make it worth while adding this type of foodstuff to the ration as a milk replacer should nothing better be available. Meals made up largely of cereal grains and their by-products, with oil . seed residues such as linseed cake and small quantities of meat or fish meals, have been widely used with good hay in many countries to save milk in calf feeding. The inclusion of an appreciable amount of dried milk solids improves mixtures of this type. The system usually, advocated is to introduce the calf to very small amounts of these feeds in the third or fourth week and gradually to substitute them for whole milk, but to feed some whole milk for eight to 10 weeks. Such a system can work quite well under good management. Growth rates are often rather slow. Care has to be taken not to rush the substitution and cut off the milk too soon or results can be disastrous. Calves vary from one individual to another in the speed with which they take to new feeds and in development of the ability to digest and utilise them; So it is particularly necessary in this type of feeding to be prepared to treat calves as individuals and to keep some on more whole milk for longer if they are not thriving. The Use of Milk By-products The butterfat .in milk supplies energy to the calf and also acts as a carrier of the fat-soluble vitamins A and D. Apart from this a small amount of fat seems to be necessary in the

diet of a very young, calf for reasons not well understood yet. However, as the calf ages the need for butterfat declines; and as most butter factory suppliers on home separation know very well good healthy calves can be reared on skim milk plus good pasture after adequate whole milk feeding for three to four weeks and some whole milk to five to six weeks of age. Under this system of feeding the calf normally receives adequate vitamin A as carotene from pasture. Being out in the sunlight, the calves do not need extra vitamin D in the feed. If we try to substitute separated milk for whole milk too early in the life of the calf, for instance, in the first week, trouble occurs. The calf suffers from the lack of a small amount of fat, may run short of vitamin A, and the food may be too dilute for the very young calf to get its nutrients within the limits of its appetite for the bulky feed. As a by-product from buttermaking we are now producing in New Zealand quite large quantities of buttermilk powder. A typical sample of this product gave the following, analysis:

Per cent Moisture . . .. .. 4 Fat ... 10 Protein .. .. .. 35 Lactose .. .. .. 42 Ash . . .. .... 8

Essentially, the composition is similar to that of skim milk powder,

except that the buttermilk powder has an appreciable amount of fat, an amount which may vary from sample to sample. The buttermilk powder can normally be bought more cheaply than skim milk powder. Buttermilk powder has been shown to be a very useful milk replacer for calf feeding, and an increasing number of farmers are finding a place for it. While the feeding value varies a little with the fat content, useful approximations are: 1 lb of buttermilk powder provides the same available energy as 1 gallon of skim milk. 2 lb of buttermilk powder provides the same available energy as 1 gallon of whole milk. Thus if 1 lb of buttermilk powder is mixed with 1 gallon of warm water the product can be used in the same way as liquid skim milk. This suggests the following feeding procedure which has proved reliable: Weeks Foodstuffs 0-3/4 Whole milk Pasture 3/4-5/6 Whole milk, buttermilk-powder-water mix Pasture 5/6-8/10 Buttermilk powder Pasture 8/10 on Pasture Within limits of convenience, the dilution is not important, provided we can think in terms of using 1 lb of the buttermilk powder where we might have used 1 gallon of skim milk. Under good management and where ample supplies of pasture are available, once a day feeding from one month onward seems to give satisfac-

tory results. At Massey Agricultural College last spring' satisfactory growth rates were obtained with the use of this feeding schedule, but feeding, once a day from three days of age onward. While this was successful in this trial it is probably a more hazardous procedure. Delaying once-a-day feeding to one month would be safer. Early Replacement of Milk How far can we go in replacing whole milk with substitutes? The more we cut the whole milk the greater the nutritional hazard will be; the better adapted the milk replacer must be to the requirements of the pre-ruminant calf; the better the rest of the management must be to give the calf the best chance of taking any nutritional hurdles. Points such as providing shelter, reducing the danger of infection, making sure each calf gets its rightful share of the food, and watching for the onset of scours and applying early remedial measures become even more than normally important. Experience at Massey College has shown that breed differences exist. It has been easier to cut the whole milk to a minimum with Friesians than with Jerseys. Milk by-products offer the best hope for very early replacement of whole milk, and of these, buttermilk powder has been used with moderate success in trials over the last few years. Friesian calves have been ~ successfully reared when changed to buttermilk powder after colostrum. It is essential to feed the colostrum because of the protection it gives a calf against infection. As the milk from newly

calved cows should not be sold for four days post calving, all milk of this type should be used for calf feeding anyway. Newly born calves need it. For older calves it can replace normal whole milk quite safely. It should be used diluted with 50 per cent of its volume of water, 1 gallon of the mixture replacing 1 gallon of normal milk. After colostrum feeding for four days, the calves may be changed from whole milk to a buttermilk powder mixture of 2 lb of buttermilk powder per gallon of warm water. (This gives a liquid which has approximately the same energy value as whole milk.) The change-over is better made over several days. In the second week the calf can be entirely on buttermilk powder plus pasture, the mixture of buttermilk powder and water being fed in the same quantities as you would use with whole milk, except that with buttermilk powder it is more important not to overfeed. If good pasture can be made available, the calf can be weaned early when it reaches the appropriate size (for example, girth 334 in. for Jerseys), or the buttermilk powder feeding can be carried on for an extended period at reduced quantities after the eight to 10 weeks stage. In our experience Friesians can be successfully reared on this system with milk reduced to something like 12 gallons, including the colostrum. In trials at the Dairy Research Institute Jersey calves were reared by changing to buttermilk powder straight after the colostrum feeding in the first week. . At eight weeks the calves were healthy, but their growth rate had

been slower than normal, especially over the first three weeks. It would seem safer with Jerseys, ' when endeavouring to reduce calf milk to a minimum by using buttermilk powder not to change over completely to powder until after the second week. There was a suggestion in some of the work at Massey College and the Dairy Research Institute that calves changed to buttermilk powder entirely during their first week might' be vitamin A deficient. The calves would be eating very little pasture at this stage. Until this point is cleared up by further work, it would seem good insurance to add a vitamin A concentrate to the diet in such cases for the first month. I would like to emphasise again that the earlier whole milk is replaced by buttermilk powder the greater the hazard. Normally it is quite safe at five to six weeks. How much earlier to make the change is a decision which depends mainly on: 1. The value of the whole milk replaced. • 2. The value of the calves. 3. The skill of the feeder and the time and care that can be given to calf rearing. 4. The suitability of the conditions for calf rearing. One final point on the use of buttermilk powder: We have found it a very, valuable food to give to calves which have had any very bad check, say through disease or nutrition, fed either as a gruel or as a dry feed mixed with a small amount of bran or crushed grain to help palatability.