Importance Of Dairy Bulls

Northern Advocate, 18 March 1939, Page 4 (Supplement)

Importance Of Dairy Bulls

LITTLE hope of success can be entertained for a dairy business which does not rest upon the foundation of good blood. Almost ' any ki«d of cow will produce milk, but the number which produce it in paying quantity and quality is relatively small. Such animals are possible only as a result of selective breeding and good care, and their kind can only be propagated by means of the same selection and breeding which created them; In her wild state the cow gives barely enough millc to support her young and immediately dries up when the calf is weaned. ,The further she is removed from the wild state through selection and breeding, the more profitable she becomes, but if this selection and breeding is not maintained through the generations she reverts to the wild state, at least so far as production

value has not yet died down. Pas- ■ teurisation is a process named after i the world-famous French scientist, Pasteur, who laid the foundations of modern medicine and bacteriology about the middle of last century. It consists in heating the milk to a temperature of 145 deg. F. for some minutes, and then rapidly cooling it to as low a temperature as is commercially feasible. It differs from sterilisation on account of the lower temperature to which the milk is raised, and also because pasteurisation does not kill all germs in the way sterilisation does. On the other hand, sterilisation gives the milk a very decided flavour, whereas pasteurised milk should not develop this. Why is this apparently beneficial and blameless procedure so hotly attacked? The reasons are numerous, and as follows; Firstly, it is stated that the necessity for, and the efficiency of pasteurisation have been greatly exaggerated. It is said that pasteurisation as carried out commercially in England, frequently fails to kill' germs in the manner claimed, but, by removing the lacti'c acid organisms, actually favours, at a later stage, the multiplication of noxious bacteria which . may gain access. Secondly, there is a tremendous amount of evidence which shows that heat destroys certain vital properties of milk, and •robs it of much of its body building and health promoting capabilities. Numerous experimenters have shown that, whilst an exclusive diet of starch and fresh milk will maintain rats and other small animals in good condition for many months, so soon as the milk is pasteurised deficiency diseases occur, health suffers, and the reproductive powers fail.

• is concerned. One of the most import- ” ant activities of the dairyfarmer is, ' ' and must be, maintenance of as much good blood in his herd as possible, and this maintenance or improvement is possible only through the continued ‘‘ use of purebred bulls of the same breed as that which predominates in the cows. Under this practice each successive generation will show a r . greater, percentage of pure breeding, and this suggests the problems of in-

breeding and line breeding, which are V of importance to any herd, though greater Where all the animals are purebred.

Preventing Milk Fever ,

As the cow is always more or less injured by attacks of milk fever, the ■"farmer ought always to take preventive measures, states an Irish authority in discussing the problem of milk '"fever. There was no absolutely sure -preventive, but there were certain precautions which had helped to reduce the number of milk fever cases in dairy herds. These included partial starvation for a few days before the cow was due to calve, plenty of exer-

What Investigations Showed Investigations on thousands of school children have shown that raw milk gives vastly better results where growth and mental alertness are concerned than milk which has been heated. Exactly what effect the application of heat to milk has is not exactly known. We may say that the vitamins are destroyed, but, no one really knows what these accessory food factors are. They may be very much more complicated than is at present believed to be the case. But, from* a practical point of view we. know enough to realise that the indiscriminate heating of milk is not in the best interests.of the consumer. Not only may it have serious results upon the physique of a large proportion of a population, but it tends to obscure the efforts which are being made to improve the British milk supply at the source. Pasteurisation will not make dirty milk clean; if the milk is clean, why should it require pasteurisation? These are two points which at present are receiving the consideration of authorities overseas. We know that milk is one of the most perfect foods and it seems to us in New Zealand that it cannot be improved by artificial means. Although we have no first hand acquaintance with British conditions, it appears that pasteurisation is much over-rated.

cise and means to prevent constipation. If any particular cow was suspected as being subject to attacks of milk fever, an aperient dose about a week before the date on which she was due to

calve should be given, and if at the end

of the week she showed signs of taking another week a second dose should be given. Also, a dose would be beneficial just at the time the cow began to show signs of calving sickness. It is not desirable that a strong purgative should be given, but a suitable mixture may be made up of one lb of Epsom Salts and one pint of treacle mixed together in warm water. Other precautions which might.be taken against

an attack are to refrain from drawing off any milk before calving even though the' udder may appear to be over-stocked, and for two weeks after calving not to milk the cow out quite dry, but leave just a little remaining "In the udder. Whenever possible, it is advisable to place milk fever cases

in the hands of qualified veterinary surgeous with the least possible delay.

Pasteurisation Necessary?

Pasteurisation has been much in the news in England during the past two years and the hot controversy as to its

Good Cultivation Necessary

Good cultivation does not do away with the necessity of applying fertilisers. As a matter of fact, the quantity of fertiliser we may apply profitably will be gauged by the degree of intensity of the cultivation. Judicious, even liberal, manuring may be the soundest economy, but in too many instances we are hiding our bad cultivation under heavy applications of fertilisers. We may grow passable crops under this system for the time being, not because of our system of cultivation, but in spite of it, and because to some extent we are indebted to the plant breeder for the introduction of more

prolific varieties of plants. It too often happens that when a valuable scientific discovery is revealed to us we pay little attention to it or ignore it altogether. The very important discovery that plants received the greater part of their food and water from the atmosphere was scientific proof of the necessity of deep and thorough .cultivation. because by no other means can we thoroughly aerate the soil and provide for the free passage of water. It should be plain that the more thorough the cultivation, the more effectually will the soil be exposed to the action of the atmosphere; yet in spite of such proof, we actually cultivate the soil in a more superficial manner today than did the best farmers of days gone by, although they were quite unaware of the fact that plants received the greater part of their nourishment from the air.

All experienced farmers will grant that four great assentials of successful cropping are: Draining (natural or artificial), liming, manuring, and cultivation, and the greatest of the four is cultivation, because in some instances draining, liming and manuring l may be omitted, but good cultivation is an everlasting necessity, and cannot be ignored in successful farming, although it makes no direct contribution to the fertility of the soil. The same may be said of draining and liming. They are the means to an end, the and being the economical exploitation of the natural 'fertility of the soil, or the fertility that is produced by the farmer himself through the application of manures of various kinds. Often when sowing down a root crop, the farmer will make careful plans as to what fertiliser he will use but does not pay the attention he should to cultivation. The. conditions must be made for the most efficient working of the manure and if the conditions are not ideal for - this purpose then much of the farmer’s energy is wasted as well as no small proportion of the manure he has applied.

Effect of Carotene The deep yellow colour of the milk obtained from cows at pasture and its grac|ual disappearnce during the winter perior are well known. The fact that the natural yellow colour is always developed when cows are at pasture led to the conclusion that it was due to some substance originally present in the herbage. It was found that a yellow colouring matter called carotene and first identified in carrots, was present in grassland herbage as well as in green fodders, though in smaller amounts. The colour passes to the milk and gives it a yellow tinge which is so noticeable in early summer when the herbage is at its greenest. Now a property of carotene much more important than its colour has emerged in recent years, it has been established beyond doubt that it is capable of being converted in the body into vitamin A and stored in the liver. Vitamin A is a potent factor in growth, and is also known to confer on the body a certain measure of resistance to disease. From the point of the health of the community, the vitamin A potency of the milk supply is of paramount importance. Colour and vitamin potency are associated with the butterfat. When butter is made they accompany the cream. Hence the resultant butter is a concentrated source of the growthpromoting factor.

Value of Palatability Palatability plays no small part in the feeding of the dairy cow. She will eat more, and make greater use of the palatable grass than she will of the unpalatable species. From casual observation, the farmer will have noticed that his cows show more appreciation of some types of pastures than of others. We do not really know what effect palatability has on digestibility,

but. even from our knowledge of the physiology of digestion, it may have an appreciable influence. It is well known that pleasant anticipation alone rn regard to food, causes an outpouring of saliva —the mouth “waters” at the sight cr smell of interesting food, even before any of it is taken in—and experiments on dogs have shown that what is true of the salivary glands is also true of the gastric glands, so that the stomach “waters” at the same time as the mouth. It may be that the other glands further down the digestive tract are also influenced. Remembering that the food is broken down ready for absorption by ferments contained in these fluids, we must recognise a distinct possibility that palatability may be useful not only ns a means of stimulating the appetite, but also ns increasing the efficiency of digestion.

Variety of Rations % There is a danger of animals going off their feed to a certain extent if

kept on one ration for a long lime, and

this means that a change of diet must be mde. Changes in feeding are undesirable, for the composition of the digestive fluids is not entirely constant, but varies appreciably with the nature of the food that is eaten. This

suiting of the fluids to the material on which they have to act has been demonstrated by overseas authorities. A change of diet means, therefore, that the animal must produce rather different secretions, and there will always be a loss of efficiency during the change over, while we know that sudden and radical changes may cause quite serious illness. If a ration contains a fair mixture of foods, animals are less likely to get tired of it, and so can be kept on one diet for a longer time. Another point is that the rate of digestion varies as between food and food, so that a good mixture distributes the work of breaking down the feeding stuffs to assimilable form, and of absorbing them into the blood stream, more evenly over the digestive tract. This, it would appear, must increase the efficiency of the process.

Scientific Reasons

The main scientific reason advanced in favour of variety of ration is that it improves the biological value of the proteins. Proteins are made up of animo-acids, which occur in very different proportions in the different acids. The argument is that if we include in the ration products from several different plants, the probability is that we will get a better mixture of animo-acids on the whole, and that the risk of having the productivity of the animal held up for lack of some particular animo-acid is reduced to a minimum. But the whole thing is a step in the dark, and no one would call it scientific. What is wanted is a complete analysis of all proteins, and then it would be possible to decide what particular proteins lack in the way of animo-acids, according to the purpose for which thsy are being fed, and what others are most suitable for making good their deficiencies. With New Zealand dairy herds having access to green grass all the year round, there is not the same chance of any deficiency as in countries where concentrates have to be fed and where there may be considerable variations in rations during the course of a year. I