MODERN PIG-KEEPING

Northern Advocate, 10 November 1934, Page 14

MODERN PIG-KEEPING

Tuberculosis. In view of the rapid development of the pig industry the elimination of tuberculosis, recommended by the Dairy Commission, is most necessary. In the case of separated milk the danger of bovine tuberculosis is not so great, but in the case of whey the danger is serious, as one cow in a district with a tuberculous udder may infect every pig receiving the factory whey. In Denmark all skim-milk must be sterilised, but there the whole milk is delivered to the factories, the suppliers taking back the skim-milk which is a mixture of all the skimmilk of the district. This drawback to skim-milk does not exist in New Zealand, where the home-separation farmer with a clean herd has a safe skim-milk to feed to his pigs. In the case of whey the case is different. Fortunately under our open-air system of keeping cows the extent of tuberculosis is nothing like what it is in older countries where the cattle are housed for a good part of the year, but the danger of passing on this disastrous disease is bad enough. In writing of the danger of pigs becoming infected with tuberculosis, Sir Ralph Jackson, M.R.C.V.S., Chief Veterinary Officer of the Home Government, says that pigs usually become affected with tuberculosis by living in association with poultry or cattle affected with the 'disease. Pigs should not, he says, be grazed or kept with poultry or cattle unless the latter are known to be free of tuberculosis. He concludes:—“A prolonged and costly effort is usually necessary to free a herd from disease and, therefore, prevention of the disease, although it requires a continued effort, will be found much cheaper than the curing of it.” In Denmark poultry are not allowed to be kept near the pigs, and avian, or poultry, tuberculosis is much more common in New Zealand than is generally supposed, due principally to the poor type of poultry housing provided. One may be fairly sure where the perches are arranged like a stepladder and the house badly ventilated that tuberculosis is present. The disease usually affects the liver of the birds which develops to an abnormal size. This forces out the leg on the affected side so that when a bird is seen to be walking with one leg well out it is a fairly sure sign that it has tuberculosis. Fecundity Records. Since the year 1930 the National Pig Breeders’ Association of England has kept fecundity records, showing the records of the number of pedigree pigs 'born and reared in the herds of members. Up to June of this year the Large Whites lead with an average of 10.79 pigs born, the average reared being 8.05. Middle Whites are next with 10.18 born and 7.29 reared. Tarnworths show an average of 7.82 born and 6.36 reared. The best year for Tamworths and Berkshires was 1932, when the Tamworth average was 8.28 born and 6.19 reared, the Berkshires average being 8.46 born and 6.87 reared. In that year the Large White average was 10.32 and 7.86. In the four years and in the six months of this year the Large Whites have an average of over ten born, while the lowest average for number reared was 7.7ci. This was in 1930. The best improvement has been made by the Large Whites, which are still shown to be easily England’s most prolific breed. In Sweden, the first country to establish pig recording and where the Large White has been developed to a better utility standard than in any other country, the average number of pigs born alive (Large Whites) was 10.68 and the average number reared 8.68, or rather this figure represents the average number of live pigs per litter at three weeks of age. A leading Swedish authority, Ivor Johansson, Ph.D., very strongly contends that “it is more important to select breeding animals for a higher number of functioning mammae and for good nursing ability of the mothers than for increased litter size.” And this is the sound view. The big consideration is that the sow should have at least twelve good teats and that she should be a good mother, haying good milking and nursing ability, for it is no use having the capacity to produce a big litter if all the litter cannot be reared. It is the number reared, not the number born, that matters. Of course, the percentage of loss between birth and three weeks of age

and the increase in weight during the first weeks of life are dependent to a considerable extent on good management, but this, it is contended, does not alter the fact that very large litters are not desirable. The sows are only wasting their energy when they give birth to more pigs than they are able to nourish and take care of, and the pigs from such large litters have a lower average weight at weaning time and are therefore less valuable than pigs from litters of normal size. The highest profit in pig-keeping will only come when sows are available that will have large litters at three weeks of'age. This not only Implies that the sows will have inherited the capacity to produce large litters but will have the capacity to nurse and feed them. Management, however, plays a big part. In short, it depends as much upon the man as upon the pig whether uniformly big litters will be developed, and thereby return the highest profit. Shows That Are Educative. In Swedish shows pigs are judged not only according to conformation (exterior quality it is called) but according to descent and efficiency of progeny. In the case of a sow the weight of litter at three weeks of ago is a big factor, points being awarded according to the actual weight of at least three litters. Lime. A correspondent raises the question: Is it necessary to give lime in a lick when pigs are receiving separated milk which is rich in lime. Certainly separated milk and whey contain high percentages of lime, but there are times when lime is required in ample supply by the pig, especially by the sow, and then it is certainly advisable to provide lime in a lick. The pregnant sow has to supply constructive material for the formation of 10 to 12 young. In lactation the draft of her body is increased. One gallon of milk per day is probably a moderate estimate of the yield of a good sow. In this amount she loses from her body over 1£ ounces of mineral matter, in which there is rather more than half an ounce of calcium. It is thus in young newly weaned pigs and in brood sows that the need for mineral matter is greatest. If calcium or any other essential constituent is ficient, in the one case the maximum growth cannot be attained and in the other the litter or the sow must suffer. Hereditary Factors. Scientific investigation has definitely disclosed that there are quite a number of factors (or qualities) which are hereditary or that are transmitted by parents to their* offspring. Some of these qualities are: Size of litters;-the sow’s ability to produce two litters a year regularly; the mothering ability of the sow; the size of the boar does not affect the size of the litters of which he is the sire, but it does affect the size of the litters of his daughters; the tendency to produce dead pigs. Blind Teats in Brood Sows. It is sometimes assumed that the whole of the udder or milk receptacle of the sow is common to each of the teatair-in other words, that the young pig, while suckling one of the teats, can obtain milk from any part of the udder. This, however, is a mistake. Just as in the case of the cow, where each teat has a separate and independent quarter of its own, so also it is with the sow. Each of the ten or twelve or more teats has its own separate receptacle, and from this, and this alone, can the milk supplies obtainable from that particular teat come. In consequence of this, it follows that when one or more teats do not yield their normal flow of milk, there is a proportionate loss in the amount of milk which the sow possessing it is capable of producing. The possession of such dead or blind teats by sows is a very serious weakness, and breeders should be careful to avoid any sow with such a blemish. Experience shows that the possession of blind teats is a shortcoming which is very liable to be transmitted by sows to their progeny.