Pig Management

New Zealand Journal of Agriculture, Volume 65, Issue 6, 15 December 1942, Page 341

Pig Management

Contributed by the Livestock Division.

LITTER PRODUCTION

IN any discussion dealing with dairyfarming, pigs must play an important part, because of their ability to utilise the by-products of the dairy industry. Skim-milk, whey and buttermilk are recognised as waste products and can be given a value only when fed to pigs. This value is determined largely by the price of pig-meat and the cost of supplementary feed. The records of many feed trials show that dairy byproducts have a value of from ljd to 3d per lb. butterfat. At the present time about 1,400,000 cows in New Zealand are milked for the production of butter and cheese. The by-product (the basic food for pigs) produces about 100,000,000 lb. of

pig-meat, or 701 b. of pig-meat per cow. At ruling price—6|d per lb.it shows a return of £1 16s per cow. Taking the average butterfat production per cow at 2401 b., pig-meat adds about 2d a lb. to the price of butterfat. These two industries cows and pigs — are so closely associated as to be inseparable. Approximately 90 per cent, of the production from cows is a waste product, which, when intelligently used as a pig-feed can increase the returns of the farmer by 3d per lb. butterfat in the case of skim-milk, and l|d per lb. in the case of whey. This fact needs to be emphasised, and while objection to such a statement may be raised by some it has been accomplished by many who have given consideration to the pig side of dairy-farm-ing. Conditions of management associated with such a return are in most cases better than the average. Slack

methods of management, feeding and housing are the factors chiefly responsible for low returns. Important Factors The following are points to which attention should be directed: — Getting pigs used to a changed diet, and living conditions providing the necessary conveniences such as proper receptacles for skim-milk or whey, troughs that are big enough, and sufficient of them. Facilities for feeding to avoid climbing fences, and a place for stor-

ing feed other than dairy by-pro-ducts. Feeding not only the quality but the quantity feeds. Pigs will do well, up to a point, on poor quality feed provided they get sufficient of it. - .. ? ... Regularity of feeding three times daily (five in the case of whey) is also of importance. Pigs should be fed according to their weight. A pig of 401 b. live weight will require 21b. of feed daily, while one of 1001 b. will require 4Jlb. daily. A pig approaching bacon weight of 2001 b. will require 71b. of feed. Quality of carcass is affected just as much by over-feeding as in underfeeding, but in a different way. Pigs under-fed become costly because of the time taken to reach marketable weights. Over-fed pigs are quite often graded down for being too fat. The happy medium is not hard to attain when a systematic policy of feeding is followed. Good Litters When a sow produces a good litter, the owner, unless he is an expert and knows exactly why the litter is so ; excellent, usually gets as much kick out of the event as if he had collected on the last sweepstake. He takes a reasonable pride in the event and tells

his friends, but perhaps he also wonders just how it happened to. be so good. Even the experts are perhaps a little surprised sometimes at the excellence of their results, because they can recollect numerous incidents that were likely to do harm to the sow while she was in pig. Although on the whole the exercise of care at the right time and the intelligent use of the best information is likely to give good results, still, there is no royal road to success in producing good litters. If there were, these would be a commonplace, but instead of that, poor litters, with their resultant loss and disappointment, make pigs still unprofitable on many farms. A good litter, should weigh between 3001 b. and 4001 b. at eight weeks old, the greater the number of piglets the better. Thus 10 piglets of 301 b. each is a better litter than 6 piglets of 501 b. each. A spring balance is a valuable, adjunct in assessing litter value. The production of good litters begins with the shedding of the eggs from the ovaries of the sow during the heat period. It is usually considered that a sow in good condition for breeding will shed 20 to" 30 ova over a period of 30 to 36 hours from the first onset of heat. The actual onset of heat and the number of eggs produced during oestrum, are determined, in the sow, as in every other animal, by the amount of improvement that is taking place in the animal at that time. This improvement is commonly spoken of as “flushing.” In the sow this flushing automatically takes place immediately after weaning, and is due to the reabsorption of milk from the udder back into the sow’s body. It is probably because of this automatic flushing that oestrum occurs so regularly within three to six days of weaning. It is also true that where the first heat period is missed and difficulty is subsequently experienced in getting a sow in pig, this difficulty is because of the absence of flushing. Treatment at Weaning Many owners turn the sow out on a bare paddock at weaning and reduce her feed supply, and even let her back to the litter once a day so as to dry her off. If the sow is in high condition this may be all right, but if the sow is in low condition such treatment may result in delayed oestrum or the shedding of few eggs, and a small litter following. Where sows fail to come on heat after weaning, they should be shut up and fed heavily for a week before the next heat period is due. On the other hand where maiden sows are in such high condition that they are incapable of rapid improvement at the onset of oestrum, small litters often result, and this can be prevented by keeping the sow always in good condition but somewhere below the peak of her form.

Time of Service

It was mentioned that 20 to 30 ova may be shed over a period of 30 to 36 hours from the time the sow first comes on heat. These eggs are shed one at a time, and if : service takes place when only a few eggs are shed, then only a few will be fertilised and a small litter will result. The sperm of the male remains active on , the uterus for about 8 to 10 hours, so that if service takes place at 24 hours after heat begins all eggs shed up to 32 to 34 hours may be fertilised. If these points are appreciated the sow will be served ideally, that is, with every prospect of a big litter, about 24 to 36 hours after she comes on heat. In practice the best thing is to give one service when the sow is well on heat, and a second one as late as the sow will stand service. Gestation If the owner has attended to these points he has laid the foundation for a big litter, and provided the sow is reasonably treated for the next four months he should not be disappointed. Experimental work at Cambridge University some years ago on in-pig sows showed that a few days after service a sow’s uterus showed the implantation of 20 fertilised living embryo with a corresponding number of “corpora lutea” in the ovaries. A month after service there were again found the implantations of 20 fertilised embryo, and corresponding corpora lutea, but only 16 to 18 of the, embryo were alive. Two months after service the evidence of 20 implantations was found, but only 14-16 of the embryo were alive. Two months after service only 10 to 12 foetuses were found, and at four months ten to twelve pigs were farrowed. .In all about 50 sows were slaughtered in collecting this information, and at the different killing stages it was found that on the average the same number of eggs were • fertilised per sow, but that as the months went by the number surviving became less and less till only half the number fertilised were born alive. At birth, while an average of ten live pigs were produced, some sows produced dead pigs, some weakly ones that died after birth, and some, of course, produced litters of even-sized pig. Foetal Mortality The explanation of the observed happenings appears to be that a sow sets out to produce a maximum number of offspring, but finds as time goes on that she cannot maintain her original intention, and by restricting the blood supply to any foetus, stops its development. Once the blood supply is cut off the foetus ceases to live, and if time permits, it is absorbed back into the maternal system. If the blood stream has been cut off late in the gestation period the little one may be born dead, absorption having been im-

"" —llli —llli—llli Illi—llli—llli—llli——llli Illi——llli 1| «£< 1.. . S g Better housing, sanitation | 1 and facilities for looking after j 1 pigs are among the first im- T j provements that are associated j | with profits. Good manage- = j ment of the sow and her litter 1 ? is important—attention at the I j right time is vital. This article I I is the first of a series that will j 1 cover all phases of pig man- f I agement. ? Illi—llli—llli—llli—llli—llli—llli—llli—HU—llli—l, •f*