ON THE LAND

Northern Advocate, 3 October 1930, Page 7

ON THE LAND

EXPERIMENTS WITH PIGS,

M A.INTENANCE NEEDS,

FOOD REQUIREMENTS.

For several years elaborate studies of the fundamental food requirements of (the Large Yorkshire pig at various stages of growth have 'been in progress in the Cambridge Animal Nutrition Research Institute, ami have furnished valuable data as to the basic energy requirements for growth of this breed. Of special interest has been the .revelation of the -abnormally high requirements iu proportion to size in the- early stages of growth, which may on occasion approach closely to the limits of appetite of thci pig. Similar data for the Middle Yorkshire and .Berkshire breeds have now been published by Deighton. and whilst (the phenomena in general follow the Jino.s of those originally discovered in the Large Yorkshire they show interesting points of difference, which perhaps for the time being are more of scientific than of practical interest.

The basic measurement in these experiments is that of the “fasting katabolism, ’ ’ by which, is meant the amount of heat radiator] from the body per unit surface, urea, under conditions of -complete starvation. This figure gives* a. measure of the min imam food requirements of the animals, and varies at different stages of igrowth, but towards the adult Phages tends to settle down to a constant level. In the case of the Largo Yorkshire pig this level was not -reached until 370 days after birth, vvhilsjt with the Berkshire pig it was reached at 175 days from 'birth. With the Middle Yorkshire pig, -on the. Other hand, no less than 300 days 1 were -required, but a, distinctly lower level was reached. I

As .compared with the requirements at the adult stage, the energy requirements (per unit body surface) in the earlier stages of growth are very high with .a.ll the breeds, but there are significant difference:; between the breeds. Thus in the case of the Large (Yorkshire the demand for extra- enterigy; (as 'Compared with the adult) does not appear until after birth, whereas in the case of the Middle Yorkshire probably, and in the case of the Berkshire certainly, it sets in before birth.

'The, (practical deduction is drawn from (this that the Large Yorkshire pow may ho expected to be in a" better position to produce large litters than either of the others, as the drain on heir resources for the nourishment of the young,, other things being equal, would be less per foetus than in the other two breeds, .Similarly one blight expect some advantage of the Middle Yorkshire over the Berkshire

in this respect. A good deal of support for these views can bo found in practical circles, and it is of interest to have- a. physical explanation of such differences in prolificacy. Tin? curves of maintenance requirement deduced from the experiment, and representing the requirements for maintenance of /the three breeds in store condition and kept in styes at

ordinary atmospheric temperatures, indicate that at equal weights between o() and 1501 b. the Berkshire has the lowest, and the Large Yorkshire the highest, maintenance requirement, fbe Middle Yorkshire being intermediate between the two. The maintenance requirement may vary with the temperature, but in this-respect the Middle Yorkshire would appear to be the least sensitive to fall of temperature of the three breeds. If the breeds be compared on the basis of age rather than weight there is little to choose as to main(tenaneo requirement between the Berkshire and Middle Yorkshire between the ages of 100 and 300 days, but the Large Yorkshire still remains well above ’them.

HAS YOUR SOIL LIME? 1 Even the soil of au old, sour field has lime in it; but it is so scarce and hard for the .plants to Jind that no big crops can be expected unless move is supplied. Very few plants have- feeding roots, strong enough! to gain a sufficient quantity; ami although many will grow when other plant foods are available „fhey will do much bettor when there is plenty of lime. The safe .course is to have plenty of lime in the soil ready for all crops. They will then do much, better. Clover and lucerne can ibe made to

grow where they wouldn’t grow before, and many crops will double their yield if lime is judiciously applied. A simple method of testing the .soil" far sourness, showing the need

for liming, is the blue litmus paper test. Blue litmus paper can be purchased from it-he chamist. To make the test a, sample of the soil is mixed with a little rain water until it is l damp, then rolled into a ball, and aj strip of blue litmus paper inserted in the centre of it and left for ffve or ten minutes. If the soil is sour and needs limestone the paper will turn pink. This/is one of the simplest, tests on the market, although there are others in general use. Litmus paper is convenlent to carry and takes little time to use.

“Limestone country is a rich conn try,” This is a proverb and a truism' much older than agriculture, but every soil can bo made a lime Moue soil simply by liberal applicant of limestone. The idea is to get the farmer to apply' it.