FARM AND STATION

Hawke's Bay Tribune, Volume XVIII, Issue 297, 1 December 1928, Page 12

FARM AND STATION

Nutritive Value of Grass

Extensive Experiments in England

Practical Application on the Farm

(By

“Sundowner.”)

(Written for the “Tribune”— All Rights Reserved.)

We have heard a lot during the past year regarding the nutritive value of closely-cropped pasturage, various English agricultural writers comparing it with concentrates such as linseed meal. The average farmer, however, does not use much linseed meal in this country, hence he may get a better idea of the nutritive value of grass rotationally grazed and thus kept short and growing, if we compare it with standards which are in common use with us.

THREE TIMES AS VALUABLE AS HAY.

rpAKING medium quality, well harvested hay as a standard, short grass has three times the feeding value of this. The best hay has only half the nourishment in its dry matter than has the similar dry matter from closely cropped grass.

Extensive experiments, both by analysis and by cutting the grass growth and feeding it to sheep kept under strictly controlled experimental conditions, have proved that, if properly grazed, the nutritive value remains at this high level throughout the season. Drought conditions bring about a slight lowering of the value and a considerable lowering of the bulk, but when rain comes again the value rises to within a short distance of the Spring level. In Autumn the grass was almost equal in nutritive value to that obtained early in the grazing year.

NO CONCENTRATES NEEDED WITH SHORT PASTURE.

This result was obtained on light sandy soil, and before a complete table of comparative values can be published, it will be necessary to experiment with every type of soil which is commonly grazed. Enough has been proved, however, to indicate that in this country where growth takes place practically the whole year round, the farmer does not need much in the way of concentrates provided he keeps his pastures short and growing throughout the year.

FEED VALUE OF DIFFERENT GRASS VARIETIES.

While this investigation of the nutr 4 e value of grass at different stage., of growth has been going forward at Cambridge, at the Aberystwyth station in Wales the feeding value of various grasses and clovers has been undertaken. For every species of grass and clover available a * chemical analysis has been made of stem, leaf, and whole plant at various dates throughout the season, so that the nutritive value of the species for grazing or hay, and the changes which take place in the values of stem and leaf respectively, have been precisely ascertained. Each species has been grown in small plots about four square yards in area, and cuts have been made at the end of each month throughout the year. From another part of the same plot two cuts have been made for hay, one when the grass is at its best, and the other a month later when it is slightly over-ripe. In each case the aftermath has been cut and analysed similarly.

PRACTICAL RESULTS FROM INVESTIGATION.

Some of the more practical results accruing from the investigation may be mentioned. It is found that with commercial varieties under grazing conditions the proportion of stem to leaf is consistently greater throughout the season than with indigenous varieties of the same species. As leaf is far superior to stem in nutritive value, it will be obvious that the pasture grown from seed procured from plants which are cultivated for seed production will be much inferior to pasture grown from seed harvested where the land is normally grazed. An examination

of the aftermath proves that it is decidedly more leafy than hay, and therefore superior in nutritive value; in fact, the stem of the aftermath grass is more nutritious than the leaf of hay.

THE BEST HAY.

As might be expected, the best 'quality hay is produced from grasses with a high proportion of leaf to stem, and there is some indication that a poor growth of clover in a mixture may be counterbalanced by the inclusion of more leafy grasses, and by cutting the crop before the grasses are fully matured. In fact it may be found advisable to cut two crops of hay off the one paddock in the same year, thus getting the same amount of hay of double the nutritive value. The difficulty at present is in finding a satisfactorymethod of cheaply curing this youny and succulent grass to convert it into hay.

EFFECTS OF DRESSING ON HAY.

In so far as the effect of manure* on the quality of the hay is concerned, it appears that an applica tion of superphosphate causes a slight increase in the percentage oi protein, lime and silica, and a considerable decrease in the percentage of chlorine. Nitrate of soda similarly increases the protein content of the grass, but lowers the coijtent of phosphoric acid and lime. THE EFFECT OF SUNLIGHT. It must not be forgotten by the farmer that the amount of sunlight which bathes his pastures very considerably affects the food-value of the grass. It is largely because short grass gets a greater amount of sunshine in all its leaf and stem than does long grass, that it has such a much higher nutritive value. This is largely the reason why stock do better in a comparatively dry summer than when there is abundance of feed with clouded skies. The sunlight is. however, not responsible for all the added nutriment of short grass when compared with that which has reached its maximum growth. It is well known that while anything is growing, be it vegetable or animal, it is more nourishing than when it has reached maturity, hence the pre fcrence of consumers for lamb, baby-beef, and meat from other young animals, not only because it is more tender and sweet, but because it is. pound for pound, actually . much more nourishing than meat from mature animals.

CLOSER SUBDIVISION MOST IMPORTANT.

Pastures can only be kept short and growing, and hence highly nourishing, by closer subdivision and intensive grazing. Practically, grazing these small paddocks in rotation has been found to be the best way of keeping the pasture short and at the same time giving the stock plenty to cat, hence there is no doubt whatever that closer subdivision into srnalle: paddocks, and a system of changing the stock regularly from one to the other, is the most profitable improvement the average farmer in New Zealand can put on his land to-dav.

“Subdivide, subdivide and again subdivide” should be the slogan on ninety per cent, of our farms, and the result would be doubled and trebled production.