ROTATIONAL GRAZING

New Zealand Herald, Volume LXXIV, Issue 22818, 27 August 1937, Page 5

ROTATIONAL GRAZING

IfOAT) TO PROSPERITY SOURCES OF FOOD VALUE SCIENCE LOGICALLY APPLIED

BY 11.8.T

Although practical observation had long established the fact that young and growing tilings were more tender, succulent and attractive in flavour than those grown to maturity, it lias only been in recent years that analytical chemists and agricultural research workers have proved tho higher food valuo of young growth. For generations both producers and consumers have looked upon bulk as of greater importance than quality, and the education of tho public to a complete reversal of this doctrine naturally takes both proof and time. But often the blind groping of practice precedes the light of scientific discovery, and in this matter of the preference. for "young" food tho consurn ing public were more than half converted when research came on tho scone to tell them why they were right. The Demand lor Young Meat

Slowly, during the past generation, the demand for ewo and wether mutton has given place to the more tender and tasty lamb. The mature "roast beef of Old England," cut from an overfat five or six-year-old bullock, has steadily lost favour in face of a supply of quickly-grown and juicy "baby beef." Baconers have lost favour to porkers: md thoy, in turn, may possibly be displaced in popular demand by suckinu pig. So one might continue to onunier ite endlessly the instances in which a lefinite preference has developed toi products derived from young and growng animals and vegetables as human ■ ood. But it remained for the chemist to disclose that the flavour, tenderness and succulence which wo approved was definitely related to protoins, amides and vitamins which are essential to health, and that they are present in greater quantity in young than in •nature life. Nutritive Value of Grass

it was no great step further to demonstrate that tho same facts held good in respect to pasture grasses. Young and vigorously-growing pasture was found to bo several times more valuable as stock food, bulk for bulk, than tho same crass at maturity. Indeed, it is contended that young grass equals in nutritive value the most expensive concentrates which are in use for stock food.

Broadly, we can classify this "nutritive value" found in rapidly growing things as vitalitv which, of course, il- - namo for life. This "life," then, is something which can be trans ferred from an individual on one plane to one in another, and perhaps higher sphere, without extinction. It is thus rather transmutation than death when tho grass absorbs tho matter of the short-lived soil bacteria, when tho sheep eats the grass, or man eats the sheep. The life does not die: it is merely transmuted to a higher form. The obvious deduction is that the more intense the vitality is of tho animal or vegetable when it is converted to food, tho more valuable this is for building life. Modern science has led us to understand, too, that tho vital matter embodied in both animals and plants is, to a largo extent, drawn from sunlight. Hoav sunlight is transmuted to matter we do not fully know, but we recognise that in growing plants the chlorophyll, or green colouring matter, is built up by sunlight, which has also a somewhat similar effect in enriching the blood of animals. Indeed sunlight provides such an important clement ot food that neither plants nor animals can live for long when completely cut off from it. This largely explains why sunbathed slopes always support more, and healthier, grass and livestock than do shady faces. It also explains why short grass, bathed from leaf-tip to crown in sunlight, is moro nourishing, or has greate/food value, than tho samo grass allowed to grow tall and < rank, when half only of its leaf can catch the sun's direct rays. Every farmer will have noticed that stock, when first turned into a paddock of rank, tall grass, eat only tho tips of the loaves at first, but later, when the sunlight has been able to penetrate deeper and vitalise the bottom growth, this also is eaten with relish. All this leads us logically to tho value of rotational grazing to secure the utmost nourishment, or vitality, from pasture grassed Tho fundamental principle of rotational grazing is to keep tho grass in a constant stage of young and active growth, receiving tho maximum of sunlight. In an area subdivided into fourteen or fifteen paddocks the stock aro moved from one to the other in n regular rotation, allows "adpaddock a rest for growth of at least a fortnight before it is again eaten off. This short grass is always bathed in sunlight for the full length of its leaf and is succulent, sweet nnd nourishing, becauso it is alwnys vigorously growing in its effort to reach reproductive maturity. Working of Nature's Laws

Nature's three greatest laws, which all life is given tlio urgo ,to obey, are survival, reproduction and balance. Once survival is reasonably assured in the pasture plant through its roots being (irmly established to draw moisture, minerals and organic food from the soil, and its foliago sufficiently luxuriant to digest the food sent up by the roots, and to absorb oxygen from the air and vitality from the sunlight, its next objective is to throw up a seed stalk and flower to reproduce its species. Once reproduction is accomplished and the bulk of the vitality of the plant lias passed to its : ned, Nature does not aid it to new and vigorous growth. If, however, in our control of the pasture, wo prevent the grass from reaching maturity, when it can seed, it continues to send its roots deeper into the soil and to throw out vigorously new leaves in an effort to fit itself for reproduction. A certain amount of growth of leaf is essential to the metabolism of the plant, and this, rotational grazing, provides for in the fortnightly, or longer, spells from grazing which nro given each paddock. Balance between root and leaf growth is likewise secured by this means, as is also the maintenance of balanco between the various species of grass which form the swards. When stock are continually depastured on an area they destroy this balanco between root and leaf growth by continuous close grazing of favoured grass species, and thus the pasturo soon loses much of its nutritive qualities through lack of variety. The value of checking reproduction in order to produce greater and more rapid growth, and a more nutritive article of food, has long been appreciated with livestock. For this reason wo emasculate the bulk of our male stock, and, when they are not required for breeding, spcy the females. These animals grow more rapidly, and their flesh is always of much finer flavour (and correspondingly of higher nutritive value) than that from entire animals. The parallel with vegetation is obvious; wo must necessarily emasculate our pasture grasses by regular grazing to prevent seeding if their growth, is to continue to be vigorous and highly nutritive throughout their lives. Rotational grazing is logical, common sense. It is not a fad of the scientist nor the theory of tho impractical. It oilers tho farmers of New Zealand the opportunity of not only increasing the quantity, but also tho quality of tlicir output. Its adoption means more money in the farmer's pocket and more health to'the consumer of liis products.