FARM AND DAIRY

Northern Advocate, 17 December 1932, Page 13

FARM AND DAIRY

PLANT RESPIRATION,

HAYMAKING PROCESSES.

MASTITIS IN DAIRY HEEDS,

v i.msixtmukatixc crocks

(By M. Irkmder, M.Sc., F.L.S.)

The ordinary plant breaths in essentially The same manner ;.s an animal, and it is partly by leason of this fact that the hospital authorities have all green decorative plants religiously lemoved from the ward at nightfall and replaced in the ward again in the morning. The plant breathing during the night contaminates the atmosphere by absorbing the oxygen and giving off carbonic acid gas, whilst during the day the opposite process takes place in that the air is purified by the absorption of carbon dioxide and the giving off of oxygen. The reason for this, apparent anomaly will be clearly seen from the present short article. The ordinary green leaf is the breathing organ, of the normal higher plant, and it would be well first to consider briefly its structure. (.eaves have a, great variety of shapes, but in internal otrnctnre they are all very much alike. The laminae of many assimilating foliage leaves exhibit a difference in structure of their upper and lower sides. The upper surface is formed by a single layer of large elongated epidermal cells which have their thick outer wall covered with a layer of cuticle. Tills upper epidermis is succeeded by one or more layers of cylindrical parenchymatous elements elongated at right angles to the leaf surface. These elongated elements are the palisade cells, and they are especially rich in chlorophyll, the green pigmented granules which -give the ordinary leaf its colour. Adjoining the palisade parenchyma, and extending to the epidermis on the under surface of the leaf, is a loose tissue called the spongy parenchyma or mesohyll tissue. In contrast to the palisade cells, the mesophyll cells are lees abundantly supplied with chlorophyll; they are irregular in shape, and have large intercellular air spaces between them.

Many-Pored Leaves

The lower epidermis is perforated by numbers of minute pores or stomata, and it is a peculiar fact that these •stomata are mostly confined to the lower surface. A leaf of lilac, for instance, has about 1(10,000 stomata in its lower epidermis and none on the upper. A vine leaf has 10,000 on the lower surface and none on the upper. The largest stoma known has only an area of .00020 square millimetres and the total openings in an ordinary leaf surface amount, to only .1.4 per cent, of the total area of the leaf. The stomata are in direct communication with the intercellular air-spaces of the mesophyll and the free passage of gases between the interior of the leaf and the atmosphere is facilitated. A certain functional analogy may be drawn between the nostrils, bronchial luboo, long tissue, and veinous blond ot animals, and the stomata, intercellular spaces, mesophyll cells and chloroplasls of the green leaf respectively. Everyone is aware how he or she inhales through the nostrils (or should) and the air passes down to the airspaces of the lungs where the oxygen diffuses through the membranous lung tissue into the blood, replacing the carbon dioxide, which io then exhaled.

Similarly, in the plant the air passes through the stomata into the intercellular spaces of the mesophyll cells, whore it diffuses across the cell wall inlo the cell and is need in the oxidation of such carbohydrates as sugars and starches with a liberation of carbon dioxide which is exhaled. The process of living requires energy, which is obtained by the alow burning or oxidation of food materials, lienee the daily habit of eating. This burning of food material is respiration. 'When sugar is the food material oxidised, the simplest of circumstances prevail. Six molecules of oxygon completely burn one molecule of ■sugar, with the formation of an equal volume (six molecules) or carbon dioxide and six molecules of water. In the above example, the volume of carbon dioxide given out is equal to the oxygen taken in—but normailv this ratio is loss than uuitv.

Prom the above it will tie appreciated that respiration is a disintegrating process which enables the plant to obtain the energy necessary to carry oil the process of living.

-Some poultry-keepers feed (heir chickens well for the first few weeks, and then ease oil. in their feeding methods, 'this is not the way to produce the best chickens. There ehonld lie no easing up as long as developing is taking place. The youngest should be kept growing all the time, as a setback a| tins period is just as harmful fo chick (hie! as it is to any other form ol life, animal or vegetable.

MAXIM.(XU AFT Mb* MOWIXU. Under many conditions a crop may suitably be turned on the afternoon of the day following mowing. The swath" Turner is gentler in action than the tedder, bat the tedder may tie more serviceable if rain lias fallen on the mown crop in that the tedder facilitates drying by the additional shaking and loosening of the crop. It is then usually well to leave the crop untouched until a day has elapsed, when it may be gathered for stacking. Sometimes, however, under dry, warm conditions it may be raked into windrows on the afternoon following turning. In the case of crops consisting largely of clover, more time for drying may be needed than for ordinary meadow hay. Cocking. If broken weather seems probable it is advisable to put hay into ‘‘codes” the day after turning. The advantages of having hay in codes is dear from the following tacts;

Half an inch of rain means 30 tons of water an acre, and if the hay crop is evenly spread over the ground it is subjected to the washing out influence of the greater portion of this water. But if the crop is in cocks that occupy only one-tenth of the urea it will be affected by only one-tenth of the rainfall —that is, by live tons instead of 50 tons of water. Clocking of hay is a. measure which should be considered more than it seems to be. Over much of the Dominion it is doubtful if a heavy crop of hay can be well saved without cocking, and with average crops, after making due allowance for the extra labour that cocking involves, it could with advantage be adopted at times when it is not practised. Cocking proves particularly serviceable in the saving of lucerne and clover hay of good quality.

Less Turned The Better. In general, the less hay is turned and tossed about the better, for the bruising and breaking of the stems and leaves which result from handling tend to destroy the protective covering of the stems and facilitate the entrance of water and the Process of decay. Consequently in continued wet weather it is well to leave the cut grass undisturbed, when it will sulfur the minimum of harm. Further, the handling of the crop causes loss of nutriment through the dropping oil of leaves, particularly those of clover and lucerne. The leaves being a particularly uutri ive portion, everything possible should lie done to avoid losing them. A considerable saving of nutriment may be expeete/ by efficient use of the modern hay sweep and stacker, as they eliminate the damage done by trampling in the carts and the double operation of forking on and off the carts. Stacking.

Only experience enables one to determine wi lh confidence when hav is fit to be stacked. A reliable test is to twist a handful of sterns tightlv into a rope. If the pressuie causes moisture to appear the material is not lit for stacking. In line weather luxuriant growth is liable to be carried in prematuiciv, for the leaves and the finer shoots dry quickly and give the bulk of the material the desired disappearance lie fore the .succulent stems have lost suflieient moisture. Special care should be taken in regard to ‘‘lover and lucerne hay to ensure that, the stems have dried sufficiently. Dry, conveniently located sites should be selected for hay stacks. Brandies of trees provide cheap and satisfactory stack bottoms and if branches are not available suitable timber should be used.

Although a (square stack enables a greater bulk to be stored for a given amount of surface, yet relatively long, narrow stacks arc often advisable because the}' admit of more ready drying and cooling of Hie stored material.

In building the stack it is highly desirable to maintain “a good heart, ” i.e., the centre of the stack should be kept, firm and higher lhan the outer portions. No one working on the .-stack should stand Tong in one place.

LARGE AND SMALL COWS,

TESTS IN AUSTRALIA

Experiments conducted in Australia show that, so far a.-i any definite state-

ment can be made on tin* subject, flu* big dairy cow is more profitable limn her smaller sister. As a rule large cows are better than the small ones for the production of milk and butterfat, says a writer in an overseas paper. The energy expended in maintaining a living body can be measured in the heat radiated from that body. Radiation is in proportion lo surface. The smaller animal has Die greater surface in proportion to its weight, and, consequently, there is a greater ia dint ion of heat from its body, and a greater coiisrunpl ion of food to .supply energy. Another reason why, for dair' purposes, a large animal is In Dor than a small one, is that the greater body space affords more room for the complicated machinery that is necessary for the manufacture of milk from food. Too often ll is forgotten that milk in only made from food consumed. The amount of work performed by the heart and lungs of a lieav. milking cow is enormous, so Dial any contraction in Die region of Die chest or any failure In pump an .adequate blood supply through and around the udder, militate against big production.

NO REMEDY FOR THE DISEASE

The problem of mastitis in dairy cattle in Victoria was discussed at a meeting of the; University Agricultural Society by .Dr, Albhmton, Director of A’eteriuarv Research at the university, and Mr U. A. Kendall, Chief 'Veterinary Inspector of the Department of Agriculture.

Dr. Albinston said the incidence of mastitis in Victoria dairy herds must be accepted as upwards of .‘>o per cent. Di four herds round Melbourne which had been examined the percentage ranged from 47 to, in one ease, SM. Attempts had been made to control infection of the otreptoeoccic form, which was the commoner, eu the assumption that the disease was transferred from cow to cow, but experiment had failed to show that this was the method of infection. Careful dairy farmers had been unable to prevent its spre.a 1 by adopting hygienic precaution-!, and it. woo probable (hat the presence of some other disease in the cow was necessary for infection. Treatment, in .acuta cases could reduce the iullammation, but in chronic ease's no remedy was known. Medicines through Die mouth and vaeciiUM lie considered to be hopeless. The commonest, form of the disease was the streptococcic, which could be readily diagnosed, though no enro was known, ft had boon considered uu-

wise to publish details of the incidence of the disease through fears of bad influence on public morale. There was no evidence of disease having been caused by the milk of a badly infected herd, however, though some of the rarer forms had caused epidemics of sore throats.

Z\Jr Ken-IaII said tliat following the insistent demand of dairy f,armors 1 hroughout (lie Commonwealth (lie Australian Dairy Research Council 1 >:i<l formulated a plan for research into the disease over a period of ten years at an estimated annual evpendiiuro of between £4OOO and fdOOd. They realised (|uite well that, .at the end of that period they might be no further ahead than at the present, day.

The di-sense was most s revalcn: in the eow which had been bred for "renter production. It simmered in herds owing to the inability of the farmer to diagnose it in its chronic stale until there wore acute eases.

Until some definite cure had been found tiie only method nf controlling the disease was to educate the farmer in llie hygienic handling of his herd.

The best layers both in early life ;md afterward will always he off the pereli tirst, and last to go on at. night. This denotes a vigorous bird in perfect health and sound throughout, and has always been observed in neavy layers by those who have had such birds under close observation.

The problem of lamb export is already receiving considerable thought from all connected with the industry in Western Australia. The mucli-dls-custsed proposal of a levy on all fat lambs sold for slaughter within the State in order to provide a bonus for those growers Avho will ship export lambs to the London market has been further ventilated. No new points have been raised, and the difficulties in the Avay of each a procedure remain nusurmounted. Already a few early consignments of new season’s lambs have reached Midland function, stated a paper On .Tune 11, and it remains to bo seen just how the somewhat unusual trend of the season to date is going to affect the lambing, before it Will be known when sufficient supplies will be available to justify the opening of the Fremantle. Meat Export "Works.