MILK FEVER IN EWES

Press, Volume LXXII, Issue 21907, 7 October 1936, Page 15

MILK FEVER IN EWES

MR ALLAN LESLIE’S

FINDINGS

FINAL INTERPRETATION OF RESEARCHES

The conditions leading to large outbreaks of milk fever In ewes some time after lambing are reviewed by Mr Allan Leslie. F.R.C.V.S„ formerly head of the veterinary department of Lincoln College, in a final interpretation of tno information collected during an investigation conducted at the college smce 1930. He emphasises depends on good steady feeding all the year round. The work was financed Dy the New Zealand Meat .Propers Board and by certain fanning organisations in the South Island, and the stock used lor experiments was tne property of Lincoln College, Oumr diseases will be dealt with in subsequent articles. • Mr Leslie’s summary and conclusions To the layman work of this nature, dealing as it does with a common disease, may seem unwarranted. The truth of the matter is that nothing has been discovered within recent years to .reduce the incidence « the disease. Practically all that is known of milk fever of cows is that the.disease is characterised by a sharp drop in the blood calcium which responds to either udder or calcium therapy. No reason has been found for its common occurrence soon after calving, and preventive measures, such as leaving the call with the dam, incomplete milking after calving, etc., have given only variable results. Need for Investigation No work has been undertaken to discover the underlying causes of the disease in ewes and no explanation has been forthcoming to explain the common occurrence of the disease some time after lambing. The most that has been done revealed that milk fever was the same disease in both ewes and cows. It was this state of affairs, and the prevalence of the disease In Canterbury ewe flocks, that prompted us to locus attention on the systems ox management and feeding associated with large outbreaks. , . , . The work has now reached an interesting stage from which it is possible to make some pronouncements, of practical value to the sheep fanner, investigation has shown that. In contradistinction to what happens in cows, (1) affected ewes are generally low to poor in condition at the time of onset of the disease, and (2) before developing the disease both susceptible and non-susceptible ewes are dull Mid lethargic. It is considered that the dullness, lethargy, and poorness of condition constitute the susceptible state, and that a sudden change of diet, a fast, or a road journey are merely subsidiary factors which find the weakness in the body mechanism which controls the amount of calcium in the blood. In other words, it is contended that ewes that develop milk fever following a change of feed or a fast do so because they were in a peculiarly susceptible stale prior to the change of diet or the fast. From the practical point of view, therefore, it is the factors which predispose to the susceptible state that arfe important in prevention.

Effect of Steady Feeding

According to field and experimental studies the chief factor which predisposes to the susceptible state is faulty feeding during the last half of pregnancy. Ewes that actually lose weight during pregnancy instead of maintaining or gaining body weight •appear to have the first stage of the susceptible state instilled into them at lambing. The second stage of the susceptible state arises from milk production stimulation, the result of a change from a low to a relatively high protein diet, during which time the animal is attempting to produce milk at the expense of body reserves, or to bufld up reserves and milk at the same time. It is under these conditions that milk fever cases have developed both at Ashley Dene and on Canterbury farms experiencing the trouble, outbreaks have not been encountered in ewes well charged with reserves at lambing, even although their diet was the same as that supplied to susceptible flocks, . These findings indicate that prevention depends on good steady feeding all the year round. They do not support the popular view that high milk production is the root cause of the trouble. The very fact that milk fever often affects ewes some time after lambing is strong evidence that the disease in ewes hja c . in s A me way. a diffmmt causation from that of cows, in which it usually develops within a few days of calving. Another resnect in which the disease seems to d'ffer in ewes, but which has not so far been recognised is in the state of fatness of the animal affected. In cows, the most susceptible subiect is usually in excellent condition; the converse appears to be true for ewes. It is generally the lair to low conditioned animal which is a£-

fected. Furthermore, in flocks in which a high incidence of the disease occurs it is usual for dullness and legarthy to be widespread among both the susceptible and non-susceptible subjects. „ x Susceptible State

The opinion has therefore been formed that poorness of condition, dullness. and lethargy constitute tne susceptible state which ultimately leads to the temporary disturbance of the “nervous endocrine” controlling mechanism of the calcium in the blood, and that a sudden change of diet, a fast, or a road jovyrney, all of which may be associated with the actual onset of the disease, are merely subsidiary factors. At the moment it seems safe to suggest that the “susceptible state” arises from the necessory maternal drain incurred in milk production. If that be so, it becomes less difficult to interpret the parts played by sudden milk stimulation or sudden glandular activity (probably In glands already working at maximum), following a change from a low to a high protein intake. Again, the effects of milk production during a fast, when the body reserves can ill afford to supply more energy, may be similarly explained. It may be the utilisation of muscle, with its high phosphorus content by the poor animal, as opposed, to fat by the goodconditioned animal, which finally precipitates acute hypocalcaemla by causing some upset m the ratio of certain ions in the blood and tissues. Whatever may be the real explanation, the fact remains that the conditions shown to be associated with large outbreaks after lambing are preventable by (1) good feeding during pregnancy, and (2) good management, including the avoidance of extreme changes In the diet.

NYDFA MEMORIAL CUP

POINTS FOR COMPETITORS

SCHOOLING (Conttnued.)

(C.) Changing leg "at a canter in a straight line. A horse canters with his fore and hind leg on each side going forward at the same time* He is said to be “leading” with the foreleg which he puts forward the furthest. When a horse is cantering correctly like this, he is said to be cantering “united,” Sometimes he misses a pace, so that a fore and hind leg are not moving forward together. Then he is not cantering united, and his gait feels v«y rough. There is no “wrong leg for a horse to lead with. I mean. leading by either will be equally comfortable, as long as he is cantering united. Most horses prefer leading with one particular fore leg. Many get very set m that idea, and are hard to school into changing their legs. Willingness to change leg is not absolutely necessary a saddle horse, but it makes them far handier, and a horse cannot be considered perfect until he can do it. The first necessity is to get him to lead in his canter with which ever leg you wish. To canter with the off fore leading, “collect” your horse, slightly bend his head to the left, close both your legs, the left leg pressing toe stronger. By bending toe bead to toe left, the freedom of toe near fore leg is contracted, causing a natural tendency of the horse to lead withtoe other (o« fore) leg. To canter with the near fore leading, reverse toe above aids. When you have got him centering tight, start making him change leg. When beginning lean over and watch the horse’s, fore legs: you will soon see which leg he is leading with. A good way to start a horse changing leg is by cantering him in a figure of 8. When cantering in a circle a horse should land with tha teg nave* to tbs

centre of the circle. To complete each figure 8, y6u have to make one circle to the right and one to the left.. Start cantering in a circle to the .right, making sure that your horse is leading with the right leg. Just before you change to a circle to the left, check yotir horse and make him trot a few ppces, then turn his head slightly to the right and press him into a canter again. Be will spring into a canter leading with the left leg. Repeat this figure 8, gradually decrease the number of trotting steps till finally, as soon as you change from the right circle to the left, the horse will change leg without needing to trot at all. Then get him to change when travelling straight, or when or how you like. . . _ (D.) Running back, moving off after backward movement at a walk, trot, or canter, as required. Begin by teaching the horse to understand the word “back." Give him the first lessons in a halter, so as, to save his mouth. Stand in front of him, say “back” and tap hie shin very lightly with a switch. Tap the leg which you wish him to move next. Only put him back about three steps at a time. Then halt him and pause. When he begins to get the idea put the bit in his mouth, and get him used to becking from the bit Don't make it one long yank at the bit but intermittent pressure, giving him time to take one step between each pressure on the bit When he begins to step back well, do it from toe saddle, using your legs to Jteep his body Straight Always collect him after each reining back. Then to move forward at walk, trot, or canter after reining back. Your horse is, or should be, “collected,’ so you have only to apply the correct aids for whatever pace you wish to start at To step back steadily and collectedly is a very important part of any horse s training; and is too commonly neglected or is taught badly. You know the good old shaft horse, who pushes his load back just on the driver’s word to back. And you have seen the other ■ sort, his head in the air, his mouth wide open to avoid a hard hand on the bit and the load not moving back at all. Saddle horses need to back to learn the use of their hocks, and to gain handiness generally. (E.) Trotting out on lead. Don’t drag your horse after you like a toboggan. Hold the reins or halter rope about one foot from the horse’s chin in one hand, and the end of the reins in the other hand. Teach him to start forward on the word "hup.” rather than by dragging at his head. Some cats or sugar lumps in your pocket will help a lot. I would certainly teach him to lead on both sides. A horse should be trained to do everything on both sides. If he is one-sided in anything, it makes him awkward, and it may cause him to be dangerous on the untrained side.

THE “DUST BOWL”

AMERICA’S PROBLEM

An informative caller on the writer the other day was Mia# Apple, who, with a companion, McMil* lan, is temporarily attached to the A.C.E. (Association for Country Education) of the Universities of Otago and Canterbury, an association instituted under a Carnegie hequs*t The ladies have been secured on exchange frcml America for a period of six deliver lectures in Otago and Southland on home science to women's institutes, and close on four months of the period have passed. At the conclusion of the six months they will return to America. _ Miss Apple lived In Texas, and was brought up in a pari of the- States which now forms the M durt bowV* a wide expanse of country between the Rockies and the Mississippi river, which has been completely denuded of vegetation by wind erosion, Miss Apple has just received a number of papers imam tans tan tttastt*

In* and describing the method* beinf there is interesting to u* as showing the resists that can be brought about from the destruction et the native grasses. As the pabtogrMM and articles have told us b btW two years the districts are living en raasae gf in * country where they can make a WWfr leaving everytoing in the way « farm improvements and dwellings abandoned behind them.

Fatal Ploughing The process of deteriorafton k*r bee» unbelievably m|d4.«cemdiagJo Wm Apple. Before 1926 thejnmww « thousands of acres which no* prise the “dust bowl" were egifkl ranch cattle on good »*tive Then toe high price of wheat intrigued farmers to plough toe countonup. tb* ploughing was only U iPW •» yet yields of more than SObtofeefc to the acre were not infrequent, A* toe comparatively high .pride* ruling fortunes were quicklymade. _ Then came the aftermath. The surface of toe soil, turned Into «u*» which jnoved in cloud* SCTOSS the landscape,.partially bmytogjßmn steadings and homes mwf Jggßgg the production of Harm «ropa awns* sible. As stated, mmqr thousamte, C« people have just walked off with toe hope that they wlli secure a of farm land that will not have toba nailed down. The land, it was learned too late, should never have -bef? P However, science is attempting * secure a "come-back” of .toe 4 A system of contour fanning Ip being adopted, which means teat tod mu m being built up into sidtifigs WWW fg furrows to hold the rains. This eon* served water is held in the fjg* rows until it percolates through the soil Besides aiding toe quick »• . mination of the grass, seed.scwn, it wg retard, so it is hoped at all svttH w soil “walking away.” An illustration in one of w.c papers received by WSi j —>le shows a "pasture contour” after a tittle more thuja an inch of rate fell. The contours appear to be homing .the water successfully. The old native grasses which clothed these millions of acres before the plough was unwisely put in will be resown. It is believed that the grass will hold and that tea regeneration of toe waste utiß weem* an accomplished toot In the course of time.