ARCHIVE FILE
This article was published in 1949
See the original document
INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.
STERILITY IN CATTLE
Some General Notes
H. E. R. BEATTIE. B.V.Sc., H.D.A., Veterinary Research Officer, Glenfield.
Applying the term in a broader sense, to cover lowered fertility in various degrees, sterility is an important and complex subject offering considerable scope for further investigational work. Inadequate though our knowledge might be regarding some of the many diseases of which sterility may be a manifestation, we do know that much of the trouble can be prevented, or overcome, by due attention to nutrition, hygiene, management and culling, and that in many instances certain accepted lines of treatment appear to be fairly effective.
In conneetion with nutrition, two case records made available in 1934 by Mr. Hindmarsh, while stationed at Glenfield, might serve as interesting examples. The first concerns a dairy farmer who sought advice because his 13 cows had failed to come into season for periods varying from seven to 16 months. Seasonal conditions had not been good and they were running on rather poor country withont any additional feeding. In view of the food materials readily available at the time, a daily supplement of 2 lb. pollard, 2 lb. corn meal and 4 to 6 oz. bone meal was given to each of the cows for five months. During this time six of them came into season and bred; while none of the four still depending solely on the natural pasture showed signs of heat.
The second case was that of four "Heifers," four years of age, which never had bred and apparently never had been in season. Their only feed was that obtained by grazing on poor sandy country. The owner was advised to offer them a daily ration of lucerne hay, maize meal and bone meal; and within four months all had bred. It will be noted that in both these instances a suitable mineral supplement was provided.
Under the hygiene heading perhaps may be included a reference to certain types of treatment often undertaken by farmers themselves or by patent nostrum vendors. He who pins his faith to, say, a foaming "vaginitis mixture" of his own concoction, and delights in the sight of a stream of innocent heifers, tails held high careering across the paddocks blowing blue and green bubbles from the vulva, may be difficult to convince that he is doing more harm than good. Apart from the fact that a dangerous degree of irritation may be set up within the vagina, such materials are all too frequently introduced by plunging a dirty, wicked-looking nozzle indiscriminately into the vaginae of cows And heifers, diseased and healthy, without any attempt to clean—let alone sterilise—the instrument of torture either before commencing or between "patients".
Again, having found a marked vaginitis or purulent metritis case a well-meaning man might proceed with the examination of other cows for similar signs without so much as washing his hands. (The same man might he scrupulous in his attention to hygiene at calving time). As well as setting an example in this regard, we of the veterinary profession should see that we are above suspicion regarding the possibility of conveying infections from farm to farm.
The matter of management would be difficult to deal with fully, but mention well may be made of one important aspect of it which seldom receives sufficient attention, vis., the keeping of full breeding records. Even the farmer progressive enough to record milk and butterfat production figures seldom enters more than service and birth dates and calf sexes in his breeding records. By extending the scope of such notes, and making them available for inspection, farmers would benefit individually, and collectively could make a considerable contribution to our knowledge. Such data might include the number of females served by each bull, and the calves resulting; the dates of all heat periods, with notes as to their duration and nature in unusual cases; any abnormality in colour or consistency of oestral mucus; and any abortions, dystocias, retentions, discharges,etc. Most farmers would plead lack of time as well as inclination, and not unreasonably; but is there sufficient excuse for the other extreme, when we cannot find out even which cows have been returning to the bull, nor how often?
Trichomoniasis is among the various diseases of which fertility reduction is a manifestation, and in the location and control of which adequate breeding records would be of great assistance. This disease, which apparently soon would disappear but for the part played by bulls acting as reservoirs of infection and vehicles of dissemination, may prove to be fairly widespread in our herds. Early abortions might occur more commonly than is realised; and certainly cases of cows returning several times to the bull, though not showing an obviously abnormal uterus or discharge, are by no means rare. It seems that cows usually will recover spontaneously from the disease within a few months if not subject to re-infection—as by mating with an infected bull. Thus it is more case in which any treatment adopted might be given undeserved credit as a "cure".
Artificial insemination offers a means of rapidly reducing the incidence of various genital diseases, including trichomoniasis. According to one report from U.S.S.R., the incidence of sterility in dairy herds on collective farms where A.I. was practised fell from almost 20 per cent. to about 6 per cent. in a three year period in the middle 1930's. Such results could be achieved only where the operation was correctly and carefully carried out, of course; and it should be made clear that in cows which already have diseased breeding organs, artificial insemination is rarely any more effective than natural service.
The question of culling is one which must be dealt with on its merits in any given case. Brucellosis might present special proldems, particularly now that "Strain 19" is being used more widely. We are fortunate in having so reliable a diagnostic measure as the agglutination test, and should not hesitate to use it. Also, we should remember that brucellosis in not necessarily the culprit in cases of lowered fertility associated with abortion and/or placental retention.
On setting out to investigate sterility trouble in a herd, having obtained as full a history as possible, (including that relating to any introductions or outside services) and considered nutrition and the animals' bodily condition, we might first look to the bull. If possible watch him at work. He may not be able to serve properly, though perhaps appearing to do so. Next, manual examination of the scrotal contents might show, for instance, flabbiness of the testes—in which case the semen should be examined. Collecting a sample from the vagina of a cow immediately after service, though not ideal, is perhaps the simplest method practicable on the farm. Rectal manipulation is not so difficult as may be imagined, but hard work for 10 minutes or more is often necessary. In some cases ejaculation occurs when one stops for a rest, so warn the assistant holding the receptacle to remain prepared. He should try also to avoid collecting any urine which might dribble out during the operation. Samples collected in this manner often show a high pfignertion of accessory secretion, and may give a misleading sperm-concentration picture.
Having secured a semen sample, if at all possible make a microscopic examination immediately, or within an hour or two, at most, for motility. Movement may be detected even with the naked eye in a good sample. The sample should not be exposed to direct sunlight. Smears suitable for staining should be very thin, and may be prepared similarly to blood smears or by blowing. If thin enough they will dry rapidly. If 96 per cent. alcohol in not available, fix by immersing for a minute or two in 5 per cent. formalin and then wash with water. Simple stains are satisfactory; or a special mixture such as 1 per cent. methylene blue in 2 per cent. borax may be preferred. In an emergency try a few drops of ink from your fountain pen.
To obtain specimens from within the prepuce for bacteriological examination it is generality necessary to throw the bull—by the half-hitches or other suitable method. Precautions should be taken against contamination. At Glenfield a piece of brass tubing sometimes is used to cover a cotton wool swab pad and portion of a length of wire to which the swab is attached. The wire passes through a cotton-wool plug in one end of the tube, the other end also being plugged except during the actual operation. The tube is inserted into the sheath, and the swab is pushed out and pulled into the tube again by means of the wire before withdrawing the tube and replacing the plug.
Coming to the cows, the owner might raise the question of a bloody discharge from the vulva a day or two after oestrus. This probably occurs far more frequently than it is observed. Some farmers regard it as a sign that the service has been successful, and some think the reverse. While the origin of this blood is not yet clear—haemorrhage from the anterior vagina, the cervix, and the cotyledons being among the explanations suggested—it seems fairly safe to take it as indicating that heat has been followed by ovulation (rather than by continued growth or by regression of the follicle). Thus all it means is that service during that heat period would have been successful. If seen about three weeks later, of course, it is a sign that another heat has occurred, perhaps unobserved, and usually will mean that the cow did not conceive to service three weeks or more earlier; though add rows do occasionally show marked signs of heat while in calf.
When examining cows in season, a whisp of clear mucus suspended from the vulva does not necessarily mean that no pus is present in the vicinity of the cervix. Also, whitish flecks may not be abnormal in the oestral mucus, particularly towards the end of heat; but something similar might be due to trichomoniasis. An oily lubricant used on the hand or speculum might make the mucus appear abnormal. Reddening due to "heat" might give rise to unwarranted suspicion of vaginitis. If doubtful as to whether or not a cow is in season, then, in addition to considering the quantity and nature of mucus one may check up on the state of the cervix (either visually, or with a finger tip against the os), which normally is relaxed, or "open" during heat. At other times it should be closed, except at and immediately after parturition. Don't try to introduce either the hand or a large speculum into the vagina of a small heifer!
Manual examination per rectum in also of assistance in this regard, the normal healthy uterus usually being tense and the cornua tightly coiled during heat; and there should be a ripe follicle in one ovary. The feel of a follicle is as of liquid under pressure, whereas that of a corpus luteum rather resembles sponge rubber.
If unaccustomed to picking up breeding organs P.R., do not be misled by the bladder. The cervix lies on the pelvic floor and should be freely movable in the nonpregnant cow. In young animals, the cervix may not be readily recognisable, but the uterus is located easily because of its shape. In many metritis cases the uterus tends to depend over the pelvic brim, or to do so to an abnormal extent.
A large, hard uterus may indicate a chronic metritis. A sub-acute case with pus might present an enlarged, flabby uterus with a doughy feel and hanging well forward over the brim. Differentiate from on early pregnancy by the fact that in the latter the contents are more resilient. the enlargement is more marked in one horn and there is a corpus in the ovary of the same side. (Some sensitive fingered folk can detect the amniotic vesicle—like a little balloon approximately 1½ inches long—about the level of the external bifurcation, by about five weeks. The hanging over the brim really begins during the third month; and from about 4½ months the cotyledons can he felt bobbing about under the fingers, while there is a strong pumping surge through the uterine artery supplying the pregnant horn. During pregnancy a sticky plug may be felt in the cervix, and the uterine mucosa feels rather dry.
History and ovary examination might reveal retained corpora lutea or cysts, which often can be expressed or ruptured manually; usually correcting nymphomaniac tendencies tendencies or the opposite extreme. Mere massage may have a salutory effect if reasonable pressure does not produce the desired result.
Stilboestrol preparations may be helpful in cases of non-pregnant animals not coming on heat, and where a retained corpus cannot be felt. We use them for various purposes; bovine dose rates usually ranging between 20 and 40 mgm., intramuscularly. Retained membranes may yield (within 24 hours or so) to one dose; or their subsequent removel might be simplified thus. A practitioner from another State claims great results in such cases from stilboestrol given by mouth. Apparently he uses 5 x 5 mgm. tablets per day for three days.
Stilboestrol sometimes is used in the treatment of metritis, alone or more usually as an adjunct to the old iodine therapy, or to intra-uterine propamidine,etc. Heat may be prolonged in this manner, or the signs may be induced—appearing usually one to four days after administration. By opening the cervix it facilitates drainage, if nothing else. We generally make the injection at the time the iodine or other substance is introduced; but if difficulty in passing the uterine catheter is anticipated it may be administered beforehand. Cows usually come back on to their normal cycles after such treatment; i.e. the next (normal) heat period generally occurs less than three weeks after that which was induced artificially.
Propamidine—an M. and B. product—is reported to have given promising results overseas in the treatment of bovine metritis. Limited experience in this district suggests that it is at least as good as iodine, and might prove better in some types of metritis. The recommended dose of the special intrauterine preparation is about 3 oz., which may be repeated on the third day. Except for one owner reporting that a heifer had behaved in such a manner on the day after treatment as to suggest marked irritation in that instance, we have not encountered any indication of ill-effects.
For introducing such fluids into the uterus, we use a 4 oz. metal syringe, connected to a uterine catheter by use of an old milking machine rubber or similar tubing. It is found that, with practice, the catheter usually can be passed, even when the cow is not in season; in the same manner as is the inseminating tube. i.e., by manipulating the cervix through the rectal wall. The alternative is to grip the rim of the cervix with vulsellum forceps per vaginam. It seldom will be possible to pass a catheter right through the cervix without holding the latter by one of these methods. We generally use a long catheter with only a slight curve towards the free end.
At least one well-known practitioner of our acquaintance prefers the "aqueous" (Lugol's) iodine preparation to the I per cent. iodine in liquid paraffin mostly used here for metritis cases, and uses up to 8 oz. for heifers and to 12 or 16 ounces for cows. He claims good results, and apparently has no reanon to suspect deleterious effects, so perhaps the writer's fears that such volumes might rupture the uterine wall or give rise to salpingitis or even peritonitis (by forcing pus and iodine through the tube!s) are illfounded. Nevertheless, some trace of the caution engendered by our trials with specimens from Homebush abattoirs lingers on. It was following such experiments that we reduced our quantities from 6 or 8 oz. to 4 oz. An alternative method is to keep pumping the mixture in until that running back between catheter and cervix appears quite clean. Though still doubtful about the wisdom of adopting this procedure, we believe that sometimes it gives better results than the 4 oz. routine.
As already mentioned, "time" seems to cope with some sterility comes unaided—and we cannot always be sure that our intervention really has helped. If planning to let time and nature have a hand in any give metritis case, do not overlook seasonal considerations—remembering that bovine pregnancy is often more difficult to bring about in winter than in spring or summer; also sometimes after a long "empty" period.
It in hoped sincerely that the patient reader may have gleaned a new clue or two from the foregoing remarks, which well might have been headed "Beating About the Sterility Bush." Frankly, the writer does not feel competent to deal with this subject in a satisfactory manner, despite a great amount of experience gained in the course of artificial insemination and other duties; but should these efforts stimulate additional interest and discussion, resulting in a pooling of resources as between Inspectors, they will have served a useful purpose. Finally, and in fairness, to his Glenfield colleagues, perhaps it would be as well if the writer were to stipulate that "though based firmly on practical experience, the opinions expressed herein are not necessarily those of this Station."