STERILITY IN COWS

Manawatu Times, Volume LIV, Issue 6849, 2 March 1929, Page 12

STERILITY IN COWS

Causes and Cures METHOD OF TREATMENT

An- interesting paper on sterility in cows and methods for its prevention, control ,and eradication, was read at the Science Congress by Dr W. C. Eing, an Auckland veterinary surgeon, who recently returned from a visit to America, where he gave particular study to the question. In treatment of his. subject, Dr Eing divided sterility into two main classes: Temporary, where reproduction occurred irregularly, or where, for a limited period, animals fail to produce, and permanent sterility. The importance of sterility to the dairy industry could hardly be over estimated. I't was a constant drain on all, and at times almost, if not actually, put some dairymen out of- business. Undoubtedly the present day craze for establishing milk records was responsible for a fair share of sterility. Cows fed highly on concentrated protein diet, and milked three or more times daily, or those fed so as to produce excessive fat for show purposes, often became sterile. The feed might not be wholly responsible; there was a heavy drain on the cow. Certain relationships between the udder and the ovary, not yet understood, might exist but continual and over-stimulation of the udder possibly reacted detrimentally upon the ovary. Cystic ovary was common in such cows.

Infection by the Bang bacillus was a great' factor in the causes of storility. The disease known as granular vaginitis, of which there was much in New Zealand to-day, yielded readily enough to suitable treatment, but Bang’s disease stood in a different light. Infection by the bacillus Bang appeared alone to be sufficient to cause sterility, but the act of abortion was only a symptom of the disease and was not. always present.

Prevention and Control. Bang’s disease might exist in a herd where certain cows delivered calves at full term, or a little before. At other times sterility was the first clinical indication of infection. In one case as in the other, if a blood test was made, the presence of tho Bang bacillus was nearly always shown, and if a laboratory test was not made a series of abortions appeared later, perhaps a year or even two years later, clarifying the situation. These facts had thrown a new light on the relations of contagious abortion and sterIn constantly infected herds the disease, abortion, manifested itself in periodic outbreaks. Dor instance, a bad season of abortions was usually followed by a milder year. The owner having in his extremity been induced to use some medicant or other, or even allowed his herd to be vaccinated, naturally believed by this time that his troubles were over and praised loudly the benefits to be obtained from certain cures. Unfortunately the tendency of Bang’s disease to manifest itself vigorously every fifth or sixth year quickly banished the cures, and opened the road for some new remedy which unscrupulous vendors were ready to offer. ■

One course only presented itself to the dairy cow owner to-day and that was prevention, control, and final eradication of Bang’s disease by means of blood testing, rigid quarantine of reactors, and the raising of non-infccted herds and keeping them free from infection.

The methods were as follow:—The systematic blood testing and prompt removal of all reactors in the herd until finally a negative herd was established. No herd could be considered negative until all its members had passed blood tests every tivo months for one year. Calves from infected dams as well as negative dams, if tested at six months old and found to be negative, were kept entirely away from any other cattle until after they calved themselves. They w r ero blood-tested onco moro after calving, and if negative might join the negative herd. Bulls after testing must only serve negative herds.

Certain Check on Disease. Ono feature of the testing must always be kept in' mind. Pregnant cows frequently failed to react to the blood test, but, if infected, they reacted in from 14 to 28 days after calving. Therefore new cows joining the herd must on no account be allowed to do so until having been tested from 14 to 28 days after calving, i The milk loss in abortion infected herds was enormous. Many animals were being maintained at a loss. It could now be stated definitely that this i condition of affairs need exist no longer. A close co-operation between dairymen and veterinarian, some patience, determination, and a rigid enforcement of the laws of the plan, | would rid the dairy industry of the greatest handicap that now hindered its i progress. | It was believed in America that the ! disease could communicate itself to human beings, particularly through milk, and the pasteurisation of all milk not obtained from negative herds was j advocated.