Loading...
The Rural Voice, 1981-01, Page 4i Artificial insemination Every farm can have its own geneticist BY BEV BROWN If you had told your grandfather that some day it would be possible for his cows to give birth to calves without ever having been near a bull, he would have taken you out to the woodshed to whip some sense intoou. It was traditional for a dairy or beef -farmer to keep a bull -- usually penned up in the barn. but often allowed to run free in a field. Almost every farm family can relate a tale about someone being chased, gored. crushed or otherwise maimed by the herd bull, and often the victims were children. But herd improvement, not personal safety, was the motivating factor behind the founding of the first artificial insem- ination unit in Ontario established at Waterloo in 1941 on the suggestion of a prominent Galt Jers4 breeder William J. Henderson. (Units in Nova Scotia and Manitoba had started in 1940). E.I. McLoughry, agricultural representative from Waterloo County at the time, was active in the development of the A.I. program right from the start. The Unit appointed Dr. J.E. Johnson. a well-known Waterloo veterinarian to act as technician in charge of the insemin- ation work. "The difficulties encountered by this pioneer group were many," Dr. Johnson wrote in later years. "The most significant was the complete absence of any enlightening literature as to the practical procedure of artificial insemin- ation. As I remember, one short article on tlie, subject gave instructions to heat _the (artificial) vagina with water to 10 to 110 degrees Fahrenheit. This alone may have been the cause of our failure with the first bull purchased by the Unit. Moreover, the usual substitute for a female was a wooden dummy covered with a buffalo robe, which our heavy Rowsdale bull broke down on the first jump." The bull was used too often, and, needless to say, this situation did not continue tor long as the animal did not stand up to this abuse. Dr. Johnson finally travelled to Bing- hampton, New York, where a successful breeding club had been functioning for several years. "This trip proved to be of great benefit for future work as the PG. 4 THE RURAL VOICE/JANUARY 1981 technique learned there is much like that used today," Dr. Johnson wrote. "Dilu- tion of semen was found to be practical and the temperature of the water used in the artificial vagina was corrected (to 120 degrees F.)." Following this trip several different bulls were selected and eventually a stable for the bulls was rented from the, Maple Lane Dairy in Waterloo. But it was inconvenient having the laboratory and office several miles from the bull, so in January, 1947 the number of bulls was increased and the complete unit, includ- ing lab and office, established under one roof. The organization was called the Waterloo Cattle Breeding Association and it serviced the countries of Waterloo, Wellington. Bruce and Huron, plus a small part of northern Perth and a narrow strip of western Grey. A LONG HISTORY But the history of A.I. goes a long way back. In fact, at least one case of an animal being bred artificially is reported to have been accomplished in the 14th Century. In 1900. Ivanoff in the U.S.S.R. began experimenting with artificial in- semination of horses. At about the time of the First World War in 1914, necessity became the mother of invention, when a venereal disease hit horses used in the Russian Army and Ivanoff's technique found application. In natural mating, nature is wasteful. Millions of sperm are ejaculated, while one eventually fertilizes the egg. By extending or diluting the semen, a bull can father literally thousands of calves in one year. Individual sires vary greatly. but an average ejaculate, when extended, will inseminate approximately 200 cows. Semen from each bull is usually collected at the breeding unit once or twice a week. It is then taken to the laboratory, immediately adjacent to the semen collection area, for evaluation and processing. Any sudden change in temp- erature is detrimental to the life of the sperm in the semen. In general, samples are selected on the basis of four tests: motility (ability to move) of sperm concentration, percentage of live and of abnormal sperm. Some samples are discarded at this point in order to supply semen that will maintain a satisfactory fertility After being evaluated, the raw semen is mixed with the extender solution (specially prepared homogenized whole milk, plus antibiotics to control bacteria, and glycerol) and then cooled to 40 degrees F. by a series of water baths over a two-hour period. One dose. in plastic straws or ampoules of extended semen containing approxi- mately 12 to 20 million live sperm. is used for each insemination. FREEZING AGENT The use of frozen bull semen increased when it was discovered that liquid nitrogen could be used as a freezing agent. Sperm cells remain dormant in a frozen condition providing the tempera- ture remains at least minus 79 degrees F. and semen can be stored in this liquid for an indefiniite length of time. Calves are being produced today from semen that has been frozen and stored for more than 15 years. However, occasionally the semen from a sire does not freeze satisfactorily. When this problem is identified, through periodic checks of the semen under the microscope. the sire is removed from the unit's stud. Today,a dairy farmer does not need to spend thousands of dollars for one bull; nor does he have to keep a dangerous bull in his herd. Through the stud units established by United Breeders Inc. (Guelph) and Western Ontario Breeders (Woodstock) he has access to superior bulls from across North America. When breeders assess the cow to be bred. for type. milk and fat production. they can choose the sire that is expected to improve on her short -comings in the resulting offspring. If a sire produces a great number of female offspring that are above breed average for butterfat production, then he is a fat production improver. This same