Animal breeding / by Laurence M. Winters.

  • Winter, Laurence Merriam, 1891-
Date:
1925
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Animal breeding / by Laurence M. Winters. Source: Wellcome Collection.

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    SPERMATOZOAN VITALITY UNDER ARTIFICIAL CONDITIONS 43 and in front of the cervix. The semen is then injected into other females by one of two methods: one is to insert the syringe directly into the vagina of another mare, injecting the seminal fluid into the uterus; the other is to take the gathered semen to a laboratory or warm room, there loading it into capsules, one of which is inserted into the uterus of each female to be bred. The latter method is more fre¬ quently practiced with the condom method of gathering semen; it allows for more wholesale breeding; but it has the disadvantage of retaining the semen outside the body walls for a longer time and also of not injecting as much semen into the uterus, thereby greatly reducing the chances of conception. 43. Spermatozoan Vitality under Artificial Conditions.— The ability of the spermatozoa to \A'ithstand light, air, heat, and cold, and remain vital outside the animal body is of immense importance in artificial insemination. As the result of detailed studies covering these points in the horse, Anderson ^ found that spermatozoa remain active longer at a temperature of 22° C. than at 38° C. (blood heat); but that in any case, 30 minutes is perhaps as long as they can be kept and used with safety. The reason for this is that the albuminous character of the semen makes it an ideal medium for bacterial growth, and the warmer temperature is more favorable to such growth than the lower one. On the other hand, exposing the semen to extreme cold (0° C.) rendered 50 per cent of the spermatozoa inactive within 30 minutes and 95 per cent inactive within 70 minutes. Extreme heat was equally disastrous, 25 per cent being rendered inactive after 321 minutes' exposure to a heat of 46° C. and 95 per cent, after 44^ minutes. Light, which has usually been regarded as very injurious to the life of the sperm cells, was found to have very little effect upon them. Direct sunlight appeared to have a stimulating affect upon the spermatozoa; but because of ^ Anderson, W. S., Kentucky Research Bui. 239.