Question re freezing ram semen

When we collect ram semen to freeze (we use Triladyl), we usually find that the first collection each day does not freeze as well as the later collection, even though semen quality is apparently the same. So..we often discard the first collection on principle, and freeze the subsequent collections.

Not sure what cause this this variability, perhaps differences in seminal plasma?

Is this a common, or reasonable policy. Or are we throwing out good semen?

One thought on “Question re freezing ram semen

  1. Peter-we see a very similar response unless the rams are on an intensive collection schedule. So, if we are only collecting rams once or twice a week then we also see what you described. However, there are situations when we are collecting rams that are fully in season, have been teased by ewes in heat, and are in a collection schedule where we collect them in the morning and afternoon for up to 3 consecutive days, then we do not observe that low sample quality that you described. This suggests that there is an “aging” of the sperm in the cauda epididymis or some effect of the seminal plasma on that “aged” sperm as you suggested. Consequently, when we collect a ram we always have multiple collection tubes (if electroejaculation is used) or multiple prepared artificial vaginas so that we can clean out via the first mount and then collect a quality sample off of the second mount. We do always check the first sample as we do not want to throw anything away either.
    -Phil Purdy, USDA National Animal Germplasm Program


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