Folks, I Have said this many times in the past and I will stand by it --
Simply put -- if you want to increase your chances of more bulls versus hfrs, if only slightly -- make sure you are breeding later in the cycle -- WELL after all activity is done. Male sperm cells swim faster, but don't live as long -- so if you breed her closer to her natural ovulation -= up to a reasonable point any way -- the chances are greater that the first cells to arrive in the ovaduct will be a higher percentage of male cells.
The earlier you breed and still get her pregnant will increase the chances of more hfrs -- due to the fact the female cells live slightly longer. Breeding too early in dangerous -- be carefull!
Terry