the collie would probably find it the easiest out of the 2 for giving birth ....
imo it wouldnt matter which way round the mating was , as it makes no difference to the pups
I thought like BBB, the greyhound pups would be bigger than collie pups, so the collie would go on top?
most half cross collies seem to level out at the same height no matter which way round there bred going by what ive seen and read