ok
so dispite no one replying here is my experience
I used royal canin ht42d food with a few bitches they ALL missed I then tried it again on the next set of seasons and again they all missed.... in this time I had 2 bitches mated by my kennel maid to earn herself overtime which I didn't want mated, these were NOT fed this food as were not to be mated, BOTH got pregnant... I started to think it was this food affecting the dogs ....
the next time I had seasons I fed the girls to be mated on proplan puppy and mated 4 up expecting and hoping that one or two took, I used this food as a friend suggested it.... all 4 got pregnant and we had 29 pups in total... complete havoc but lovely....
over the last few years ive had small litters other than darcey having a litter of newfies 9 in total, she spent her season away from here and fed proplan puppy.....
just saying......