Using a birthing rack will probably end with close results.
I mean in theory if all 43 females dropped litters of 10=430 babies....
one month gestation+one month in the birthing rack+ one more month of gestation= 430 babies over 3 months time frame
that's roughly 144 a month.(430/3)
That's building of 2 racks and down time you could be producing for a gain of 19 babies a month.