As soon as the testicles have desended I believe, which happens around 6 months, or earlier, I think. However, unless a female is in heat she cannot get pregnant. Females generally have their first heat between 6 & 12 months of age though. So a 5 & 7 month old pair is very risky. That is plenty old enough to get spayed & neutered even for the most conservative vet or owner.
A sirloin roast of 8- to 12-lbs will take 16-20 minutes for rare, 20-22 for medium rare, 23-25 for medium, and 26-30 for well done. A boneless top round, by contrast, will take 28-30 minutes for rare, 30-33 for medium rare, 34-38 for medium, and 40-45 for well done.If you roast at 325Â°F (160Â°C), subtract 2 minutes or so per pound. If the roast is refrigerated just before going into the oven, add 2 or 3 minutes per pound.ow long and at what temperature should I cook a beef roast in the oven? Roasting is a great cooking method for a large, tender cut of beef  such as a rib or sirloin roast.
If youâre cooking carrots and potatoes with the meat, consider adding them about halfway through. A four-pound roast will take four to five hours on HIGH, or eight to nine hours on LOW. Cabbage doesnât take much time to cook, and can be added in the last hour.