Answers first, then the math
Most farm questions have a number at the end of them: how long she's pregnant, how many bales to buy, how much meat comes back from the butcher, what day the eggs hatch. These guides give that number in the first two lines, then explain what moves it — breed, body weight, weather, waste, how the animal is fed — and hand you the calculator to run your own figures.
Every number here comes from typical university extension and breed-association guidance, and matches the calculators on this site, so a guide and a tool never tell you two different things. Where a range is normal, we print the range rather than pretending a single day or pound is exact. For anything to do with an animal's health, medication or a dose, talk to your vet: those pages don't exist here on purpose.