Currently, sacrificing an animal gets you 7 favor, maximum, possibly getting you less depending on the age of the animal.
This is really bad.
Animals aren't exactly in infinite supply, so why not increase the amount of favor you get from sacrificing one? 1-7 favor is so low it's hardly worth doing except in case of emergency. Multiplying the current values by 4 or 5 would actually give people an incentive to do it.