Bucket training calves will save time. When doing a couple calves, bottles are a great option. When trying to feed 20+ calves in a short period of time, buckets are the only way to go. When I worked on a big dairy in high school we had about 50 bottle calves at a time. For the first few days of their lives, they were on bottles. After about 4 or 5 days, we bucket trained them. They were in hutches and there were pail holders so the calves couldn't spill them.