A number of studies suggest that calves purchased as steers gain faster and require fewer treatments the first 30 days following arrival at a feedlot than calves purchased as bulls and castrated upon arrival. Moreover, the steers continue to gain at a faster rate than their newly-cut counterparts. He says the best time to castrate is between birth and four weeks of age, when there is less stress on the bull calf. Also, in a spring calving herd, the fly population is from small to nonexistent at the time of calving. This results in a reduced chance of wound infestations by parasites and reduces excessive bleeding.
Thrift favors knife cutting bulls.
The Extension livestock specialist recommends twisting the scrotum and cutting about halfway down, then removing both testicles with a pulling motion, severing the cord. But it's been my experience that you can cut two or three with a knife by the time you can band one. If bands are used, the ring must be tightened enough to cut off the blood supply to the scrotum. If the procedure is completed properly, the scrotum, with the Ring and Clip intact, will drop off within 20 to 40 days. At this stage of the process the scrotum should be healed and the possibility of infection minimal.