RUMA and almost all farming and veterinary organisations in the UK do not support routine preventative treatment, and agree that preventive treatment or prophylaxis with antibiotics:
must only be applied to animals diagnosed at high risk of bacterial disease, and
must only occur under prescription by a veterinarian on the basis of epidemiological and clinical knowledge, and
must not be applied systematically or routinely, and
must not be used to compensate for poor hygiene or for inadequate husbandry conditions or where improvements in animal husbandry could reduce the need for antibiotic treatment.
may be appropriate on a temporary basis, to prevent disease in animals while the vet and farmer make improvements to bio-security and animal husbandry on the farm, to reduce the likelihood of subsequent batches of animals requiring treatment in this manner.
Thus there sometimes is a strategic or veterinary need for preventative treatment hence preventative treatment should not be banned, but preventative use should not be routine.