Effects of intratesticularly administered zinc tannate (ZT) on growth performance, sexual development, slaughter, carcass and meat quality characteristics of young bull calves (-225 kg, 7 months old) were investigated. Comparisons were made across a three (treatments: ZT animals, intact bulls and burdizzo-castrated steers) by two (slaughter masses: 350 and 440 kg) factorial arrangement. In a separate trial, sexual male behaviour of ZT animals was compared to that of bulls, surgically- and burdizzo-castrated animals. Bulls (B) and ZT animals gained mass faster (P <0.05) and more efficiently (P <0.05) and produced carcasses with less total fat (P <0.05) and more muscle (P <0.05) than steers (S). These differences coincided with higher plasma testosterone levels (P <0.05) in the B and ZT animals in comparison with that of steers. However, higher relative mass and meat distribution in the forequarters, lower meat quality (tenderness) and persistent bull-like behaviour of ZT animals were detrimental. These characteristics could also be ascribed to retained testosterone production. ZT administration caused excessive swelling of the testes and necrosis of the testis parenchyma, especially in the direct vicinity of application. No live sperm could be detected 30 days after application of ZT. Sufficient Leydig cells were left intact, however, to maintain plasma testosterone levels comparable to that of bulls (P >0.05). Signs of pain and discomfort were observed directly after treatment with ZT. The study of the behaviour of ZT animals in a feedlot, indicated that they persisted with bulling and mounting behaviour normally associated with intact animals. Although ZT offers positive growth response and therefore seems to be a promising alternative to surgical or burdizzo castration, the negative side-effects hamper its further development.