Review on the consequences of using Improvac TM in modern pig production

In Europe growing concerns regarding animal welfare issues in pig production have forced the pig industry to introduce alternative methods to conventional castration procedures. Besides the raising of entire males and castration in combination with analgesia and anaesthesia the vaccination against GnRF (Gonadotropin-releasing factor) seems to be the most promising long-term solution. Immunised male pigs (IM) show higher average daily weight gain than surgically castrated males (CM). Additionally the feed intake in IM is lower than in CM and feed conversion ratio is consequently better. Carcass weight, back fat depth and dressing percentage of IM pigs are intermediate between CM and entire males while meat quality seems not to be influenced by castration technique since CM and IM show comparable results. Steroid hormone concentrations in IM decline to very low levels (below detection line) after the second administration of the anti-GnRF vaccine and boar taint compounds are reliably metabolized. Pigs which received two injections of the anti-GnRF vaccine reduce their sexual and aggressive behaviour to levels of CM pigs which results in low incidents of injury and carcass damages. Surveys analyzing the consumers’ attitude to vaccination against boar taint reveal that if profound information on the technique is provided, the acceptance of meat from vaccinated animals is even better than the acceptance of meat from pigs castrated under current farm conditions. Furthermore economic analyses reveal that immunisation against GnRF provides a potential for a return on investment since better feed efficiency compensates for the additional costs of drug and labour time.