Investigation of prevalence of supernumerary teat in livestock

Abstract

Supernumerary mammary teat or "polythelia" is a congenital and inherited defect in the mammary gland of cattle, sheep, goats and swine. This report intends to investigate the genetics behind the disorder in each of these species and the consequences it has. The normal Bovine udder consists of four mammary teat each connected to a milk producing mammary gland while Ovine and Caprine species usually have two teats to feed their young and Swine have six or seven pairs on average. The anomaly that some individuals could be seen to have extra or supernumerary mammary teat (Figure 1) gave rise to the suspicion that these animals may be able to produce more milk for their young and that they would be more liable to have multiple offspring. This lead to much research in order to see if we could capitalise on this genetic property. For my thesis I have chosen to base my knowledge on several journals in which I have collected and are listed in my references. I utilised many journal databases for my search; such as ‘pubmed’, ‘Science Direct’, 'Taylor Francis online' and ‘CAB abstracts’ to obtain several up to date publications related to my topic. I then analysed and investigated the results to which have referenced when relevant throughout my work.