| dc.description.abstract | Background Two bovine species contribute to the Indonesian livestock, zebu (Bos indicus) and banteng (Bos javanicus), respectively. Although male hybrid offspring of these species is not fertile, Indonesian cattle breeds are supposed to be of mixed species origin. However, this has not been documented and is so far only supported by preliminary molecular analysis. Methods and Findings Analysis of mitochondrial, Y-chromosomal and microsatellite DNA showed a banteng introgression of 10–16% in Indonesian zebu breeds. East-Javanese Madura and Galekan cattle have higher levels of autosomal banteng introgression (20–30%) and combine a zebu paternal lineage with a predominant (Madura) or even complete (Galekan) maternal banteng origin. Two Madura bulls carried taurine Y-chromosomal haplotypes, presumably of French Limousin origin. In contrast, we did not find evidence for zebu introgression in five populations of the Bali cattle, a domestic form of the banteng. Conclusions Because of their unique species composition Indonesian cattle represent a valuable genetic resource, which potentially may also be exploited in other tropical regions. Introduction Several bovine species have contributed worldwide to cattle livestock [1]. Most domestic cattle belong to the species Bos taurus or Bos indicus (zebu), which both descend from the wild aurochs (Bos primigenius). Domestic yak (Bos grunniens) is kept in and around Tibet, the gayal (Bos frontalis) of Eastern India is derived from the gaur (Bos gaurus), while the Indonesian Bali cattle is a domestic form of the banteng (Bos javanicus). Despite their obvious role as livestock during our cultural development, the history of domestic cattle has been poorly documented. For the past 15 years, DNA analysis has allowed a phylogenetic reconstruction of the earliest events during domestication [2], [3]. For instance, analysis of mitochondrial DNA established a taurine maternal origin of zebu breeds outside Asia [4], [5]. Indonesian cattle breeds are supposed to be derived from zebu as well as from banteng [6]. Domestic Bali cattle is kept on Bali, East Java and on isolated regions on Sumatera and Sulawesi. It offers the advantage of a high resistance against most diseases, a remarkable ability to grow on low-quality fodder and a high fertility [7]. On the other hand, Bali cattle cannot be reared very well together with sheep because of their susceptibility to malignant catarrhal, while juvenile mortality is relatively high. A deer-like temperament makes them most suitable for intensive village-based management for plowing rice paddy fields [8], but their hoofs are too soft for draught on paved roads. Meat from young animals has a reputation of being exceptionally tender. Crosses of banteng and zebu produce viable offspring, but male hybrids are not fertile [1]. However, the mixed banteng zebu species origin is not supported by breeding records, while only sporadic molecular data are available [9], [10], [11], [12], [13], [14]. Via an analysis of the maternal, paternal and autosomal species origin of five zebu breeds and five populations of Bali cattle, we show here that the species composition of Indonesian zebu breeds is unique and varies from mainly zebu to completely banteng. This information is of direct relevance for the genetic management and conservation of Indonesian cattle breeds. | id |
