A survey of the mineral status of livestock in the Tibet Autonomous Region of China

Foreword Livestock production is the predominant industry in Tibet Autonomous Region of China with significant numbers of yaks, cattle, horses, sheep and goats raised under various production systems. Little is known about the mineral and trace element status of these animals although it is suspected that they may be at risk from iodine and selenium deficiency. This report is the outcome of a cooperative program involving scientists from the Tibet Academy of Agricultural and Animal Sciences, the Institute of Animal Science, Chinese Academy of Agricultural Sciences and Australia. They assessed the mineral and trace element status of yaks, cattle, horses and sheep from different environment and management systems. This assessment involved the collection of blood, milk, urine and dung samples from animals and samples of grazed pasture and feed supplements for chemical analyses. The investigation has provided a comprehensive assessment of the mineral and trace element status of livestock and identified a number of major and trace minerals that may limit livestock productivity. Marginal deficiencies of these minerals can result in reduced milk production, growth rate, wool production and fertility, and severe deficiencies can result in rapid weight loss and increased mortality. Often the problem encountered in the field is not a severe clinical deficiency but a marginal disorder that is not readily identified. Economically, these marginal disorders can be of considerable significance because productivity is depressed without the problem being detected by the livestock owner. The researchers suggest that field experiments should be undertaken to assess the magnitude of any responses in milk or wool production or body weight gain to mineral supplements and to evaluate the most cost-effective way of providing these supplements. The work has increased awareness in the livestock industry about the mineral and trace element needs of farm animals in Tibet Autonomous Region of China and introduced new techniques in the diagnosis of cobalt and iodine deficiency in livestock. Yaks plough a field in the Lhasa River valley. A range of mineral deficiencies may be limiting productivity of livestock in Tibet. Lactating cows are one of the groups most at risk from mineral deficiencies.