In this paper, we offer a general equilibrium analysis of the impacts of US and EU biofuel mandates for the global livestock sector. Our simulation boosts biofuel production in the US and EU from 2006 levels to mandated 2015 levels. We show that mandates will encourage crop production in both biofuel and non biofuel producing regions, while reducing livestock and livestock production in most regions of the world. The non-ruminant industry curtails its production more than other livestock industries. The numerical results suggest that the biofuel mandates reduce food production in most regions while they increase crude vegetable oils in almost all regions. Implementing biofuel mandates in the US and EU will increase croplands within the biofuel and non-biofuel producer regions. A large portion of this increase will be obtained from reduced grazing lands. The biofuel producing regions are expected to reduce their coarse grains exports and raise imports of oilseeds and vegetable oils. While all livestock industries use more biofuel byproducts in their animal feed rations, the dairy and other ruminant industry benefit most from the expansion of DDGS. We finally conclude that, while biofuel mandates have important consequences for the livestock industry, they do not harshly curtail these industries. This is largely due to the important role of byproducts in substituting for higher priced feedstuffs. In addition, with relatively inelastic food demands, producers are able to pass much of the price rise on to consumers. In general, US, EU, Meddle East & North Africa, and Russia will experience significant welfare loses due to the combined US and EU mandates, while Brazil, Japan, India, and East Asia are expected to get major gains.