Grains are mixed to lower early Wednesday with livestock mostly higher.  Tomm Pfitzenmaier with Summit Commodity Brokerage says wheat is start to look tired after pricing in Black Sea war premium and running into chart resistance.  The higher dollar is a headwind for all the grains.  Soybeans are fading flash export sales and continue to slide with lower bean oil, the big Brazil crop and their deal with China.  Corn is also seeing spillover pressure but isn't breaking hard due to strong demand.  Cattle futures are building on the strong technical close Tuesday, and hogs are also trying to recover.