(Adds background) MEXICO CITY, Feb 16 (Reuters) - Mexico has postponed plans to reopen its borders to dairy cattle imports from Canada after a case of mad cow disease was found in an Alberta bull last week. Enrique Sanchez, Mexico's head of animal health, told Reuters on Friday that Mexico would carry out new tests before considering allowing Canadian dairy cow imports. "This means we have to go back and revise everything again," Sanchez said. "We were three months away from starting trade with Canada, but this is going to take one or two years, we don't know." Mexico stopped importing beef and cattle from Canada following an outbreak of bovine spongiform encephalopathy in 2003. It has since restarted imports of most beef and cattle products, and in December officials said dairy imports would be restarted soon. Sanchez said one more case of mad cow disease in Canada would be enough for Mexico to close the two countries' beef and cattle trade once again., Between 2001 and 2004, Mexico went from being the second to fourth leading destination for Canadian dairy products, which include milk, cheese, live dairy cows and genetic material such as bull semen, according to Canadian export statistics. Canadian global exports of dairy cattle and dairy genetic material dropped by more than 70 percent between 2003 and 2005, to about $60 million.
