herd infection造句

• It has successfully reduced cattle and deer herd infection rates from more than 1700 in 1994 to fewer than 100 herds in July 2011.
• Derek Belton, Ministry of Agriculture's animal biosecurity director, played down any longterm impact a herd infection could have on the country's industry, noting that many countries have found brucella suis infection in their pig herds.
• Although vaccinating cattle is a recognised method of avoiding killing wildlife but reducing the prevalence, incidence and spread of bTB in the cattle population and could also reduce the severity of a herd infection regardless of whether infection is introduced by wildlife or cattle it has three problems.