多次重复地 meaning in English

in an everlasting manner

The results also indicated that the virulence of the most ibdv field collected in recent years was between the typical very virulent and standard virulent strains . a very virulent strain gx8 / 99 of ibdv was studied for its mortality in spf chickens and commercial egg - type chickens at different age inoculated with bursal suspension of 20 - 2000 eld50 in repeated experiments
选择致病性最强的来自广西的gx8 99株，在对法氏囊悬液中病毒用鸡胚半数致死量( eld _ ( 50 ) )定量测定后，在不同年龄的spf鸡和商品代蛋用型坞多次重复地比较研究了该毒株的致病性。