The effect of methoprene on horn fly numbers and mastitis in dairy heifers

摘要

A study was conducted to determine if the insect growth regulator methoprene could suppress horn fly numbers sufficiently to reduce the incidence of mastitis in dairy heifers. Two groups d heifers were evaluated, one group received a mineral supplement containing methoprene, the other group served as a control. Results indicate that horn fly nm above 50 per animal are sufficient to transmit S aureus mastitis. The methoprene fly control product was not able to suppress horn fly numbers sufficiently to prevent S aureus mastitis in heifers. Additional fly control methods will be necessary for dairy heifers to keep fly numbers below 50 per animal and protect them from S aureus mastitis transmitted by horn flies.