| serological study of the frequency of leptospiral infections among dairy cows in farms with suboptimal reproductive efficiency in galicia, spain. | between march 1996 and september 1997, 15 farms located in galicia (nw spain) and experiencing suboptimal reproductive efficiency were visited and blood samples were obtained from all the lactating cows (n=442). additionally, 1060 samples were obtained monthly from a cohort of 219 lactating cows belonging to nine of the farms between march 1996 and april 1997. all the samples were tested by microscopic agglutination (mat) using live antigens representing the following leptospira interrogans sero ... | 2001 | 11337143 |