Prevalence and reproductive effects of Ureaplasma diversum in beef replacement heifers and the relationship to blood urea nitrogen level

A systematic sample of replacement heifers from 5 herds underwent prebreedi ng vaginal swab cultures for <(Ureaplasma diversum)under bar>. Heifers from three of the herds were subsequently sampled at pregnancy examination. Sam pled heifers were given a vaginal lesion score (VLS), reproductive tract sc ore (RTS) and body condition score (BCS), and peripheral blood was collecte d for serum blood urea nitrogen (BUN) estimation. Culture results revealed an overall prevalence of <(Ureaplasma diversum)under bar> of 51% (87/171) a t prebreeding and 65% (64/98) at pregnancy examination. Within herd prevale nce ranged from 36% to 64% at prebreeding and 54% to 76% at pregnancy exami nation. Prevalence tended to differ between herds (P=0.08). At the prebreed ing examination, heifers with a BCS of 5.5 or less were more likely to be c ulture positive than heifers with a BCS greater than 5.5 (p<0.05). No relat ionship was noted between BUN, VLS, RTS, or pregnancy status and prebreedin g culture status. There was little variability among the heifers for any of these variables, with vaginal lesion scores generally being mild, RTS scor es being high and BCS scores being moderate. At pregnancy examination, heif ers that were culture negative tended to be more likely to be pregnant (odd s 3.7, P=0.10) than culture positive heifers. (C) 2000 by Elsevier Science Inc.