PERIPARTURIENT RISE IN FECAL EGG COUNTS ASSOCIATED WITH PROLACTIN CONCENTRATION INCREASE IN FRENCH ALPINE DAIRY GOATS

Previous data on periparturient relaxation of immunity during gastroin testinal nematode infection in goals are scarce and conflicting, one s tudy carried out in fiber (Angora) goats showed a positive association of fecal egg counts with prolactin concentrations around parturition, whereas the two other available studies dealing with dairy goats, gav e divergent results. The objectives of the study were thus to assess t he occurrence of a periparturient rise in fecal egg counts in dairy go als and to examine a possible relationship between the level of milk p roduction and the intensity of the periparturient rise. A total of 28 French Alpine grazing dairy goats naturally infected with Teladorsagia , Trichostrongylus, and Oesophagostomum were allocated into two groups according to their reproductive status; group 1 (n = 7) consisted of nonpregnant lactating animals in the 3(rd) month of lactation, whereas group 2 (n = 21) was composed of dry goats at 6 weeks before term. Fe cal egg counts, pepsinogen and phosphate blood concentrations, blood e osinophil counts, and prolactin concentrations were individually monit ored at weekly intervals for 12 weeks (from midwinter to early spring) . The mean fecal egg counts were significantly higher in pregnant goat s during the 2 weeks before (668 versus 242 eggs per gram of feces (ep g), P < 0.05) and the 2 weeks after (962 Versus 279 epg, P < 0.01) par turition as compared with nonpregnant lactating animals. No significan t difference was seen in the composition of larval cultures between th e two groups of animals, with Oesophagostomum infective larvae being f ound predominantly, particularly at the time of parturition. Pepsinoge n and phosphate concentrations as well as blood eosinophil counts were similar between the two groups throughout the survey and indicated a moderate larval challenge. The mean prolactin concentration measured i n pregnant goats was significantly higher (P < 0.01) at the time of pa rturition (298 versus 130 ng ml(-1)) and at 4 weeks after parturition (387 versus 193 ng ml(-1)) than that determined in nonpregnant animals . Furthermore, a significant correlation (r(s) = 0.30, df = 79; P < 0. 01) between fecal egg counts and prolactin concentrations was recorded for the pregnant goats during the 4-weeks period around parturition.