Detecção de anticorpos anti-Neospora caninum em colostro e leite de cabras naturalmente infectadas

Abstract

Neosporosis is a parasitic disease responsible for major economic losses in the global beef and dairy cattle industry. In goats, complications in pregnant females include abortions, stillbirths,

and birth of weak or normal but infected animals. As a diagnostic method, the detection of anti- Neospora caninum antibodies in serum by Indirect Fluorescent Antibody Test (IFAT), the

presence of lesions and the parasite in aborted fetuses, associated with immunohistochemical labelling or detection of N. caninum DNA in tissues, can be used. The detection of anti-N. caninum antibodies in bovine milk has shown good agreement when compared to blood titers by IFAT. In goats, there are no studies comparing antibody levels in colostrum and milk with blood serum. Therefore, the objective of this study is to identify anti-Neospora caninum antibodies in colostrum and milk of naturally infected goats and to evaluate the kinetics of antibodies. Nine naturally infected goats, confirmed by the presence of anti-N. caninum antibodies by IFAT, and three seronegative goats were used as negative controls. Blood samples were collected from the goats on the day of parturition (mother and kid before suckling colostrum) and monthly from the mother until day 120 postpartum. Ten mL of colostrum and milk were also found by manual ordering on the day of parturition (D0), day 3 (D3), D6, D9, D12, D15, D30, D60, D90 and D120, totaling 81 samples from positive animals. The results revealed that anti-N. caninum in 100% of serum samples (9/9) on the day of calving, in 88.88% of colostrum (8/9) and in 58.33% (42/72) of milk samples, considering that one goat was euthanized during the experimental period, with goats with higher serum titers tending to present higher titers in colostrum and only 25% of the goats (2/8) presented anti-N. caninum antibodies throughout the 120 days of lactation, which were progressively decreasing in the milk samples. The results demonstrate that IFAT can be used to track goat herds positive for N. caninum, mainly in colostrum and in milk from 75% of the animals up to the fifteenth day of lactation.