Contagem de células somáticas e bacteriana total, sequenciamento dos exons 1 e 2 do gene Mannose-binding Lectin (MBL) em caprinos de rebanhos pernambucanos

Abstract

Mastitis is the inflammatory process of mammary gland which has infectious origin or not. It is characterized by physic-chemical and bacteriological alterations of milk and unrepairable lesions on the mammary tissue. In goats used for milk production, mastitis is a serious problem, as much for increasing production costs as for public health risks. In this work, the sequencing of exons 1 and 2 of MBL (mannose-binding lectin) gene was made and they were related to subclinic mastitis susceptibility in goats. 145 strain and age varied goats which were not at colostral time and drying time were used to collect blood and milk samples. These samples were evaluated through auxiliary diagnosis method, somatic cell count (SCC) to identify subclinic mastitis. Evaluations of milk physic-chemical characteristics (fat, protein, lactose and total solids) and bacteriological examination were also made. DNA was extracted from blood samples and exons 1 and 2 of MBL gene were sequenced. It was observed the presence of polymorphisms on exon 2 of MBL gene in 8 samples of the 1662 region of animals considered as healthy. It was seen that 60% of samples presented SCC values lower than 1.0 x 106 cells/mL, which reveals lack of subclinic mastitis and 40% of samples showed SCC values higher than 1.0 x 106 cells/mL, which reveals presence of subclinic mastitis. 87.5% of the milk samples presented total bacteriological counting (TBC) lower than 500,000 and 11.5% had values higher than 500,000. Although, by comparing results obtained on sequencing and lack of polymorphisms for exon 2 of MBL gene on samples with and without subclinic mastitis, it can not be affirmed that presence of subclinic mastitis is related to MBL gene polymorphism.