INFLUENCE OF INFECTION WITH CAPRINE ARTHRITIS ENCEPHALITIS VIRUS ON MILK PRODUCTION OF FRENCH ALPINE GOATS HERDS FROM NORTHWEST CROATIA

Istraživanje je provedeno sa svrhom utvrđivanja utjecaja infekcije virusom artritis encefalitisa koza (AEK) na ukupnu količinu i sastav mlijeka u trajanju od jedne laktacije. Istraživanje je provedeno na 259 francuskih alpskih koza iz komercijalnih farmi sjeverozapadne Hrvatske. Koze su držane i hranjene na sličan način. Kontrola i uzorkovanje mlijeka provedeno 2009. godine ICAR4 metodom. Istovremeno su prikupljeni uzorci krvi za serološko testiranje na prisutnost AEK antitijela koje je provedeno imunoenzim-nim testom (ELISA). Utjecaj infekcije na ukupno mlijeko , trajanje laktacije i sastav mlijeka (mast, protein i laktozu) testirano je analizom varijance (PROC GLM). Utjecaj kliničkoh artritisa na laktaciju također je testiran. AEK je serološki potvrđen u 37% koza. Nadalje, 24% AEK pozitivnih koza je imalo klinički artritis. Potvrđen je utjecaj serološkog statusa na sva istraživana svojstva. Klinički artritis utjecalo je na količinu (%) proteina i masti u mlijeku.The objective of this study was to investigate the influence of infection with Caprine Arthritis Encephalitis Virus (CAEV) on estimated milk yield per lactation and its composition. The study was carried out on 259 goats of French Alpine breed from production farms in NW Croatia. All goats were kept under similar intensive feeding and management conditions. Milk control was preformed and milk samples were collected using the ICAR method A4 during the year 2009. At the same time, blood samples were collected and presence of CAEV antibodies in the sera was detected using enzyme-linked immunosorbent assay (ELISA). The influence of infection status on milk yield, length of lactation and milk composition (fat, protein and lactose) were tested by analysis of variance (PROC GLM). Influence of clinical form of arthritis on lactation was also investigated. CAEV was serologically confirmed in 37% of goats. In addition, 24% of CAEV positive animals were expressing clinical symptoms of arthritis. Strong influence of serological status on all recorded traits has been confirmed.Presence of clinical arthritis has confirmed influence only on protein and fat content in milk