title: Colostrum and milk can transmit jaagsiekte retrovirus to lambs.
abstract: Ovine pulmonary adenocarcinoma (OPA) is a contagious disease caused by jaagsiekte sheep retrovirus (JSRV). In the three studies performed, we have obtained data of the importance of colostrum/milk (C/M) in the transmission of JSRV. In the first study, a group of sheep from a flock with a long history of OPA, samples from colostrum and peripheral blood leucocytes (PBLs) were collected. Two specific PCRs (U3-LTR and env of the JSRV) were carried out. Using U3PCR 8/34 sheep were positive in colostrum whereas with envPCR 7/34 were positive. From these animals only one was positive with U3PCR in the PBLs. Evidence of the transmission of JSRV infection by C/M was obtained in two more separate studies. In the second study, PBLs from five lambs from JSRV+ ewes and two from JSRV-ewes were tested by the U3PCR. They were fed C/M by their mothers during 3 months and slaughtered 7 months after birth. Three out of five lambs from the JSRV+ sheep become PBL positive at 3-4 months old and the other two were also positive at 4-6 months of age. One lamb of the JSRV-sheep became also PBL positive at an age of 3 months. In the third study, a group of lambs from JSRV negative mothers were fed with C/M from JSRV+ sheep and housed in separate unit. For comparison, another group of the same origin and maintained in another different unit, were fed with C/M containing a JSRV virus preparation. All lambs were blood sampled monthly and JSRV infection was detected as early as 15 days and several times onwards in both groups. Control groups fed with C/M from JSRV free flock and JSRV blood test negative sheep were always negative. Together these results indicate that suckling is an important natural transmission route for JSRV.
authors.affiliation: Dipartimento di Produzioni Animali Epidemiologia ed Ecologia, Facoltà di Medicina Veterinaria, Università degli Studi di Torino, Grugliasco, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Grego
authors.forename: Daniele
authors.initials: D
authors.lastname: De Meneghi
authors.forename: Vega
authors.initials: V
authors.lastname: Alvarez
authors.forename: Alfredo A
authors.initials: AA
authors.lastname: Benito
authors.forename: Esmeralda
authors.initials: E
authors.lastname: Minguijón
authors.forename: Aurora
authors.initials: A
authors.lastname: Ortín
authors.forename: Mario
authors.initials: M
authors.lastname: Mattoni
authors.forename: Bernardino
authors.initials: B
authors.lastname: Moreno
authors.forename: Maider
authors.initials: M
authors.lastname: Pérez de Villarreal
authors.forename: Alberto
authors.initials: A
authors.lastname: Alberti
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Capucchio
authors.forename: Marco
authors.initials: M
authors.lastname: Caporale
authors.forename: Ramón
authors.initials: R
authors.lastname: Juste
authors.forename: Sergio
authors.initials: S
authors.lastname: Rosati
authors.forename: Marcelo
authors.initials: M
authors.lastname: De las Heras
mesh_terms: D000821:Animal Feed; D000818:Animals; D003126:Colostrum / Q000821:virology*; D004032:Diet / Q000662:veterinary; D005260:Female; D041943:Infant Formula; D018445:Infectious Disease Transmission, Vertical / Q000662:veterinary*; D022141:Jaagsiekte sheep retrovirus; D008892:Milk / Q000821:virology*; D011648:Pulmonary Adenomatosis, Ovine / Q000635:transmission* / Q000821:virology; D012756:Sheep