Estimation of infectious titre in colostrum and milk from scrapie incubating ewes with apparently healthy mammary glands or lymphoproliferative mastitis (consecutive to Maedi infection).

For each fraction (cell pellet, casein whey, cream) the quantity of the material submitted to immunoprecipitation process is detailed and linked to the initial volume of colostrum or milk from which it was prepared. In samples for which a 100% attack rate was observed, mean incubation period were used to estimate the infectious titre (Figure 3E). For each considered fraction the infectious titre per ml of starting material was calculated. The global infectious titre per ml of colostrum and milk was finally obtained by adding the value corresponding to each fraction.
N.A: not available at the moment of writing. *Infectivity was estimated from the only those fractions for which results are available. Consequently the calculated infectious titre/ml of milk is certainly underestimated.