Mike
Well-known member
Experimental BSE Oral Attack Rate Study
An oral attack rate study in cattle (Dawson 1993) provides some insights. The study used untreated brain material from a pool of brains derived from cattle with clinically confirmed BSE. Groups of cattle were exposed to four different treatments regimes:100g of untreated brain material given orally on three occasions, or 100g given on one occasion; 10g given on one occasion; or 1g given on one occasion. The infectivity titre of the brain pool used in this study was about i/c ID50/g (refer to Appendix 2 for explanation); Dawson et al., 1993; Wells et al., 1994, 1996, 1998, 1999.
All four groups developed the disease. The attack rate was not 100% in the two low-dose groups (1g and 10g) and the incubation period was longer than in the high dose groups. It can be concluded that 1g of brain with an infectivity titre of 10 x 3.5 i/c ID 50g is probably not a limiting oral dose for cattle.
An oral attack rate study in cattle (Dawson 1993) provides some insights. The study used untreated brain material from a pool of brains derived from cattle with clinically confirmed BSE. Groups of cattle were exposed to four different treatments regimes:100g of untreated brain material given orally on three occasions, or 100g given on one occasion; 10g given on one occasion; or 1g given on one occasion. The infectivity titre of the brain pool used in this study was about i/c ID50/g (refer to Appendix 2 for explanation); Dawson et al., 1993; Wells et al., 1994, 1996, 1998, 1999.
All four groups developed the disease. The attack rate was not 100% in the two low-dose groups (1g and 10g) and the incubation period was longer than in the high dose groups. It can be concluded that 1g of brain with an infectivity titre of 10 x 3.5 i/c ID 50g is probably not a limiting oral dose for cattle.