Lupinosis and reproduction reduce the wool growth of Merino ewes

Abstract

Summary. Lupinosis was induced in Merino ewes by subcutaneous injections of phomopsins. Liver damage and impairment of liver function was measured by increases in plasma activities of glutamate dehydrogenase and gamma glutamyl transferase, plasma concentrations of bilirubin, and plasma clearance of bromosulfthalein. The wool growth of the ewes during and after exposure to phomopsins at different periods relative to mating was measured, and the impact of lupinosis on annual wool production assessed. Phomopsin administration decreased the length of staple grown during, and for at least 6 weeks after, exposure to phomopsins. Mean fibre diameter of wool grown during this time was also reduced. Annual wool production of the ewes was affected by exposure to phomopsins, with effects noted on fleece weight, yield, fibre diameter, strength and position of break. These effects were minor and varied between experiments. The adverse effects of reproduction on annual wool production were more significant than those of phomopsins.

Scientific Opinion on the risks for animal and public health related to the presence of phomopsins in feed and food

“…However, the disease was produced in mice with crude extracts of cultures of D. toxica in which the phomopsins content was unknown, except in one case. On the other hand, Barnes (1993) produced toxicity in mice given a single i.p. injection.…”

“…without showing any observable toxic effect. On the other hand, Barnes (1993) produced toxicity in mice given a single i.p. injection of 2 mg phomopsin A/kg b.w.…”

“…Crude extract used by Barnes (1993) and Barnes et al (1996Barnes et al ( , 1997 was derived from the C4274 (Department of Agriculture and Food Culture Collection Number) isolate of D. toxica. One laboratory (CSIRO) primarily used purified, crystalline phomopsin in their studies, while the other (DAFWA) primarily used a crude extract of cultures of D. toxica.…”

“…Developmental and reproductive toxicity Barnes (1993) investigated the effect of phomopsins on fertility and the early development of the mouse embryo. A crude extract of D. toxica was used to provide the phomopsins challenge.…”

“…In the majority of the studies, both the crystalline phomopsin and the crude extract were sourced from the same isolate of D. toxica (Department of Agriculture and Food Culture Collection Number WA1515, also identified by Commonwealth Mycological Institute Collection Number IMI 153063). Crude extract used by Barnes (1993) and Barnes et al (1996Barnes et al ( , 1997 was derived from the C4274 (Department of Agriculture and Food Culture Collection Number) isolate of D. toxica.…”