Toxicity of endophyte-infected ryegrass hay containing high XXXX level in lactating ewes.

@entity1785 @entity858 @entity2041 @entity18960 @entity701 @entity5369
The symbiotic association of var. (formerly named ) with @entity5369 () leads to the production of @entity18960 (EV) and lolitrem B (LB) that are toxic for livestock. The objectives of this study were to determine the effects of feeding endophyte-infected ryegrass (SE+) hay on 16 lactating ewes (BW 80    10 kg) in comparison with endophyte-free ryegrass (SE-) hay to investigate the putative mechanisms of action of EV and LB and to evaluate their persistence in milk and animal tissues. The mean EV and LB concentrations in SE+ hay were 851 and 884  g/kg DM, respectively, whereas these alkaloids were below the limit of detection in SE- hay. No effect of SE+ was observed on animal health and skin temperature whereas prolactin decreased and significant differences between hays were observed from d 7 to 28 of the study ( < 0.03) but had no effect on milk production. Hematocrit and biochemical analyses of plasma revealed no significant difference between SE+ and SE-, whereas @entity701 concentration differed significantly on d 28 ( = 0.001). Measurement of oxidative damage and antioxidant enzyme activities in plasma, liver, and kidneys revealed a slight increase in some enzyme activities involved in defense against oxidative damage in the SE+ fed ewes. Slight variations in the activities of hepatic and kidney @entity1785 monooxygenase enzymes were observed, whereas in the kidney, @entity2041 -transferase activity decreased significantly ( = 0.002) in the SE+ fed ewes, whereas @entity858 glucuronosyltransferase activity increased ( = 0.001). After 28 d of exposure of ewes to the SE+ hay, low EV and LB concentrations were measured in tissues. The highest concentration of EV was observed in the liver (0.68  g/kg) whereas fat contained the highest concentration of LB (2.39  g/kg). Both toxins were also identified at the trace level in milk.
