Effects of feeding drunken horse grass infected with Epichloë gansuensis endophyte on animal performance, clinical symptoms and physiological parameters in sheep

Effects of feeding drunken horse grass infected with Epichloë gansuensis endophyte on animal performance, clinical symptoms and physiological parameters in sheep

BMC Veterinary Research, July 2017

28724414

Ying Liang, Hucheng Wang, Chunjie Li, Zhibiao Nan, Fadi Li

Many reports showed that grass-endophyte symbiosis induced livestock poisoned. Yet, there is no study evaluating clinical symptoms and physiological parameters in sheep fed Epichloë gansuensis endophyte-infected grass. The objective of the present study was to investigate these indexes by feeding sheep with endophyte-infected A. inebrians (E+ Group) or endophyte-free A. inebrians (E- Group) drunken horse grass or alfalfa hay (Control Group). The Epichloë endophyte caused obvious toxicity symptoms in the sheep fed E+ A. inebrians, with 1 of the 5 sheep having died by the 35th day. The feed intake and body weight gain of the E+ Group were significantly less than the E- and control groups (P < 0.05). Serum concentrations of alanine aminotransferase (ALT, 45.5 mmol/L) and aspartate aminotransferase for the E+ group (AST, 139.3 mmol/L) were significantly (P < 0.05) greater than for the E- (ALT, 31.2 mmol/L; AST, 78.6 mmol/L) and control (ALT, 32.6 mmol/L; AST, 56.6 mmol/L) groups at the fifth week; serum concentration of creatinine for the E+ group (63.8 mmol/L) was also significantly (P < 0.05) greater than for E- (56.6 mmol/L) and control groups (58.5 mmol/L). Meanwhile, urine biochemical indices for the E+ group indicated that ketone and occult blood were significantly (P < 0.05) elevated compared to the other groups while urine pH values were significantly (P < 0.05) acidic. The relative weight of heart, brain, liver, lung and kidney for Group E+ were almost two fold more than the other groups, but uterus weight was about half that found for Group E- or Control. We conclude that the Epichloë endophyte infection is the cause of A. inebrians toxicity to sheep. Interestingly, none of the measured parameters differed significantly between E- and the control groups, which implied that drunken horse grass could be utilized efficiently by sheep when not infected by the Epichloë endophyte.