Start Date

21-2-2017 10:30 AM

Description

A major problem for the cattle producer that utilizes tall fescue forage is the unrealized or reduced gains in body weight in growing animals. This result has been reproduced across numerous studies evaluating cattle performance on tall fescue (Hoveland et al., 1983; Boling, 1985; Schmidt et al., 1986; Goetsch et al., 1987). Cattle have gained from 30 to 100% less consuming toxic endophyte-infected tall fescue compared to consumption of an endophyte-free tall fescue (Paterson et al., 1995). This effect of reduced gain is a consequence of a fungal endophyte present within the grass that produces toxins called ergot alkaloids. Fungal production of these toxins benefits the grass and fungus by causing a decrease in intake and has likely evolved as a strategy to prevent over grazing by cattle and other livestock. Not surprisingly, grazing time is reduced high endophyte-infected tall fescue pastures compared to pastures with low infection levels (Bond et al., 1984). The forage quality of endophyte-infected compared to endophyte-free tall fescues are similar, suggesting that the ergot alkaloids are responsible for the drop in weight gain (Burns, 2009). An understanding of how ergot alkaloids cause the observed decreased weight gain in cattle will permit the development of strategies aimed at mitigating or alleviating this source of loss.

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Feb 21st, 10:30 AM

Why is Intake Reduced When Cattle are Fed Tall Fescue?

A major problem for the cattle producer that utilizes tall fescue forage is the unrealized or reduced gains in body weight in growing animals. This result has been reproduced across numerous studies evaluating cattle performance on tall fescue (Hoveland et al., 1983; Boling, 1985; Schmidt et al., 1986; Goetsch et al., 1987). Cattle have gained from 30 to 100% less consuming toxic endophyte-infected tall fescue compared to consumption of an endophyte-free tall fescue (Paterson et al., 1995). This effect of reduced gain is a consequence of a fungal endophyte present within the grass that produces toxins called ergot alkaloids. Fungal production of these toxins benefits the grass and fungus by causing a decrease in intake and has likely evolved as a strategy to prevent over grazing by cattle and other livestock. Not surprisingly, grazing time is reduced high endophyte-infected tall fescue pastures compared to pastures with low infection levels (Bond et al., 1984). The forage quality of endophyte-infected compared to endophyte-free tall fescues are similar, suggesting that the ergot alkaloids are responsible for the drop in weight gain (Burns, 2009). An understanding of how ergot alkaloids cause the observed decreased weight gain in cattle will permit the development of strategies aimed at mitigating or alleviating this source of loss.