Author
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Aiken, Glen |
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Submitted to: Proceedings of the Heart of America Grazing Conference
Publication Type: Proceedings Publication Acceptance Date: 12/9/2010 Publication Date: 1/25/2011 Citation: Aiken, G.E. 2011. Impact of the endophyte on animal production. In: 10th Heart of America Grazing Conference and 11th Kentucky Grazing Conference, January 25-26, 2011, Louisville, KY. p. 12-16. Interpretive Summary: Tall fescue is widely utilized for forage in the eastern half of the USA. The grass is productive and persistent under low management; whish is attributed to alkaloids produced by a fungal endophyte that infects most tall fescue plants. Unfortunately, the endophyte also produces ergot alkaloids that induce fescue toxicosis, which that causes hormonal imbalances and constriction of blood flow to peripheral tissue. Calf weight gain can be very low, particularly in warm environments, which There has been limited use of tall fescue for stocker production because calf weight gains are typically very low. Therefore, the grass is primarily used for cow-calf production, but ergot alkaloids can also reduce certain hormones needed for reproduction and lactation that has an adverse effect on calving percentages, milk yields, and weaning weights. Reduction in calf numbers and weaning weights annually costs the U.S. beef industry approximately $800 million. A review paper discusses the impact of toxic endophyte-infected tall fescue on profitability of beef cattle production from nursing to finishing. Management options will be discussed for avoiding fescue toxicosis or reducing the severity of fescue toxicosis. Technical Abstract: Tall fescue (Lolium arundinaceum L.) is widely utilized for forage in the eastern half of the USA. The grass is productive and persistent under low management; whish is attributed to alkaloids produced by a fungal endophyte (Neotyphodium coenophialum) that infects most tall fescue plants. Unfortuantely, the endophyte also produces ergot alkaloids that can induce fescue toxicosis in cattle, a malady caused by hormonal imbalances and constriction of blood flow to peripheral tissues that restrict the animal’s ability to dissipate core body heat. Calf weight gain can be very low on toxic tall fescue, particularly in warm environments, which has limited the use of fescue for stocker production. Although the grass is primarily used for cow-calf production, reductions in certain hormones needed for reproduction and lactation can occur that reduce calving percentages, milk yields, and weaning weights. Further, there is concern of carry-over effects of ergot alkaloids on performance of calves consuming finishing rations in the feedyard. This paper discusses the impact of toxic endophyte-infected tall fescue on beef cattle production from nursing to finishing, and presents management options to avoid or reduce the severity of toxicosis. |
