Effect of sorghum ergot (Claviceps africana) on the performance of steers (Bos taurus) in a feedlot

Blaney, B. J., McLennan, S. R., Kidd, J. F., Connell, J. A., McKenzie, R. A. and Downing, J. A. (2011) Effect of sorghum ergot (Claviceps africana) on the performance of steers (Bos taurus) in a feedlot. Animal Production Science, 51 2: 156-166. doi:10.1071/AN10086

Author Blaney, B. J.
McLennan, S. R.
Kidd, J. F.
Connell, J. A.
McKenzie, R. A.
Downing, J. A.
Title Effect of sorghum ergot (Claviceps africana) on the performance of steers (Bos taurus) in a feedlot
Journal name Animal Production Science   Check publisher's open access policy
ISSN 1836-0939
Publication date 2011-01-28
Sub-type Article (original research)
DOI 10.1071/AN10086
Volume 51
Issue 2
Start page 156
End page 166
Total pages 11
Place of publication Australia
Publisher C S I R O Publishing
Collection year 2012
Language eng
Abstract The effect of ergot (Claviceps africana) in naturally infected sorghum was assessed in feedlot rations. Thirty-two Hereford steers (Bos taurus) in individual pens with access to shade were adapted to feedlot conditions and then offered one of four rations containing 0, 4.4, 8.8 or 17.6 mg/kg of ergot alkaloids (84% dihydroergosine, 10% dihydroelymoclavine and 6% festuclavine), equivalent to ∼0, 10, 20 or 40 g/kg ergot (sclerotia/sphacelia) in the rations. These rations were withdrawn at noon on the second day because of severe hyperthermia and almost complete feed refusal in ergot-fed steers. After recovery on ergot-free rations for 5 days, treatment groups were incrementally introduced, over a further 312 days, to rations containing 0, 1.1, 2.2 or 4.4 mg/kg of alkaloids (∼0, 2.5, 5 or 10 g/kg ergot, respectively). Relative exposure to ergot was maintained, so that the zero- (control), low-, medium- and high-ergot groups remained so. Steers were individually fed ad libitum, and water was freely available. Steers in all ergot-fed groups had significantly elevated rectal temperatures at 08001000 hours, even when the temperaturehumidity index was only moderate (∼70), and displayed other signs of hyperthermia (increased respiration rate, mouth breathing, excessive salivation and urination), as the temperaturehumidity index increased to 7379 during the day. Plasma prolactin was significantly reduced in ergot-fed groups. Voluntary feed intakes (liveweight basis) of the ergot-fed groups were significantly reduced, averaging 94, 86 and 86%, respectively, of the feed intakes of the control group. Hair coats were rough. While the control steers grew from a mean initial liveweight of 275 kg to a suitable slaughter weight of 455 kg in 17 weeks (growth rate 1.45 kg/day), ergot-fed groups gained only 0.771.10 kg/day and took at least 5 weeks longer to reach the slaughter weight, despite removal of ergot at the same time as control steers were sent to slaughter. Sorghum ergot, even at low concentrations (1.1 mg alkaloids/kg feed) is severely detrimental to the performance of steers in the feedlot. © 2011 CSIRO.
Keyword Fungus
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status Non-UQ
Additional Notes Published: 28 January 2011

Document type: Journal Article
Sub-type: Article (original research)
Collections: Non HERDC
School of Agriculture and Food Sciences
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Citation counts: TR Web of Science Citation Count  Cited 5 times in Thomson Reuters Web of Science Article | Citations
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Created: Fri, 18 Mar 2011, 15:41:28 EST by Samantha Richards on behalf of Qld Alliance for Agriculture and Food Innovation