Author
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Goff, Jesse |
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Horst, Ronald |
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Submitted to: International Animal Agriculture and Food Science Conference
Publication Type: Abstract Only Publication Acceptance Date: 7/25/2001 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Glycerol can be converted to glucose in the liver of cattle. Glycerol enters the gluconeogenic pathway at the level of dihydroxyacetone phosphate and 3-phosphoglyceraldehyde. This is several biochemical steps closer to glucose than the traditional gluconeogenic precursers, propionate and propylene glycol. We examined the effect of glycerol administration on blood glucose in dry cows and did a dose titration to determine the maximal tolerable dose. Treatment groups consisted of 3 cows (one of which had a rumen fistula) which were given 1, 2, or 3 L of glycerol via esophageal pump. Blood samples were taken hourly for the next 8 h and also at 24 h. At 0.5 h after treatment mean blood glucose increased 16, 20 and 25%, respectively, over pretreatment values. They remained elevated for the next 8 h . All cows had returned to baseline glucose values at 24 h. Two of 3 cows given 3 L glycerol exhibited staggering and depression. They recovered within 4 h. Rumen pH was unaffected by treatment with glycerol. Two lactating cows with clinical ketosis, which had been previously treated for 2 or 3 d with IV glucose with little response suggesting fatty liver involvement, were treated with 1 L glycerol. In both cases ketone level in urine was reduced to trace amounts by 24 h and milk production increased 4-6 lb. In the first cow, blood glucose increased from 48-75 mg/dl 0.5 h after treatment and was 109 mg/dl 5 h after treatment. In the second cow, blood glucose did not increase until about 4 h after treatment when it increased from 48-74 mg/dl and was just 64 mg/dl 8 h after treatment. Glycerol offers another means of treating cows for ketosis. |
