Ruminant Energy Metabolism Flashcards
1) A volatile fatty acid (VFA) product of ruminant fermentation
BHB (beta-hydroxy-butyrate)
Cortisol, Catecholamines
Glucose
Insulin
NEFA (non-esterified fatty acids)
Propionate
Triglycerides
VLDL - Very Low Density Lipoprotein
Propionate
The 3 VFAs produced in the greatest quantities are:
Acetate - contributes to milk fat synthesis more produced relative to propionate on higher forage rations.
Propionate - enters the Krebs TCA cycle in the mitochondria of hepatocytes for gluconeogenesis; more produced relative to acetate on higher concentrate rations
Butyrate - energy for rumen wall; metabolized to BHB in the liver (small amts, won’t lead to hyperketonemia)
2) An energy source required for milk and babies
BHB (beta-hydroxy-butyrate)
Cortisol, Catecholamines
Glucose
Insulin
NEFA (non-esterified fatty acids)
Propionate
Triglycerides
VLDL - Very Low Density Lipoprotein
Glucose
3) A free fatty acid, alternative energy source during negative energy balance
BHB (beta-hydroxy-butyrate)
Cortisol, Catecholamines
Glucose
Insulin
NEFA (non-esterified fatty acids)
Propionate
Triglycerides
VLDL - Very Low Density Lipoprotein
NEFA (non-esterified fatty acids)
4) Catabolic hormones that favor lipolysis (release of the stored energy in adipose tissue)
BHB (beta-hydroxy-butyrate)
Cortisol, Catecholamines
Glucose
Insulin
NEFA (non-esterified fatty acids)
Propionate
Triglycerides
VLDL - Very Low Density Lipoprotein
Cortisol, Catecholamines
5) Hormone that drives glucose into cells and favors lipogenesis (storage of excess energy)
BHB (beta-hydroxy-butyrate)
Cortisol, Catecholamines
Glucose
Insulin
NEFA (non-esterified fatty acids)
Propionate
Triglycerides
VLDL - Very Low Density Lipoprotein
Insulin
The action of insulin is important when considering treatment to address ENEB and the sign of Ketosis or better referred to as Hyperketonemia. A mainstay of treatment has been 500 mL bottle of 50% Dextrose solution IV. The IV carbohydrate does provide energy, however, the impact is small compared to the energy deficit, and that bolus almost immediately results in excess glucose spilling over into the urine.
THE KEY benefit of this treatment is the resultant increase in endogenous insulin due to the hyperglycemia. The benefit is to reduce Lipolysis in an animal that already has more than enough NEFA circulating and entering the liver.
6) Ketone produced as an alternative energy source during negative energy balance
BHB (beta-hydroxy-butyrate)
Cortisol, Catecholamines
Glucose
Insulin
NEFA (non-esterified fatty acids)
Priopionate
Triglycerides
VLDL - Very Low Density Lipoprotein
BHB (beta-hydroxy-butyrate)
7) Packaged stored form of energy for transport in the blood
BHB (beta-hydroxy-butyrate)
Cortisol, Catecholamines
Glucose
Insulin
NEFA (non-esterified fatty acids)
Priopionate
Triglycerides
VLDL - Very Low Density Lipoprotein
VLDL
