On Fri, Jul 09, 2004 at 08:51:00AM +1000, David Siems wrote:
> A question for the knowledgeable, a cattle farmer
> stated to my sister that three Tasmanian Native Hens eat as much grass
> in a day as one cow, is this true? Didn't seem right to me, as I think
> he may want a reason to get a permit for shooting.
Tasmanian Native Hens are ~0.4kg and cows ~400kg. Basal metabolic
rates scale with body mass roughlty to the power of 0.75. So other things
being equal a cow's BMR will be (400/0.4)**0.75 = 178 times.
So this back-of-the envelope calculations suggests the resting energy
requirement of a cow will be the same as 150+ Tasmanian Native Hens.
BMRs are said to be similar between mamals and non-passerines. Actual
energy requirements will be a small multiple, maybe 1.5-2x, the BMR.
I don't know what differences should be expected in this multiplier
in cows versus TNHs.
The very specialized digestive system of the cow may be more efficient
that of the TMR allowing it to consume less grass for the same energy.
Anyway three Tasmanian Native Hens seems very unlikely,
one hundred would be more plausible.
Andrew taylor
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