I really like what you've been able to add to the chart! Plus it's so much more organized! :bounce:
You’re certainly right-the nutrient density in hay is measured by respiration for plant tissue, leaf shattering, exposure to moisture/rain, and storage of hay/size of bales, etc. Every single one of these factors can play a huge role in altering amounts. Even if we are working with a single species of hay for example, yours could have entirely different ingredient content than mine, simply by how we produced and treated it.
Some examples of slight variation:
-A round bale stored outside for 1 year can lose up to 22% of its dry matter, however in two years it can lose only 25% dry matter.
-Hay exposed on the outside and bottom of a bale will lose protein almost 7 times faster than hay on the inside of a bale.
-As well, hay exposed to high amounts of humidity will use 10%-15% of the readily digestible carbohydrates. Hay that has contacted with rain will be higher in acid detergent fiber and neutral detergent fibers.
- At the same time, crude protein can drop from 11.1% at the first cutting to 8.9% after just two days of drying.
Unfortunately, without both field and laboratory analysis, there is no definite way to examine the exact contents of a specific cut of hay. So we are therefore left with an average idea.
So perhaps we should list two columns next to each value, indicating the minimum and maximum amount?
Even if we did that, it may still be rather vague; however it will give a general idea of what one is working with and what to expect. I’m still conducting further research on various hay species, but the difference in timing and percentage of nutrient loss in each one is greatly diverse and apparent.
For example with alfalfa:
-On average, alfalfa will lose its digestibility 0.5% per day after flowering. Bermuda grass drops about 0.2% per day between 4-8 weeks of age.
-With alfalfa, we lose roughly around 12% moisture and 4%-7% dry matter with each cut (depending on storage).
So in order to obtain relative feed value-
We need to calculate the amount of digestible dry matter and dry matter intake of each species of hay.
DDM = Digestible Dry Matter = 88.9 - (0.779 x % ADF)
DMI = Dry Matter Intake = 120 / ( % NDF )
RFV = (DDM x DMI) / 1.29
I do like the concept of requiring detailed nutrient content of manure, especially for gardening.
In
general:
The nitrogen content found in rabbit manure is 2.4%, the phosphorus content is 1.4%, and the potassium content is 0.6%. There are also trace elements of calcium, magnesium, boron, zinc, manganese, sulfur, copper, and cobolt in it. (I can’t find the exact numbers of these just yet!
)