figuring percentages on a dry mstter basis

Figuring Percentages on a Dry Matter Basis: A Step-by-Step Guide for Organic Dairy Farmers

As an organic dairy farmer, meeting the new pasture regulation from the National Organic Program (NOP) requires more than just providing lush pastures for your ruminants. You need to document and calculate the dry matter intake (DMI) of your animals, specifically ensuring that they receive at least 30% of their DMI from pasture during the grazing season. Categorizing groups of animals by feeding group and figuring dry matter intake can help you achieve this goal.

To start, subtract the dry matter from feedstuffs fed to each feeding group during the grazing season from the amount you feed during the non-grazing season. This will give you an idea of how much DMI comes from pasture versus other sources like grain, hay, and silage.

Next, calculate the percentage of DMI from pasture by dividing the dry matter intake from pasture by the total DMI for each feeding group. To do this, subtract the DMI from feed from the dry matter demand (DMD) for each feeding group during both the grazing and non-grazing seasons.

For example, let's say you have a herd of dairy cows with two feeding groups: lactating cows and dry cows. During the grazing season, lactating cows receive 20 tons of dry matter from pasture, while dry cows receive 10 tons. Meanwhile, during the non-grazing season, both groups receive 15 tons of dry matter from feedstuffs.

Subtracting the dry matter from pasture from the total amount fed during the non-grazing season gives you:

* Lactating cows: 15 - 20 = -5 tons (you need to provide more DMI from pasture)

* Dry cows: 15 - 10 = 5 tons (you're already meeting the target)

Now, calculate the percentage of DMI from pasture for each feeding group:

* Lactating cows: (-5 / 15) x 100% ≈ -33.3%

* Dry cows: (5 / 15) x 100% ≈ 33.3%

Based on these calculations, you'll need to increase the dry matter intake from pasture for lactating cows and continue providing adequate DMI from pasture for dry cows.

To determine the length of your grazing season, take note of when your pastures become too mature or too weathered for optimal grazing. This will help you calculate the average pasture DMI over the grazing season.

In conclusion, figuring percentages on a dry matter basis requires attention to detail and accuracy. By following these steps and understanding the requirements for organic dairy farmers, you can ensure that your ruminants receive the necessary dry matter intake from pasture during the grazing season, meeting the NOP regulation.

Figuring percentages on a dry mstter basis