Hay Calculator for Cow

What is Cow Hay?

Cow hay refers to the dried grass or legume crops that are grown specifically to be fed to cows. It’s like a tasty, nutritious buffet for our mooing friends!

How Do You Calculate Cow Hay?

Now, when it comes to calculating how much hay you need for your cows, we can use a handy-dandy formula called the Total Digestible Nutrients (TDN) method. It helps us figure out the right amount of hay to keep those cows happy and healthy.

So, let’s dive right in!

First things first, we need to know a couple of things: the weight of your cows and the TDN requirement for their specific stage of production. You see, different cows have different needs depending on factors like age, pregnancy, or lactation. For simplicity’s sake, let’s take an example of a lactating cow.

Step 1: Determine the weight of your cow. You can use a scale or estimate it based on their breed and body condition. Let’s say our lactating cow weighs around 1,200 pounds.

Step 2: Find out the TDN requirement for a lactating cow. This information can be obtained from feed tables or consulted with an animal nutritionist. Let’s assume our lactating cow needs 60 pounds of TDN per day to meet her nutritional needs.

Step 3: Calculate the daily dry matter intake (DMI) of your cow. Dry matter is the amount of feed consumed without water content. Generally, cows consume around 2-2.5% of their body weight in dry matter. Let’s take 2.2% for our calculation.

Daily DMI = Cow weight (in pounds) x Dry Matter Intake percentage

Daily DMI = 1,200 pounds x 2.2% = 26.4 pounds


Step 4: Determine the TDN content of your hay. You can find this information on the hay analysis report or consult with your local agricultural extension office. Let’s say our cow hay has a TDN value of 55%.

Step 5: Calculate the amount of hay needed. We’ll divide the daily TDN requirement by the TDN content of the hay to get the weight of hay needed.

Hay needed = Daily TDN requirement (in pounds) / TDN content of hay (as a decimal)

Hay needed = 60 pounds / 0.55 = 109.1 pounds


Ta-da! We’ve got our answer.

Our lactating cow will need approximately 109.1 pounds of cow hay each day to meet her TDN requirements.

Now, keep in mind that these calculations may vary depending on factors like forage quality, cow condition, and other feed sources.

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