Drought and Animal Feed Requirements

— Written By and last updated by JoAnne Gryder

droughtLivestock producers in western North Carolina have been impacted by the worst drought in recent years.  There has been little rainfall in the region since mid-summer and the available forage in pastures has been eaten, forcing producers to start feeding hay early.  It is critical that farmers with livestock determine how much hay or other feeds they will need to make it through the winter and to obtain it soon.  Because drought has also impacted Tennessee, Georgia and Alabama, we expect a shortage of hay and anticipate that hay will eventually have to be shipped in from long distances.

To determine how much hay is needed, farmers need to inventory the number of animals they have and their average weight.  Then they need to determine how much hay they have on hand, and their expected shortage that they need to be shopping for.  Now is the time to evaluate winter feed supplies vs. requirements and develop a plan of action. If the feed supply is inadequate, additional feed must be acquired, or cattle numbers reduced (culling).

The first step is determining the number of days feed will be required. Typically this is 100 to 120 days. However, this can vary greatly depending on our weather, stocking density of pastures, and the amount of stockpiled forage and this year will be longer.  Stockpiling is an excellent way to reduce stored feed requirements . . . but stockpiling all depends on the weather and this year almost impossible.  

A quick, easy way to estimate feed requirements is on the basis of animal units. This can be done based on a mature cow equal to one unit, a mature bull equal to one and a half units, yearling cattle equal to one-half unit, and calves equal to one-fourth unit. Utilizing this method, each animal unit will require approximately 25 pounds of hay or 50 pounds of corn silage per day, assuming average to good quality hay or silage. This also assumes less than 10% waste during feeding and storage.

For an average sized herd of 35 cows, one bull, 8 replacement heifers and 16 yearling steers with a winter feeding period of 120 days, the following is an example calculation of stored feed requirements:

35 cows x 1 animal unit = 35 animal units

1 bull x 1.5 animal unit = 1.5 animal units

8 replacement heifers x 0.5 animal unit = 4 animal units

16 yearling steers x 0.5 animal unit = 8 animal units

The herd total is 48.5 animal units.

48.5 animal units x 120 days x 25 pounds of hay per day = 145,500 pounds of hay

How many 500 pound round bales are needed?

145,500 pounds / 500 lb bales = 291 bales

You also must have a good estimate of the quantity of feed available to determine if the animals’ needs can be met. When estimating quantity of hay, it is best to obtain the average weight of several bales and then multiply this times the number of bales.

Remember this is only a very quick estimate. To be more accurate, you need to consider nutritional requirements for the size of animal and stage of reproduction or growth desired. Also, feed supply can be more accurately estimated if you have a forage analysis to determine the exact nutrient content.

Cooperative Extension Livestock Agents have the ability to work with farmers to determine their hay needs and to help them locate hay or alternative feeds that can be purchased.  When hay is not available, it is possible to feed silage or concentrate feeds, but they require different management, so, again, ask your agent for help.

There are several tools that can be used to locate hay and other feeds including the Hay Alert website maintained by the North Carolina Department of Agriculture and Consumer Services (www.ncagr.gov/hayalert).  This website can be used to advertise hay for sale and producers can also use it to advertise that they need hay.  There also are listings of trucking companies available to help move hay.  If you need help using this tool, your Cooperative Extension Livestock Agent can also help you with that.

NCSU Extension

Written By

Photo of John CothrenJohn CothrenCounty Extension Director and Ext Agent, Agriculture - Livestock and Field Crops (336) 651-7348 john_cothren@ncsu.eduWilkes County, North Carolina
Updated on Nov 22, 2016
Was the information on this page helpful? Yes check No close
This page can also be accessed from: go.ncsu.edu/readext?436221