by Karla A. Hernandez, PhD
SDSU Extension Forages Field Specialist
A simple cattle and feed inventory is valuable when planning this winter’s livestock feeding program. Things to take into consideration are: (1) estimate total feed needs for the herd size; (2) determine available feed supply, type and quantity; and (3) determine how to adjust for excess or deficiencies, based on prices.
In order to get a rough estimate of cow hay needs, take the average weight of cows multiplied by 3%. This is an approximate amount of feed per cow per day. Take this figure multiplied by the number of head and number of days on feed to determine the total need. Waste needs to be calculated in because no matter what type of processing, there will be some loss. For hay, this should be calculated at 10-20%.
Example: 1350 lb cow * 3%=40.5 lbs feed/day *150 head * 180 days * 120% (20% for waste) /2000 lbs per ton=656 ton needed. Forage quality is an important aspect to consider on determining the needed hay supply. This is the main reason to test hay before feeding it to livestock. In general terms, feeding livestock with good quality hay will increase production and animal performance. Cheaper hay that is low forage quality is generally more mature and provides a lower nutrient dense feed than expensive hay that is higher quality. However it may be more cost effective to utilize the cheaper, low quality forage and a protein supplement than to purchase expensive hay.
The question becomes what resources are available on the operation and how can they be utilized, versus what needs to be purchased. For feedstuff inventory it is important to consider hay storage and feeding methods. Most of the hay losses will occur when the hay is left outside without protection. Storing hay in a barn or under tarps will save around 20% more than hay stored outside. Evaluating the hay feeding system before winter begins will help minimize feeding losses and reduce number of bales of hay needed.