From wildfires, droughts, hurricanes and flooding, it’s been a challenging year for hay production. Whether you’re buying hay this year, or managed to get your own hay baled, every forage dollar needs to be spent wisely.
Don’t get caught by higher hay prices later; estimate your hay needs as accurately as possible now while you still have time to adjust your feeding plans.
“The two pieces of information you need are an approximate weight of your cows, because the size of the cow is going to dictate how much she needs, and her stage of production,” says Amy Radunz, associate professor at the University of Wisconsin.
For example, if you have a dry cow weighing 1,600 lb. and medium quality forage, you can estimate they will eat about 2% of their body weight per day and 2.5% later as a lactating cow, Radunz says. “That’s going to get you pretty close to the cow’s average daily intake needs.”
Anything less, and cows are likely to lose body condition ahead of calving. As cows get further along in gestation, their nutrient needs increase.
Cows should have a body condition score (BCS) of 5 to 6 at calving, and maintain that through the months of lactation until breeding, Radunz adds. “If producers wait to address BCS until fall and early winter, it will cost them more in the quantity and quality of forage.”
To Estimate Minimum Hay Needs, Put Pencil to Paper
1. Convert dry matter intake per day to as-fed intake.
If a 1,200-lb. cow’s intake is 24 lb. per day and dry matter of forage is 70%, then as-fed intake is 34 lb. per day.
1,200 lb. cow x 2% = 24 lb. DMI
24 lb. DMI ÷ 0.70% dry matter = 34 lb. as-fed intake per day
2. Estimate forage needed based on the number of cows and days feeding forage.
If a 50-cow herd is expected to winter feed for 150 days, the herd would need 127.5 tons of hay.
34 lb. as-fed intake x 50 cows x 150 days ÷ 2,000 lb. per ton = 127.5 tons
3. Estimate hay losses from storage and feeding method.
“Will your method of feeding create additional waste and storage losses you need to account for? If you are feeding on the ground, you are going to lose more than if you are feeding in a hay feeder,” Radunz says.
A general assumption of 20% hay loss would raise the total hay needed to 153 tons of hay.
127.5 tons hay needed x 1.2 = 153 tons
Weather, temperature and feeding environment also play a role in the amount of hay needed. Small changes to facility design or feeding method might help conserve hay quality.