Dairies trying to feed through the drought need to take a systematic approach for determining their forage needs, says Ellen Jordan, Texas AgriLife Extension Service dairy specialist.
She suggests inventorying the current forage supply, analyzing all forages for nutritional value and working with a nutritionist to determine how much forage will be needed for the herd, including replacements and dry cows, for the coming year.
Dairy owners should expect more variability in crops grown under drought conditions, Jordan cautions. Also, depending on the crop and growing conditions, they should check for nitrates and prussic acid.
To get a ballpark estimate of the forage dry matter needed to feed a herd, she provides the following equations: 1.5% of the body weight per day times the number of cows and 1.1% of the body weight per day times the number of heifers equals the pounds of dry matter per day needed for the herd.
To determine the total amount needed, figure the pounds per day for cows and for heifers and then multiply that number times the number of days they will be needing feed.
For example, if the average body weight of a 100-cow herd was 1,400 lbs, the herd would need 1,400 lbs x 0.015 per day x 100 cows = 2,100 lbs of forage dry matter per day just for the cows. If the herd has 90 heifers of all ages that average 700 lbs, the herd needs an additional 700 lbs x 0.011 per day x 90 or 693 lbs of forage dry matter per day for the heifers.
“If you estimate it will be 250 days until you’ll be able to get more forage from a winter crop, you’ll need 2,100 plus 693 times 250, or 698,250 lbs of forage dry matter,” she says.
To determine how much hay that would be on an as-fed basis, divide the pounds of forage dry matter needed by the percent dry matter in the hay.
“Typically, rations are developed to maximize the use of high-quality forages, but this year ask your nutritionist what is the minimum amount you must have to keep the animals healthy,” she says.
And, because of the dryness, some failed crops are being harvested for forage rather than for the use originally intended. Fiber content may be higher, so less forage may be required to get the same fiber benefit.
The next step in the systematic approach is to locate forages and high-fiber byproduct feeds. Again, work with the nutritionist to determine ways to stretch forages with products such as beet pulp, soy hulls, corncobs or other fibrous products that are not typically used.
“Analyze these feeds as well so you can get the most out of them,” Jordan says. “Test, don’t guess.”
Next is the hardest part: Compare how much forage is needed to what can be located and then decide if animals need to be sold or relocated to make the two figures meet.
“It may be better to send heifers somewhere else to feed rather than bring more feed to them. Or you may decide to sell heifers and concentrate on the cows. But evaluate the cows in your milking herd. Now is the time to cull those cows that aren’t producing enough to cover their feed costs.”
Producers can consider the forage shortage as an “opportunity” to cull cows with reduced fertility, poor feet and legs, or high somatic cell counts, she says. “If you have bulls, ask if this is the time to switch to artificial insemination and ship the bulls.”
The final step of the systematic approach is to conserve the forages that are gathered. Reduce shrink by storing hay in barns, if possible. Place hay stored outside in a well-drained location or on a gravel pad to reduce losses. Consider tarping the hay to further reduce rain damage.
“If you’ve been feeding free choice in bale rings, move to a total mixed ration to reduce waste,” she says.
“Mother Nature has provided yet another challenge,” says Jordan. “Make systematic decisions rather than buying on impulse. If fall rains permit, consider planting winter forage crops such as small grains to help meet the forage needs of your herd.”