Gordie Jones, a consulting veterinarian/nutritionist and dairy farmer who milks 3,500 cows at Nekoosa, Wis., is pretty blunt when it comes to managing dry cows: “In North America, there has been a failure of the transition period,” he says.
Cows entering the dry period can have too much body condition or too little, too much time in the dry pen or too little, too much ration energy, too much over-crowding, too little selenium, too little dry matter intake, too little fiber and too little cow comfort.
What often results are milk fevers, displaced abomasums (DAs), cows that get off to poor starts and far too much culling in the first 60 days of lactation.
Consequently, dry cow diets are being asked to solve all of these problems. What’s first needed is cow comfort, where dry cows are not over-crowded and have bunk space defined of 2′ per cow.
Next is back-to-basics nutrition with low-energy, high-fiber diets that provide just the right amount of nutrition—the Goldilocks Diet, if you will, Jones says.
“These diets should contain no more than 8 lb. of corn silage dry matter, 4 lb. to 6 lb. of dry, high-quality, low- energy straw chopped short and 2 lb. to 3 lb. of total grain (most or all of which will come from corn silage),” he says.
The diets should contain at least 1,000 grams of metabolizable protein, net energy of lactation levels of 0.58 to 0.62 Mcal/lb and forage neutral detergent (NDF) fiber levels of 40% to 44%. The NDF forage intake should be 12 lb. to 13 lb., the same as milking cows. Magnesium should be 0.4%, and the magnesium to potassium ratio should be in the 1:4 ratio range to avoid grass tetany, Jones says.
Formulated, mixed and fed properly, these diets can virtually eliminate milk fevers (even without adding anionic salts) and DAs can drop drastically, Jones says. “Most dairies have a goal of 4% to 6% DAs, but with these low-energy, high fiber dry cow diets, less than 1% is achievable,” he says.
When these diets fail—and they can—it’s usually the result of particle lengths being too long that allows sorting. Or rations might be still too high in energy, or cows that were on the diets for less than three weeks.
Poor quality forages—too high in fiber or too low in protein—can also be a problem. Mold and mycotoxins and excess potassium are also watch-outs.
These low-energy, high-fiber dry cow diets can work, says Mike Hutjens, a retired University of Illinois Extension dairy specialist who still actively advises producers.
“Low-energy dry cow diets are effective if mature cows consume more than 30 lb. of dry matter and springing heifers eat more than 25 lb.,” he says.
“We estimate 30% of U.S. cows (not herds) are on the program with international successes also reported.”
Hutjens adds the diets can be successful without anionic salts. But cows have to be watched closely. “If dietary potassium is over 1.2% and cows signal low blood calcium is occurring—that is if they respond to calcium boluses or calcium IV or subcutaneous treatment, I recommend second-generation anionic products in the close-up ration only,” he says.
“If you’re using an anionic product program, urine pH must be conducted weekly,” he adds.
Once cows freshen, providing access to fresh, well-balanced rations is perhaps the most important thing you can do to keep cows healthy, happy and accelerating toward peak milk.
The critical thing is to have fresh feed available when cows want to eat, says Rick Grant, with the William H. Miner Institute in Chazy, N.Y. He helps manage the Institute’s 350-cow herd, which has a current rolling herd average of 31,000 lb. per cow.
He notes cows naturally evolved to be crepuscular (they prefer to eat at dusk and dawn), alleomimetic (they prefer to eat together as a herd) and yet competitive for the best feed.
That suggests dairy managers need to provide fresh feed twice a day and have adequate bunk space so they can all eat at the same time. Overcrowding creates a hyper-competitive environment where dominant cows will displace more timid animals and, in some cases, not allow them to eat.
Recent research backs that up. It shows feeding fresh TMR twice a day will result in less sorting and increased dry matter intake (DMI). In one study, DMI went up 3 lb. per cow per day and milk increased 4.4 lb. per cow per day when fresh TMR was fed twice per day.
But feeding more frequently than twice per day might be counter-productive, Grant says. “In particular, feeding four times per day can be antagonistic between resting and feeding at night,” he says.
Competition among cows is most prevalent one to two hours after fresh feed is delivered, and studies show the most cow displacements occur then. Pushing up feed every half hour after feed is delivered for the first two hours will reduce some of this competition.
Studies show that this frequent push-up will improve milk production and feed efficiency (though not dry matter intake).
Bunk space is also critical. Research shows cow displacements increase as bunk space per cow
decreases; 30″ of bunk space is recommended.
Close-up and fresh cows should have five feeding spaces for every four cows (80% stocking density).
Lactating cows can be crowded a bit more. “But don’t exceed 115% to 120% of stalls in a four-row barn. If you have a mix of first-calf heifers and older cows, one stall per feeding space might be best,” Grant says.
And if you have just 24″ of bunk space per cow, stocking density should be 100% or less. In six-row barns, try to maintain one cow per stall since the feed bunk will be overcrowded even at this stall stocking density.
The next thing is to provide clean, comfortable stalls where cows can rest and ruminate after each bout at the bunk. “Management that impairs resting and ruminating will reduce feed activity,” Grant says.
“Rumination and dry matter intake are correlated positively. Cows prefer to ruminate while lying down.”
By Jim Dickrell, Dairy Today Editor
Source: AgWeb.com