Higher forage diets for dairy cattle are gaining in popularity as farmers deal with the continuing high price of feeds like soybean meal and corn.
These kinds of high-forage diets are a passion of Dr. Larry Chase, professor of dairy nutrition at Cornell University, where he teaches, serves the Extension service and does research.
Chase spoke at a series of sessions around the state last week, sponsored by Byron Seeds.
The use of more forage in the dairy cow's diet can help with reducing the purchased feed needs and lowering nutrient imports to the farm, he said. It may also lead to better herd health.
With any type of forage there is a lot of variability in digestibility and a 10-15 unit difference can mean a difference in per-cow production of six-eight pounds of milk per day, Chase said
"Your nutritionist is only as good as your forage," says a western New York dairy producer, quoted by Chase.
"What determines how much forage a cow can eat? The rumen of a dairy cow is a fixed-volume container and it all depends on how much you put in and how long it stays there."
How much forage can be put into the dairy ration depends on the quality, the digestibility, the rate of passage and the palatability.
Farmers would also be well advised, he said, to keep a close eye on their inventory if they are planning to utilize more forage in their cows' diet. For farmers who are looking at upping the forage percentage in their cow's diet, Chase advised adding it incrementally so the rumen bacteria have time to adjust.
Older guidelines from the U.S. Dairy Forage Research Center suggested cows can eat 1.2 percent of their body weight in the form of forage or up to 75 percent of the ration.
"But we've got herds eating a lot more than that. Now we have larger cows and they are more productive."
Research suggests that cows on really well-managed pasture will eat 1.3-1.5 percent of their bodyweight, which equates to 200-250 pounds of wet pasture intake per day for a 1,400-pound cow.
Chase said he has seen similar intakes for cows fed with green-chopped forage.
More digestible forages have more energy per pound, he added, and Michigan State research showed that there is a half-pound of milk gain for every additional unit of NDF (neutral detergent fiber.)
One thing that is beginning to show up in higher-forage rations is that some forages are just too soft and dairy producers find they must add straw to get enough "chew factor," Chase said.
The other thing researchers are starting to see is that some components of the forage are totally indigestible.
A crucial element in the idea of higher-forage rations is this — of the potentially digestible fiber how much is slowly available, how much is available quickly and how much is totally no use to the cow.
At the U.S. Dairy Forage Research Center, way back in 1979, Dr. Dave Mertens proposed that there were faster and slower digestible fractions of the NDF and science is beginning to catch up, providing data to back him up.
"Better understanding of digestible and indigestible NDF and the fast and slow pools is needed," he said.
In northern New York, farmers cannot grow alfalfa and rely on grass forages. "It doesn't make sense to put the wrong forage on the wrong soils," he said.
As a result, much of Cornell's on-farm research deals with forages other than alfalfa.
One trial Chase was involved in tested the herd's milk response when fed brown-mid-rib (BMR) corn silage at the beginning of their lactation. The cows were fed BMR silage for three weeks, which kicked up the peak of their milk production.
The interesting part was that the peak held up as the cows were transitioned to other feeds. This is a key point for farmers who have limited inventories of the highest-quality feeds.
Chase recommended that farmers consider ways to inventory their feed and use their best material on the early-lactation cows to get the best milk production.
In the case of BMR corn silage, it is known for having a lower yield than other varieties, he said, so it pays to know where that feed is and which cattle to use it on.
High-quality grasses compare well to high-quality alfalfa feeds. "High-quality grass can result in similar milk production to high-quality alfalfa," he told the group of farmers and nutritionists who attended the first Byron Seed meeting at Arlington, during a snowstorm.
Chase encouraged them to think of the dairy ration like the U.S. Department of Agriculture's old food pyramid for humans. The base of the pyramid should include forages and physical fiber and form the largest part of the cow's diet.
Above that are grains, by-products and rumen-degradable proteins. Higher up on the pyramid are minerals and vitamins, fat supplements and bypass proteins.
One of the most important things farmers can deliver to their cows is consistency.
Cows want a consistent supply of high-quality, highly digestible feed with effective fiber that includes palatable, well-fermented silage. "The closer we come to that the better off we're going to be."
Feeding more forage in general is going to lower the cost of the ration and increase income per cow per day, he said.
For farmers feeding total mixed rations, 60 percent is considered a high-forage ration, but for some grazers the ration is 100 percent forage. They feed no grain.
Some farms would like to feed higher forage rations — as high as 70-75 percent, but they have inventory constraints.
Cornell is keeping data on 30-35 dairy herds that are using high-forage diets — 60 percent or more — and getting 80 pounds of milk per cow. Chase has one herd using a diet that is 78 percent forage and getting 81 pounds of milk.
Chase said better milk components come along with these higher-forage diets. Farmers also notice lower acidosis risk and better foot health, lower culling rates, reduced veterinary bills, an increase in the number of lactations per cow and an increase in profitability.
But for farmers to go into a high-forage system they need the right management outlook and attitude. "If either the farmer or the nutritionist thinks it isn't going to work, then it isn't going to work."
The farm also needs to have adequate quantities of high-quality consistent forages since it will require more total forage.
Forage digestibility must be better than average too, he added.
Most farms don't have 15-30 percent more forage just sitting around, but that's what it will take, since the forage is displacing other feeds. It will take that kind of addition to feed the same number of cows.
This kind of system requires a better job of managing crops.
"It may take two-four years to adjust forage production and management."
While the higher-forage diet will displace grain, that also means there is less of a ration component to buffer or make changes in the ration.
At the same time farmers must also consider bunk management and cow comfort. This kind of system also requires feed managers to monitor and adjust for changes in forage dry matter.
There are nutrient management questions because farms will be importing less feed. Chase encouraged farmers to put together a plan and set the forage NDF intake at one percent of body weight and then increase this if the forages are wet, soft or highly digestible.
They should continue to observe the cows for dry matter intake and daily variation in milk production and components.
When implementing this kind of change, Chase recommended that if a ration is 52 percent forage, it shouldn't be upped to 60 percent. Rather the ration should move up one or two percent at a time.
Using this kind of higher-forage system means that farmers will need to do a good job of inventorying feed stuffs so they can allocate certain feeds to certain animals. Even farmers who aren't planning to use a high-forage ration should be considering this, he said.
"Why would you waste the best feed on heifers. Every farmer should be thinking about this even if you don't feed high-forage diets."
Forage analysis should be done more frequently to keep the rations on target when using high-forage diets.
"There ought to be fresh, palatable, high-quality rations in front of the cows any time they want to eat."
With these higher-forage rations, cows will need more time to eat and issues of frequency of pushing up the feed and freshness of the ration will become more important.
Another question for farmers looking at this concept is whether or not their feed mixer is big enough to do the job. Feeding more forage will require more cubic feet of mixer space because it will be bulkier.
"A mixer that is too small will not mix as well."
He urged farmers to consider this kind of ration change and to move slowly.
"High-quality forage does not assure high milk production, but low-quality forage guarantees low milk production."