Farming Magazine - July, 2012
Dairy Nutrition: Focus on High-Quality Forage
It's mid-April and my backyard is coming back to life. The daffodils are way ahead of schedule this year, the tulips are already done, the hostas are peaking through the mulch, and the birch and maple trees are starting to leaf out earlier than I can remember. The lawn has been fertilized and limed and the lawn mowers are tuned and ready for action. I'm still debating if it's worth spending the money on the preemergent crabgrass stuff and the dandelions are already driving me crazy.
This past winter has been one for the record books with nearly no snow ,and so far this spring has been one of the warmest. With all the ground moisture from the torrential rains last fall, the pastures are a good two to three weeks ahead of normal and are looking pretty good. With another unpredictable spring coming to the Northeast, it's going to be a challenge as to when to turn cows out on pasture or consider when that first cutting should be mowed and baled.
The guys who have the pastures are looking forward to getting the cows out a little bit early to maybe cut back on the grain bill. The guys with hay fields are hoping they can make a little bit of hay to help stretch the corn silage, which for a lot of dairies in southern New England was a dismal crop due to the weather of 2011. How I wish making good hay or haylage in New England wasn't such a challenge.
Most farmers seem to hit it right at least once during the season for putting up good hay or haylage. However, more often than not, for every ton of primo hay you bring home, there's always nine more that are just a notch or two above straw. New England farmers are at the mercy of the weather when it comes to making high-quality hay. For the dairy farmer, high forage quality drives feed intakes and feed intakes drive milk production. The best nutritionists in the world can't get cows to make milk when they're stuck with poor-quality forages.
Not long ago I was visiting a young couple with a small herd of cows and was duly surprised and impressed with the hay they had in inventory - second cutting from last year. It was gorgeous and tested over 16 percent crude protein. They also had some wrapped bales they were just about through with that tested nearly as good. Without sounding too condescending, I don't get to see this kind of hay in a Connecticut hayloft very often.
Orchardgrass grows prodigiously in New England and when harvested in a timely manner will result in very digestible hay or haylage. Orchardgrass is particularly appealing because of its relatively high yield and persistence on poor soils. Perennial grasses have advantages over legumes in the Northeast because they can use nitrogen from manure, support vehicle traffic and tolerate marginal soils better than legumes can. Perennial grass also can remove over twice the nitrogen per acre compared with corn, making perennial grasses attractive choices for nutrient management, regardless of soil conditions.
But we all know how quickly a field of orchardgrass can go from immature to fully seeded in just a matter of days. Making good hay out of orchardgrass is more about timing - and the cooperation of the weather. Sometimes the best-laid plans just don't work out. Research has shown that the decline in digestibility is quite rapid in most grass forages after the boot stage of development. Not only is the extent of digestibility of forages affected by maturity, but the rate of digestibility also declines with advancing maturity. The lignification that comes with plant maturity stops the rumen bugs dead in their tracks.
A cow's rumen was designed to make the most of forage, and the economic benefits of high-quality forage in a dairy ration are substantial. I know how easy it is to pontificate about the economic importance of high-quality forage as I sit in my easy chair typing away on my laptop. I've never had to produce a bale of hay in New England. Sadly though, many dairy farmers go on year after year, missing the boat as it were, with poor hay and haylage and feeding efficiencies are missed.
Today, forage quality is defined by fiber (measured as neutral detergent fiber, or NDF) and NDF digestibility along with protein levels. Protein and fiber levels in forages are essentially inverse. The higher the protein in a forage, the lower the fiber and vice versa.
Quality, of course, is always a relative term. For the most part, grass hay and haylage that tests above 15 percent crude protein and below 60 percent NDF are very good forages and should be utilized as much as possible in a dairy cow diet. If you can get some grass hay that tests in the 55 percent NDF range or lower, you've got some excellent grass forage with an energy level that rivals some corn silages.
It takes a little bit of balancing to figure out what's the best fit for forages because of the variability of the forage quality. What works one year almost certainly will not the next year. Grain and energy requirements to meet a certain production level will fluctuate, as well.
There's really no standard as to how much forage you can feed to your cows. There is the limiting factor of forage fill, which is dependent upon the NDF value of the forage. A high-forage diet on one farm may be 50 percent forage at 24 pounds of forage dry matter. Another farm with the same production level could have 60 percent forage and 30 pounds of forage dry matter. The difference is the quality of the forage that reaches the cow. If the quality is superior and you have access to plenty of it, don't be afraid to feed it and balance the rest of the grain ration around it to support the optimal feeding efficiency and milk production.
The author is a dairy nutritional consultant and works for Central Connecticut Farmer's Cooperative in Manchester, Conn.