Improving forage quality
Boosting the quality of forage can directly affect a farm’s bottom line. Jessica Williams, marketing manager for green harvesting for Massey Ferguson North American, presented “Optimizing Forage Quality in Harvested Forages” as part of the recent Cornell Organic Field Crops & Dairy Conference hosted by USDA and the New York State Department of Ag & Markets.
“‘Forage quality is defined as the extent to which a forage has the potential to produce desired animal response,’” Williams said, quoting Don Ball’s “Forage Quality.” “The end user is not the guy buying your hay, but is the animal consuming it.”
She added that it’s important for forage growers to remember that forage quality changes with stage of growth. As alfalfa plants grow taller, digestibility, crude protein and intake potential decreases while dry matter fiber increases. Neutral detergent fiber (NDF) is inversely correlated with dietary intake.
“Neutral detergent fiber is the accumulation of all the fiber,” Williams said. “Relative feed value gives a baseline of the quality of your forage.” (It’s a marketing tool for comparing similar types of forages.)
“With your dairy cattle, you have nutrients to match their ration with stage of development when providing your own forage,” Williams said. But that doesn’t mean lesser forage is worthless.
“Even if we have poor quality forage, there will be someone who can use that,” she said.
Typically, lactating dairy cows have the highest forage nutritional needs, followed by background stock, replacement heifers and beef cows. Among dairy cows, it goes by those lactating in their first 200 days since calving; those in the last 200 days and heifers three – 12 months old; heifers 12 – 18 months old; then heifers 18 – 24 months old and dry cows.
“There’s significant neutral detergent fiber in grass versus legumes,” William said. “That’s why animals get so much more performance from alfalfa than orchard grass.”
Forage isn’t just about volume. It’s about quality. Quality forage has more leaves because the more leaves each plant has, the more nutrients animals can access.
“It doesn’t matter what forage; it will have more nutrients,” Williams said.
Leaf material contains more crude protein and lower fiber content than the stem. Unfortunately, the harvesting process causes leaf loss – dry matter loss.
Dry matter loss can include leaves that are shattered and not baled; leaching during curing; leaching due to precipitation; microbial utilization of carbohydrates; and denaturing of proteins with heating.
“Microbial can be during dry down and harvest or in the gut of the animal,” Williams said.
Drying hay faster – to the point where 60% of the moisture is out – can help preserve more nutrients.
“We want it to stop respirating as quickly as possible,” Williams said. “Get it in the silo or wrapped as quickly as possible.”
During respiration after cutting, 2% – 8% of dry matter is consumed, accounting for a 2% – 8% yield loss. There’s also a 4% loss in sugar and starch that raises NDF slightly over 3%.
“When forage moisture drops below 60%, respiration is greatly reduced,” Williams said. She said conditioning will reduce the time of drying by exposing the crop surface area to dissipate moisture. Reducing harvest time leads to better forage quality and yield.
When comparing rollers to crush or crimp the stem or impeller conditioners that slice the stem and leaves to dissipate stem moisture, she prefers roller conditioners.
“With steel-on-steel, you’re getting a nice crimp of the stem,” Williams said. “The tine slices the stem and does a good job if you’re in grass, but it slices the leaf.”
Using a rubber-on-rubber roller bruises the leaves, often leaving dark spots, and it doesn’t last as long as steel-on-steel. With steel-on-steel roller conditioners, farmers can bale three to four hours sooner.
“You want to get that crop in storage as quickly as possible,” Williams reiterated. “The time of mowing affects dry down.”
A wider swath width during mowing may also improve drying rate and total digestible nutrients. Williams’s research showed that a wider swath reduced time to dry to 65% moisture from 29.7 hours to 19.5 hours, which can make a big difference on a time-strapped operation. The crude protein also improved from 18.7 to 19.3.
As for the moisture when mowing, wet soils increased moisture moving into hay and result in the bottom portion of the swath remaining wet longer. One way to mitigate this is to keep the swath off the ground by cutting higher, which allows for better air circulation.
She encouraged farmers to rethink their planting and hay cutting time. Instead of literally making hay when the sun shines, perhaps planting during the day and cutting hay at night might make more sense as “at night, the plant is not doing photosynthesis,” she said.
But she also understands that “you do what you can when you can.”
To avoid raking losses, Williams encouraged farmers to keep forage on top of stubble in the field and avoid tines touching the ground, which boosts ash content.
“Mergers and rotary rakes decrease loss,” Williams said. “Wheel rakes typically cause higher loss and more ash contamination. A rotary rake does a significantly better job as the windrow ropes together.”
