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Feeding High-Quality Forage Helps Milk Production
If a cow eats, she produces milk. Forage quality and overall feed quality can make a big difference in how much milk is delivered.
“Cows are creatures of habit. They will eat when new feed is delivered to their feeding area and every time the feed is pushed up, so they can eat more,” says Hugo Ramirez, Iowa State University Extension dairy specialist. “The amount of time they spend eating isn’t always based on how much they eat, but rather if they are getting their nutritional needs covered while they are eating.”
One bite of feed at different dairy operations will likely have different feed values. Providing cows with forages – silage and hay – with high feed value will mean the cows are meeting nutritional needs in the diet.
proper storage preserves quality
Ramirez stresses the importance of testing all feeds at harvest and prior to feeding. Good storage helps to reduce spoilage of the feeds and to preserve the quality. With corn silage, quality begins with hybrid selection, but it is also affected by growing conditions, harvest, and storage.
After harvest, he says it is important to pack the silage tightly in the bunker to create an anaerobic environment for the bacteria responsible for the fermentation of the silage.
“To minimize dry matter and nutrient losses of silage, an oxygen barrier film surrounding the sides and top of the pile will help make a perfect environment for the fermentation of the silage,” Ramirez says.
He recommends covering the whole pile with black or white plastic and weighing it down with tires or other weights.
The oxygen barrier film is used on the silage crops at the Iowa State University dairy farm. Manager Miguel Rangel says it has made all the difference in the quality of the 4,500 tons of silage harvested at the farm each year.
“It’s important to pay attention to details when feeding dairy cows. We currently milk about 360 cows that average 86 pounds per day with 4.4% fat and 3.2% protein. Without high-quality feeds, this wouldn’t be possible,” Rangel says.
Good storage, like the oxygen barrier, will keep the silage quality high and with very little waste, which Ramirez says is important with the poor economic times dairy producers are currently dealing with.
“Producers want to save money where they’re able, and good storage can certainly do that,” he says.
Hays, especially alfalfa, are affected by storage also. At Iowa State, alfalfa bales are stored in plastic to help the quality last longer. Knowing the relative feed value (RFV) for alfalfa is important, as the higher the number, the better the quality. Ramirez says the relative feed value of grass hay could be low, but it is still a good feed.
“Alfalfa has a higher RFV because it has the stem and leaf present when harvested. Grass hays are higher in fiber, which lowers the RFV, but that hay is still useful in the dairy diet,” Ramirez says. RFV helps rank the potential energy intake of different hays by lactating dairy cows.
Relative forage quality (RFQ) will give producers a better estimate of the digestibility of the fiber of grasses. Ramirez says the RFQ results will tell the producer how well cows are optimizing forage quality.
“It’s important to remember that the sample sent in for analysis needs to be representative of the entire hay crop, and the results will only be as good as the sample,” he says. “Making adjustments to a cow’s diet based on her nutritional needs is very important, and feeding forages to different groups based on its quality is also important.”
When looking for other forage options, know what the nutrient content is of each, Ramirez says. Sorghum silage can be a good alternative, but nitrate levels must be known as sorghum will store nitrates in the stalk. The ensiling process will reduce nitrate content, but testing should be done if any problem is suspected.
Cover crops are another option. Winter or spring oats or wheat, triticale, or other unconventional forages are a very good option, especially for dry cows or heifers, according to Ramirez.
“By using other forages for dry cows or heifers, corn silage can be saved for lactating dairy cows to help save or extend the amount of stored silage at the operation,” he says.
Along with feeding forages, producers should be aware of the health concerns or challenges that can occur. A balanced diet and feed-quality testing usually help prevent these issues, but Ramirez says it is good to know the warning signs.
Feeds with a high nitrate content can be managed, according to Virginia Ishler, Penn State University Extension dairy specialist. Nitrate testing is available for forages and drinking water. Forages may contain elevated levels of nitrate when fields are heavily fertilized with manure and nitrogen-containing fertilizers. Rainy weather with lack of sunshine in the spring or fall and drought can all be causes of nitrate problems. These are more commonly seen in sorghum, Sudan grass, perennial grasses, and legumes, but they’re also seen in corn silage.
“Testing suspect feedstuffs can prevent a problem,” Ishler says.
Wet weather conditions may also play a part in the increase of moldy field conditions in corn and corn silage. Ishler says dilution is the solution when mycotoxins and other toxins are present in a crop. Limiting the suspect forage will minimize the impact to animal performance. Feed additives are an alternative if mycotoxins are a problem.
Acidosis is a complex issue seen in ruminant animals and is caused by several different factors.
“It can result from the ration being formulated very high in starch and low in fiber,” Ishler says. “It can be because the cows are sorting their feed, or it can be a result of animals being restricted from the feed bunk.”
Good management practices help prevent challenges with feed and keep cows producing milk at high qualities and quantities.
Ramirez says feeding highly digestible feedstuffs may help keep feed prices down and profits higher, especially in the poor economic conditions the dairy industry is currently facing.