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According to the U.S. Drought Monitor, approximately 40 states are experiencing drought on some level, which has also affected feed production in those states. With few reasonably priced feed options available, many cattle producers are looking at what they already have for feed resources, including hay that may be older from previous years. However, there are risks involved in feeding older hay, especially if that hay is moldy.
Keeping cattle at adequate body condition is the name of the game and should be monitored regularly. Cows should be ranked at a body condition score of 5, and heifers should be at a 6.
Nutrition is essential
How well hay has aged depends on how well it was stored. Dr. Scott Fritz, clinical assistant professor of toxicology, Kansas State (K-State) University, stated that if bales are wrapped tightly, they are most likely going to shed water fairly well.
“Moisture is the biggest enemy,” Fritz said. “I recommend doing nutritive analysis on any older hay to identify nutritional quality.”
As hay ages, microbial fermentation occurs within the plants, depleting the soluble carbohydrates that are available, according to Dr. Phillip Lancaster, clinical assistant professor, K-State.
“We’re left with a higher proportion of the plant cell wall, so the overall digestibility of the forage is lower than if it was freshly cut hay,” Lancaster said. “It deteriorates slowly from day one, and although it’s a relatively slow process, hay that is over a year old is going to be somewhat depleted.”
Hay that is two years old or more probably has no soluble carbohydrates left and really only provides the structural part of the cell wall, which still offers energy to cattle, but it is not nearly as effective. Alfalfa is worse than grass hay when it comes to losing soluble carbohydrates, because it has a higher lignin content, so the plant cell wall that is leftover is a lot less digestible than grass hay.
“That means that a producer is going to have to supplement with additional feeds to make up for that,” Lancaster added. “They can supplement additional wheat midds, soyhulls, distillers’ grains, or other additional energy sources that also provide a high source of fiber.”
The best way for cattlemen to determine digestibility of hay is to send samples for chemical analysis. The good news is that protein content seems to stay about the same, although the type of protein may change forms.
One of the main nutrients that is transferred to cattle through hay is beta carotene, which Lancaster said can be deteriorated by ultraviolet light if hay has been stored outside for a couple of years.
“If the hay is brown all the way through the bale and weathered, then it probably has very little vitamin A potential left,” Lancaster said.
Vitamin A is essential to cattle for tissue integrity in the digestive and reproductive tracts, according to Dr. Bob Larson, professor of production medicine, K-State.
“We can see poor reproductive performance with vitamin A insufficiency,” Larson said. “Lung health, gut health and reproductive tract health all require vitamin A.”
Green grass or hay are typically good sources of vitamin A for cattle, and cows can store vitamin A in their liver for a while, but it depletes over time.
“Hay will lose beta carotene as it cures, and if you feed poor quality forages, there is a decrease in vitamin A,” Larson added. “Older hay will also be less digestible which can decrease the daily consumption of important minerals like calcium and phosphorus.”
Minerals leach out of hay if it has been sitting outside and exposed to rain and snow.
“Vitamins D and E are less susceptible to ultraviolet light, but the amounts available to cattle decrease,” Lancaster explained.
Abortion concerns with moldy hay
Feeding moldy hay is not safe, Fritz insisted.
“Typically, it would only affect a few cows, but we still recommend trying to avoid feeding hay with visible mold on it,” suggested Larson. “The temptation is to try to dilute it if you have to, but the safest recommendation is not to feed it at all.”
Spring-calving cows that eat moldy hay in the later part of pregnancy are at risk of abortion, and it does not matter if the mold is white or black.
“There is no differentiation in aspergillus, the species of mold that causes abortions,” Larson said. “If you are not sure about old hay, you may want to have it analyzed again or assume that you will need to supplement more than usual with those feed sources.”
If you have never forage tested hay before, Larson recommends that this is the year to do so. Testing hay samples typically costs about $25 per sample, and your local Extension agent can help locate a lab near you.
“Hay was put up in different conditions, and many producers have feedstuffs that are different than what they are used to,” Larson explained. “It’s important to know if you need to balance the nutrient profile in the hay with supplementation.”
Be efficient
Efficiently feeding the hay you have available can be a key to stretching beef cattle diets, according to information from the University of Minnesota. Avoiding waste means losing less money in the long run.
One way to be more efficient when feeding hay is to feed hay that has been stored outdoors first, saving those bales that are already stored inside. If you end up buying hay, you can ask the seller if they will store your hay inside until you take delivery of it.
Round bale feeders allow cattle to waste up to 25% of hay. That waste can be cut to 10% if cattle are only offered access to the round bale feeder for 8-12 hours a day in a 24-hour period. Cattle should have adequate space around the round bale feeder so all of them can eat at the same time.
Hay can be processed or mixed in such a way as to make it more homogeneous and less likely to have a hot spot, any poisonous plants or nitrates that may harm cattle, said Dr. Steve Ensley, clinical veterinary toxicologist, K-State.
Processing or grinding hay is the most efficient method of limit-feeding hay but rolling bales out on the frozen ground is also an option for most cattle producers.
Hay rings should also be moved periodically so any unconsumed hay is distributed throughout the field as fertilizer. — Sarah Hill for the Red Angus Magazine
