Hay may not be enough to keep condition on cows in the fall and winter months
A wet spring forced many producers to delay cutting hay, which can lead to lower nutritional quality. Hay supplies might be good going into the winter months, but the quality may not be enough to sustain the condition of a herd.
“Nutritional supplements are usually provided when the diet is inadequate in a particular nutrient or there is an imbalance of nutrients,” Dr. Shane Gadberry, professor of ruminant nutrition for the University of Arkansas System Division of Agriculture, said. “Grazing livestock receive most of their nutrients from growing or harvested and stored forages. The nutrient composition of these forages varies for many reasons, like forage type, season, soil type, soil fertility and harvest conditions. A forage test can help determine both macro- and micro-nutrient shortcomings.”
Testing prior to feeding gives an accurate look at the nutritional values of the forage.
“The main thing is testing before you feed,” Dr. Patrick Davis, University of Missouri Extension livestock field specialist, said. “There’s going to be a sweating process while it’s baled, and you’re going to have some changing in dry matter, some changes in quality as it goes through that drying process in the bale. I know a lot of people who buy a lot of hay and buy hay from different areas, so maybe taking the route every so often of testing and adjusting, like you would for silage, is a good idea.”
There are several factors involved in forage nutritional values, and each plays a role in the overall nutrition of a herd, including dry matter, total digestible nutrients, fiber and digestibility. Most producers look at protein more than any other result, but is it available protein?
“If the hay has been baled wet, or the hay is excessively heated during the baling process, the heating may cause protein to be unavailable. If the protein is unavailable, you can feed all of it you want to, but the animal is not going to get (any protein),” Davis said. “The protein is heated to the point where the microbes in the rumen can’t break it down and it can’t be digested. What you can do in a hay test is test for available protein and that will tell you what crude protein is actually available, so you would use the available crude protein percentage, not the crude protein percentage.”
“Hay can be low in protein, energy (total digestible nutrients) or both,” Gadberry added. “Samples of Bermudagrass and fescue that come through our lab are usually adequate in protein and energy for dry cows, but are inadequate in TDN about 70 percent of the time for lactating cows and inadequate in protein about 40 percent of the time for lactating cows. Just like pasture grasses, some major minerals like phosphorus and sodium can be deficient in hay as well as trace minerals like copper, zinc, and selenium and vitamins. This is why most producers keep mineral and vitamin supplements available year-round,”
While a basic hay test is a good start, there are additional areas that can be evaluated in forage samples, which could be an additional charge, but provide valuable information.
“Neutral detergent fiber (NDF) is a predictor of intake and it’s very important on hay tests because as the quality of the hay decreases, that NDF and acid detergent fiber (ADF) will increase,” Davis said. “What that means is poorer quality hay has more ADF and NDF percentages, meaning that hay is less digestible and the animal has less intake to meet their gut fill. The amount of NDF, is representative of gut fill, the more NDF in the hay, the quicker that animal meets gut fill, so they have less intake and the slower that hay passes through the animal. Then you add on the ADF, the higher that number is, the less digestible the hay is.
“Grass hays run pretty high in NDF, legume hays run in the 40s, alfalfa runs in the mid 40s, fescue runs in the high 50s, low 60s or even high than that. Basically, cattle will be able to eat more of the alfalfa because of that lower NDF than fescue. On a 1,200-pound lactating beef animal, they can pretty much eat all of their requirements at about 30 pounds of dry matter, where that same cow is going to get about 20 pounds of dry matter on fescue. She might have enough to meet her protein requirements, but she’s going to be deficient in energy so you’re going to have to supplement 6 to 7 pounds of corn to meet her needs.”
Davis added that when developing a feed ration, calcium and phosphorus should be considered.
“In legume hay, they are going to be very high in calcium and phosphorus,” he said. “The reason why I look at that, if I’m needing to supplement, I’m going to supplement with things that are higher in phosphorus compared to calcium. A lot of grain-based supplements – corn, distiller’s grains – you’re going to need to add a little limestone to balance out the calcium and the phosphorus ratio; we’d like to see that at a 2 to 1, two parts calcium to one part phosphorus.”
Knowing what nutrients are lacking can not only be beneficial to the animal, but to the producer’s bottom line.
“Before I tell a producer to go out and buy feed, I want to know how long the hay feeding season lasts, what stage of production the cows will be in during this time, the body condition of the cows, and hay test results,” Gadberry said. “Hay testing is a tool that helps producers avoid spending too much money on the wrong kind of supplement. A common mistake we see is cattle producers spending money for supplements that are limited to 1 pound intake but the hay test shows the cows need 3 to 5 pounds of supplement. Supplement feed cost must also be consider. Some feeds you can buy 3 pounds for the same price as 1 pound of another feed. The worst-case scenario is not supplementing when conditions prove otherwise. Thin cows take longer to breed back which disrupts the calving season, market timing and management which are all hidden costs compared to obvious costs like buying feed.”