Welcome back to the Extension Connection Podcast. I'm Cassie LeMaster, Livestock, Equine and forage agent for Polk County, North Carolina. Today we're gonna talk about hay quality and the factors that affect it. Then I'll briefly explain how quality is evaluated and how we can use that information to match a forge to our animal's unique nutrient requirements. So what is hay quality? Essentially it is the capacity of a hay or forage to supply an animal with their nutrient requirements. This also includes palatability, digestibility, and chemical composition. Will the animal consume it and will they be able to digest it? Once digested, will the forage provide the needed nutrients for growth and good health? The conversion of that forage to maintained animal health and performance is going to be the ultimate measure of forage quality. One really important tool for measuring that outcome is going to be body condition scoring. If you want to learn more about how to body condition score your animals, feel free to reach out to me at the extension office or by email and I'll be happy to walk you through it or come out and talk to you about it on your animals. Now most livestock and equine owners probably think of the sensory characteristics when they think of hay quality. This is the color, the smell, and the cleanliness of that forage. But in addition to that, nutritionists want to know what the chemical composition is. Good quality hay is going to be free of debris, like sticks and leaves, mold, dust, and weeds, especially the toxic ones. Some overweight animals may require a more mature hay, but in general we don't want it overly mature and stemy. This affects the digestibility and whether or not the animal will consume it. Horses have a shorter retention time in the digestive tract than ruminant. So this is especially true for them and the digestibility of that fiber. So what factors affect forage quality? First is the species of the plant that's being harvested. In general, legumes like alfalfa and clover are going to be higher quality than grasses in that they're higher in protein, energy, or calorie content, calcium, and have faster rates of fiber digestion. Of the grass species. Cool season grasses such as fescue or orchard grass or rye grass are more digestible than warm season grasses part is due to anatomy differences in the plant, but also because my next point is that temperature affects this as well. This is because plants grown at higher temperatures are less digestible due to a process called lignification. Lignin is a fiber component of plants, especially high in tree bark and the grass stems, and that is indigestible. And also it acts as a physical barrier to the more digestible fiber portions within the plant cells. So as the plant grows and becomes more mature, that indigestible portion of the plant gets larger. This is why the most important factor in determining the quality of any species of forage is the maturity stage of that plant at harvest. When the plant is young, it's made up of mostly young tender leaves, which are highly digestible and very palatable for the animal to eat. As the plant grows and the stem grows taller, the plant will become less digestible. In an ideal world, the hay producer or the farmer will try to target that sweet spot between high yield, which goes up as the plant gets taller and quality, which of course does the opposite. So what about cutting? It's often thought that a second cutting hay is the highest quality, but actually maturity at harvest is still the most important factor. Any cutting can be high quality if it's cut at the correct maturity. Take this example Farmer one makes their first fescue hay harvest on May 2nd, and it's in the boot stage. If we compare that to farmer two, who makes their first fescue hay cutting on June 18th when it's in the late bloom stage. The first farmer's hay is going to be much more digestible and therefore higher quality, assuming that all the other factors are similar. Another factor that is along the same lines but might help when we are visually inspecting hay to estimate quality is the stem to leaf ratio. Leaves are higher in digestibility than stems, and the proportion of leaves decline as the plant matures. Some hay crops also experience what we call leaf shatter, where the leaves disintegrate and fall out of the bale prior to feeding, leaving only the less digestible stem portion. Fertilization also plays a role in determining hay quality. Nitrogen fertilization directly impacts the crude protein of a plant, especially grasses that are not able to fix their own nitrogen. Other essential minerals will also be affected by the ability of the soil or fertilizer to supply those nutrients to that growing forage. The next factor I'll mention is harvesting and storage techniques. Nutrient losses in the field can occur due to rain damage, leaf loss, and continued plant respiration. Rain can leach water soluble vitamins and minerals from the hay. It depends when the rain occurred after harvest. A short or light rainfall event shortly after harvest won't do much to impact the quality, but a heavy rain after the plant has almost dried, might drastically reduce the quality. Storage is also a big component. Most people in Polk County are feeding small square bales that can be stored in a barn undercover. But round bales that are stored outside can have up to 40% losses to the nutrient levels. These bales also become less palatable, so animals then waste 20 to 25% on top of that. This is where a covered hay storage really can pay for itself in just a few years. Factor seven is one you may look at quite differently depending on what animal species you're feeding it to. Most horse owners are aware that non-structural carbohydrates or the sugar fraction of the forage changes seasonally and even daily. The proportion of these sugars will impact the overall energy density of the hay. A dairy producer would need forage high in these carbohydrates. But most horses do not. Since these highly digestible carbohydrates increase in the plant throughout the day, hay that is cut in the afternoon tends to be higher in those non-structural carbohydrates than hay that is harvested in the morning. This would also be true for hay cut in the spring versus hay cut in the summer. We would expect that spring cut hay to be higher in carbohydrate values. Lastly, I'll mention what we consider to be anti quality components. These are things that would contribute to illness, poor animal condition, low consumption, or reproductive difficulties. This includes foreign material like wire, sticks or weeds, biophysical factors like thorny weeds or foxtail. Which is a grass that has a seed head with sharp awns that can embed and cause ulcerations in the animal's mouth. Then there's also biochemical factors, one being lignin like I've already mentioned, and then there's tannins, which can be high in species of lespedeza. There's nitrates and prussic acid, which is a cyanide like compound, which accumulates in wilting leaves of some plants. Johnson grass is one example that can accumulate prussic acid during times of stress like drought or frost. Then there's endophytes, like the one that causes reproduction problems in livestock, and especially in mares that eat Kentucky 31 fescue. To determine the nutrient content of any forage, you'll need to have it analyzed by a lab. The North Carolina Department of Agriculture has a lab that offers the service pretty inexpensively, only about$10. This will help you match the nutrients provided in the hay with the animal's, energy, protein, and other mineral requirements, and help you understand if and how much additional feed supplementation is needed. For horses with special metabolic sensitivities samples will need to be sent to another lab for more specific sugar fraction testing. If you need help with sampling your hay or interpreting your results, please call me at the extension office. Also, we'll soon have the results from our first Polk County Hay Contest. So tune in next time to hear the winners announced here. Thanks for listening.