[MUSIC] Hello, my name is Kathy Soder. I am a research animal scientist with the USDA agricultural research service. Today, I will be presenting the first of two lectures on grazing management from the Dairy Production and Management MOOC Series. While the majority of milk produced in the United States is from dairy herds fed conserved forages such as silage, baleage and hay. There are a number of herds that use grazing as a feeding management strategy for reducing feed costs, increasing profit margins or meeting the requirements of a specific milk market. Additionally, while larger dairy herds typically do not graze their lactating herd, they may graze other categories of animals such as dry cows, late lactation cows, or heifers. Therefore, understanding basic nutrition and management of pasture is essential for herds grazing any category of animal. The challenges of managing a grazing system are quite different from managing a confinement dairy. The manage of the grazing dairy must react quickly to changes in environment, such as weather, soil, and forage conditions on a daily basis. Managers of confinement dairy systems are usually very production oriented, so they can profit from high levels of milk production. Grazing systems, on the other hand, are frequently characterized by lower levels of milk production. However, emphasis is placed on high milk production per acre at a reduced cost since the cows are harvesting much of their own feed and spreading their own manure. The key to any successful dairy grazing system is providing high-quality forage in sufficient quantities such that dry matter intake and nutrient intakes are not deficient, as these are two of the main driving factors for milk production. The main nutritional influences on milk yield from pasture include, high-quality forage grown per unit of land, amount of pasture allocated per cow, pasture management, and quality of supplemental feed to complement pasture nutrition. While dairy farmers grazed cows generations ago, as technology advanced, it was found to be more advantageous from a milk production standpoint, to bring cows to the barn and feed them under more controlled conditions. However, as economics have changed over the last few decades, some dairy farmers have revisited the use of lower cost pasture as a main forage source. Grazing management today is not the same as grazing management several generations ago. In the past, cows were grazed in uncontrolled or continuous pasture system for a long period of time. Because the cows have access to the entire pasture all the time, they're able to select their favorite forage species and ignore the others. This will result in cows overgrazing desirable species and decreased forage yield. In addition, due to stressing the forage plants from overgrazing, this will provide an opportunity for weeds to move in. As a result of this management, one can expect lower milk and forage production. Additionally, nutrient deposition will be uneven as cows deposit greater amounts of manure in favorite hangouts such as under shade trees or near water tanks. Unlike continuous grazing, rotational grazing involves dividing large pastures with fencing to graze smaller pastures more intensively for shorter periods of time. Usually one-half to one day. Then moving cows to another pasture to allow that pasture foraged to rest, regrow, and regenerate energy stores to improve pasture productivity and longevity, and decrease weed issues due to improved forage vigor. This system has greater capital investment than continuous grazing, mostly in fencing and watering systems. Requires a bit more labor to do the daily moves to new pasture, but still less investment than a confinement system. Since the cows are limited to a smaller pasture area, competition for forages is greater, and opportunity for diet selection is lower, which will improve forage use. Forage quality is typically higher since forages are grazed at optimum maturity. If forages get too mature to graze, they can be harvested as silage or hay, unlike a continuously grazed pasture or harvesting would not be an option. The farm manager is able to control the forage tight at which the cows are removed which is crucial to the plants ability to survive. One of the advantages of feeding cows in confinement is the ability to control the cows diet, resulting in greater milk production. Feed is provided in the feed bunk and cows have a limited ability to pick and choose, especially if a total mixed ration is fed. In addition, herds in confinement are often larger as they're not restricted by the amount of pasture within walking distance of the barn or milking parlor, the way grazing herds can be limited. However, confinement herds require greater amounts of fuel, labor, and time, greater manure storage, hauling, and spreading capabilities, and the potential for greater soil erosion in crop lands due to tillage or lack of full coverage of the soil surface throughout the year. The type of feeding management used in dairy herds, will depend greatly on resources, skills, business plans, milk markets, and desires of the owner. Some dairy producers have been grazing cows for decades, while others become frustrated when pasture does not produce quality forage, due to poor pasture management. Grazing is one option that has helped some smaller family farms stay in business through decreased costs, feed inputs, and or increased income, such as grass-fed labels or organic milk markets. Now that we've discussed the basic types of grazing systems, understanding that there are many variations within each, let's now briefly discuss pasture management. We mentioned previously that we want to manage forages by quickly harvesting the forage, not overgraze the pastures to allow sufficient forage cover, then resting the plants to allow them regrow. But why is this beneficial? Most forage plants store energy in either the bottom few inches of the forage, and/or in the roots. This will vary by species, so check with local agronomy experts for information on local forages. If the plant is grazed too closely to the ground, this energy storage bank is removed. In addition, too many leaves are removed which serve as solar panels to capture the Sun's energy to grow. This stresses the plant, forcing it to draw energy from the root reserves to regrow. Repeated overgrazing will stunt plant growth, decrease root mass, and weaken the plants. Sometimes to the point of death. Once stunted, these plants do not regrow as quickly, resulting in decreased forage production and number of animals that the pasture can support. This will increase the need for either additional pasture acreage or supplemental feeding to meet the nutrient needs of the herd. While it is easy to see what happens above ground, what we don't see is what is happening beneath the soil surface. When forage plants are overgrazed, the root mass and the root depth decrease. This decreases the soil's ability to absorb water, as well as decreases the plant's ability to take up water and nutrients from the soil, particularly during periods of drought. To illustrate this concept, the plant on the left was allowed to grow for three months without clipping. It has a very healthy root system. The plant in the middle was clipped to 7.5 centimeters or 3 inches every 3 weeks for 3 months. It also has a healthy root system, although not quite as dense as the first plant. The plant on the right was clipped at 2.5 centimeters or 1 inch every week for 3 months. This plant has a very weak and shallow root system and may not survive a drought. Clearly, management of a profitable grazing system requires different management skills when compared to confinement systems. There is an art as well as a science to managing a grazing dairy herd that could only be gained with knowledge and experience. Keeping the pasture feed bunk full of nutritious feed is one of the most important aspects of grazing nutrition. In the next session, we will discuss nutrition in dairy grazing systems. [MUSIC]