There are six to seven months out of the year when pasture can figure into the feeding management strategy for all animal groups on Pennsylvania dairies. There are numerous benefits to the animal and producer who can incorporate pasture into the ration however there are also some challenges that go along with grazing.
By: Virginia Ishler, Extension Dairy Specialist, Penn State University
For the twelve years managing the dairy barns at Penn State, pasture figured prominently into the management scheme. Pasture is a great way to get animals off concrete and can stretch out forage inventories. Pasture was used for pre-breeding age and pregnant heifers. In the spring, with lush pasture available, a small amount of supplemental grain (corn and a mineral mix) would be fed. Animals would be rotated through various paddocks to keep pastures growing. As the summer progressed and depending on rainfall, a total mixed ration (TMR) would be fed to supplement the pasture quality and quantity available. This required constant monitoring of the pasture and the animals to record how much supplemental TMR was needed. A parasite control protocol was implemented. There was the occasional foot rot so constant observation of animals was critical.
Pasture was used for the early mature dry cows and springing heifers. They would receive a supplemental ration to compliment the pasture. This can be a great strategy for animals with long days in milk and that have excess body condition. Observing animals for foot rot and the possible abortion is important. Groundhog holes and downed tree limbs were an occasional problem so monitoring cows routinely for any signs of injury was required.
Incorporating pasture into a low group ration is a strategy to help late lactation animals achieve an ideal body condition. Our approach was to keep cows in during the day and limit the amount of TMR fed. After the evening milking cows would go onto pasture and return to the free-stall barn after the morning milking. This strategy was extremely beneficial when I first started as manager when the herd had reproductive problems. There were too many animals with extremely long days in milk that were over conditioned. This was setting our fresh cows up for metabolic problems, especially ketosis and fatty livers. Grazing the low producers and late lactation animals coupled with the proper supplementation allowed animals to lose some condition prior to dry off. Continuing grazing for the early dry cows helped maintain condition. This strategy was instrumental in eliminating ketosis and fatty liver problems in the herd. It was so effective, that improvements were observed in reproductive performance, in ideal body condition scores and in fresh cow performance. Eventually there were no longer enough cows in late lactation milking under 60 pounds to make a low group utilizing pasture.
Incorporating grazing into a feeding management strategy is very beneficial for all animal groups. Every farm is different so strategies and protocols will be customized that best meet the needs of the animals and producer.
Action plan for utilizing pasture
Goal – Develop a grazing strategy for the animal groups utilizing pasture from April through October.
Step 1: Fertilize pastures and check that fencing and waterers are working.
Step 2: Start grazing grasses over 8 inches tall and rotate animals out when grass height falls below 3 inches.
Step 3. Develop a parasite control program with the herd veterinarian.
Step 4. Designate a person to routinely check animals on a daily basis during supplemental feeding times and observe animals for any health or injury problems.
Monitoring must include an economic component to determine if a management strategy is working or not. For the lactating cows income over feed costs is a good way to check that feed costs are in line for the level of milk production. Starting with July’s milk price, income over feed costs will be calculated using average intake and production for the last six years from the Penn State dairy herd. The ration will contain 63% forage consisting of corn silage, haylage and hay. The concentrate portion will include corn grain, candy meal, sugar, canola meal, roasted soybeans, Optigen and a mineral vitamin mix. All market prices will be used.
Also included are the feed costs for dry cows, springing heifers, pregnant heifers and growing heifers. The rations reflect what has been fed to these animal groups at the Penn State dairy herd for the past 6 years. All market prices will be used.