One of the many challenges you probably face with grazing is how to help the cows adjust to a new feed source in the fall. Changing from high-quality pasture to lower-quality stored forages is much like changing silos. If the change is made too quickly, milk production drops until the cows and the rumen microbes become accustomed to the new feed. The rumen microbes are especially sensitive to sudden changes, because it takes time to shift their numbers and types to those that are more adapted to lower quality forage.
In the fall, the concerns about changing to new feeds are essentially the same as they are in the spring. However, there are a few new challenges. The stored forages to be fed are most likely from the most recent growing season. Since no two growing seasons are the same, the quality of the forages will be different from what was being fed last winter and earlier in the spring. It is hard to predict how the cows will respond to the new forages, in terms of both intake and performance. Also, most confinement dairymen will begin feeding out this year’s crop of hay or haylage sometime in the middle of the summer. This gives them an opportunity to do some fine-tuning before the new crop of corn silage is in. Once the corn is in and ready to be fed, they can do some additional fine-tuning. The challenge for many graziers is that this year’s crop may not be fed at all until transition time, and both types of stored forages are being introduced within the same timeframe. Many graziers report loss of milk production during transition time, and it is probably related to these factors.
Determining when the grazing season will end can be difficult to predict, but it can be one of the more important things to do at this time of the year, especially in northern areas. Too many farmers have called up and said, “I’m running out of grass and don’t know what to do” because they didn’t plan their grass supply ahead of the cold weather and frost, and they haven’t started to feed other forages. Many farmers try to keep the cows out as long as possible, but aren’t thinking about what to do before the grass is gone. The thought is that if transitioning begins too early, the opportunity to capture cheap, high quality feed may be lost, and nobody wants to increase their costs too early!
However, if it is begun too late, the grass could run out before the stored forages have been introduced. Predicting the end of the grazing season will be different every year depending on the weather and management of the pastures. If you try to predict the last day of grazing by using some simple planning techniques, you will avoid a crash in milk production.
Walk Your Pastures So You’ll Know How Much Feed You Have
Paddocks should be walked about once a week beginning right about now (although earlier would be better), and the total amount of the grass dry matter available on the farm should be measured using a pasture stick or other tool. Once the total “cover” on the farm is known, that number should be divided by the total amount of grass dry matter needed per day. If you don’t know how much grass your animals need every day, you should figure that out too! Here’s a tool from On Pasture for that. The resulting number is an indication of approximately how many more days of grazing remain if the feeding program stays the same. When there is a significant difference in total grass available from week to week, a transition plan should be put in place.
Strategies for transitioning in the fall will be similar to spring – except things will happen in reverse. Stored forages should be introduced or increased in the barn. Depending upon what the “final” barn ration is going to look like, protein forages such as haylage, baleage, and dry hay should be increased first. Next the amount of protein from grain or concentrate should be increased, because the cows will be decreasing their intake of protein from pasture. If feeding a Total Mixed Ration (TMR), the easiest way to make the transition is to mix for 5 to10 more cows (depending on herd size) each day as they are beginning to look for more anyway. When the TMR is being fed at a rate that is more than 50% of the full ration, begin increasing protein levels by 1 pound every 3 days. When the TMR is above 70% of normal, protein and NFC levels should be checked to make sure they are in balance, and at this time the TMR may need to be reformulated.
At some point, consideration needs to be given to whether cows should be kept in the barn at night, perhaps once the temperatures begin to fall below 35 degrees (unless the plan is to outwinter). Eventually the amount of time the cows spend on pasture will be minimal, especially after a frost has killed the grass and there is little to no new growth. At this point the plan for the winter ration should be in place, because the majority of intake will be provided in the barn.
Good planning and management at this time of year can help you and your cows make a smooth transition to winter!