Rumination is a window to cow health
MANY producers have adopted individual cow rumination monitoring technologies to help them identify calving time, metabolic problems, mastitis, lameness and standing heat.Typically, cows ruminate 400 to 600 minutes per day, and a reduction of 30 to 50 minutes from the baseline is generally significant.Less rumination tells you that something has changed. Rumination monitors help to identify health problems earlier, before clinical signs show and before a significant drop in milk production occurs. Rumination is a function both the cow’s diet and how much she rests, so it can also be used to evaluate nutrition, cow comfort and management.
2. Rumination and cow comfort
Cows primarily should be doing four things: milking, eating, drinking and lying down. Often, inadequate resting and rumination are associated with situations where cows spend more than three hours per day in the milking parlor and holding area. In one study, it was found that cows that were 30 percent overcrowded ruminated 25 percent less than cows on the same ration that were not overcrowded.Every time you move a cow,she gets a bit stressed, especially with a new social order. Stress can reduce dry matter intake, increase metabolic problems and elevate fat mobilization. Dry cows resulted in 9 percent less time per day spent ruminating for one to two days. Many new facilities have been designed to limit pen moves. Changes in rumination can help evaluate your regrouping strategies to determine the least stressful option for your barn.
3. Rumination and transition
Rumination time can be used as a management tool to identify cows that are close to calving. At calving, rumination time typically goes down by about 70 percent. But, as a nutritionist, I want to know if the transition cow diet and management are resulting in a quick and steady return in rumination. Healthy cows will increase their rumination time by about 50 minutes per day during the first week after calving. Cows that are going to develop metabolic problems typically will have lower rumination times during their first week of lactation. In an Italian study (Soriana et al., 2012, see figure), cows that ruminated less before calving also ruminated less after calving. Cows that ruminated less before calving had higher levels of plasma BHBA in the three weeks after calving, indicating a greater ketosis risk. If you are considering adopting rumination monitors for breeding and individual cow management, don’t forget the other benefits they may have for you and your nutritionist!
4. Detect changes sooner
After using best judgment to formulate a ration, must rely on the cows to tell us if I got it right. We like to see 50 to 60 percent of the cows that aren’t sleeping, eating or drinking chewing their cuds. This indicates that the diet has adequate effective fiber. It is great when technology can be used to more accurately identify changes in rumination associated with diet changes. A change in rumination time of 30 to 50 minutes for a pen of cows can be a “heads-up” that something has changed in the diet. For example, what if your weekend feeder doesn’t follow your protocols by accounting for forage dry matter changes or he tends to overmix the TMR? This day-to-day lack of consistency could be more apparent with rumination monitors than it is when there is a long-term drop in daily bulk tank weights. Perhaps you need to stretch your forage inventory and you opt to replace some hay crop silage with a nonforage fiber source like soybean hulls. It would be much better to know within a few days that cows did not ruminate as much with the new diet and fix it sooner rather than to wait until milkfat droppedor laminitis developed! Rumination monitors may also help to evaluate feed additives intended to improve rumen health. In a recent study at the University of Guelph, cows fed a live yeast supplement tended to ruminate more (570 versus 545 minutes per day), had lower rumen temperatures which potentially indicated improved rumen pH and tended to produce milk with a higher fat content (3.71 versus 3.55 percent).