Whole Herd Dry Matter Intake Should Be Monitored
Dairy Pipeline: March 2008
Extension Dairy Scientist, Nutrition & Forage Quality
(540) 231-3066, firstname.lastname@example.org
Do you know how much your cows are eating? If you say yes because the nutritionist has a printout with the number on it, you may not know.
Actual on-farm monitoring is needed to determine if the projected is close to what is being consumed. To do this the total amount of feed offered minus the refusal needs to be measured. Next, the dry matter content of the total mixed ration needs to be determined.
Dry matter can be determined by sending a sample of the feed to a lab or, better yet, by on-farm determination. Koster testers work well and the dry matter of wet feeds can be determined in only a matter of minutes. This tester works by drying the sample and then using the sample weight before and after drying. To assist with the weights, a scale is included with the tester.
Weekly dry matter determination is recommended, but dry matter should also be checked any time feeds change. We project dry matter consumption on our Phosphorus Feeding Incentive Program from the NRC 2001. This dry matter intake prediction (listed below) is based on milk production and body weight and accounts for having a certain proportion first lactation cows in the herd.
Compare your dry matter intakes on a whole herd or group basis to the numbers below. If your numbers are lower ask why. Reasons can include: a higher number of first lactation animals than was predicted here, inadequate amounts of feed delivered, moldy feed, excessively wet or dry feeds, high fiber rations, or imbalanced rations. Monitoring your herds dry matter consumption can also alert you to unexpected changes that occur that need to be addressed.
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