Monitor these key areas to verify how your cows are responding to their feeding program.
With Mike Hutjens
As milk prices hover around break-even, dairy managers need to optimize their feeding program and ration their delivery system. Each day, cows "talk" to us about how they are responding to their ration and feeding programs, helping us to set the right target values (see chart at left).
Cow talk: Locomotion scoring assesses cow comfort, environment and ration balance, especially fiber levels, source and level of carbohydrates, and protein sources.
Target: 33% of each group, on a scale of 1 (no roachingof the back or signs of lameness) to 4 (visually lame cow).Each group should have less than 10% with a score of 3 (head bobbing, roached back and shortened walking gait).
Cow talk: Milk fat and protein percentages and milk protein test. Milk fat test ratio reflects ration nutrient content, rumen microbial output and dry matter intake.
Target: For Holstein herds, >3.7% milk fat, >3.0% true milk protein and 0.82 ratio of true protein to milk fat. For Jersey herds, >4.8% milk fat, >3.8% true milk protein and 0.80 ratio of true protein to milk fat.
Cow talk: Milk urea nitrogen reflects the level and type of protein, carbohydrate balance and rumen health.
Target: Bulk tank should range between 8 and 12 mg/dl. If the value changes by two points or more, a ration change may have occurred.
Cow talk: Body condition score reflects dry matter intake, nutrient intake, grouping pattern and optimal reproductive performance.
Target: In the high group, <10% at 2.5 or less. In the low group, <10% at 3.5 or higher. For dry cows, <10% at 3.5 or higher. For springing heifers, <10% at 3.25 or higher.
Cow talk: The fecal score reflects nutrient balance, rate of feed passage, rumen fermentation and fiber status.
Target: 33% of the group. In the high group, <20% under 3. In the low group, no cows under 3.
Cow talk: Corn particle size should allow for optimized rumen fermentation and microbial growth.
Target:For dry ground corn, 800 to 1,000 micron. Steam-flaked corn, 26 lb. to 28 lb. bushel weight. High-moisture shelled corn, 26% to 30% moisture.
Cow talk: Ration particle size reflects the chopping of silages, impact of total mixed ration mixing and grain processing.
Target:Using the Penn State particle box, the top box should contain5% to 15% of wet weight, the middle box >40%, and the bottom box (in athree-box unit) or bottom two boxes(in a four-box unit) should be <50%.
Cow talk: Silage pH reflects if the forage was harvested at the optimal maturity, dry matter contents, proper packing and use of an effective silage inoculant.
Target:For corn silage, pH 3.6 to 4.2. Legume-grass or small-grain silage should be under pH 4.5.
- May 2012