Contact Information

Dr. Tony Pescatore, Ph.D.
Interim Department Chair

900 W.P. Garrigus Building Lexington, KY 40546-0215

+1 (859) 257-2686

Normal Variation Expected in Butterfat Tests

Normal Variation Expected in Butterfat Tests

Normal Variation Expected in Butterfat Tests


Variation is normally seen in milk butterfat tests. This variation is seen between morning and night milkings for the same day and between different days. An example of the normal variation in milk production and milkfat test for two first-calf heifers (6-10 weeks into lactation) over a 6-day period is shown in the table below. Each heifer was fed the same amount of feed each day in two equal feedings. Cows were milked in a stanchion barn with a milk bucket at 6:30AM and 5:00PM. Although these data are from a small number of cows, they do show the normal variation seen in milk production and butterfat test.

 

Day Milk Production (lbs) Fat %
Cow # 8907
Monday 69 3.76
Tuesday 67 3.24
Wednesday 67 3.46
Thursday 68 3.02
Friday 66 3.31
Saturday 72 3.21
Cow #8907
Monday 59 No samples
Tuesday 61 4.08
Wednesay 61 3.49
Thursday 60 4.05
Friday 61 3.62
Saturday 64 4.48

Fat % listed is a weighted average of AM and PM milkings which were collected separately.


Author: Donna Amaral-Phillips

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Contact Information

Dr. Tony Pescatore, Ph.D.
Interim Department Chair

900 W.P. Garrigus Building Lexington, KY 40546-0215

+1 (859) 257-2686