Tuesday, February 18, 2014

Everyone Knows the Dry Matter 
Composition of Waste Milk. Right?
Everyone knows that the dry matter composition of waste milk is 13 percent. Right?
No. Wrong!
I was pleased to find in a recent press release from Penn State the results of monitoring waste milk dry matter composition on nine dairy farms over a period fifteen days.
Farm  Average  Minimum  Maximum
#        D.M.       D.M.          D.M.
1          10.7        10.1           11.2
2          10.5          9.4           13.9     
3          10.1          9.3        10.8
4          10.5          8.6           11.7
5          10.3          8.3           11.0
6          10.1          9.0           10.9
7          10.2          9.8           10.7
8          10.8        10.2           11.8
9          10.3          9.7           10.6
Given the average dry matter from these nine farms is about 10.4 percent, the question is,"What rate of gain would we expect from feeding this milk to calves?"
If we assume a 90 pound calf in cold housing (20F) being fed this milk that tests 3.5% protein and 4.4% fat, then with the 10.4 dry matter waste milk:
Feeding  Estimated
Level      Rate of Gain
(Daily)    (Daily)
   4              Weight Loss
   5              0.5
   6              0.9
   7              1.3
   8              1.5
This can be compared with the same conditions feeding waste milk averaging 14% dry matter:
Feeding  Estimated
Level      Rate of Gain
(Daily)    (Daily)
  4               0.2
  5               0.8
  6               1.3
  7               1.7 
  8               1.9
Remember:
1. Measure, don't guess, dry matter in waste milk - it's easy to be very wrong.
2. Higher dry matter does make a difference in cold weather feeding for young calves. 

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