Wednesday, October 24, 2018

Ad Lib Milk Intake Results:
High variation among calves documented

One of the treatments in a calf growth study was feeding "ad lib" milk replacer. This was a rather unique approach to manual ad-lib feeding compared to using an automatic computer-controlled feeder.

They fed a 25-17 (protein:fat) milk replacer reconstituted to 14% solids. The MR was offered at 0600 and 1530. The "ad-lib treatment" was all the calves voluntarily consumed in a two-hour period at these two feedings. Any leftover MR was weighed and discarded. 

Thus, twice a day a calf had an opportunity to drink all the MR that she desired for a two-hour period. Note that the feeding intervals were quite uneven - daytime = 9.5 hours, overnight = 14.5 hours. 

Variation in intakes among calves was HUGE!

Day of study    Milk Intake (quarts/day)              Average Intake
                            Lowest   Highest                         quarts/day
                              Calf        Calf
       6                        3.0        8.3                                   6.6              
      20                       4.2      10.6                                   8.7
      35                       7.5      14.7                                 11.3

[Note: I converted their reported g/d intakes to quarts because most of us feed by volume.] 

 It is worth noting that blood serum total protein values for all these calves were close to 6.0 and health events (meaning sick calves) were low throughout the time calves were fed milk in the nursery. Thus, the variation of MR intakes among calves was not due to sickness. 

Reference: Dennis, T.S. and Others, "Effects of gradual and later weaning ages when feeding high milk replacer rates on growth, textured starter digestibility and behavior in Holstein calves from 0 to 4 months of age." Journal of Dairy Science 101:9863-9875 November 2018 

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