Friday, September 2, 2016

More Than One Feeding of Colostrum?

Apart from the process of creating immune defenses against pathogens another good reason to feed colostrum to newborn calves is to provide energy.

In a unique analysis of energy needs of newborn calves and energy provided by colostrum we can see how colostrum feeding provides for maintenance needs of these young animals. 

The author selected four difference environmental temperatures: Thermoneutral (about 60F), 52F, 43F and 34F. then she calculated the number of grams of fat needed per hour to meet the newborn calf's needs to maintain her normal body temperature (102F). 

This is what is needed:
                                    Environmental Temperature (F)
                                         60       52       43       34
Grams of Fat                    8.2      9.9      11.6    13.4

It's easy to see that as the temperature goes down the grams of fat needed go up. 

Then she calculated how many hours at each temperature one 3.8L (4 quarts) feeding of maternal colostrum containing 20 percent fat would sustain the calf.

These are the hours one feeding of 4 quarts of 20 percent fat colostrum would support the calf:
                                    Environmental Temperature (F)
                                         60      52       43       34
Hours of support              9.2     7.7      6.5      5.6

What do these numbers tell us? 

First, as temperatures go down, the number of hours one 4 qt. feeding of colostrum also go down. 

Second, when temperatures come close to freezing at less than six hours post feeding with the 20% fat colostrum the calf must begin to draw on body stores of fat to maintain her core body temperature.

Using data from Davis, C.L. and J. K.Drackley,"The Development, Nutrition and Management of the Young Calf." Iowa State Univ. Press, 1998, p 182 I picked up the the average dairy cow colostrum (first milking) fat content as 28.8 percent. That is higher than the 20 percent used by the author. 

Using the 28.8 percent fat value the hours of support given by one 4 quart feeding look like this:
                                     Environmental Temperature (F)
                                          60       52       43       34
Hours of support               13.2    11.1    9.4      8.1

If one uses a colostrum replacer with 25 percent fat the same support hours values are:
                                     Environmental Temperature (F)                                                                                                                     60       52       43       34
Hours of support               11.5    9.6      8.1      7.0
[note that this colostrum replacer fat content is much higher than the average replacer.]

BOTTOM LINE? Second and third feedings of colostrum can do a lot to support the energy needs of newborn calves.

And, as temperature fall closer to or below freezing the additional feedings of colostrum with its highly digestible fat are an ideal way to meet energy needs of newborn calves.

Reference: Haines, Debbie, "Colostral Immunity - Improving Passive Transfer in Calves." 25th DISCOVER conference, "New Developments in Immunity, Nutrition and Management of the Preruminant Calf." May 2013

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