Genetics of butterfat and protein

 From the Oct/Dec 2018 Dairy Conceptions newsletter

For all the decades of the indexing era, the typical genetics recommendation was to “breed pounds” not “percents”.     This really was poor advice, as dairymen who bred only on pounds too often found their milk check price was lower than the cost of all the incremental pounds produced.

 

The genetics of butterfat and protein are inherent in the percentage of total milk solids produced from any given volume of milk.    Heritability of butterfat percent and protein percent are the highest of all measured traits, at roughly 50% and 55% respectfully.   The heritability of butterfat and protein pounds is basically half that of percent—in other words, more influenced by factors other than genetics (as in feeding management).    

 

Especially in the “multiple component pricing” milk check formulas in use, where we receive specific prices for pounds of butterfat, protein, other solids and “fluid carrier” (water in bottled milk, which has a declining share of the total milk market) – if you can increase your percentage of butterfat and protein in your bulk tank, per unit of fluid on which you pay trucking, your milk check price will increase.  

 

So YES—it appears you are selling pounds but the higher the percent especially of butterfat, you raise your milk price.     This is why the west coast began converting from Holstein to Jersey a decade ago – their cost of producing incremental milk volume was greater than what they were being paid.   Now with the lowest net milk prices in the nation, Michigan dairymen face the same environment as California.

 

Breeding for butterfat and protein is accumulative (and easy in Holsteins)

 

If you look at page 6 of the new International Protein Sires bull book you will find 566HO1288 Live One, whose dam and grandam both show 4.8% butterfat  first lactations.    Consistent mating selection over six generations raised butterfat in this cow line from 3.1% (substandard) to 4.8% (protein of 3.3% also gained to 3.6% over this same genetic progression).     You will note that Genomic values for milk butterfat and protein from Live One are +1278m, +.09% butterfat and +.05% protein.     This is the kind of bull who will raise your milk price.      (By the way, this is a Michigan cow—she produces as she does under the same geo-climatic conditions your cows face.)

 

Another interesting bull we offer is 706HO0408 Hulk P Red, whose dam and grandam both have had individual lactations over 5.0% butterfat with lifetime totals averaging 4.8% and 4.9% butterfat.