Adding genomics to genetic evaluations brings more attention to young heifers. There is increased accuracy to heifer indexes and new population benchmarks. Even more significant are the Direct Genetic Values (DGVs) that are generated from the DNA results. As you will see, the the very top heifers increase their genetic indexes significantly, while their full sisters, without high DGVs are not on the list. The DGV value makes the difference.
The Bullvine continually receives the question, “Why are the top heifers at the top?” In order to assist the industry to better know how high is great, the Bullvine has done an analysis of the top 25 Canadian Holstein heifers published in April 2012 by Canadian Dairy Network.
|GLPI (Range)||DGV (Range)|
|LPI||3533 (3339 to 3979)||3761 (3342 to 4406)|
|Milk||2239 (1526 to 3254)||2271 (1374 to 3711)|
|Fat||106 (81 to 133)||113 (72 to 148)|
|% Fat||+.23 (-.22 to +.56)||+.29 (-.28 to +.71)|
|Protein||86 (56 to 120)||90 (54 to 136)|
|% Protein||+.12 (-.03 to +.29)||+.15 (-.04 to +.37)|
|F&P||192 (151 to 253)||203 (159 to 284)|
|Conf.||13.0 (9 to 18)||13.8 (6 to 19)|
|MS||11.4 (7 to 17)||13.0 (6 to 19)|
|F/L||10.9 (5 to 16)||11.7 (5 to 19)|
|DS||8.5 (2 to 15)||9.2 (1 to 15)|
|Rump||5.2 (0 to 11)||5.3 (-2 to 14)|
This is a truly exceptional group. What other Top 25 female list would be able to boast of an average value of 192 kg. for fat plus protein and 13 for conformation on their Parent Average Genetic Indexes? And look at their DGVs. They are even higher at 203 kgs. for fat plus protein and 13.8 for conformation.
Average numbers are a good place to start, but there are additional facts that can assist us in understanding the Top 25.
In future articles, The Bullvine will be bringing forward ideas on the genetic needs of dairy cattle and strategies to use in selecting and breeding.
When deciding to invest in a high genomics heifer, it is important to study both the heifer’s PA GLPI and her DGV. Although 25 may be too small a group to depend on for everything. Nevertheless from this small snapshot we get a clearer picture of the potential that genomics and DGVs provide. The Bullvine is excited to provide this perspective on an ongoing basis.
Not sure what all this hype about genomics is all about?
Want to learn what it is and what it means to your breeding program?