Recent research has identified several genetic recessive lethal defects affecting fertility in Holstein and Jersey cattle. They are termed Haplotypes.         Todate they have received scant media attention.


                Holsteins have currently indentified HH1, HH2, HH3, HH4 and HH5 - Jersey JH1. There are likely to be more found in the future.


                Each is traced back to a particular blood line - some modern day sires that are affected are - Oman, Boss Iron (HH3), Jocko, Roumare (HH4), Shottle   (HH5). Top Brass, Sooner, Berretta, Jace (JH1).


                The frequency of these genes in the population will vary from region to region depending on the popular bulls of the past. We do not know the Haplotype status of historical high use Australian sires. As can be seen by some of the Jersey sires affected the prevalence in that breed would be assumed to be very high.


                You will have an unknown number of cows that carry one or more of these recessive genes.


                If a cow carrying a recessive gene, eg.HH4, is mated to a sire who carries the HH4 gene, 25% of the conceived embryo's will be lost.


                The timing of the embryo loss is different for the various Haplotypes. Some are lost before day 60, some are before day100 and some can be lost at all stages of pregnancy.


                All sires in this recommended Sire Directory are Tested Non-Carriers of these genetic recessives or have no pedigree link to them. The same applies for the physical recessive genes, BLAD, CVM and BY (eg.Bolton).


                15 of the top 20 APR Holstein sires in August are either tested to have one of these recessive genes or is sired by a known carrier (50% chance of being a carrier).


                All sires from All companies are available through NHD.


                Your sire selection is your decision, we feel that the above information may be of importance to you.


Northern Herd Development Co-Op