Twinner Cattle Newsletter -- Spring 2015
Twinner cattle discussion group: In an attempt to foster communication between folks that
have an interest in twinner cattle, I set up a Twinner Interest Google Group a little over a year
ago. At this point there have been twelve individuals who have responded to the invitation to
join the group, which is a fraction of the number of people on my mailing list. I suspect that a
number of email addresses that I sent invitations to previously are no longer current. If you
would like to participate in the online discussion group, just put your current email and your
name on the enclosed postcard. The postcard is stamped and pre-addressed, so you can simply
write down your name and email address and drop it in a mailbox. If you are already part of the
discussion group and your email address has not changed, you do not need to return the enclosed
postcard.
Going forward, the discussion group will be a more cost-effective way to communicate and will
provide you with the opportunity to communicate directly with one another. I periodically get
requests for information about availability of twinner cattle, semen or embryos, and it would be
more effective if you could communicate directly with each other through a forum such as this.
Also, questions come up from time to time concerning management of twinner cattle or twinning
in general. Posing these question to the discussion group would facilitate more people
contributing to and hearing the responses. Posted messages are archived, so regardless when you
join the group you will be able to look at past discussions.
Twinning research work: We continue to study the genetics of twinning at the University of
Wisconsin-Madison. As mentioned in the last newsletter, much of our work at the moment
involves a single gene with a dramatic effect on ovulation rate. The ovulation rate we have
observed for this gene in mature females is roughly three and a half eggs per cycle. An ovulation
rate that high frequently leads to multiple births that are higher than desirable (triplets and
quadruplets that are frequently aborted). Consequently, one of the things we are currently
working on is testing whether the ovulation rate can be reduced through administration of a
commercially available implant used to increase growth rate in feedlot cattle. This work was
suggested by a similar study in sheep that have a gene for high ovulation rate; in that case
administration of estradiol reduced ovulation rate from roughly 3.2 to 2.0 ova and litter size from
2.5 to 1.5 lambs.
The other work we are engaged in with this gene involves determining the causal mutation and
getting an understanding of how the mutation ultimately causes a change in ovulation rate. To
that end, we have mapped the gene to a narrow genomic location that we will be screening
comprehensively later this year in an effort to discover the causative mutation. Multiple studies
are ongoing or planned which will look at effects of the mutation on expression of genes,
production of proteins, and hormonal changes in an effort to understand the physiology of the
gene.
Brian Kirkpatrick
Department of Animal Sciences
University of Wisconsin-Madison
Phone: 608-263-4323
Email: bwkirkpa@wisc.edu