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Professor
201 D McCord
2640 Morgan Circle
Knoxville, TN 37996-4588
(865) 974-7289
Fax: (865) 974-9043
Email: grogers2@tennessee.edu
Research Appointment: 30%
Extension Appointment: 70%
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EDUCATION and TRAINING
B.S. University of Tennessee in Animal Sci. 1979-1983
M.S. North Carolina State University in Animal Sci. (An. breeding)
1983-1986
Ph.D. North Carolina State University in Animal Sci.(An. breeding)
1986-1988
RESEARCH INTERESTS
BREEDING AND GENETICS RESEARCH: My recent research
and that of my students and collaborators has focused on the improving
health,
reproduction, husbandry traits and survival in dairy cattle. Our
current research focuses on the value of selecting for electrical
conductivity of milk to improve mastitis resistance. A second focus
is the use of somatic cell counts for selection to reduce mastitis
in the national dairy herd and the potential use of body condition
scores and milk urea nitrogen in selection to improve reproduction
and reduce metabolic diseases in dairy cattle. The plan is to establish
the importance (or lack of importance) of selection for body condition
scores and milk urea nitrogen measures and to improve disease resistance
and reproductive performance.
In the recent past we have investigated the impact of Bovine Leukocyte
Adhesion Deficiency on udder health in Holsteins and in the future
we hope to look at other candidate genes or genetic markers that
might be related to mastitis or other diseases.
In past research we have analyzed individual physical traits of
dairy cattle, somatic cell scores, and their relationship to disease
and survival. We have demonstrated the importance of selecting for
several physical traits and the unimportance of selection for some
other traits. It is clear that selection for higher more tightly
udders and lower somatic cell counts will reduce the incidence of
clinical mastitis caused by both contagious and environmental pathogens.
In addition, we have shown that selection for higher dairy form
scores will result in an undesirable increase in most metabolic,
reproductive and locomotive diseases. As a consequence, we hope
that selection for higher body condition scores or lower dairy form
scores will help to improve reproductive performance and reduce
metabolic diseases in dairy cattle.
Another major goal of our research is to improve national selection
indexes like Lifetime Net Merit, Fluid Merit and Cheese Merit. Potential
modifications of these indexes include the inclusion of body condition
score information, the inclusion of maternal calving ease, and the
inclusion of female reproductive
measures.
Several years ago we created a new index based on genetic and
investment principles called Expected Net Revenue Dollars (ENR$).
ENR$ is designed to help commercial producers make the most economical
sire selection decisions. The ENR$ index incorporates information
on production, somatic cell counts, productive life, and physical
traits as well as associated costs. Lists of sires ranked on ENR$
for six breeds are accessible on our web site and are published
four times a year by a leading dairy trade publication.
We are participating in a limited manner with several other major
universities to do some crossbreeding studies. We hope to evaluate
the potential of using crossbred dairy cows in modern management
systems using contemporary lines and families. We especially are
interested in the impact of crossbreeding on health, reproduction
and survival in commercial dairy herds. If crossbreeding provides
healthier, more fit and more efficient
cows, the global strategy for dairy cattle improvement could dramatically
change. We could see a change to primarily crossbred cows in commercial
herds produced by purebred lines from more traditional breeding
approaches.
DAIRY MANAGEMENT RESEARCH: At UT we hope to acquire
new facilities that will involve automated milking (robotic milking).
Our plans are to evaluate the potential of using robotic milking
systems in the industry like we have in Tennessee and surrounding
states. We plan to experiment with how to make robotic milking work
in medium size herds that characterize the industry in the region.
We wish to see if robotic milking can fit into a management scheme
that relies on intensive rotational grazing for a significant portion
of the forage supplied to lactating cows. We plan to study the impact
of robotic milking on milk quality and the subsequent safety of
milk for human consumption.
In the dairy management area, we plan to evaluate the potential
of using electrical conductivity of milk for improving milk quality
and udder health of dairy cows. Data from robotic milking will be
used in this research as well as data from traditional milking parlors
where conductivity is measured. We hope to help producers learn
how to use the conductivity data more efficiently in making daily
decisions. In addition, we plan some research with dairy cow activity
(measured by pedometer). We hope to establish how to better use
the activity data in making daily management decisions.
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