The long-term goal of my research program is to improve ruminant production using an
integrated approach to controlling parasites. My area of special expertise is gastrointestinal
nematode parasitism, which is arguably the most serious constraint affecting ruminant production
world-wide. Economic losses are caused by decreased production, costs of prophylaxis, costs of
treatment, and the death of infected animals. It is difficult to establish precise figures on losses
incurred in ruminant production from infection and disease. Problems with nematode parasitism
are often classified as production disease (i.e. chronic subclinical condition affecting productivity).
The control of nematodes traditionally relies on grazing management and/or anthelmintic
treatment. However, grazing management schemes are often impractical and the evolution of
anthelmintic resistance in nematode populations (specifically affecting small ruminants) threatens
the success of drug treatment programs. Therefore, my research is directed at developing
alternative strategies for control of nematode infections.
My current research program is two-fold: 1) To determine why, and/or how, Gulf Coast Native
(Native) sheep are relatively more resistant to gastrointestinal nematode infection than Suffolk
sheep, and to identify genetic markers for nematode resistance that can be used for selection
purposes; and 2) To evaluate vaccination protocols for protection against nematode infection. In
1), we are evaluating heterosis for infection and segregation of resistance. If resistance segregates
we will try to identify closely linked genetic microsatellite markers associated with resistance
using an F2 reference family approach. It is generally thought that resistance is a quantitative trait
loci (QTL) trait and the QTL may be able to be mapped using such genetic markers. In 2), we
are using crude and nematode specific antigens, with various adjuvants, in ewes and lambs and
monitoring infection levels.
I also continually evaluate new ruminant anthelmintics for efficacy against nematodes and
production response to deworming.
Teaching assignments include undergraduate courses in Parasite Effects on Animal Production
and Sheep Production, and several graduate courses in the School of Veterinary Medicine.
Current activities in professional organizations include: American Association of Veterinary
Parasitologists (AAVP), Liaison to the American Association of Small Ruminant Practitioners
(AASRP) and member of the Education and Awards Committees; and Vice-Chair of the USDA
W-102 Western Regional Project. Previously, I served as Chair of the Research/Outreach
Committee for both the AAVP and AASRP.
Awards include: Beecham Award for Research Excellence in Veterinary Medicine, Achievement
Reward for College Scientist (ARCS) Scholarship, and Livestock Disease Research Laboratory
Fellowship.
Bahirathan, M., Miller, J.E., Barras, S.R., Kearney, M.T., 1996. Susceptibility of Suffolk and
Gulf Coast Native suckling lambs to naturally acquired strongylate nematode infections. Vet
Parasitol (In Press).
Miller, J.E., Baker, D.G., Gershwin, L.J., Canalas, J., and Kearney, M.T., 1996. Serum IgE level
in dairy calves: Effect of exposure to nematode parasitism and environmental allergens. Vet
Parasitol 63: 337-343.
Bahirathan, M., Weilgama, D.J., de S. Wijesundera, M.K., and Miller, J.E., 1995. Prevalence and
abundance of eimerian oocysts in buffalo calves on a farm in Sri Lanka. Buffalo J 2: 183-191.
Bahirathan, M. and Miller, J.E., 1995. Susceptibility of Suffolk and Louisiana Native suckling
lambs to Haemonchus contortus infection. J. Anim Sci 73(Suppl 1): 28.
Miller, J.E., Cockett, N.E., Baker, R.L. and Stear, M.J., 1995. Susceptibility to nematode
infection and genetic variation in the MHC class II region between Dorper and Red Maasai sheep
from Kenya. J Anim Sci 73(Suppl 1): 3.
Miller, J.E. and Barras, S.R., 1994. Ivermectin resistant Haemonchus contortus in Louisiana
Lambs. Vet Parasitol 55: 343-346.
Fernandez, J.M., Miller, J.E., Khalaf-Allah, S., Barras, S.R., Chapa, A.M., Hoover, D.T., Roberts,
N.L., and Pond, K.R., 1994. Adaptability of hair vs. wool sheep lambs to climatic and production
conditions common to the gulf coast region. J Anim Sci 72(Suppl 2): 10.
Schultz, S.R., Barry, R.X., Johnson, M.K., Miller, J.E., and Forbes, W.A., 1994. Effects of food
plots on fecal egg counts of white-tailed deer. Small Rumin Res 13: 93-97.
Miller, J.E., 1993. Observations on nematode parasitism in cow-calf production systems in
southcentral/southwestern USA. Vet Parasitol 46: 289-295.
Miller, J.E., Kearney, M.T., Olson, T.A., Myers, G.H., and Williams, J.C., 1992. Effect of
fenbendazole molasses supplement block treatment on nematode infection and subsequent weight
gain of weanling beef calves. Vet Parasitol 44: 329-337.
Miller, J.E. and Morrison, D.G., 1992. Effect of fenbendazole and ivermectin on development
of strongylate nematode eggs and larvae in calf feces. Vet Parasitol 43: 265-270.
Hoyt, P.G., French, D.D., Miller, J.E., Williams, J.C., Hackett, G.E. Jr., Kearney, M.T., and
Hoyt, M.J., 1992. Critical evaluation of ivermectin against experimental infections of
Haemonchus contortus and Trichostrongylus colubriformis in goats. Vet Parasitol 42: 257-263.
da Silva, N.R.S. and Miller, J.E., 1991. Distribution of Eimeria spp. oocysts in feces from
Louisiana State University ewes. Vet Parasitol 40: 147-150.