Prevalence of two inherited disorders in US Holstein cattle
J.L. Robinson, R.D. Shanks
Department of Animal Sciences, University of Illinois, 1207 West
Gregory Drive, Urbana, IL 61801, USA.
Proceedings of the New Zealand Society of Animal Production 1994,
54: 35-38
The deficiency of uridine monophosphate synthase is a disorder of
the de novo pathway for pyrimidine nucleotide biosynthesis. Inherited as an
autosomal recessive, it results in early embryonic mortality for the homozygous
recessive genotype. In the mid-1980's, heterozygotes were estimated at 1 - 2%
among US Holstein cattle. The institution of a testing program for carriers and
refusal by US artificial insemination companies to accept carriers into their
progeny testing programs has eliminated the condition from the top 400 US
Holstein bulls. Bovine citrullinaemia is a defect of the urea cycle. Also
inherited as an autosomal recessive, it results in early postnatal mortality for
the homozygous recessive genotype. In 1990, heterozygotes constituted 0.3% of
US Holstein cattle. At present, no known carriers are among the top 400 US
Holstein bulls. Carriers for either condition can be detected by convenient
and inexpensive DNA based testing. To guard against these conditions
reappearing, a modest testing program among prominent US bulls should be
continued and importers should insist that imported Holstein germplasm have
no evidence of these conditions.
Keywords: NZSAPAB;
inherited disorders; dairy cattle; genetics.
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Last Updated 25-01-1997
