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Archives (2001)
Scientists find twinning
technology in dairy cattle successful
by Mary Charlotte O. Fresco |
January-March
2001
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The cow (Bos taurus for European breeds
and Bos indicus for Indian Breeds), belonging to the
family Bovidae, is characterized as a uniparous large ruminant
- an animal capable of producing only a single offspring per
birth.
The low prolificacy of cattle coupled with the
small population used in breeding have contributed to the
dwindling cattle production in the country. This problem may
just have found solution in the first successful induced twinning
in dairy cattle spearheaded by Dr. Antonio A. Rayos, veterinarian
and assistant professor at the Dairy Training and Research
Institute (DTRI), UP Los Banos.
In a series of laboratory tests, two healthy
calves (male and female), each weighing 18 kg were successfully
conceived after 254 days of gestation, with the female co-twin
having a normal reproductive tract on examination.
Scientists used two pure Holstein Friesians
as donor and recipient cows in this study. Both cows were
injected with dinoprost tromethamine to synchronize estrus
period. Three days after the injection, both cows were in
estrus and were artificially inseminated with frozen-thawed
semen from two superior bulls, with the Holstein-Sahiwal bull
for the donor and the Holstein Friesians for the recipient
cow. Having reached its initial stage of development after
one week, the embryo was flushed out of the donor cow and
was transferred non-surgically using an embryo transfer gun
to the uterine horn of the recipient cow previously bred by
artificial insemination (AI). Forty-five days after the embryo
transfer, the left and right uterine horns of the recipient
cow were confirmed pregnant.
Fifty days after birth, the male calf weighed
45 kg while the female calf weighed 54 kg, indicating normal
growth.
Induced twinning in dairy cattle was adopted
from the Japanese practice of multiplying the wagyu or Japanese
black cattle, the source of very expensive and famous KOBE
and Matsusaka beef. Dairy cows were used in this study to
prove whether induced twinning can overcome the problem of
"Freemartinism", an inhibition of the development
of the female co-twin's reproductive organs caused by some
chemical substances secreted by the developing male co-twin
embryo through the blood vessels of the placenta. This phenomenon
occurs usually in twins that developed in the same uterine
horn. Further, to determine if this technology can solve the
problem of "Freemartinism", scientists placed the
embryos in separate uterine horns. Although initial examination
one week after birth showed a normal vagina of the female
calf, the cervix, uterus and ovaries were found under-developed
after the animal was slaughtered at 18 months of age.
Aside from AI and embryo transfer, there are
two other methods to induce twinning in cattle. These are:
(1) transfer of two embryos into the uterine horn/horns of
the surrogate cow; and (2) ovulation of two ova by administration
of low dosage of follicle-stimulating hormone or pregnant
mare serum gonadotrophin. 
(For more information, please contact: Dr.
Antonio A. Rayos, Dr. Demetrio Marcial, Mr. Juan Malabanan,
DTRI, UPLB, College, Laguna at tel. no. (049) 536-2513) More Articles:
Vol. 3 No. 1
January-March 2001
»»
P15M high impact projects approved for livestock and poultry RDE network
»» Montemayor
bans UK meat imports
»» LDPs of
the DA: an analysis
»» Renewed
role of orivate sector valuable in livestock R&D - study reveals
»» Botanicals
effective against ectoparasites
»» Trichantera:
cheaper feed substitute to soybean oil meal
»» ELISA effective
in FMD diagnosis
»» National
integrated RDE agenda and program for livestock and fisheries
»» Mad cow
disease: know the risks
»»
The livestock and poultry industry: an overview
»» Scientists
find twinning technology in dairy cattle successful
[More
2001 Articles]
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