Vie CONG. INTERN. REPROD. ANIM. INSEM. ARTIF., PARIS, 1968, VOL. Il

While work continues on the timing of
insemination it appears that inseminations carried
out between four to eight hours atter the apparent
onset of oestrus can give satisfactory results.

Table 1 : Conceptions Following AT by 2 Routes

-

No. Ewes No. Ewes CR %

SR Treated in Lamb
e e sk
Intra-uterine
by laparotomy 10 6 60
Intra- & epi-
cervical per vaginum o 12 31
Table 2 : Cheviot Flock AT Results 167 - 168

e

Oestrous No. Ewes No. Ewes Lambing

Period Inseminated Lambed Rate %
1st 39 e 24
1st & 2nd combined 34 19 56
lst, 2nd & 3rd combined 30 24 80

e

Conclusions

No single development has led to a spectacular
improvement in fertility rates but the total effect
of the various improvements reported above has been
to raise the flock fertility rate for the year 1967
from 43% to 56% for first and second inseminations
combined and 80% for inseminations done over a period
of up to three oestruses (Table 2).

References

First, N.L., Sevinge, A. and Henneman, H.A. (1961).
J. Anim. SCi. ;Z_O, 79 - 84’0
Fraser, A.F. (1962). Canad. Vet. J. 3, 133 - 1l44.

Kalev, G. and Venkov, T. (1961). Animal Breeding
Abstracts. 32, 3, 290.

Nagase, H. and Niwa, T. (1963). Jap. J. An. Reprod. 9, T35

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