Pregnancy percentage following deposition of sex-sorted sperm at different sites within the uterus in estrus-synchronized heifers.
Our objective was to assess the effect on heifer pregnancy rate of deposition at three sites within the uterus of frozen-thawed sex-sorted sperm at a fixed time after estrus synchronization. Estrus was synchronized in 209 heifers by administration of PGF2a 14 days apart. At 80-82 h after the second PGF2a injection, X-chromosomes bearing fractions of semen with 2.2 x 10(6) sperm in insemination dose were used for single insemination into the uterine body (UB-AI, n=91) or for intracornual deposition in the middle of the uterine horn (MH-AI, n=57) or close to the utero-tubal junction (UTJ-AI, n=61). The overall pregnancy rate was 43.1%. Pregnancy rates did not differ (P>0.05) among sites of sperm sperm deposition, between the two farms at which the heifers were kept or between the two bulls producing the semen. Within UB-AI, MH-AI and UTJ-AI treatments, pregnancy rates were 41.8%, 49.1% and 39.3%, respectively (P>0.05). Pooled across classes for deposition site, pregnancy rate was 25.1% higher (P<0.01) for heifers showing strong signs of estrus than for heifers showing weak signs of estrus (45.9 versus 20.8%, respectively). Embryonic and fetal loss from diagnosis of pregnancy to term and at calving equalled 5.6%. Of 88 calves of identified sex, 93.2% were female. In conclusion, pregnancy rates of heifers did not differ significantly following deposition of 2.2 x 10(6) sex-sorted sperm 80-82 h after the second PGF2a injection near the utero-tubal junction, in the middle of the horn or into the uterine body.
Kurykin
J
J
Department of Reproductive Biology, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, 46 Kreutzwaldi Street, 51006 Tartu, Estonia. Jevgeni.Kurykin@emu.ee
Jaakma
U
U
Jalakas
M
M
Aidnik
M
M
Waldmann
A
A
Majas
L
L
D000818:Animals; D002417:Cattle; D004973:Estrus Synchronization; D005260:Female; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D012099:Reproductive Techniques / Q000662:veterinary*; D012743:Sex Preselection / Q000379:methods / Q000662:veterinary*; D013094:Spermatozoa / Q000502:physiology*; D013997:Time Factors; D014599:Uterus / Q000502:physiology*