Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

16 t h International Congress on Animal Reproduction
90 Poster Abstracts
allele and genotype frequencies and Hardy-Weinberg equilibrium
were calculated. Allele frequency is 0.44 % for allele C and 0.56 %
for allele T; population is in Hardy-Weinberg equilibrium. Genotype
frequency is 20% for the genotype C/C, 34.5% for T/T and 45.5% for
C/T. Statistical analysis indicated that buffaloes carrying the genotype
C/C showed their reproductive activity (7 vs. 4; P 0.05 and for G2, T1 = 15.0% (3/20) and
T2 = 14.3% (3/21) P> 0.05. Although, when comparing treatments of
the two different groups T1 from G1, 57.1% vs T1 from G2, 15.0%;
P< 0.05 and T2 from G1, 52.4% vs T2 from G2, 14.3%; P< 0.05 and
T1 from G1, 57.1% vs T1 from G2, 15.0%, P< 0.05, it was observed
statistical difference.
Conclusions Although in the northeast of Brazil, the buffaloes are not
submitted to a marked day length variation between the favorable and
unfavorable reproductive seasons, the Ovsynch protocol did not show
acceptable conception rate in the unfavorable season what may be due
to the lack of progeserone during this period. Yet, the use of half of
the dose of GnRH in the second application showed to be as efficient
as the full dose what reduces the cost of the protocol without
compromising the conception rate.
P189
Production of sex-preselected embryos and offspring in
water buffalo (Bubalus bubalis)
Lu, YQ 1 *; Liang, XW 2 ; Chen, MT 2 ; Zhang, XF 2 ; Lu, SS 1 ; Zhang, M 1 ; Pang,
CY 2 ; Lu, KH 1
1Animal Reproduction Institute, Guangxi Key Laboratory of Subtropical
Bioresource Conservation and Utilization, Guangxi University, Nanning
530004, China; 2 Guangxi Buffalo Research Institute, Chinese Academy of
Agricultural Science, Nanning 530001, China
Buffalo is an important livestock resource in many Asian and
Mediterranean countries. Sex-preselection via sperm sexing would be
of great interest in buffalo species both in biological and economic
terms. The objective of the present study was to evaluate the potential
of OPU-IVEP system to produce sexed embryos and offspring in
buffalo species. Buffalo sperm was sorted into X-sperm enriched
population following the general procedure described by Johnson and
Welch (Theriogenology 1999;52:1323-41). Oocytes were picked up
from fertile Murrah and Nili-Ravi buffalo cows by ultrasound
transvaginal ovum retrieval. The oocytes (grade A and B) derived
from OPU were matured in TCM199 supplemented with 5% estrous
cow serum and 10 μg/mL FSH and then fertilized in vitro with sexed
or unsexed sperm in modified Tyrode’s medium supplemented with
0.6% BSA, 2.0 mM caffeine and 20 µg/mL Heparin (Anim Reprod
Sci, 2007;100:192-6). Twenty cycling Murrah and Nili-Ravi buffaloes
were repeatedly submitted to OPU in this study. An average of 4.6
oocytes was retrieved per session per animal, 70.9% of which was
Grade A and B. A total of 1064 oocytes were submitted to in vitro
maturation and fertilization. The results indicated that the
developmental competence of oocytes fertilized with sexed and