Effect of increased ovulation rate on embryo and foetal survival as a model for selection by ovulation rate in rabbits

A.Y. Badawy, R. Peiro, A. Blasco, M.A. Santacreu

Abstract

Selection for ovulation rate in prolific species has not improved litter size, due to an increase in prenatal mortality, with most mortality observed in the foetal period. The aim of this study was to investigate the magnitude and timing of embryo and early foetal survival in females with high ovulation rate using hormonal treatment as a model for selection by ovulation rate. Two groups of females (treated and untreated) were used. Treated females were injected with 50 IU equine chorionic gonadotropin 48 h before mating. Females were slaughtered at 18 d of gestation. Ovulation rate (OR), number of implanted embryos (IE), number of live foetuses at 12 and 18 d (LF12 and LF18, respectively) were recorded. In addition, embryo survival (ES=IE/OR), foetal survival at 18 d of gestation (FSLF18=LF18/IE), foetal survival between 12 and 18 d of gestation (FSLF18/LF12=LF18/LF12) and prenatal survival (PSLF18=LF18/OR) were estimated. For each female, the mean and variability of the weight for live foetuses (LFWm and LFWv, respectively) and their placentas (LFPWm and LFPWv, respectively) were calculated. Treated females had a higher ovulation rate (+3.02 ova) than untreated females, with a probability of 0.99. An increase in the differences (D) between treated and untreated females was observed from implantation to 18 d of gestation (D=–0.33, –0.70 and –1.28 for IE, LF12 and LF18, respectively). These differences had a low accuracy and the probability that treated females would have a lower number of foetuses also increased throughout gestation (0.60, 0.70 and 0.86 for IE, LF12 and LF18, respectively). According to the previous results for OR and LF18, treated females showed a lower survival rate from ovulation to 18 d of gestation (D=–0.12, P=0.98 for PSLF18). Treated females also had lower embryo and foetal survival (D=–0.10 and P=0.94 for ES and D=–0.08 and P=0.93 for FSLF18). Main differences in foetal survival appeared from 12 to 18 d of gestation (D=–0.09 and P=0.98 for FSLF18/LF12). Unexpectedly, treated females showed similar foetus weight and higher foetal placenta weight than untreated females (D=0.25 g, P=0.98) and lower variability for these traits (D=–0.02 g, P=0.72 for LFWv and D=–0.05 g, P=0.83 for LFPWv). These results are not related to a lower number of IE or LF18. Thus, the effect of increasing by three ova in rabbits leads to a lower embryo and early foetal survival. There seems to be no relationship between foetal mortality and foetus weight.

Keywords

early foetal survival; embryo survival; high ovulation rate; rabbit

Full Text:

PDF

References

Adams C.E. 1960a. Prenatal mortality in the rabbit Oryctolagus cuniculus. J. Reprod. Fertil., 1: 36-44. doi:10.1530/jrf.0.0010036

Adams C.E. 1960b. Studies on prenatal mortality in the rabbit, Oryctolagus cuniculus: the amount and distribution of loss before and after implantation. J. Endocrinol., 19: 325-344. doi:10.1677/joe.0.0190325

Al-Shorepy S.A., Clutter A.C., Blair R.M., Nielsen M.K. 1992. Effects of three methods of selection for litter size in mice on pre-implantation embryonic development. Biol. Reprod., 46: 958-963. doi:10.1095/biolreprod46.5.958

Argente M.J., Santacreu M.A., Climent A., Blasco A. 2003. Relationships between uterine and fetal traits in rabbit selected on uterine capacity. J. Anim. Sci., 81: 1265-1273.

Argente M.J., Santacreu M.A., Climent A., Blasco A. 2006. Influence of available uterine space per fetus on fetal development and prenatal survival in rabbits selected for uterine capacity. Livest. Sci., 102: 83-91. doi:10.1016/j.livprodsci.2005.11.022

Argente M.J., Santacreu M.A., Climent A., Blasco A. 2008. Effect of intrauterine crowding on available uterine space per fetus in rabbits. Livest. Sci., 114: 211-219. doi:10.1016/j.livsci.2007.05.008

Freking B.A., Leymaster K.A., Vallet J.L., Christenson R.K. 2007. Number of fetuses and conceptus growth throughout gestation in lines of pigs selected for ovulation rate or uterine capacity. J. Anim. Sci., 85: 2093-2103.

doi:10.2527/jas.2006-766

García M.L., Baselga M. 2002. Estimation of genetic response to selection in litter size of rabbits using a cryopreserved control population. Livest. Prod. Sci., 74: 45-53. doi:10.1016/S0301-6226(01)00280-9

Geisert R.D., Schmitt R.A.M. 2002. Early embryonic survival in the pig: Can it be improved? J. Anim. Sci., 80: E54-E65.

Hafez E.S.E. 1969. Fetal survival in undercrowded and overcrowded unilaterally pregnant uteri in the rabbit. In Proc.: 6th International Congress Reproduction Animal, 22-26 July, 1969. Paris, France. 1: 575.

Knight J., Bazer W.F.W., Thatcher W.W., Franke D.E., Wallace H.D. 1977. Conceptus development in intact and unilaterally hysterectomized-ovariectomized gilts. Interrelations among hormonal status, placental development fetal fluids and fetal growth. J. Anim. Sci., 44: 620-637.

Koenig J.L.F., Zimmerman D.R., Eldrige F.E., Kopf J.D. 1986. The effect of superovulation and selection for high ovulation rate on chromosomal abnormalities in swine ova. J. Anim. Sci., 63: 202.

Laborda P., Mocé M.L., Santacreu M.A., Blasco A. 2011. Selection for ovulation rate in rabbits: Genetic parameters, direct response, and correlated response on litter size. J. Anim. Sci., 89: 2981-2987. doi:10.2527/jas.2011-3906

Laborda P., Mocé M.L., Blasco A., Santacreu M.A. 2012a. Selection for ovulation rate in rabbits: Genetics parameters and correlated responses on survival rates. J. Anim. Sci., 90: 439-446. doi:10.2527/jas.2011-4219

Laborda P., Santacreu M.A., Blasco A., Mocé M.L. 2012b. Selection for ovulation rate in rabbits: Direct and correlated responses estimated with a cryopreserved control population. J. Anim. Sci., 90: 3392-3397. doi:10.2527/jas.2011-4837

Legarra A., Varona L., López de Maturana E. 2008. Program TM. Retrieved February 2016 on http://snp.toulouse.inra. fr/~alegarra/.

Leymaster K.A., Christenson R. 2000. Direct and correlated responses to selection for ovulation rate or uterine capacity in swine. J. Anim. Sci., 78(Suppl. 1): 68.

Mocé M.L., Blasco A., Santacreu M.A. 2010. In vivo development of vitrified embryos: Effects on prenatal survival and placental development. Theriogenology, 73: 704-710. doi:10.1016/j.theriogenology.2009.11.010

Mehaisen G.M., Vicente J.S., Lavara R., Viudes-de-Castro M.P. 2005. Effect of eCG dose and ovulation induction treatments on embryo recovery and in vitro development post-vitrification in two selected lines of rabbit does. Anim. Reprod. Sci., 90: 175-184. doi:10.1016/j.anireprosci.2005.01.015

Pope W.F. 1988. Uterine asynchrony: A cause of embryonic loss. Biol. Reprod., 39: 999-1003. doi:10.1095/biolreprod39.5.999

Rosendo A., Druet T., Gogué J., Bidanel J.P. 2007. Direct response to six generations of selection for ovulation rate or prenatal survival in Large White pigs. J. Anim. Sci., 85: 356-364. doi:10.2527/jas.2006-507

Santacreu M.A., Mocé M.L., Climent A., Blasco A. 2005. Divergent selection for uterine capacity in rabbits. II. Correlated response on litter size and its components estimated with a cryopreserved control population. J. Anim. Sci., 83: 2303-2307.

Sorensen D., Gianola D. 2002. Likelihood, Bayesian and MCMC methods in quantitative genetics. New York: Springer. doi:10.1007/b98952

Torres S., Hulot F., Meunier M. 1984. Étude comparée du développement et de la mortalité embryonnaire chez deux genotypes de lapines. In Proc.: 3rd World Rabbit Congress, 4-8 April, 1984. Rome, Italy. 2: 417-425.

Torres S., Hulot F., Meunier M., Sevellec C. 1987. Comparative study of preimplantation development and embryonic loss in two rabbit strains. Reprod. Nutr. Develop., 27: 707-714. doi:10.1051/rnd:19870510

van der Waaij E.H., Hazeleger W., Soede N.M., Laurenssen B.F.A., Kemp B. 2010. Effect of excessive, hormonally induced intrauterine crowding in the gilt on fetal development on d 40 of pregnancy. J. Anim. Sci., 88: 2611-2619. doi:10.2527/jas.2009-2561

Wilde M.H., Xie S., Day M.L., Pope W.F. 1988. Survival of small and large littermate blastocysts in swine after synchronous and asynchronous transfer procedures. Theriogenology, 30:1069-1074.

doi:10.1016/0093-691X(88)90281-6

Wilmut I., Sales D.I., Ashworth C.J. 1986. Maternal and embryonic factors associated with prenatal loss in mammals. J. Reprod. Fert., 76: 851-864. doi:10.1530/jrf.0.0760851

Wintenberger-Torres S. 1974. Relation entre la taille des blastocystes de lapine a l´implantation et la survie embryonnaire. Ann. Biol. Anim. Bioch. Biophys., 14: 41-52. doi:10.1051/rnd:19740105

Xie S., Broermann D.M., Nephew K.P., Geisert R.D., Pope W.F.

Ovulation and early embryogenesis in swine. Biol. Reprod., 43: 236-240. doi:10.1095/biolreprod43.2.236

Ziadi C., Mocé M.L., Laborda P., Blasco A., Santacreu M.A. 2013. Genetic selection for ovulation rate and litter size in rabbits: Estimation of genetic parameters and direct and correlated responses. J. Anim. Sci., 91: 3113-3120. doi:10.2527/jas.2012-6043

Abstract Views

829
Metrics Loading ...

Metrics powered by PLOS ALM




Official journal of the World Rabbit Science Association (WRSA)

© Universitat Politècnica de València. All rights reserved

© World Rabbit Science Associated. All rights reserved

e-ISSN: 1989-8886     ISSN: 1257-5011