Searchable, peer-reviewed, open-access proceedings from bioscience and biomedical conferences

bp0006rdr21 | Embryo Technologies | REDR2006

Nuclear reprogramming by somatic cell nuclear transfer – the cattle story

Tian XC , Smith SL , Zhang SQ , Kubota C , Curchoe C , Xue F , Yang L , Du F , Sung L-Y , Yang X

Somatic cell nuclear transfer (cloning) returns a differentiated cell to a totipotent status; a process termed nuclear reprogramming. Nuclear transfer has potential applications in agriculture and biomedicine, but is limited by low efficiency. To understand the deficiencies of nuclear reprogramming, our research has focused on both candidate genes (imprinted and X-linked genes) and global gene expression patterns in cloned bovine embryos/offspring as compared to those generate...

bp0007rdr30 | Managing Fertility in Domestic Ruminants | REDR2010

Causes and consequences of the variation in the number of ovarian follicles in cattle

Evans ACO , Mossa F , Fair T , Lonergan P , Butler ST , Zielak-Steciwko AE , Smith GW , Jimenez-Krassel F , Folger JK , Ireland JLH , Ireland JJ

Summary. In cattle we have noted that the antral follicle count (AFC, follicles ≥3 mm in diameter) varies greatly among animals (from 5 to 50), is repeatable within animals, and is highly correlated with the total number of healthy follicles in ovaries. Also, animals with low AFC have higher serum concentrations of FSH and LH, but lower concentrations of Anti-Mullerian Hormone, progesterone and androgens than animals with high AFC. We have investigated t...

bp0015cpr11 | Embryonic and Fetal Development in The Pig | CPR1997

Extracellular matrix and the implantation cascade in pigs

Burghardt R. C. , Bowen J. A. , Newton G. R. , Bazer F. W.

The structural and functional alterations of uterine epithelial cells that permit the apical-apical union of conceptus and uterine epithelium are complex and are likely to involve many different adhesion molecules with distinct but inter-related functions. A number of changes in the molecular composition at the apical surface of uterine epithelial cells associated with the transition from the pre-receptive to the receptive state in the pig uterus are reviewed. Molecules t...

bp0017cpr19 | (1) | CPR2005

Strategies to improve the fertility of frozen-thawed boar semen for artificial insemination

Roca J. , Rodriguez-Martinez H. , Vazquez J.M. , Bolarin A. , Hernandez M. , Saravia F. , Wallgren M. , Martinez E.A.

Although cryopreservation of boar semen for artificial insemination (Al) was developed 35 years ago, cryopreservation conditions and Al strategies are still considered sub-optimal. Al with excessive numbers of frozenthawed sperm (5-6 x 109 cells), still does not achieve fertility levels similar to Al using liquid semen because of reduced sperm survival. Frozenthawed (FT) spermatozoa have therefore not been the preferred option for commercial breeding programme...

bp0018cpr19 | Management of Ovarian Activity in Swine | CPR2009

Studies on fixed-time ovulation induction in the pig

Brussow K.P. , Schneider F. , Kanitz W. , Ratky J. , Kauffold J. , Wahner M.

A technology that allows for manipulating of oestrus and ovulation, and would then also allow for fixed-time insemination, can be of great benefit for swine farms that operate using sow batch management due, at least in part, to savings in labour and the production of large batches of evenly developed pigs. Thanks to the current knowledge on endocrine regulation of follicle development and ovulation, and the availability of numerous reproductively active substances such ...

bp0008rdr2 | Genomes, Proteomics, Metabolomics | REDR2014

Genetic improvement in cattle — are we sacrificing reproduction in favor of production?

Cushman Robert A , McNeel Anthony K , Tait Jr. Robert G , Lindholm-Perry Amanda K , Perry George A , Snelling Warren M , Bennett Gary L

Summary. Reproductive traits can range from lowly to moderately heritable. Genomic technologies provide a powerful tool for improving selection for traits that are lowly heritable, sex-linked, or not expressed until later in life. Therefore, as genomic technologies become a part of selection decisions, there is a critical need to understand how specific gene variants affect reproductive traits in cattle. Both classical quantitative genetics approaches and geno...