Patrick Blondin

Semex & Boviteq

Cryopreservation provides a critical tool for dairy herd genetics management. Due to widely varying inter- and within-bull post thaw fertility, recent research on cryoprotectant extender medium has not dramatically improved suboptimal post-thaw recovery in industry. This progress is stymied by the interactions between samples and the many component...

Cryopreservation provides a critical tool for dairy herd genetics management. Due to widely varying inter- and within-bull post thaw fertility, recent research on cryoprotectant extender medium has not dramatically improved suboptimal post-thaw recovery in industry. This progress is stymied by the interactions between samples and the many component...

There is considerable interest in breeding programs to “rescue” semen with poor post-thaw fertility from bulls known as “bad freezers”. We hypothesized that there may be an interaction between the post-thaw recovery of sperm and the efficacy of antioxidant addition to extenders. The current study assesses the effects of antioxidant additives hydrox...

Approximately one million in vitro produced (IVP) cattle embryos are transferred worldwide each year as a way to improve the rates of genetic gain. The most advanced programmes also apply genomic selection at the embryonic stage by SNP genotyping and the calculation of genomic estimated breeding values (GEBVs). However, a high proportion of cattle...

Fertility is a multiparametric phenomenon that relies on the use of semen of sufficient quality and quantity, accurate timing and method of insemination, and appropriate herd management. When using artificial insemination, the dairy producer must manage a range of these factors, including heat detection, timing of insemination in relation to estrus...

Contemporary systems for oocyte retrieval and culture of both cattle and human embryos are suboptimal with respect to pregnancy outcomes following transfer. In humans, chromosome abnormalities are the leading cause of early pregnancy loss in assisted reproduction. Consequently, pre-implantation genetic testing for aneuploidy (PGT-A) is widespread a...

The production of bovine embryos through in vitro maturation and fertilization is an important tool of the genomic revolution in dairy cattle. Gene expression analysis of these embryos revealed differences according to the culture conditions or oocyte donor’s pubertal status compared to in vivo derived embryos. We hypothesized that some of the meth...

Background Sperm miRNAs were reported to regulate spermatogenesis and early embryonic development in some mammals including bovine. The dairy cattle breeding industry now tends to collect semen from younger bulls under high selection pressure at a time when semen quality may be suboptimal compared to adult bulls. Whether the patterns of spermatic m...

Two experiments were performed to determine effects of follicular ablation (FA) and GnRH treatment on conception rate and synchronization in timing of ovulation among Holstein heifers. In Experiment 1, heifers were randomly allocated to four groups: Control (n = 84): prostaglandin F2α (PGF) IM on Day 0; FA-5/GnRH (n = 43): FA 5 days before PGF and...

In the dairy industry, the high selection pressure combined with the increased efficiency of assisted reproduction technologies (ART) are leading toward the use of younger females for reproduction purposes, with the aim to reduce the interval between generations. This situation could impair embryo quality, decreasing the success rate of the ART pro...

A number of studies have explored the use of membrane permeable (usually metabolizable) and membrane impermeable saccharides to protect cells in general, and sperm in particular during cryopreservation. Critical concentrations for protective levels of sugars frequently range between 50 mmol/L and 500 mmol/L, where efficacy is attributed to the suga...

Background Sperm miRNAs were reported to regulate spermatogenesis and early embryonic development in some mammals including bovine. The dairy cattle breeding industry now tends to collect semen from younger bulls under high selection pressure at a time when semen quality may be suboptimal compared to adult bulls. Whether the patterns of spermatic m...

Background: Sperm miRNAs were reported to regulate spermatogenesis and early embryonic development in some mammals including bovine. The dairy cattle breeding industry now tends to collect semen from younger bulls under high selection pressure at a time when semen quality may be suboptimal compared to adult bulls. Whether the patterns of spermatic...

Background: Sperm miRNAs were reported to regulate spermatogenesis and early embryonic development in some mammals including bovine. The dairy cattle breeding industry now tends to collect semen from younger bulls under high selection pressure at a time when semen quality may be suboptimal compared to adult bulls. Whether the patterns of spermatic...

Cumulus cells have an important role to play in the final preparation of the oocyte before ovulation. During the final phase of follicular differentiation, FSH levels are low and LH maintains follicular growth; however, it is not known if at that time LH has an influence on cumulus cells inside the follicle. In humans, LH is often inhibited to avoi...

Genetic selection for the best suited offspring drives the dairy industry to use young genitors and assisted reproductive technologies (ART) to reduce generation intervals. However, sperm samples collected from peri-pubertal bulls have lower counts and quality compared to samples from adult bulls. Moreover, our previous study identified differentia...

One of the major challenges of artificial reproductive technologies is to develop new methods for producing greater numbers of embryos. An oocyte fosters the ability to develop into an embryo before oocyte meiotic resumption. The aim of the present study was to assess the effect of adenosine (ADO), a purine nucleoside found in follicular fluid, on...

In the context of artificial insemination, male fertility is defined as the ability to produce functional spermatozoa able to withstand cryopreservation. We hypothesized that interindividual variations in fertility depend on the proportion of the fully functional sperm population contained in the insemination dose. The objective of this study was t...

Genetic selection for the best suited offspring’s drives the dairy industry to use young genitors with assisted reproductive technologies (ART) to reduce generation intervals. However, sperms collected from peri-pubertal bulls have lower quality compared to adults. Moreover, new evidences suggest that sperm can transfer not only the paternal genome...

Laparoscopic Ovum Pick-Up (LOPU) in calves followed by in vitro embryo production (IVEP) and transfer (ET) into adult recipients has great potential for accelerated genetic gain through shortening of the generation interval. In this study, 11 Holstein calves were subjected to up to six LOPU procedures between the ages of 2-6 months at 2-3 weeks int...

The selection of the best dairy heifers is mainly driven by the genetic value of their parents. The phenotype analysis of cows and of the daughters of bulls has been used to identify the best genetic value for decades before being replaced by genomic selection of individuals that are not yet parents. Because it is possible to predict the future val...

In Holstein heifer recipients that are synchronized with a single dose of prostaglandin F2α (PGF2α), only 65% (on average) are eligible to receive an IVF embryo 7 ± 1 days after oestrus. The high variability in time to onset of oestrus after PGF2α treatment and the small size of the corpus luteum (CL) on the day of embryo transfer (ET) may explain...

Genomic selection is accelerating genetic gain in dairy cattle. Decreasing generation time by using younger gamete donors would further accelerate breed improvement programs. Although ovarian stimulation of peripubertal animals is possible and embryos produced in vitro from the resulting oocytes are viable, developmental competence is lower than wh...

Mammalian semen contains a heterogeneous population of sperm cells. This heterogeneity results from variability in the complex processes of cell differentiation in the testis, biochemical modifications undergone by spermatozoa during transit along the male reproductive tract, interactions with secretions from accessory sex glands at ejaculation, an...

In the dairy industry, using semen as soon as the bull is mature enough to produce it is advantageous for breeding purposes. Mammalian spermatogenesis is a hormone-dependent developmental program in which a complex cascade of events must take place to ensure that germ cells reach the proper stage of development at the proper time. Conventional indi...

The use of oocytes recovered from prepubertal donors for in vitro embryo production has great potential for accelerating the rate of genetic gain in the dairy industry. However, these oocytes are known to be less developmentally competent than those from adult donors. In this study, we investigated the effect of age and gonadotropin stimulation in...

In cows, the use of follicle-stimulating hormone (FSH) to stimulate follicular growth followed by a short period of FSH withdrawal has been shown to be beneficial for oocyte developmental competence. Although this treatment represents a useful optimization to generate highly competent oocytes, the underlying physiological process is not completely...

Ovarian stimulation with exogenous FSH followed by FSH withdrawal or 'coasting' is an effective means of increasing the number of oocytes obtainable for the in vitro production of cattle embryos. However, the quality of the oocytes thus obtained varies considerably from one cow to the next. The aim of the present study was to gain a better understa...

Study question: Can region-specific transcriptional profiling of the epididymis from fertile and sub-fertile bulls predict the etiology of fertility/sub-fertility in males? Summary answer: The highly regulated gene expression along the bovine epididymis is affected by the fertility status of bulls used for artificial insemination. What is known...

Assisted reproduction technologies (ART) and high selection pressure in the dairy industry are leading towards the use of younger females for reproduction, thereby reducing the interval between generations. This situation may have a negative impact on embryo quality, thus reducing the success rate of the procedures. This study aimed to document the...

Embryo transfer and artificial insemination are utilised nationally and internationally for the introduction, improvement, and preservation of livestock genetics. Embryos present a lower risk of infectious disease transmission than do live animals. In order to maintain the sanitary security and to facilitate the trade of embryos and semen worldwide...

ains a huge challenge. To be successful, there has to be a partnership betwee The use of IVF in agriculture is growing worldwide. This can be explained by the development of better IVF media and techniques, development of sexed semen and the recent introduction of bovine genomics on farms. Being able to perform IVF on a large scale, with multiple o...

Background: Cyclic adenosine monophosphate (cAMP) plays a crucial role as a signaling molecule for sperm functions such as capacitation, motility and acrosome reaction. It is well known that cAMP degradation by phosphodiesterase (PDE) enzyme has a major impact on sperm functions. The present study was undertaken to characterize cAMP-PDE activity i...

Cyclic adenosine monophosphate (cAMP) plays a crucial role as a signaling molecule for capacitation, motility, and acrosome reaction in mammalian spermatozoa. It is well-known that cAMP degradation by phosphodiesterase (PDE) enzyme has a major impact on sperm functions. This study was undertaken to characterize cAMP-PDE activity in bovine spermatoz...

The second messenger cyclic adenosine monophosphate (cAMP) has a central role in sperm physiology. Extracellular cAMP can be sequentially degraded into 5′AMP and adenosine by ecto-phosphodiesterases (ecto-PDE) and ecto-nucleotidases, a phenomenon called extracellular cAMP-adenosine pathway. As cAMP-adenosine pathway is involved in sperm capacitatio...

Oocyte developmental competence in super-stimulated cows is dependent in part on the duration of the FSH coasting. FSH coasting refers to super-stimulation with FSH (two days of endogenous FSH following follicle ablation and three days of FSH injections) followed by no FSH for a specific duration. The optimal duration varies among individuals. FSH...

The use of oocytes obtained from younger donors for in vitro fertilisation (IVF) followed by embryo transfer (ET) represents an opportunity to accelerate genetic gain by reducing generation time. In this study, we investigated the relationship between donor age and the in vitro developmental competence of oocytes obtained from Holstein females (age...

Enhanced early-life nutrition (∼130% of required energy and protein) increased testes size and weight (∼20-25%) and reduced age at puberty (∼1 mo) in beef and dairy bulls, compared to those fed 70% of dietary requirements. The objective was to determine effects of early-life (2 to 31 wk) nutritional modulation on feed costs, predicted number of har...

Monozygotic (MZ) twins are of great interest to elucidate the contributions of pre- and postnatal environmental factors on epigenetics in the expression of complex traits and diseases. Progeny testing recently revealed that MZ twin bulls do not necessarily lead to identical genetic merit estimates (i.e. breeding values). Therefore, to explain diffe...

Commercial IVF programs in Holstein (HO) donors in North America require that not only quantity, but also quality of embryos be increased. These programs are intended to produce the maximal number of offspring from elite females and males over a short period of time. Optimal embryo quality is needed for cryopreservation (for embryo trade and a recu...

Some embryos exhibit better survival potential to cryopreservation than others. The cause of such a phenotype is still unclear and may be due to cell damage during cryopreservation, resulting from overaccumulation and composition of lipids. In cattle embryos, in vitro culture conditions have been shown to impact the number of lipid droplets within...

A successful in vitro fertilisation (IVF) programme relies on three areas: optimal donor preparation/superovulation, a highly quality controlled (QC) IVF laboratory, and an efficient recipient herd to assure maximal pregnancies. This review will cover the first two areas of such a programme established in North America. To produce the maximal numbe...

Early estimation of bull fertility is highly desirable for the conservation of male genetics of endangered species and for the exploitation of genetically superior sires in artificial insemination programs. The present work was conducted as a proof-of-principle study to identify fertility-associated metabolites in dairy bull seminal plasma and bloo...

Holstein bull calves often reach artificial insemination centers in suboptimal body condition. Early-life nutrition is reported to increase reproductive performance in beef bulls. The objective was to determine whether early-life nutrition in Holstein bulls had effects similar to those reported in beef bulls. Twenty-six Holstein bull calves were ra...

The objective was to determine effects of early-life nutrition on reproductive potential of Holstein bulls. Twenty-six bull calves were randomly allotted to 3 groups and fed ~70, 100, or 130% of National Research Council recommendations for both energy and protein from 2 to 31 wk; thereafter, all were fed a 100% diet (adequate vitamins and minerals...

Background Genome-wide profiling of single-nucleotide polymorphisms is receiving increasing attention as a method of pre-implantation genetic diagnosis in humans and of commercial genotyping of pre-transfer embryos in cattle. However, the very small quantity of genomic DNA in biopsy material from early embryos poses daunting technical challenges. A...

Background Oocyte fertilization and successful embryo implantation are key events marking the onset of pregnancy. In sexually reproducing organisms, embryogenesis begins with the fusion of two haploid gametes, each of which has undergone progressive stages of maturation. In the final stages of oocyte maturation, minimal transcriptional activity is...

Mitochondria play an important role during early development in mammalian embryos. It has been shown that properly controlled follicular preparation increases the likelihood of in-vitro-produced bovine embryos reaching the blastocyst stage and that competent embryos exhibit heightened expression of genes associated with mitochondrial function. We h...

The current world population is increasing at a fast rate. In order to feed this larger population, food production must increase by 70 percent. Recent reports show a record global production of 58.9 Carcass Equivalent Weight million metric tonnes of beef expected for 2014. It becomes clear that the worldwide agricultural community will have to int...

Ovarian stimulation with FSH combined with an appropriate period of FSH withdrawal (coasting) before ovum pick-up (OPU) now appears to be a successful way to obtain oocytes with high developmental competence in bovine. Recent results showed that extending follicular growth by only 24 hours has a detrimental effect on oocyte quality as shown by the...

Mitochondria play an important role during early mammalian embryo development through their diverse cellular functions, in particular creating balance between production of ATP by electron transport chain and oxidative stress. Embryonic mitochondria are inherited maternally and independently of the nuclear genome. They show limited activity during...

The final days before ovulation impact significantly on follicular function and oocyte quality. This study investigated the cumulus cell (CC) transcriptomic changes during the oocyte developmental competence acquisition period. Six dairy cows were used for 24 oocyte collections and received FSH twice daily over 3 days, followed by FSH withdrawal fo...

Background: The neonatal period is associated with high morbidity and mortality in cloned calves. Objective: To describe morbidity and mortality in cloned calves from birth to 2 years of age. Animals: Thirty-one somatic cell-derived Holstein calves delivered at a veterinary teaching hospital. Methods: Medical files were retrospectively analy...

Background It was recently established that changes in methylation during development are dynamic and involve both methylation and demethylation processes. Yet, which genomic sites are changing and what are the contributions of methylation (5mC) and hydroxymethylation (5hmC) to this epigenetic remodeling is still unknown. When studying early develo...

One of the challenges in mammalian reproduction is to understand basic physiology of oocyte quality. It is believed that the follicle status is linked to developmental competence of the enclosed oocyte. To explore the link between follicles and competence in cows, a previous experiment from our laboratory has developed an ovarian stimulation protoc...

Recent progress in the ovarian stimulation protocol used for bovine in vitro maturation and fertilization, especially through optimization of the follicle-stimulating hormone (FSH) withdrawal period ("coasting") after ovarian pre-treatment with FSH, has significantly improved blastocyst outcome. Despite this important success, the underlying factor...

Previously, we showed that epididymal sperm binding protein 1 (ELSPBP1) characterizes spermatozoa already dead before ejaculation in bovine. In this study, we investigated the presence of ELSPBP1 in bull genital tract as well as its acquisition by spermatozoa during epididymal transit. As assessed by real-time RT-PCR, ELSPBP1 was highly expressed i...

In cow, follicular growth stimulation (FSH) followed by a 44h-68h coasting (no FSH) period has been shown to be beneficial for developmental competence of aspirated oocytes. This process has been optimized but the associated physiology is not perfectly understood. During the above treatment LH pulse frequency is basal as the animal are in the lutea...

Fertility is a multiparametric phenomenon that relies on the use of semen of sufficient quality and quantity, accurate timing and method of insemination, and appropriate herd management. When using artificial insemination (AI), the dairy producer must manage a range of these factors, including heat detection, timing of insemination in relation to e...

The major challenge in assisted reproduction technologies remains producing oocytes with optimal developmental competence. Such developmental competence can be defined as the ability of the oocyte to fulfill maturation, undergo successful fertilization, reach the blastocyst stage and yield a viable and healthy progeny. The main follicular parameter...

Testis-specific protein Y-encoded (TSPY) is present in varying copy number in both human (20-76 copies) and cattle (37-200 copies), and some studies have linked this variation to semen quality in men. The purpose of this study was to determine if TSPY copy number is associated with fertility in bulls by using adjusted non-return rates, a commonly u...

Bovine embryo production is practiced worldwide for commercial purposes. A major concern of embryo suppliers is the impact of in vitro production systems on embryo quality. In the present study, we compared Buffalo Rat Liver cell coculture with semidefined, medium-based culture, oocytes recovered postmortem with those obtained from live animals, an...

Previously, we showed that binder of sperm 1 (BSP1) and epididymal sperm binding protein 1 (ELSPBP1) proteins are more abundant in the immotile bovine sperm subpopulation following cryopreservation. In this study, we investigated the association of BSP1 and ELSPBP1 with sperm in relation to their ability to survive the cryopreservation process. Fre...

In the case of in vitro embryonic production, it is known that not all oocytes detain the developmental capacity to form an embryo. This capacity appears to be acquired through completion of folliculogenesis, during which the oocyte and follicular cells influence their respective destinies. The differentiation status of granulosa cells (GCs) could...

One of the main objectives related to performing comparative analysis of embryonic transcriptomes is to share information with other reproductive biologists or commercial service providers. Biological extracts influence performance of in vitro production systems and affect the reproducibility of results between production sites; these sources of va...

When examining gene expression profiles for the purposes of assessing embryo quality, it is imperative that sex be considered, because many embryonic transcripts have sex-related expression patterns. The objective of this study was to systematically examine eight Y chromosome linked genes (DDX3Y, EIF1AY, HSFY, SRY, TSPY, USP9Y, ZFY, and ZRSR2Y) to...

The predetermination of sex is an appealing means of controlling the sex ratio in a selected population of production animals or wildlife. The sexing of mammalian sperm by flow cytometry for its use in artificial insemination (AI) or in vitro fertilization (IVF) has led to the birth of hundreds of thousands of offspring in numerous species, and rem...

The objectives were to compare testicular physical characteristics and post-thaw sperm characteristics and their associations with fertility in Holstein bulls used for AI. Ten Holstein bulls (4-5 y old) were classified as either high-fertility (HF) or low-fertility (LF; n = 5 each), based on adjusted 56-d non-return rates [non-return rate (NRR); ra...

Despite hundreds of scientific papers published, no system has resulted in in vitro embryos comparable to those produced in vivo. We hypothesised that assembling the most pertinent elements of IVF studies into one system would result in a highly efficient in vitro culture system. Here we report the in vitro production of bovine embryos using a cult...