Development of in vitro tests to predict fertility of bulls

Abstract

of in vitro tests to predict fertility of bulls. Can. J. Anim. Sci. 85: 47-52. The overall objective was to develop an in vitro test to predict fertility of bulls in the field. We investigated the bull effect on in vitro embryo production, zona binding and acrosome reaction, and the correlation of this effect to field fertility measured by 60-90 d non-return rate. Frozen semen from three separate ejaculates of eight unrelated young bulls, obtained from an artificial insemination (AI) center, was used. On thawing, ejaculates from each bull were pooled, motile sperm were selected and (a) subjected to immunofluorescent assay at 0 and 4 h of incubation in capacitation medium to assess acrosome status, (b) used in an in vitro fertilization assay system to assess cleavage and blastocyst production rates, and (c) sperm-zona binding assay was carried out to determine the number of sperm bound to the zona pellucida of mature oocytes. Percentage of pre-freeze motile sperm (PrFM) and non-return rate data were obtained from the AI center. PrFM, percentage of acrosome reacted sperm at 0 h (AR1), increase in percentage of acrosome reacted sperm after 4 h (InAR) and sperm-zona binding rates (ZB) differed (P < 0.05) among sperm samples obtained from different young bulls. Significant correlations (P < 0.05) were observed between PrFM and AR1 (r = -0.31), InAR (r = 0.36), and ZB (r = 0.32). AR1 was negatively correlated to ZB (r = -0.27) and cleavage rate (r = -0.20), InAR was positively correlated with ZB (r = 0.31) and cleavage rate (r = 0.26). None of the in vitro tests was correlated with non-return rate. These findings indicate that along with pre-freeze motility, a combination of in vitro tests including the percentage of spontaneously acrosome reacted sperm at thawing, might be useful in predicting bull field fertility. Such a combination of assays, however, has yet to be determined. (r = 0,26). Aucun test in vitro ne présente de corrélation avec le taux de non-retour. Ces constatations indiquent qu'outre la motilité des spermatozoïdes avant congélation, la combinaison de divers tests in vitro, dont le pourcentage de spermatozoïdes dont l'acrosome réagit spontanément à la décongélation pourrait avoir son utilité pour prédire la fécondité des taureaux sur le terrain. Reste à établir la combinaison de tests qui convient à un tel usage. Mots clés:Fécondité sur le terrain, réaction de l'acrosome, fixation à la zone pellucide, fécondation IV, évaluation de la féconditéArtificial insemination is one of the most successful reproductive technologies developed to improve reproductive efficiency of farm animals, especially dairy cattle. Accurate evaluation of the fertility of bulls used for AI purposes is of utmost importance since a single ejaculate provides several insemination doses and shows much influence on the reproductive potential of a herd (Rodriguez-Martinez and Larsson 1998). Therefore, the basic purpose of semen evaluation procedures is to ensure that only good quality and highly fertile semen is used for AI purposes....

Relationship between acrosome integrity changes and in vitro fertilising ability of bovine spermatozoa

“…A positive correlation (r = 0.26) between the percentage of acrosome-reacted spermatozoa after 4 h of capacitation and embryo cleavage rate was found by Giritharan et al (2005). In our study, the bulls with greater and intermediate response to heparin showed the best results in percentages of penetrated and fertilised oocytes and D7 and D8 embryo rates.…”

“…Values with different superscripts differ significantly (a-b, P < 0.05) doi: 10.17221/8437-VETMED bation. On the other hand, Giritharan et al (2005) described a maximum increase in the acrosomereacted spermatozoa rate already after 4 h. In our study, sperm capacitation reached its maximum after 5 h, but only in bulls with no response to heparin, whereas in bulls with greater and intermediate response to heparin, the percentage of acrosomereacted sperm further increased between 5 and 6 h and reached its maximum after 6 h of capacitation, similarly as reported in Molnarova et al (2006). Dhanju et al (2006) demonstrated that in individual bulls the proportion of acrosome-reacted spermatozoa after 6 h ranged from 62% to 87%.…”

In vitro induction of the acrosome reaction in spermatozoa from endangered Spanish bulls: Effect of breed, culture media and incubation time

“…Although it has been previously demonstrated the influence of several paternal factors, such as male (Katska and Smorag, 1996;Ward et al, 2001), age (Ward et al, 2002), breed , species (Pontes et al, 2010), and semen collection method (García-Á lvarez et al, 2009) on IVF outcomes, this is the first attempt to assess the effect of cattle breed on induced AR results. Early reports suggest that the ability of spermatozoa to undergo AR in vitro may be a useful method for predicting the result of IVF in cattle (Costa et al, 2010;Giritharan et al, 2005;Mukhopadhyay et al, 2008). In fact, AR status has been previously used as predictor of both freezability (Molnarova et al, 2006) and in vivo fertility (Birck et al, 2010;Collin et al, 2000;Giritharan et al, 2005) in cattle.…”

“…Early reports suggest that the ability of spermatozoa to undergo AR in vitro may be a useful method for predicting the result of IVF in cattle (Costa et al, 2010;Giritharan et al, 2005;Mukhopadhyay et al, 2008). In fact, AR status has been previously used as predictor of both freezability (Molnarova et al, 2006) and in vivo fertility (Birck et al, 2010;Collin et al, 2000;Giritharan et al, 2005) in cattle. However, it has been widely demonstrated that in vitro AR rates depend on both the incubation time (Dode et al, 2002;Fukui et al, 1990;Gliedt et al, 1996;Pavlok et al, 2001) and the culture medium (Januskauskas et al, 2000;Sharma et al, 1999;Vadnais et al, 2005).…”

Effect of Pre‐freeze Addition of Cysteine Hydrochloride and Reduced Glutathione in Semen of Crossbred Jersey Bulls on Sperm Parameters and Conception Rates

“…Hyperactivation in turn implied high energy state of the spermatozoa, which is essential for sperm penetration through cervical mucus and fuse with the oocytes (Aitken et al 1985;Aitken et al 1992;Aitken and Fisher 1994;Mortimer 1994). It had been established that the assessment of sperm motility in a semen sample might not be a reliable index for semen evaluation (Jeyendran et al 1984;Bailey et al 1994;Zhang et al 1998;Giritharan et al 2005). The objective and quantitative measurement of other sperm motion characteristics of individual cells assessed by CASA found to be more efficient in predicting semen sample's potential fertility (Mortimer 1994).…”