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Abstract: Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is a selenoperoxidase accounting for most of the selenium content in mammalian testis, which has been found to be linked to fertility in humans. In this study, we addressed the issue whether PHGPx content in spermatozoa could be a predictive index of fertilization capacity for sire selection in bulls. Measurement of PHGPx in spermatozoa of 92 yearling bulls of three different Italian breeds (Chianina, Romagnola, and Marchigiana) revealed the presence of two quite well separated populations. A PHGPx activity of 130mU/mg separated the high-PHGPx group (H-PHGPx, n=73) from the low-PHGPx group (L-PHGPx, n=19). Forward motility was markedly higher in the H-PHGPx group, which also contained a lower percentage of detached heads, abnormal midpiece, and proximal droplets. On the other hand, differently from the human studies, no correlation was observed between PHGPx activity and number of spermatozoa in the ejaculate. Apart from sperm count, which typically differed among breeds, and number of detached heads in the L-PHGPx group, which correlated with higher sperm count, no other significant difference in seminal parameters among breeds was apparent. The assay for sperm PHGPx activity therefore emerges as a unique tool to evaluate semen quality for sire selection. [Copyright &y& Elsevier]

Abstract: The objectives of the present study were (i) to establish the mean value of scrotal circumference (SC), sperm motility, concentration and morphology at 13±1 months of age for Chianina, Marchigiana, and Romagnola breeds and (ii) to assign Italian beef bulls at the end of a growth performance test to a potential breeder category by applying the guidelines of the Society for Theriogenology in 1993 (SFT93). Of 1,315 bulls, 869 were not given the breeding soundness examination for the following reasons: not passing the growth performance test (n =445), no training for semen collection (n =404), and presence of genital abnormalities (n =20). Testicular length and diameter and SC exhibited a logarithmic trend over time, with an R 2 value of 0.963, 0.979, and 0.978 (P <0.001), respectively. The SC of Romagnola (33.82±2.47cm) was higher than those of Chianina (33.28±2.65cm, P <0.001) and Marchigiana (33.05±2.20cm, P <0.001). Sperm concentration in Romagnola (875.89±416.13×106 cells/mL) was higher than those in Chianina (751.63±444.45×106 cells/mL, P <0.05) and Marchigiana (862.57±421.87×106 cells/mL). Progressive sperm motility was 61.30±11.24%, 62.18±11.17%, and 58.48±14.40% in Romagnola, Marchigiana, and Chianina, respectively. Total spermatozoal abnormalities were higher in Chianina (23.35±15.41%). Sperm concentration was positively related to testicular length (P <0.01), diameter (P <0.001), and SC (P <0.001). Satisfactory breeders presented high sperm motility compared with deferred and unsatisfactory ones, whereas unsatisfactory breeders had a higher number of abnormal spermatozoa. By applying the SFT93 guidelines, we showed that 74.72%, 78.01%, and 80.16% of Chianina, Marchigiana, and Romagnola bulls, respectively, have been classified as satisfactory potential breeders. [Copyright &y& Elsevier]

Abstract: Growing evidence suggests that among the causes which deteriorate qualitative and functional characteristics of semen after freezing and thawing, there are those linked to oxidative stress and decrease detoxification of antioxidants present in the cells and seminal plasma. Overall, cryopreservation reduces the spermatozoal GSH content. In the present study we assessed the motility, capacitation status, ability to undergo acrosome reaction and levels of GSH in bovine spermatozoa after freezing and thawing, and compared the effects of the egg yolk tris-citrate and a commercial extenders (Bioxcell®). Six semen samples were collected from each of five bulls and frozen and thawed in the two extenders. The level of total GSH of bovine spermatozoa detected in the raw semen ranged from 246.5 to 776.2pmoles/mg of protein. The Bioxcell® extender was superior in preserving GSH content (647.2±300.1 versus 223.6±154.0pmoles/mL; P <0.05), motility levels (44.3±4.8 versus 41.8±4.0%; P <0.05), non-capacitated state (68.3±13.6 versus 61.3±17%; P <0.05) and a lower proportion of acrosome reacted spermatozoa post thaw (3.8±2.1 versus 6.3±3.1%; P <0.001) compared to egg yolk tris-citrate extender. These findings could be partially ascribed to the high GSH level contained in the commercial extender which seem able to alleviate oxidative damages to spermatozoa surviving freezing thawing procedures. Further researches are required in order to validate in vivo these results. [Copyright &y& Elsevier]