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Germplasm banking is a fundamental tool for the preservation of autochthonous breeds. Semen cryopreservation is effective for this task, but protocols are adapted to commercial species, and post‐thawing sperm quality could be sensitive to environmental cues. We compared the post‐thawing sperm quality in doses from the CBA‐SERIDA bank in northern Spain for the Asturiana de la Montaña (AM) and Asturiana de los Valles (AV) autochthonous cattle breeds. Doses from 23 AM and 16 AV bulls (ejaculates from at least three different seasons) were assessed for motility (computer‐assisted sperm analysis), physiology and chromatin status (flow cytometry) after thawing and after 5 h at 38°C. Data were analysed using linear mixed‐effects and cosinor models for seasonal and breed effects and by correlations with the association of sperm quality with temperature‐humidity index (THI), considering the interval of spermatogenesis plus maturation. The breed affected sperm quality, with higher motility for AV and higher apoptotic ratio, mitochondrial activity, reactive oxygen species, DNA fragmentation and chromatin immaturity for AM. However, seasonality effects were minimal, and THI was not associated with sperm quality. In summary, the season seems to be a minor factor in the post‐thawing quality of the AM and AV autochthonous breeds, well‐adapted to their local environment. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the sperm nuclear and acrosomal morphometry of three species of domestic artiodactyls; cattle (Bos taurus), sheep (Ovis aries), and pigs (Sus scrofa). Semen smears of twenty ejaculates from each species were fixed and labeled with a propidium iodide-Pisum sativum agglutinin (PI/PSA) combination. Digital images of the sperm nucleus, acrosome, and whole sperm head were captured and analyzed. The use of the PI/PSA combination and CASA-Morph fluorescence-based method allowed the capture, morphometric analysis, and differentiation of most sperm nuclei, acrosomes and whole heads, and the assessment of acrosomal integrity with a high precision in the three species studied. For the size of the head and nuclear area, the relationship between the three species may be summarized as bull > ram > boar. However, for the other morphometric parameters (length, width, and perimeter), there were differences in the relationships between species for sperm nuclei and whole sperm heads. Bull sperm acrosomes were clearly smaller than those in the other species studied and covered a smaller proportion of the sperm head. The acrosomal morphology, small in the bull, large and broad in the sheep, and large, long, and with a pronounced equatorial segment curve in the boar, was species-characteristic. It was concluded that there are clear variations in the size and shape of the sperm head components between the three species studied, the acrosome being the structure showing the most variability, allowing a clear distinction of the spermatozoa of each species. [ABSTRACT FROM AUTHOR]