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Schulze M.,Institute For The Reproduction Of Farm Animals Schonow E V Ifn | Ruediger K.,Institute For The Reproduction Of Farm Animals Schonow E V Ifn | Mueller K.,Leibniz Institute for Zoo and Wildlife Research | Jung M.,Institute For The Reproduction Of Farm Animals Schonow E V Ifn | And 2 more authors.
Animal Reproduction Science | Year: 2013

The aim of this research was the selection of spermatozoa parameters related to boar fertility performance and their combination into an in vitro index. A first set (data set 1) of 36 Pietrain boars with 138 ejaculates from two seasons with 5083 single-sire inseminations from 34 farms was used to determine correlations between in vitro sperm quality parameters and fertility performance. 2970 ejaculates representing a second set (data set 2) served calculation of seasonal and age effects on semen quality. Morphological spermatozoa parameters were estimated manually with a phase contrast microscope on the day of semen collection, whereas mitochondrial activity and viability were analyzed by double-staining with rhodamine123/propidium iodide on day 2 of semen storage using flow cytometry. Sperm motility was tested on day 7 by thermoresistance (TRT) after 30min (TRT1) and 300min (TRT2) incubation at 38̊C using computer-assisted semen analysis (CASA).Correlations revealed four independent sperm quality parameters qualifying as relevant predictors of boar fertility: (i) percentage of spermatozoa with proximal cytoplasmic droplets, (ii) percentage of spermatozoa with active mitochondria, (iii) beat cross frequency of progressively motile spermatozoa in TRT1, and (iv) oscillation measure of the actual path of progressively motile spermatozoa in TRT2. There were no significant effects of sperm concentration, ejaculate volume, and total number of sperm cells per ejaculate on litter size (LS) and on pregnancy rate (PR). Our findings suggest the usefulness of sperm quality parameters based on adjusted range of methods and enable the construction of an in vitro index as a means to predicting boar fertility. © 2013 Elsevier B.V.

Schulze M.,Institute For The Reproduction Of Farm Animals Schonow E V Ifn | Henning H.,University of Veterinary Medicine Hannover | Rudiger K.,Institute For The Reproduction Of Farm Animals Schonow E V Ifn | Wallner U.,University of Veterinary Medicine Hannover | Waberski D.,University of Veterinary Medicine Hannover
Theriogenology | Year: 2013

Freshly collected boar spermatozoa are sensitive to a fast reduction in temperature because of lipid phase transition and phase separation processes. Temperature management during semen processing may determine the quality of stored samples. The aim of this study was to evaluate the influence of isothermic and hypothermic semen processing protocols on boar sperm quality under laboratory and field conditions. In the laboratory study, ejaculates (n = 12) were first diluted (1:1) with Beltsville Thawing Solution (BTS) at 32 °C, then processed either with isothermic (32 °C) or hypothermic (21 °C) BTS, stored at 17 °C, and assessed on days 1, 3, and 6. Temperature curves showed that 150 minutes after the first dilution, semen doses of both groups reached the same temperature. Two-step hypothermic processing resulted in lower sperm motility on days 1 and 6 (P < 0.05). Concomitantly, hypothermally processed samples contained less membrane intact sperm on days 3 and 6 (P < 0.05). Using AndroStar Plus extender instead of BTS reduced the negative effect of hypothermic processing. In the field study, 15 semen samples from each of 23 European artificial insemination studs were evaluated as part of an external quality control program. Semen quality based on motility, membrane integrity, mitochondrial activity, and a thermoresistance test was higher for stations using one-step isothermic dilutions (n = 7) compared with artificial insemination centers using two-step hypothermic protocols (n = 16). Both studies show that chilling injury associated with hypothermic dilution results in lower quality of stored boar semen compared with isothermic dilution and that the type of semen extender affects the outcomes. © 2013 Elsevier Inc.

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