Relationship between pubertal testicular ultrasonographic evaluation and future reproductive performance potential in Piétrain boars

New ways of predicting sperm quality and output performance in young artificial insemination (AI) boars are important for breeding companies to ensure that the pubertal boars delivered to the AI studs have a high chance of meeting minimum quality standards to be used for insemination and therewith dissemination of desirable characteristics. The aim of the current study was to characterize the testicular development of 218 pubertal Piétrain boars (Line 408, Pig Improvement Company) to identify traits with predictable characteristics relative to their sperm quality as an adult AI boar. Scrotum, testes and epididymis were examined ultrasonographically at day (d) 100 (on-test) and 170 (off-test) followed by a computer-assisted grayscale analysis (GSA). Over the test period, paired testicular volume increased 7.3-fold from 22.7 ± 10.8 cm³ to 166.6 ± 62.2 cm³. The right testis was significantly (P = 0.014) larger than the left one at the off-test. Based on the sperm quality (ejaculate volume, sperm concentration, total sperm number, morphologically abnormal sperm and total sperm motility at day 3 of semen storage), 82.11% (n = 179) of the boars were classified as "productive" boars. These boars had a significantly (P = 0.039) larger paired testicular volume than "non-productive" boars (45.9 ± 19.9 cm³vs. 38.5 ± 12.6 cm³) at the on-test. For the right testis at on-test, significant differences for the standard deviation of mean gray value (P = 0.022), area under the curve (P = 0.004) and mean gradient value (GRAD, P = 0.030) regarding the future sperm production capacity (SPC) were shown. At off-test, there was a significant difference for minimum gray value (MIN GV, P = 0.003) and mean gray value (P = 0.001) related to SPC. To find SPC related cut-off values for GSA data, a two segmental non-linear regression analysis was carried out indicating breakpoints for GRAD ≥12 and MIN GV ≥ 40 for boars with low SPC. Off-test boars with MIN GV ≥ 40 showed a 2.4 higher risk to display low SPC (Odds ratio = 2.4 [1.1, 5.4]; P = 0.024). The results may enable breeding companies to include new sperm quality associated traits in their boar testing and selection programs.

Antibacterial defense in bull and boar semen: A putative link to the microbiome and reproductive strategy?

Several domestic and wildlife species have been shown to possess antibacterial defenses in their ejaculate most probably in order to increase the fertilization success and protect against sexually transmitted pathogens. However, very little is known about the consequences and factors influencing the differences within and between species as far as ejaculate-associated immunity. In the present study, we have analyzed bacterial killing activity (BKA) against Escherichia (E.) coli and Staphylococcus (S.) aureus as well as lysozyme concentrations (LC) in seminal plasma from 60 Fleckvieh bulls. Further, sperm quality and its association with BKA and LC were determined. Twenty percent of the individuals displayed BKA against both bacteria, 78.3% against S. aureus only and 1.7% of the bulls did not indicate any BKA in seminal plasma. No bulls with seminal plasma BKA only against E. coli were identified; implying that 80.0% of the tested bulls had no ejaculate associated defense mechanisms against this gram-negative bacterial species in place. This is in striking contrast to results of Pietrain boars within our previous study, in which 42.8% of the 119 boars expressed an antibacterial activity against E. coli in seminal plasma, 10.9% amongst them with BKA against E. coli only. LC was higher in the bull group with BKA against both bacteria (1.2 ± 0.6 μg/mL) compared to the group with BKA against S. aureus only (0.7 ± 0.3 μg/mL), but - if calculated over all individuals - LC in bulls (0.8 ± 0.4 μg/mL) was lower compared to boars (2.4 ± 1.2 μg/mL). LC showed positive correlations to the age of the bulls and sperm quality as well as a negative relation to bacterial load in raw semen although the highest bacterial contamination was found in animals with seminal plasma BKA against both strains. We discuss the obtained results with regards to possible differences within the microbiome of female and male genital tracts and the reproductive strategies (vaginal vs. uterine depositors) in these two livestock species. Besides identifying the responsible molecules, future phylogenetically controlled comparative studies are needed for a better understanding of the evolution of species differences in ejaculate-associated antibacterial defenses.

Effects of an extension of the equilibration period up to 96 hours on the characteristics of cryopreserved bull semen

This study was designed to investigate the effects of an equilibration period up to 96 hours and three extenders (AndroMed, OPTIXcell, and Triladyl) on the quality of cryopreserved bull semen and to evaluate, whether an extension of the equilibration time to 72 hours does affect fertility in the field. One ejaculate of 17 bulls was collected and divided into three equal aliquots and diluted, respectively, with the three extenders. Each aliquot was again divided into five parts and equilibrated for 4, 24, 48, 72, and 96 hours before freezing in an automatic freezer. Sperm motility, plasma membrane and acrosome integrity (PMAI), and DNA fragmentation index (% DFI) were measured during equilibration. In addition to the parameters measured during equilibration, the percentage of viable sperm cells with high mitochondrial membrane potential (HMMP) was measured immediately after thawing, and after 3 hours of incubation at 37 °C. Sperm motility was assessed using CASA, and PMAI, HMMP, and % DFI were measured using flow cytometry. Equilibration time did affect all parameters before freezing (P < 0.01), and also the extender affected all parameters except HMMP (P < 0.05). After thawing, all parameters except HMMP immediately after thawing were influenced by the equilibration period (P < 0.001), whereas all parameters except % DFI immediately after thawing were influenced by the extender (P < 0.001). The changes of semen characteristics during 3 hours of incubation were also dependent on the equilibration time and the extender used in all parameters (P < 0.01). In the field study, semen of nine bulls was collected thrice weekly, processed using Triladyl egg yolk extender, and frozen in 0.25 mL straws with 15 × 10⁶ spermatozoa per straw. In total, the nonreturn rates on Day 90 after insemination (NRR90) of 263,816 inseminations in two periods were evaluated. Whereas semen collected on Mondays and Wednesdays was equilibrated for 24 hours in both periods, semen collected on Fridays was equilibrated for 4 hours in period one and equilibrated for 72 hours in period 2. No differences in NRR90 could be found (P > 0.05). In conclusion, extension of the equilibration time from 4 hours to 24-72 hours can improve motility and viability of cryopreserved semen after thawing. The extent of improvement in semen quality is dependent on the extender used. Prolongation of the equilibration period from 4 hours to 72 hours had no effect on fertility in the field.

Laktationsinzidenzen von Produktionskrankheiten bei Fleckviehkühen in sechs bayerischen Milchviehbetrieben

Ziel: Erfassung der Laktationsinzidenzen (LI) von Produktionskrankheiten (PK) bei Deutsch-Fleckvieh-Milchkühen und Charakterisierung der betriebsspezifischen Varianz. Material und Methode: Auf sechs bayerischen Milchviehbetrieben (Herdendurchschnittsleistung 2008: 7834 ± 708 kg [Mittelwert ± SD]; Boxenlaufställe; Voll- oder aufgewertete Teilmischration auf Basis von Gras- und Maissilage) wurden insgesamt 116 pluripare und 58 primipare Kühe täglich standardisiert über 14 Tage post partum klinisch untersucht und gegebenenfalls standardisiert therapiert. Die Erfassung von Erkrankungen im weiteren Laktationsverlauf erfolgte durch regelmäßige Betriebsbesuche sowie die Kommunikation mit Betriebsleiter und Hoftierarzt. Ergebnisse: Die LI der erfassten PK (hypokalzämische Gebärparese, Retentio secundinarum, Ketose, Labmagenverlagerung, Metritis, Endometritis, Ovarialzysten, Mastitis) lagen bei Pluripara deutlich höher als bei Primipara: 33,3% bzw. 46,4% aller pluri- bzw. primiparen Tiere blieben klinisch gesund, 24,8 bzw. 30,4% der Kühe erkrankten in den ersten zwei Laktationswochen an einer PK und 41,9 bzw. 23,2% der Tiere litten an mehr als einer PK. Die LI der PK variierten vor allem bei den Pluripara erheblich zwischen den Betrieben: Retentio secundinarum 16,8 ± 13,2%, hypokalzämische Gebärparese 15,1 ± 7,0%, klinische Ketose 16,8 ± 12,4%, Metritis 3,8 ± 3,1%, Labmagenverlagerung 1,1% (Median 0,0%; 0,0/0,0), Endometritis 11,7 ± 7,0%. An mindestens einer Mastitis erkrankten 56,0 ± 7,4% der pluriparen Kühe; im Durchschnitt erkrankten diese 1,7-mal an Mastitis. Mindestens eine Follikel-Theka-Zyste wurde bei 28,4 ± 8,6% der Kühe diagnostiziert. In den ersten beiden Laktationswochen zeigten 18,5 ± 13,5% der primi- und pluriparen Kühe eine Lahmheit. Schlussfolgerung: Die LI der PK differierten nicht signifikant von publizierten Daten für Holstein-Friesian-Kühe mit Ausnahme der selteneren Labmagenverlagerung bei Fleckvieh-Kühen. Die Resultate deuten darauf hin, dass das Betriebsmanagement wesentlich größeren Einfluss auf die Inzidenz der PK hat als andere Faktoren wie z. B. die Rasse der Milchkühe.

[Lactational incidences of production diseases in German Fleckvieh cows of six Bavarian dairy farms]

OBJECTIVE

The aim of this study was to assess lactation incidences of production diseases in German Fleckvieh cows.

MATERIAL AND METHODS

Investigations were carried out on six dairy farms (mean milk yield of herds 2008: 7834 ± 708kg milk [mean ± SD]) in Bavaria. All farms kept the cows in free stall barns and fed them a total or partial mixed ration based on grass silage and corn silage. In total, 116 cows and 58 heifers were examined daily for 14 days post partum and treated - if necessary - according to standard protocols. The acquisition of data for diseases in the further lactation was carried out by regular visits to the farm as well as communication with the herd manager and the farm veterinarian.

RESULTS

Pluriparous cows suffered more frequently from production diseases (milk fever, retained placenta, clinical ketosis, abomasal displacement, metritis, endometritis, ovarian cysts, mastitis) than primiparous heifers: 33.3% and 46.4% of pluriparous and primiparous cows, respectively, remained clinically healthy, while 24.8% and 30.4%, respectively, suffered from one production disease during the first 2 weeks of lactation; more than one production disease was diagnosed in 41.9% and 23.2% of pluriparous and primiparous cows, respectively. The lactation incidences of production diseases varied considerably among pluriparous cows of the six farms: retained placenta 16.8 ± 13.2%, milk fever 15.1 ± 7.0%, clinical ketosis 16.8 ± 12.4%, metritis 3.8 ± 3.1%, abomasal displacement 1.1% (median 0.0; 0.0/0.0%), endometritis 11.7 ± 7.0%. Mastitis affected 56.0 ± 7.4% of the pluriparous cows, which experienced 1.7 mastitis episodes on average. At least one follicular cyst was diagnosed among 28.4 ± 8.6% of the cows. Lameness affected 18.5 ± 13.5% of pluriparous cows and heifers during the first 2 weeks of lactation.

CONCLUSION

The lactation incidences of production diseases did not significantly differ from reference values reported for Holstein Friesian cows except the lower incidence of LDA among German Fleckvieh cows. The results indicate that the farm management affected lactation incidences of production diseases to a greater degree than additional factors, such as the breed of the cows.

Liposomes for cryopreservation of bovine sperm

In this study, the effect of various unilamellar liposomes on cryopreservation of bovine spermatozoa has been investigated. Liposomes were composed of saturated lipids with various acyl chain lengths: DSPC (18:0), DPPC (16:0), DMPC (14:0), or DLPC (12:0). Alternatively, liposomes were prepared using unsaturated egg phosphatidylcholine (EPC) or DOPC (18:1, neutral), alone or in combination with lipids with various head groups: DOPS (negatively charged), DOPG (negatively charged), and DOPE (neutral). Fourier transform infrared spectroscopy studies showed that bovine sperm membranes display a gradual phase transition from 10 to 24 (o)C. Phase transition temperatures of the liposomes varied from -20 to +53 (o)C. Sperm was incubated in the presence of liposomes for either 6 or 24 h at 4 °C prior to freezing. Postfreeze survival rates were determined based on the percentage of progressively motile cells as well as the percentage of acrosome- and plasma membrane-intact cells. With DOPC liposomes a postthaw progressive motility of 43% was obtained compared with 59% using standard egg yolk freezing extender. Postthaw progressive motility increased up to 52% using DOPC:DOPG (9:1) liposomes, whereas DOPC:DOPS or DOPC:DOPE liposomes did not increase survival compared with DOPC liposomes. Among the saturated lipids, only DMPC was found to increase cryosurvival, up to 44% based on progressive motility. DLPC liposomes caused a complete loss in cell viability, already prior to freezing, whereas DPPC and DSPC liposomes neither positively nor negatively affected cryosurvival. Taken together, the higher postthaw survival obtained with DOPC:DOPG liposomes as compared with DOPC liposomes can likely be attributed to increased liposome-sperm interactions between the charged phosphatidylglycerol groups and charged regions in the sperm membranes. Interestingly, the lipid phase state of the liposomes during preincubation is not the decisive factor for their cryoprotective action.

326 OPTIMIZING FREQUENCY OF FSH APPLICATION FOR SUPEROVULATORY TREATMENT IN CATTLE

The aim of the study was to examine the influence of the application frequency of Pluset® (Calier, Spain) and Folltropin® (Vetrepharm, London, Ontario, Canada) on the results of embryo recovery in Simmental cattle. Moreover, pulsatility of LH concentrations in plasma should be studied before and after application of Pluset. FSH was given in a treatment of eight or four injections on four consecutive days starting between Days 9 and 13 of the estrous cycle. Luteolysis was induced by application of 500 μg Estrumate® (Essex Tierarznei, Munich, Germany), applied 72 and 84 h after the first FSH injection. Embryo recovery was performed non-surgically on Day 7 of the following estrous cycle. Heifers received either a total amount of 500 IU Pluset according to the International Standard for human urine FSH and LH (P1: 8 injections, n = 20; P2: 4 injections, n = 54) or 200 mg Folltropin according to NIH bFSH-B1 (F1: 8 injections, n = 117; F2: 4 injections, n = 60). Cows received either 550 IU Pluset (P3: 8 injections, n = 54; P4: 4 injections, n = 183) or 260 mg Folltropin (F3: 8 injections, n = 36; F4: 4 injections, n = 159). Altogether 8 heifers were bled throughout 8 h every 10 min on Days 9 and 12 (before and during stimulation with FSH). The samples were analyzed for LH by ECLIA (intra-assay coefficient of variation (VK) 6.4%, inter-assay VK 8.9%). The evaluation of the data was carried out with the procedure ‘GLM’ of the statistics software package SAS (SAS Institute, Inc., Cary, NC, USA) and PULSAR analysis. As a post hoc test Student's t-test was used. Significance was set at P = 0.05. Results of embryo recovery are shown in the table. Number of LH pulses in 8 h (LSM ± SE) was 2.3 ± 0.4 on Day 9 and 0.6 ± 0.4 on Day 12 (P < 0.05). We conclude that four injections of both FSH products can lead to results comparable with those reached with eight injections in a 12 hours interval. Therefore, the effort for superovulatory treatments can be reduced. However, it has to be considered that the portion of transferable embryos was reduced, partly significantly, after four FSH injections. This result was independent of the drug used. Table 1. Results of embryo recovery

307CHARACTERIZATION OF PROTEIN PHOSPHORYLATIONS IN THE COURSE OF MEIOTIC MATURATION OF BOVINE OOCYTES

The importance of protein phosphorylations during meiotic maturation (transition from prophase I to metaphase II) of oocytes is documented by the fact that the inhibition of the M-phase kinases, cdc2k or MAPK, arrests the oocytes in the GV stage. A detailed knowledge of the targets of these kinases during this stage of development is still missing. Therefore, we have analyzed the proteome of bovine oocytes by high resolution 2D-gel electrophoresis to detect differences in the expression and phosphorylation state of proteins in the course of in vitro maturation (IVM). Bovine oocytes were matured for different times in TCM 199 containing 3% BSA and 300 oocytes each in GV stage (0-h maturation), in GVBD/M I (10-h maturation) or in M II stage (240h maturation) were separated on the gels. The proteins were visualized by staining them with silver or with the fluorescence dye Sypro Ruby, and phosphorylated proteins were detected by Western Blotting with Ser-, Thr-, or Tyr-phosphorylation specific antibodies or by staining with the phosphoprotein specific fluorescence dye Pro-Q Diamond. Gels made from oocytes at the above mentioned maturation stages were compared by a computerized gel-overlay software program (2D Decodon, Greitswald, Germany). The overall protein synthesis was statistically analysed by ANOVA (SigmaStat, Ekrath, Germany), pairwise multiple comparison procedure. Only distinct spots with a difference greater than 30% in their optical densities were considered to be differently expressed or phosphorylated. The results showed a three-fold increase in the rate of overall protein synthesis (p 0.05) during GVBD. Newly synthesized proteins were detected mainly in the higher molecular weight (MW) range (60–80kDa), and protein degradations were found mainly in the lower MW range (20–40kDa) after GVBD. Preliminary data obtained by analyzing the phosphorylation pattern showed that obviously no phosphorylated proteins could be detected in the GV-stage oocytes. Phosphorylation of different proteins was observed at the time of GVBD after 6 to 10h IVM, concomitantly with the activation of cdc2k and MAPK. A maximum of phosphorylated proteins was observed in metaphase II. The first results obtained by performing peptide mass fingerprinting using MALDI-Tof showed that members of the family of heat-shock proteins, ribosomal proteins and putative zinc finger proteins (transcription regulators) were differently expressed or phosphorylated during IVM. This work was supported by the DFG, To 178/1-1, 2 and by the Eibl-Stiftung.