Effect of astaxanthin in extenders on sperm quality and functional variables of frozen-thawed boar semen.

The aim of the study was to determine whether the presence of astaxanthin (ASX) protects boar spermatozoa against damage related to cryopreservation. Pooled ejaculates extended in Beltsville Thawing Solution (BTS) were used. Three experiments were conducted: 1) sperm samples were pre-incubated overnight (17 °C) with ASX (0, 0.5, 5, 15 µM) prior to freezing and then frozen using cooling and thawing extenders supplemented with ASX (0, 0.5, 5, 15 µM); 2) sperm samples were treated with ASX (0, 0.5, 5, 15 µM) only during overnight pre-incubation (17 °C) prior to cryopreservation; and 3) a thawing extender was supplemented with ASX (0, 0.5, 5, 15 µM). The groups were as follows: control (C; no treatment), ASX 1 (0.5 µM), ASX 2 (5 µM) and ASX 3 (15 µM). Total (TM) and progressive (PM) motility was analyzed using CASA, while sperm viability, reactive oxygen species generation, lipid peroxidation and apoptoticlike changes were analyzed using flow cytometry. Sperm variables were evaluated prior to freezing as well as 30 and 150 min after thawing. In Experiment 1, the values of TM and sperm viability post-thaw were less in the ASX 3 than C group. In Experiment 2, there was no effect of ASX on any of the sperm variables evaluated, while in Experiment 3, apoptotic-like changes were less in the ASX 1 than C group. In conclusion, there was a subtle beneficial effect on cryopreserved boar spermatozoa after addition of ASX to thawing media.

Effect of astaxanthin on the quality of boar sperm stored at 17°C, incubated at 37°C or under in vitro conditions.

The aim of the study was to investigate the effect of the antioxidant astaxanthin on boar semen. Twenty ejaculates from 10 boars (two ejaculates/boar) were extended and split in three groups: semen control (SC), solvent control (C; semen with dimethyl sulfoxide, the diluent of astaxanthin) and semen with astaxanthin (A) in concentration 0.5 µmol/L. Sperm quality parameters (motility and kinetics, morphology, viability, functional integrity of sperm plasma membrane by Hypo-Osmotic Swelling Test [HOST] and DNA integrity) were assessed at 0, 24 and 48 hr of storage at 17°C (experiment I), before (0 hr) and after (1 hr) of sperm thermal resistance assay at 37°C (experiment II) and finally before (0 hr) and after (1 hr) sperm in vitro incubation (38.5°C, 5% CO2 , maximum humidity [experiment III]). In experiment I, group A performed overall better than group SC and as a tendency better than group C regarding viability. Total motility, rapid spermatozoa and HOST remained constant across time in group A, whereas they decreased in the remaining groups. In experiment II, regarding motility and viability, group A displayed better results across time than the other two groups. In experiment III, viability and total motility decreased in groups SC and C, while in group A, these parameters were not significantly different between the examination time points. In conclusion, astaxanthin has a beneficial and protective effect on boar semen quality under the investigated conditions.

Selected steps of swine ICSI method to overcome seasonal effect and achieve acceptable early embryonic development, a preliminary study.

Porcine intra cytoplasmic sperm injection's (ICSI) efficacy by selected protocol steps was investigated. Three trials per year's period (hot, medium, cold) were carried out. Only large size follicles (6-8mm) were aspirated, brilliant cresyl blue (BCB) test was performed and only the BCB+ oocytes were in vitro maturated (40h) and involved to ICSI process. The presumptive embryos were in vitro cultured (15h). Raw boar semen and SpermCatch® as slowing medium were used. No differences were observed between periods regarding early embryonic development and maturation competence. ICSI achieves acceptable porcine early embryonic development rates under the investigated conditions.

Dietary omega-3 polyunsaturated fatty acids induce plasminogen activator activity and DNA damage in rabbit spermatozoa.

The aim of this study was to determine the effect(s) of dietary omega-3 polyunsaturated fatty acids (ω-3 PUFA) on rabbit semen. Adult rabbit bucks were assigned to two groups that were given two diets, a standard diet (control) and a diet supplemented with ω-3 PUFA. Sperm samples were collected from all bucks with the use of an artificial vagina in 20-day intervals, for a total period of 120 days. The enrichment of membranes in ω-3 PUFA was manifested by the elevation of the 22:5 ω-3 (docosapentaenoic acid [DPA]) levels within 40 days. This increase in DPA content did not affect semen characteristics (i.e., concentration, motility and viability). However, it was associated with the induction of lipid peroxidation in spermatozoa, as determined on the basis of the malondialdehyde content. Lipid peroxidation was associated with DNA fragmentation in ω-3 PUFA-enriched spermatozoa and a concomitant increase in plasminogen activator (PA) activity. The effects of ω-3 PUFA on sperm cells were evident within 40 days of ω-3 PUFA dietary intake and exhibited peack values on day 120. Our findings suggest that an ω-3 PUFA-rich diet may not affect semen characteristics; however, it may have a negative impact on the oxidative status and DNA integrity of the spermatozoa, which was associated with an induction of PAs activity.

Breed differences of bull frozen-thawed semen.

The objective of this study was to investigate the quality of frozen-thawed semen from different bull breeds. Commercial frozen-thawed bull semen samples (26 per breed, 130 totally) of five breeds (Holstein [Η], Brown Swiss [BS], Limousin [L], Belgian Blue [BB], Blonde d' Aquitaine [BA]) were used. After thawing, each semen sample was subjected to thermal resistance test (TR) for 0.5 and 1 hr at 38°C and hypo-osmotic swelling test (HOST) for 1 hr at 150 mOsm at 37°C. Additionally, all samples were evaluated at times 0 hr (thawing), 0.5 hr (TR), 1 hr (TR) for kinetics by CASA [progressive, immotile, rapid, medium, slow moving spermatozoa, curvilinear velocity (VCL), average path velocity (VAP), straight line velocity (VSL), linearity (LIN), straightness (STR), beat cross-frequency (BCF), amplitude of lateral head displacement (ALH), wobble (WOB)]. Moreover, directly after thawing, all semen samples were evaluated for morphometry, morphology, viability and DNA fragmentation. Statistical analysis was conducted using a mixed model for repeated measures. The results showed (a) higher VCL after thawing in H, L breeds compared to BB and BA, (b) higher VAP after thawing in L compared to BB, BA, (c) higher values of progressive spermatozoa after TR in H, BS compared to BB, BA, (d) higher values of rapid spermatozoa after thawing and 0.5 hr of TR in H, BS, L compared to BB, BA, (e) lower viability in BA after thawing compared to H, BS, BB, (f) lower morphological abnormalities in H compared to L, BB, (g) higher head length in Η compared to BB. No significant differences were observed in the results from HOST and DNA fragmentation between breeds. In conclusion, quality characteristics of frozen-thawed bull semen are dependent on the breed. Frozen semen from BB and BA breeds should be handled more carefully after thawing, as it is more sensitive to stress.

Chromatin integrity of ram spermatozoa. Relationships to annual fluctuations of scrotal surface temperature and temperature-humidity index.

The objective of the present study was to explore the potential relationships of ovine sperm chromatin integrity, quantified using the sperm chromatin structure assay (SCSA), to the heat load of the scrotum and the discomfort felt by the animals because of fluctuations of microclimatic factors at different time periods before ejaculation. Ejaculates were collected once per week from five Chios rams and four East Friesian rams for 12 months and stored in liquid nitrogen. Frozen-thawed semen samples were analyzed using the SCSA, to determine the DNA fragmentation index (DFI) and the percentage of cells outside the main sperm population (%DFI) in each one of the samples. Scrotal surface temperature (SST) of each ram was measured using an infrared thermometer on a daily basis. Ambient air temperature and relative humidity were recorded at hourly intervals throughout the experimental period and temperature-humidity index (THI) was used to assess the discomfort felt by the rams. Mean values of SST (SST mean) and THI (THI mean) were computed for eight different time periods (up to 61 days) preceding each ejaculation day (Day 0). A linear mixed-effect model analysis was performed to describe the relation of SCSA parameters to collection month, SST mean, and THI mean of different time periods before ejaculation. The results of the statistical analysis revealed a relation of %DFI to the SST mean of the last 12 days preceding ejaculation, namely the period that resembled the phase of epididymal maturation. On the contrary, the variation of DFI was most adequately described by the linear mixed-effect model applied for Days 54 to 48 before ejaculation, which resembled the phase of spermatogonial mitoses. The effect of collection month was significant for DFI and %DFI, with semen samples collected in September and February exhibiting the lowest DFI values; a less profound seasonal pattern was detected for %DFI. The effect of THI mean on DFI and %DFI was proven nonsignificant in regard to all time periods. In conclusion, a relation of SCSA parameters to SST mean of different periods before ejaculation was shown in the present study, implying an effect of scrotal microenvironment on intratesticular and epididymal sperm population. In contrast, we failed to detect any effect of microclimate-induced discomfort felt by the animals on the chromatin integrity of frozen-thawed ram spermatozoa.

Histological features in the mammary glands of female dogs throughout lactation.

The objective of this study was to describe the histology of the mammary glands of female dogs throughout lactation. Twelve lactating female dogs were operated 4, 7, 10, 14, 21, 28, 35, 42, 56, 70 and 84 days post-partum; four mammary glands of each animal were excised for histological, ultrastructural and morphometric examination. During early lactation and mid-lactation, all lobes and lobules within the same gland had similar features; alveoli were well developed and distended and had a spherical to slightly ovoid structure, with muscular fibres grasping them around; inflammatory cells were seen in the inter- and intra-alveolar space; mammary lobules were separated with a scant amount of connective tissue. In late lactation, connective tissue was abundant and dense, with large numbers of inflammatory cells; alveoli appeared to be irregularly shaped and collapsing, shrunken or fully collapsed. Number of alveoli per lobule and number of epithelial cells per alveolus, as well as diameter of alveoli and height of epithelial cells decreased as lactation progressed. The third mammary glands (from caudal to cranial) had a significantly smaller number of alveoli, but not of epithelial cells per alveolus, than each of the two mammary glands caudally to that. The results suggest that progressive involution of the normal mammary gland starts around the end of the 2nd month of lactation and continues until the end of the 3rd month.

Effect of N-acetyl-L-cysteine supplementation in semen extenders on semen quality and reactive oxygen species of chilled canine spermatozoa.

The objective of this study was to evaluate the quality of chilled dog semen processed with extenders containing various concentrations of N-acetyl-L-cysteine (NAC). Ejaculates from five dogs were collected, pooled and evaluated for concentration, motility, rapid steady forward movement (RSF-movement), viability, acrosomal integrity and by the hypo-osmotic swelling test (HOST). In addition, superoxide anion (O(2)(-*)) production, hydroxyl radicals (OH(*)) and total reactive oxygen species (tROS) were determined. The pool was divided into five aliquots, which were diluted to a final concentration of 66.66 x 10(6) spermatozoa/ml with Tris-glucose-egg yolk extender containing one of the following concentrations of NAC (0, 0.5, 1, 2.5 or 5 mm). The semen aliquots were chilled and preserved at 4 degrees C. Semen quality was evaluated after rewarming at 72 h. Sperm motility was significantly higher with the 0.5 mm concentration compared with the control group (p = 0.001). Rapid steady forward movement was higher with the 0.5 and 1 mm concentrations compared with the control and 5 mm group (p < 0.001). Viability and HOST percentages were not significantly altered. Compared with the control, the 5 mm concentration showed significantly reduced percentages of spermatozoa with normal acrosomes (p = 0.049). None of the ROS values at 72 h were significantly affected by the presence of NAC in semen extenders, although all NAC concentrations showed lower O(2)(-*) and OH(*) values compared with the control. Only the concentrations of 1 and 5 mm inhibited the significant increase of tROS values after 72 h, compared with the fresh semen value. In conclusion, NAC supplementation of semen extenders is beneficial to semen motility of canine spermatozoa during chilling with the 0.5 mm concentration being the most effective, although no significant ROS inhibition was observed at 72 h.

The induction of lymphoid follicle-like structures in the ovine teat duct following experimental infection with Mannheimia haemolytica.

The objectives of this study were to investigate the early stages of experimental infection of the ovine mammary gland with Mannheimia haemolytica and to identify the lymphocyte subsets accumulating at the teat duct. M. haemolytica was inoculated into one teat of each of 25 ewes and clinical, bacteriological, cytological, haematological, physicochemical, gross pathological, histopathological and immunohistochemical examinations were carried out. Clinical signs of inflammation were evident by 8 h but had subsided 2 days after challenge. Polymorphonuclear neutrophils (PMN) predominated in milk films up to 1 day following challenge, but the proportion of lymphocytes and macrophages progressively increased thereafter. Total blood leucocyte counts decreased immediately after challenge and then rose until 1 day after challenge with immature PMNs comprising >3% of the total. The pH of the mammary secretions from the challenged side was increased (>7.0). Focal lymphoid accumulations were observed in the lamina propria at the junction of the teat duct and cistern, including CD79(+), CD3(+) and gammadelta T cells, CD68(+) and MHC-II(+) cells with a particular increase in the numbers of CD8(+) T cells from days 3 to 5 after challenge. The findings suggest that these organised lymphoid structures are inducible and contribute to the defence of the infected teat when the PMN-macrophage response is overwhelmed.

Post-partum involution of the canine uterus - gross anatomical and histological features.

We aimed to study the normal puerperium in the bitch. Ovariohysterectomy was performed in nine bitches, each at a different day after normal whelping; their genital tract was subject to gross anatomical examination, as well as to histological examination and electron microscopy scanning. Corpora albicans were evenly distributed in the left and right ovaries and placental sites were evenly distributed among left and right uterine horns. Placental sites were initially of dark green to grey colour, later becoming dark brown; their length and height progressively decreased. Height of the myometrium and diameter of the uterine glands progressively decreased. Trophoblast-like cells were consistently observed at the placental sites and on the surface of the interplacental areas, at all time points where hysterectomy had been performed. It is suggested that involution of the canine genital tract can last up to 3 months and is slow. Continuous (up to D84 post-partum) presence of prominent placental sites should be considered a normal feature of canine uterine post-partum involution.

Effect of antioxidant supplementation in semen extenders on semen quality and reactive oxygen species of chilled canine spermatozoa.

The objective of this study was to evaluate quality of chilled dog semen processed with extenders containing various antioxidants. Single ejaculates from five dogs were always pooled and evaluated for concentration, sperm motility, progressive motility (RSF-movement), viability, acrosomal integrity and by the hypo-osmotic swelling (HOS)-test. Also, superoxide (O(2)(-)) production, hydroxyl radicals (OH) and total reactive oxygen species (tROS) were determined. Pooled semen was divided in seven aliquots (for control and test conditions), which were diluted to a final concentration of 67x10(6)spermatozoa/ml with TRIS-glucose-egg yolk extender with or without the following supplements: control (without antioxidants), vitamin C (0.5mM), N-acetyl-l-cysteine (NAC; 0.5mM), taurine (0.2mM), catalase (100u/ml), vitamin E (0.1mM) and 5-(4-dimethylamino-phenyl)-2-phenyl-penta-2,4-dienoic acid (B16; 0.1mM). The semen aliquots were chilled and preserved at 4 degrees C. Portions of chilled semen were removed at 24 and 72h, and semen quality was evaluated after rewarming. At 24h the mean (+/-S.E.M.) sperm motility was higher (p<0.001) when vitamin E, taurine and B16 were added in the extender, whereas more spermatozoa with RSF-movement were observed (p<0.001) in the vitamin E, catalase, B16 and taurine groups. Sperm viability was higher (p=0.040) in B16 and vitamin E groups and the percentage of swollen spermatozoa was higher (p=0.002) only in the B16 group. Acrosomal integrity and OH were not significantly influenced by any of the antioxidants tested. Superoxide production was significantly lower when vitamin C, B16 and vitamin E were added in semen extenders compared with the control (p=0.017). All antioxidant groups, except vitamin C and NAC, contained less tROS compared to the control group, but only the B16 group value differed significantly (p=0.05). At 72h sperm motility was higher (p<0.001) when vitamin E, catalase, B16, taurine and NAC were added in the extender. More spermatozoa with RSF-movement were observed (p<0.001) in the vitamin E, catalase, B16, taurine and NAC treatment groups. Sperm viability was higher (p=0.001) when vitamin E, B16, taurine and vitamin C were added in semen extenders. HOS-test percentages were higher (p=0.016) in the B16, vitamin E, catalase and NAC groups. Acrosomal integrity was not influenced in any case. Production of O(2)(-) was significantly higher using catalase compared to all the other groups (p=0.006), while OH was not significantly influenced by any of the antioxidants tested. The addition of vitamin E, catalase and B16 in semen extenders resulted in significantly lower tROS values compared with the controls (p<0.0005). The results suggest that vitamin E and B16 had the most pronounced effect in preserving semen quality of chilled dog spermatozoa.

Quality and reactive oxygen species of extended canine semen after vitamin C supplementation.

The objective of this study was to evaluate the quality of extended dog semen processed with diluents containing various concentrations of vitamin C. Ejaculates from five dogs were collected, pooled and evaluated for concentration, sperm motility, rapid steady forward movement (RSF-movement), viability, acrosomal integrity and by the hypo-osmotic swelling test. Also, superoxide (O(2)(-)*) production, hydroxyl radicals (OH*) and total reactive oxygen species (tROS) were determined. The pool was divided in five aliquots, which were diluted to a final concentration of 66 x 10(6) spermatozoa/ml with a Tris-glucose-egg yolk extender containing one of the following concentrations of vitamin C (0, 0.1, 0.5, 1 or 2.5 mM). The semen aliquots were chilled and preserved at 4 degrees C. Portions of chilled semen were removed at 24 and 72 h, and semen quality was evaluated after rewarming. This process was repeated 10 times in pooled semen of the same origin and data were analysed by one-way analysis of variance. At both times, none of the semen quality parameters were positively influenced (p>0.05) by vitamin C supplementation. At 24 h, none of the reactive oxygen species (O(2)(-)*, OH*, tROS) were significantly altered. At 72 h, significant reductions of O(2)(-)* production were observed by the concentrations of 0.1, 0.5 and 2.5 mM compared with the 0 mM concentration (p=0.049). Also, at 72 h, the 2.5 mM concentration showed significantly lower OH* values in comparison with the control group (p=0.048). In conclusion, addition of vitamin C to semen extenders does not benefit the quality of canine extended spermatozoa.

Efficiency assessment of a swift method to enhance substandard viability ram ejaculates.

Semen availability in ram semen processing facilities is of great importance for the genetic improvement of sheep. Accordingly, any method that would increase sperm viability in low viability ejaculates could be useful. In this study, the possibility of a glass beads filtration method by estimating the beads total surface provided (TSP) for adhesion of spermatozoa, was evaluated. Initially, two different TSP (102 and 154 cm(2)) achieved by various sizes of beads (1500, 2000 and 3000 microm) were tested and no significant difference in sperm viability improvement was noticed for the same TSP by different beads (p > 0.05). Next optimization tests were performed in which three different funnels were used for filtration at a standard TSP (154 cm(2)). The pear-shaped funnel was found to be the most appropriate for filtration, as semen volume recovery and sperm viability improvement were more pronounced (p < 0.05). Finally, filtration tests were conducted with pear-shaped funnels with different TSP (102 and 154 cm(2)) obtained by the aforementioned beads sizes (1500, 2000 and 3000 microm) in equal aliquots. Total surface provided of 102 cm(2) proved to be the more appropriate for filtration than 154 cm(2), as shown by the significant improvement of sperm viability (p < 0.01) and the significantly higher filtrate semen volume (p < 0.05). In conclusion, ram sperm viability improvement by more than 20% of its initial value and semen volume recovery by more than 60%, along with the fact that the total filtration time did not exceed 6 min in any case, suggest that through further development this method could be successfully used during ram semen processing.

Teat lesions predispose to invasion of the ovine mammary gland by Mannheimia haemolytica.

Teat lesions, produced in ewes by an experimental chapping procedure, were found to facilitate experimental infection with Mannheimia haemolytica, as assessed by observations on infection of the teat skin, teat duct and mammary gland, and on the production of mastitis. The origin of the M. haemolytica strain used (ovine tonsillar or mammary infection) did not appear to influence the results. In a second experiment, in which ewes continued to suckle their lambs but were not deliberately infected, chapping was shown to favour infection by Staphylococcus epidermidis, Staphylococcus aureus and M. haemolytica.

Effect of norgestomet treatment on plasminogen activator activity in the cervical mucus and the endometrium in dairy cows.

The aim of this study was to determine the effect of norgestomet treatment, in the absence or the presence of a functional corpus luteum (CL), on plasminogen activators activity (PAA) in the cervical mucus and the endometrium in dairy cows. Eleven days after oestrus (Day 0 = oestrus), 38 cows were randomly assigned to one untreated control group (n = 9) and three treatment groups (S(1), S(2) and S(3)). Animals of S(1) group (n = 9) received an implantation of norgestomet on the outer surface of the ear for 8 days, simultaneous injection of oestradiol valerate 5 mg and norgestomet 3 mg, i.m., and on Day 19 an injection of ECG 500 IU, i.m. Animals of S(2) group (n = 11) received the treatment of S(1) group, plus an administration of PGF(2)alpha on Day 10 for the regression of CL. Animals of S(3) group received the treatment of S(2) group, plus two additional norgestomet implants inserted on Day 16 for 36 h. Both types of plasminogen activators [the tissue-type (t-PA) and the urokinase-type (u-PA)] were detected in the cervical mucus and the endometrium of the cows. Plasminogen activators activity in the cervical mucus was higher in control group than in S(1), S(2) and S(3) groups (P < 0.001). In contrast, endometrial PAA did not differ among groups (P > 0.05). Oestradiol-17beta concentrations on Day 21 were higher in S(2) group than in control group (P < 0.01) and S(3) group (P < 0.05). Progesterone concentrations did not differ among groups (P > 0.05). Oestradiol-17beta concentrations could positively affect cervical mucus PAA in control group (P < 0.1), but not in other groups (P > 0.05). These findings suggest that control of estrous cycle by norgestomet administration, in dairy cows, exerts a suppressive effect on plasminogen activators synthesis and/or secretion in the cervical mucus, regardless of the absence or the presence of the CL. On the contrary, endometrial PAA is not affected by norgestomet treatment.

Experimental staphylococcal mastitis in bitches: clinical, bacteriological, cytological, haematological and pathological features.

The objectives of the work were to study the features of experimentally induced canine mastitis and to present hypotheses regarding the pathogenesis of the disease. The right caudal abdominal mammary gland of six bitches was inoculated on day 8 after whelping with Staphylococcus intermedius to induce mastitis; adjacent mammary glands were used as controls. Clinical examination, bacteriological and cytological (whiteside test, Giemsa) examination of mammary secretion, as well as haematological tests were performed from 5 days before until 34 days after challenge. Mastectomy was sequentially performed 1, 2, 4, 18, 26 and 34 days after challenge in each of the bitches, in order to carry out a pathological examination of mammary glands. All animals developed clinical mastitis: challenged glands became painful, hot, enlarged and oedematous; secretion was brownish, purulent, with flakes or clots, subsequently becoming yellowish and thick. Staphylococci were isolated from all inoculated glands (up to 22 days). WST was positive in 41/46 samples from inoculated glands and 66/138 samples from control glands; neutrophils predominated during the acute stage. Blood leukocyte counts increased, whilst platelet counts decreased. Gross pathological findings initially included congestion, purulent discharge and subcutaneous oedema; then abscesses, brownish areas and size decrease were seen. Salient histopathological features were initially neutrophilic infiltration, haemorrhages, destruction of mammary epithelial cells and alveoli, and then infiltration by lymphocytes, shrunken alveoli, loss of glandular architecture and fibrous tissue proliferation. We conclude that in bitches, intrammamary inoculation of Staphylococcus intermedius can induce clinical mastitis, followed by subclinical disease. The disorder is characterized by bacterial isolation and leukocyte influx in challenged glands, by leukocyte presence in adjacent mammary glands, by increased blood leukocyte counts and by destruction of mammary parenchyma.

Study on the in vitro effect of zearalenone and alpha-zearalenol on boar sperm-zona pellucida interaction by hemizona assay application.

The mycotoxin zearalenone (zen) impairs fertility in farm animals. The aim of the present study was to investigate the effect of zearalenone and its major metabolite (alpha-zearalenol) on boar semen binding capacity, under in vitro conditions. Extended boar semen was exposed to three different concentrations of zen and alpha-zen (40, 60 and 80 microg ml(-1) of semen) for 1 h. Afterwards, the semen was washed and incubated with homologous oocyte hemizona for 4 h. A significant decrease (P < 0.001) in the number of tightly attached spermatozoa on the hemizona was obtained at concentrations of 60 microg ml(-1) and 80 microg ml(-1) of zen and alpha-zen. In conclusion, zen and alpha-zen affected the sperm-zona interaction by reducing the ability of boar spermatozoa to bind to the zona pellucida.

In vitro effect of zearalenone and alpha-zearalenol on boar sperm characteristics and acrosome reaction.

This study was conducted to determine the in vitro effects of three different concentrations (125, 187.5 and 250 microM in diluted semen) of zearalenone (zen) and alpha-zearalenol (alpha-zen) on boar sperm. Semen parameters such as motility, viability and spontaneous acrosome reaction were evaluated. From the results it was shown that both zen and alpha-zen affected the sperm characteristics significantly (p < 0.05), except for alpha-zen at the low concentration which did not decrease the percentage of live reacted spermatozoa significantly. In conclusion, zen and alpha-zen are directly toxic when they affect boar semen in vitro and consequently decrease the fertilization ability of the sperm. The higher the concentration of mycotoxin tested, the greater the decline of sperm parameters noticed. The influence of mycotoxins was found to be time- and dose-dependent.

Effect of kappa-casein and beta-lactoglobulin loci on milk production traits and reproductive performance of Holstein cows.

The effects of kappa-casein (kappa-CN) and beta-lactoglobulin (beta-LG) loci on milk production traits (milk, fat, protein, and lactose yield, fat, protein, and lactose content) and reproductive performance (gestation length, calving interval, age at first and second calving, number of services per conception) was estimated for 278 Holstein cows in the first 2 lactations. Genotypes of kappa-CN and beta-LG were determined by alkaline and acidic polyacrylamide gel electrophoresis. Milk production was recorded daily. Single-trait, mixed, linear models were used for the statistical analysis of the data. Results indicated that kappa-CN genotypes affected significantly protein yield and content (genotype AB > genotype AA). A tendency for increased milk and fat yield of animals having AB kappa-CN genotype was also found. Fat content and lactose yield and content were not affected. In the beta-LG system, significant differences were detected for milk yield (AB > AA), fat yield (BB and AB > AA), fat content (BB > AA and AB), and lactose yield (AB > AA). A tendency for higher protein yield was also observed (AB > AA). The beta-LG locus had no significant effect on protein and lactose content. No associations between polymorphisms at the kappa-CN locus and reproductive performance were found. There was a tendency, however, for cows with AB genotype to have older age at first and second calving. In the beta-LG system, cows with AA genotype had significantly shorter gestation length than did those with AB or BB genotype. No differences were detected between beta-LG polymorphisms for the other reproductive traits.

Involvement of the plasminogen activation system in cow endometritis.

The objectives of this study were to investigate the: (a) presence and activity of components of the "plasminogen activators/plasmin" system in dairy cows with or without endometritis; (b) variations in enzyme activity according to the degree of endometritis; and (c) associations between these enzymes and changes in endometrial histology after intrauterine antibiotic treatment. Endometrial biopsies were collected from anestrus (no palpable ovarian structures and milk progesterone <1 ng/ml) Holstein cows, 30-40 days postpartum. On the basis of a vaginoscopic examination, rectal palpation of the cervix and uterus, and endometrial histology, there were 92 cows with endometritis and 20 cows without endometritis. After biopsy collection, each cow was given an intrauterine infusion of 1.5x10(6) IU of procaine penicillin G. In cows with endometritis, genital tract examinations and biopsies were repeated 2 weeks later. Both plasminogen activators (PAs), tissue type (t-PA) and urokinase (u-PA), were immunologically identified in all uterine biopsies. Plasminogen activator activity (PAA) increased, whereas plasminogen activator inhibition (PAI) and plasmin inhibition (PI) decreased in proportion to the degree of inflammation. Two weeks after intrauterine treatment, PAA had decreased significantly in all cows that had reduced severity of endometrial inflammation and had increased significantly in all cows with increased severity of inflammation. The change in the degree of inflammation depended upon plasminogen activator activity; cows with higher PAA were more likely to improve. In conclusion, there was evidence for a role of the plasminogen activation proteolytic system in bovine endometritis.