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.

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.

Effect of antioxidant supplementation on semen quality and reactive oxygen species of frozen-thawed canine spermatozoa.

The objective of this study was to evaluate post-thaw quality of frozen dog semen processed with diluents containing different antioxidants. Ejaculates were collected, pooled and evaluated for concentration, motility, rapid steady forward movement (RSF movement), viability, acrosomal integrity and by the hypo-osmotic swelling test. Also, superoxide production, hydroxyl radicals and total reactive oxygen species (tROS) were determined. The pool was divided in seven aliquots, for control and test conditions, which were processed for cryopreservation. The sperm pellets were diluted to a final concentration of 200x10(6)sperm/ml with TRIS-glucose-egg yolk extender containing one of the following supplements: vitamin C (1.5mM), NAC (N-acetyl-l-cysteine; 1.5mM), taurine (0.6mM), catalase (300U/ml), vitamin E (0.3mM) and B16 [5-(4-dimethylamino-phenyl)-2-phenyl-penta-2,4-dienoic acid; 0.3mM]. Post-thaw semen evaluation showed that mean (+/-S.E.M.) motility was increased (p<0.001) after addition of catalase (49.75+/-3.63 versus 39.00+/-2.90 in controls), whereas more spermatozoa with RSF movement were observed (p<0.001) after the catalase, NAC and vitamin E treatments (31.75+/-3.46, 28.00+/-3.27, 26.75+/-3.15, respectively, versus 17.00+/-2.26 in controls). Viability was increased (p<0.001) after addition of catalase, taurine, NAC and tocopherol (66.00+/-3.03, 61.90+/-2.48, 60.60+/-1.93 and 60.50+/-4.12, respectively, versus 51.70+/-2.81 in controls). The percentage of swollen spermatozoa was increased after addition of catalase and taurine (61.75+/-1.61 and 61.25+/-1.49, respectively, versus 55.65+/-1.64 in controls). Acrosomal integrity was not influenced in any case. B16 addition had adverse effects on all parameters evaluated. None of the reactive oxygen species were significantly reduced post-thaw in antioxidant treated semen. The results suggest that catalase had the most pronounced effect in improving post-thaw quality of canine spermatozoa.

A prospective randomised evaluation of G-CSF or G-CSF plus oral antibiotics in chemotherapy-treated patients at high risk of developing febrile neutropenia.

BACKGROUND: Febrile neutropenia (FN) remains a major dose-limiting complication among patients treated with chemotherapy. Haematopoietic colony stimulating factors (G-CSF and GM-CSF) made possible a significant improvement in the management of FN, both in the therapeutic and in the prophylactic approach. The use of antibiotic prophylaxis also permits a definite reduction of severe infections during neutropenia. Nevertheless, the possible role of these two interventions for secondary prevention of FN is still unclear. PATIENTS AND METHODS: We conducted a prospective randomised trial by comparing the efficacy of granulocyte-colony stimulating factor (G-CSF) and the association of G-CSF with oral antibiotics in the secondary prevention of FN. We included in our study those patients who, after an episode of FN, continued to be treated with the same chemotherapy without reduction of dose intensity. They were randomised into two groups: the first received G-CSF (group G; filgrastim, 5 microg/kg day), and the second was treated with an association of G-CSF and amoxicillin/clavulanate plus ciprofloxacin (group G/ACC). RESULTS: Forty-eight patients were randomised (group G: n=23 and group G/ACC: n=25). There was no recurrence of FN among the patients receiving G-CSF and only one episode in the combined therapy group (p=1). With regard to the side effects, there was no significant difference in the two groups. CONCLUSION: The use of G-CSF for the secondary prevention of FN is extremely effective and allows the maintenance of chemotherapy dose intensity. Our study showed that the addition of antibiotics does not seem to be required.

The effects of the periodical use of in-feed chlortetracycline on the reproductive performance of gilts and sows of a commercial pig farm with a history of clinical and subclinical viral and bacterial infections.

The objective of this study was to assess the effects of in-feed chlortetracycline (CTC) as a measure of preventing or minimizing infectious problems of reproductive failure in gilts and sows. In a farm of 400 Large White x Landrace gilts and sows with a clinical history of porcine respiratory and reproductive syndrome (PRRS) virus, the animals were treated with CTC. Treatment consisted of 10 g CTC sow/day for 15 days every 3 months. It improved the health status of sows by decreasing post-farrowing clinical mastitis and vaginal discharges, abortions, return-to-oestrus and irregular return-to-oestrus rates. These beneficial effects had a positive impact on the performance of the litter. More piglets were born live and weaned. These positive effects improved with repeated use of CTC. The serological evidence of PRRS virus, Leptospira spp. and Chlamydia spp. and the subsequent beneficial use of the antimicrobial agent indicate that reproductive failure, possibly resulting from the bacterial agents can be controlled with in-feed use of broad spectrum antimicrobials.

A field study on the effect of in-feed inclusion of a natural zeolite (clinoptilolite) on health status and performance of sows/gilts and their litters.

The study was conducted to evaluate the effect of the long-term dietary use of a natural zeolite (clinoptilolite, NZ) on health status and reproductive performance of sows/gilts and performance of their litters, along with its compatibility with antibacterials (chlortetracycline, CTC) periodically used in medication programmes. Two hundred and forty sows/gilts and their litters were assigned to two main experimental groups and four subgroups, depending on the inclusion of NZ and CTC in their feed. During the trial, frequent sampling of pregnancy feed for mycotoxicological analysis revealed a high contamination level with zearalenone. No adverse or side effects attributed to NZ were noticed. Furthermore, the combined use of NZ and CTC revealed no clinically apparent interactive effect on the availability of the latter. Reproductive performance was significantly improved by the dietary inclusion of both NZ and CTC. The results also suggested that the beneficial effect of NZ could be additionally considered as an indicator of the amelioration of zearalenone exposure consequences.

Effect of in-feed inclusion of a natural zeolite (clinoptilolite) on certain vitamin, macro and trace element concentrations in the blood, liver and kidney tissues of sows.

The study was conducted to evaluate, under field conditions, the effect of the long-term dietary use of a natural zeolite (clinoptilolite, CLI) and antibacterials (chlortetracycline, CTC) on the concentrations of certain vitamins (vitamin A and vitamin E) and minerals (K, Na, P, Ca, Mg, Cu and Zn) in blood and body tissues of the sow. Twenty-four sows were assigned to two main experimental groups and four subgroups, depending on the presence or absence of CLI and CTC in their feed, respectively. CLI was provided to the sows from weaning, during the service, gestation and lactation periods and up to the date of the next service, while CTC was administered for a 2-week period post-service, as well as for a 2-week period following the allocation of the sows in the farrowing house, around 5 days prior to the expected parturition. Blood samples were collected on the starting day of the trial, on the 30th and the 90th day of each pregnancy, on the day of each parturition and on the day of each weaning. Furthermore, 20 sows were similarly distributed in the same experimental groups and subgroups and at the end of the trial they were slaughtered and liver and kidney samples were collected for biochemical analysis. Neither CLI nor CTC supplementation of the diets had any significant effect on vitamins' and minerals' uptake and their distribution in the body, since there was no alteration in their blood serum and liver/kidney concentrations. Furthermore, no CLI x CTC interaction was noticed.

The effect of salinomycin on health status and performance of sows and their litters: a dose titration study.

Two hundred and fifty gilts and sows (Dalland parent stock) were divided randomly and allocated into the following five experimental groups: SAL0 = negative controls, SAL20 = 20 mg salinomycin per kg of feed, SAL40 = 40 mg salinomycin per kg of feed, SAL60 = 60 mg salinomycin per kg of feed and SAL80 = 80 mg salinomycin per kg of feed. Each gilt and sow was allocated to one of the five groups after the confirmation of the pregnancy using the ultrasonic method and remained under treatment for two consecutive breeding cycles. Throughout the experimental period several parameters related to sow health status, performance and fertility, as well as to health status and performance of their litters were recorded and calculated. Results indicated that salinomycin improves most of the parameters examined, as it leads to significantly higher (P < 0.05): (i) sow body weight gain during gestation; (ii) number of piglets born alive and weaned; (iii) piglet body weight at birth and at weaning, as well as to significantly lower (P < 0.05): (i) prevalence of thin sow syndrome at weaning; (ii) sow body weight loss during lactation; (iii) weaning-to-oestrus interval; (iv) piglet diarrhoea score during lactation; and (v) preweaning mortality. The best results were obtained at the inclusion levels of 40 and 60 mg salinomycin per kg of feed.