Absence of detectable fumonisins in the milk of cows fed Fusarium proliferatun (Matsushima) Nirenberg culture material

Fumonisins, a group of mycotoxins produced by the ubiquitous fungi Fusarium moniliforme and F. proliferatum, were first identified about eight years ago. They have been shown to cause a variety of health effects in animals, including epidemiological evidence of esophageal cancer in humans. Cattle are less sensitive to ill effects than horses and swine. Fumonisins are common contaminants of low quality grain fed to cattle. Culture material containing fumonisins (FB1, FB2, and FB3) was mixed into the total diet and fed for 14 days to two midlactation Jersey cows to determine if fumonisins are excreted in milk. The dietary equivalent of fumonisin was approximately 75 ppm and the two cows consumed an average of 3 mg fumonisin Bl /kg body weight (b wt)/day. Fumonisins were not detected in any of the milk samples by two analytical laboratories using methods with a sensitivity of 5 ng/ml. Except for transient diarrhea at the beginning of the contaminant feeding period and an increase in serum cholesterol, clinical and hematologie changes were not observed in the animals. The appearance or carry over of fumonisins from feed to milk in dairy cows does not appear to be significant and likely not a hazard or food safety concern for humans.     

Nickel deficiency diminishes sperm quantity and movement in rats

Early studies on nickel essentiality with rats and goats indicated that nickel deprivation impaired reproductive performance. Nickel also has been found to influence cyclic nucleotide gated channels (CNG); these types of channels are important in sperm physiology. Thus, two experiments were conducted to test the hypothesis that nickel deficiency affects sperm physiology in a manner consistent with nickel having an essential function related to CNG channel functions. The experiments were factorially arranged with four treatment groups of eight weanling rats in each. In experiment 1, the treatments were supplemental dietary nickel of 0 and 1 mg/kg and N ^ω -nitro-l-arginine methyl ester (l-NAME, a nitric oxide synthase inhibitor) added to the drinking water (50 mg/100 mL) the last 3 wk of an 8-wk experiment. In experment 2, the treatments were supplemental dietary nickel at 0 and 1 mg/kg and supplemental dietary sodium chloride (NaCl) at 0 and 80 g/kg. The NaCl and l-NAME variables were included to act as stressors affecting CNG channel activity. The basal diet contained per kilogram about 27 μg of nickel and 1 g of sodium. After 8 wk in experiment 1 and 16 wk in experiment 2, urine while fasting and testes and epididymis in both experiments, and seminal vesicles and prostates in experiment 2 were harvested for analysis. Nickel deprivation significantly decreased spermatozoa motility and density in the epididymides, epididymal transit time of spermatozoa, and testes sperm production rate. Nickel deficiency also significantly decreased the weights of the seminal vesicles and prostate glands. Excessive NaCl had no effect on sperm physiology; however, it decreased prostate gland weights. The findings support the hypothesis that nickel has an essential function that possibly could affect reproductive performance in higher animals, perhaps through affecting a CNG channel function. Part of the data was presented at the Experimental Biology 2001 Meeting, Orlando, FL, March 31–April 4, 2001. (F. H. Nielsen, E. O. Uthus and K. Yokoi, Dietary nickel deprivation decreases sperm motility and evokes hypertension in rats, FASEB J. 15, A972 (2001), and K. Yokoi, E. O. Uthus and F. H. Nielsen, Nickel deficiency induces renal damages and hypertension in rats which is augmented by sodium chloride, FASEB J. 15, A973 (2001). The US Department of Agriculture, Agricultural Research Service, Northern Plains Area, is an equal opportunity/affirmative action employer and all agency services are available without discrimination. Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the US Department of Agriculture and does not imply its approval to the exclusion of the products that may also be suitable.     

HPLC determination of fumonisin mycotoxins in maize: a comparative study of naphthalene-2,3-dicarboxaldehyde and o-phthaldialdehyde derivatization reagents for fluorescence and diode array detection

Fumonisins are mycotoxins produced by various species of Fusarium and occur naturally in contaminated maize and maize-based foods. Ingestion of fumonisins has considerable health implications for humans and animals. Since fumonisins lack a useful chromophore or fluorophore, their determination in maize is routinely achieved via HPLC with fluorescence detection (FLD) after precolumn derivatization. This study optimized naphthalene-2,3-dicarboxaldehyde (NDA) derivatization of fumonisins in naturally contaminated maize following strong anion exchange (SAX) solid phase extraction (SPE) clean-up and utilizing diode array detection (DAD) as a practical alternative simultaneously to FLD. The limit of detection (LOD) for fumonisin B(1) (FB(1)), fumonisin B(2) (FB(2)) and fumonisin B(3) (FB(3)) with FLD was 0.11 ng, 0.50 ng and 0.27 ng, respectively, and with DAD it was 13.8 ng, 12.5 ng and 6.6 ng, respectively injected on column. The coefficient of variation (CV, n = 6) for FB(1), FB(2) and FB(3) in a naturally contaminated samples obtained with FLD was 2.6%, 1.8% and 5.3%, respectively, compared to 6.0%, 3.4% and 9.5%, respectively, obtained with DAD. Subsequently the optimized NDA derivatization was compared to the widely used o-phthaldialdehyde (OPA) derivatization agent as well as alternative sample clean-up with immunoaffinity column (IAC) by analyzing naturally contaminated maize samples (n = 15) ranging in total fumonisin (TFB = FB(1)+FB(2)+FB(3)) levels from 106 to 6000 μg/kg. After immunoaffinity column clean-up of extracted samples, the recoveries of spiked maize samples for NDA-FLD of FB(1), FB(2) and FB(3) were 62%, 94% and 64%, respectively. NDA proved to be an effective derivatization reagent of fumonisin in naturally contaminated maize samples following IAC clean-up, except for DAD at TFB levels below 1000 μg/kg. In contrast NDA derivatization following SAX clean-up produced results comparable to OPA only for levels below 1000 μg/kg. Aside from the difference in detection limits, FLD and DAD produced comparable results irrespective of the clean-up method or the derivatization agent.     

Effects of dietary L-carnitine supplementation on semen characteristics in boars

In some species, dietary supplementation with L-carnitine has been reported to increase sperm concentration and sperm motility. The objective of these experiments was to test the hypothesis that L-carnitine supplementation improves the semen characteristics of boars. In Experiment 1, boars (258 days of age) were fed daily a control diet (n = 9) or the control diet plus L-carnitine (500mg per day; n = 9 ). Semen was collected weekly from Weeks 0 to 15 and on 4 consecutive days during Week 16. Experiment 2 was similar to Experiment 1 except boars ( n = 10 per treatment) were 504 days of age. For the weekly and intensive collections there were no consistently positive effects of treatment on semen volume, sperm concentration, total spermatozoa, or sperm motility. Spermatozoa from L-carnitine-treated boars did not display an enhanced ability to maintain motility during 7-day liquid storage. In conclusion, indicators of semen quality were not enhanced by dietary supplementation of L-carnitine in boars.     

Growth,testicular and endocrine function of boars exposed to 8, 16 or 24 hours of light daily before puberty

Sixty Yorkshire boars were used in two replicates to evaluate the influence of duration of photoperiod on growth, testicular and reproductive endocrine function. Boars born in May and July were exposed to either 8, 16 or 24 h of fluorescent light (200 1x) daily between 2 and 8 months of age. Body weights were obtained at 2-week intervals. At 4, 6 and 8 months of age, venous cannulae were placed in five boars from each treatment and samples of serum were collected to evaluate concentrations of luteinizing hormone (LH) and testosterone. Samples of boars from each treatment were castrated at 6 and 8 months of age, and weights and sperm content of the testes and epididymides were determined. Body weights of boars were similar for all treatments throughout the experiment. Duration of photoperiod did not affect weights of the testes or epididymides or total numbers of sperm within these tissues at either 6 or 8 months of age. Testicular and epididymidal weights and epididymidal sperm numbers increased between 6 and 8 months of age. Concentrations of luteinizing hormone (LH) and testosterone in serum at 4, 6 or 8 months of age were not affected by duration of photoperiod. These results indicate that growth rate and testicular development of prepubertal Yorkshire boars born in May and July are not influenced by duration of photoperiod.     

Dietary l-arginine supplementation improves semen quality and libido of boars under high ambient temperature

l-Arginine is a nutritionally essential amino acid for spermatogenesis and plays versatile roles in animal health and can be utilized as a potential agent to improve reproductive performance of boars under high ambient temperature. The present study aimed to determine whether dietary l-arginine could alleviate heat stress-induced infertility in boars. In all, 20 boars (PIC 1040; 248.59±3.84 kg BW and 407.65±6.40 days of age) were selected and randomly assigned to four groups (group 0.0%, basal diet; group 0.6%, 0.8% or 1.0%, basal diet added with 0.6%, 0.8% or 1.0% l-arginine (wt:wt), respectively.) The four diets were made isonitrogenous by addition of appropriate amounts of l-alanine. Boars were pre-fed the corresponding experimental diet for 42 days. Then, the semen characteristics and libido were accessed for 6 weeks during the hot summer period (25.5° to 33.0°C). Results show that dietary l-arginine remarkably improved sperm motility, normality, total sperm number and effective total sperm number. Also, dietary l-arginine improved semen antioxidant capacity, such as decrease of malondialdehyde and 8-Hydroxy-2'-deoxyguanosine content in sperm (P<0.05), increase of the ratio of glutathione and oxidized glutathione, total antioxidant capacity, glutathione peroxidase and catalase activities in seminal plasma (P<0.05). Most of mitochondria contained intact ultrastructure in l-arginine-supplemented group which also accompany with higher ATP content than the 0.0% group. The boars fed 0.8% l-arginine show increased levels of estradiol-17β and testosterone and exhibit improved libido performance than boars in the 0.0% group. Adding dietary l-arginine linearly increased (P=0.002) nitric oxide content (as l-arginine increased). The scrotal surface temperature in the 0.6%, 0.8% and 1.0% group were decreased by 0.9°C, 0.9°C and 0.4°C, respectively, compared with the 0.0% group. l-Arginine levels caused linear effect on semen quality and antioxidant capacity, also caused quadratic effect on libido performance. During the hot summer months, the predicted optimal l-arginine levels for best semen quality and antioxidant capacity was 0.8% to 1.0% and for best libido performance was 0.8%. It can be concluded that l-arginine can be used as an effective agent to alleviate heat stress-induced infertility of boar, and that 0.8% to 1.0% can be considered as the optimum dosage.     

Dietary supplementation with a source of omega-3 fatty acids increases sperm number and the duration of ejaculation in boars

Development of nutritional strategies to increase the production of fertile sperm would further enhance the distribution of superior genetic material by AI. The objective was to determine the effects of a dietary source of omega-3 fatty acids in boars on semen characteristics and sexual behavior. Boars were fed daily 2.2 kg of a diet top-dressed with 0.3 kg of corn (controls; n=12) or 0.3 kg of a supplement containing 31% omega-3 fatty acids (n=12) for 16 weeks. Semen was collected weekly and for boars that received the supplement containing omega-3 fatty acids, total sperm per ejaculate averaged 84.3+/-2.3 x 10(9) (mean+/-S.E.M.) during Weeks 0-7, and increased (P=0.02) to 95.6+/-2.3 x 10(9) during Weeks 8-15. Control boars averaged 86.3+/-2.3 x 10(9) sperm per ejaculate during Weeks 0-7 and 86.4+/-2.3 x 10(9) during Weeks 8-15. Other semen characteristics were similar (P>0.1) between groups. Duration of ejaculation was affected by treatment (343.9s for controls and 388.8s for boars fed omega-3 fatty acids; S.E.M.=15.7; P=0.05). In summary, semen characteristics and sexual behavior were altered in boars fed a supplement containing omega-3 fatty acids. Boar semen is typically diluted to create AI doses containing 3 x 10(9) sperm each; therefore, use of the supplement increased the number of potential AI doses by approximately three per ejaculate after the initial 7 week supplementation period.     

Dietary omega-3 fatty acids (fish oils) have limited effects on boar semen stored at 17 °C or cryopreserved

To evaluate the influence of dietary supplementation of omega-3 polyunsaturated fatty acids (n-3 PUFA) on storage of boar semen, three experiments were conducted: two involved long-term, fresh semen storage (Exp. 1 and Exp. 2), whereas the other involved cryopreservation (Exp. 3). Boars were allocated randomly to three dietary treatments (for 6-7 mo). In addition to a daily allowance of 2.5 kg of a basal diet, they received: 1) 62 g of hydrogenated animal fat (AF); 2) 60 g of menhaden oil (MO), containing 18% docosahexanoic acid (DHA) and 15% eicosapentanoic acid (EPA); or 3) 60 g of tuna oil (TO), containing 33% DHA and 6.5% EPA. In Experiment 1 (n = 26) and Experiment 2 (n = 18), semen was cooled and stored in vitro for several days at 17 °C before assessment, whereas in Experiment 3 (n = 18), viability, motility, acrosomal integrity, susceptibility to peroxidation (LPO), and DNA fragmentation were determined in fresh and frozen-thawed sperm. In Experiment 1, sperm from boars fed TO had better resistance to fresh storage; even after 7 or 9 d of storage at 17 °C, there were more (P = 0.03) motile sperm in boars fed TO (>60%) than in those fed AF or MO. In Experiment 2, fish oil supplementation did not influence any aspect of sperm quality during semen storage (P > 0.10). In Experiment 3, cryopreservation decreased the proportion of motile and viable frozen-thawed sperm as well as acrosomal integrity and increased DNA fragmentation and LPO (P < 0.01) relative to fresh semen, although sperm quality was unaffected by treatments (P > 0.09). In conclusion, although adding fish oil to the diet failed to significantly improve the quality of cryopreserved boar sperm, inconsistent responses of long-term storage of cooled sperm to dietary n-3 PUFA supplementation warrant further investigation.     

Effects of dietary selenium and vitamin E concentrations on phospholipid hydroperoxide glutathione peroxidase expression in reproductive tissues of pubertal maturing male rats

Phospholipid hydroperoxide glutathione peroxidase (PHGPX) is the second intracellular selenium (Se)-dependent glutathione peroxidase (GSH-Px) identified in mammals. Our objectives were to determine the effect of dietary vitamin E and Se levels on PHGPX activity expression in testis, epididymis, and seminal vesicles of pubertal maturing rats, and the relationship of PHGPX expression with testicular development and sperm quality. Forty Sprague-Dawley male weanling rats (21-d old), were initially fed for 3 wk a torula yeast basal diet (containing 0.05 mg Se/kg) supplemented with marginal levels of Se (0.1 mg/kg as Na₂SeO₃) and vitamin E (25 IU/kg as all-rac-α-tocopheryl acetate). Then, rats were fed the basal diets supplemented with 0 or 0.2 mg Se/kg and 0 or 100 IU vitamin E/kg diet during the 3-wk period of pubertal maturing. Compared with the Se-supplemented rats, those fed the Se-deficient diets retained 31, 88, 67, and 50% of Se-dependent GSH-Px activities in liver, testis, epididymis, and seminal vesicles, respectively. Testes and seminal vesicles had substantially higher (5-to 20-fold) PHGPX activity than liver. Dietary Se deficiency did not affect PHGPX activities in the reproductive tissues, but reduced PHGPX activity in liver by 28% (P < 0.0001). Dietary vitamin E supplementation did not affect PHGPX activity in liver, whereas it raised PHGPX activity in seminal vesicles by 43% (P < 0.005). Neither dietary vitamin E nor Se levels affected body weight gains, reproductive organ weights, or sperm counts and morphology. In conclusion, expression of PHGPX activity in testis and seminal vesicles was high and regulated by dietary Se and vitamin E differently from that in liver.     

The Effect of two Different Feed Levels on the Development of the Reproductive Organs in Boars

The aim of the present investigation was to study the development of the reproductive organs in boars fed restrictively and fed ad libitum. A total of 120 boars were purchased by the experimental station at 20 kg live weight. Three groups of 4 litter mates were selected after each of 10 A.I. boars (7 Swedish Landrace and 3 Swedish Yorkshire). The dams were unselected sows from pigletproducing herds. Two boar pigs from each litter were allocated at random among 2 treatment groups. One group ( = N) was fed restrictively and the other group (=A) ad libitum. The boars were slaughtered at 90 kg or at 120 kg live weight. The reproductive organs were removed at slaughter and examined. The ad libitum fed boars were about 2 weeks younger at slaughter than those fed restrictively (16.5 and 13.7 days respectively for the 2 weight classes). The weights of the testes were somewhat higher for ad libitum fed than for restrictively fed boars. Out of 94 examined pairs of testes, epididymides, seminal vesicles and bulbo-urethral glands, the left was heavier than the right in 68%, 62%, 48%, and 36%, respectively. Fewer (4/23) ad libitum fed than restrictively fed boars (9/26) had reached puberty at 90 kg live weight. Age at puberty thus seems to be less variable than body size in boars.     

Biosynthetic and genetic relationships of B-series fumonisins produced by Gibberella fujikuroi mating population A

Fumonisins are mycotoxins produced by the maize pathogen Gibberella fujikuroi mating population A and frequently contaminate maize. Wild-type G. fujikuroi produces four B-series fumonisins, FB1, FB2, FR3 and FB4. These toxins are identical in structure except for the number and positions of hydroxyls along their linear carbon backbone. To elucidate the genetic and biosynthetic relationships among these fumonisins, we conducted meiotic and biochemical analyses of G. fujikuroi mutants with altered fumonisin production that resulted from defective alleles at three loci, Fum1, Fum2 and Fum3. These mutants produced either no fumonisins, only FR2 and FB4, or only FR3 and FR4. Genetic analyses revealed the orientation of the Fum loci along linkage group 1 of the fungus. The mutants were grown together in pair-wise combinations to determine if their fumonisin production phenotypes could be complemented. When FR3- and FB2-producing mutants were grown together, complementation occurred. However, when a nonproducing mutant was grown with a FR2- or FB3-producing mutant, complementation did not occur or was incomplete. When purified FR2, FR3, or FB4 was fed to mutant cultures, FR4 was converted primarily to FR2, FR3 was converted to FB1 and FB2 was not converted. The results from these assays suggest a previously unrecognized branch in the fumonisin biosynthetic pathway.     

Effects of increased levels of supplemental vitamins during the summer in a commercial artificial insemination boar stud

Heat stress due to increasing extremes in ambient temperature and humidity results in reduced semen quality in boars. This has caused reduced efficiency of the swine industry, requiring more boars to breed the same number of sows. Vitamins such as vitamin C (VC) and E (VE) have been shown to improve semen quality in boars. Recently, vitamin D has been shown to improve semen quality in boars. The purpose of this experiment was to evaluate the effects of increased supplemental vitamins on boar reproduction during the summer season in a commercial boar stud. One hundred and sixty Pig Improvement Company (PIC) terminal line boars (n = 32 per treatment) and 39 maternal, heat-sensitive boars (n = 7 or 8 per treatment) were randomly allocated to treatment and fed a corn and soybean meal-based diet adjusted based on individual boar body condition score. A control (CNT) diet was used that met PIC recommendations for boars. Increased supplementation of specific vitamins was given in the form of a top-dress and consisted of CNT wheat middlings, CNT plus VC (560 mg/day), CNT plus 25-hydroxy vitamin D₃ (VD) (125 µg/day), CNT plus VE (275 mg/day) and CNT plus VC, VD and VE (CDE). The experiment was split into three periods based on maximum daily high temperatures in the barn, where period 1 was weeks 1 to 4, period 2 was weeks 5 to 11 and period 3 was weeks 12 to 14. Semen was collected from boars as needed using the stud’s normal production schedule and was analyzed for sperm quantity and quality characteristics. There were no dietary effects on semen volume, sperm concentration or total sperm production (P ≥ 0.553). Total motility of sperm was not impacted by diet (P = 0.115); although, VC tended (P = 0.064) to have a greater progressive motility than CDE. Percentages of morphologically normal sperm and normal acrosomes were not affected by dietary supplementation (P ≥ 0.157). Period effects were observed for most semen quality parameters, with quality generally becoming reduced over time. The present study demonstrates that increased supplementation of vitamins beyond PIC recommendations was not beneficial for boar reproduction during the summer.     

Fumonisins production by Fusarium proliferatum strains isolated from asparagus crown

The present work deals with the capability for producing fumonisin by Fusarium proliferatum strains isolated from asparagus in China. Fifty of F. proliferatum strains were randomly selected and incubated on cultures of maize grain and asparagus spear, respectively. Fumonisin levels (FB₁ and FB₂) were determined by high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The results showed that all 50 strains produced fumonisins in maize culture within a wide range of concentrations, 10–11,499 μg/g and 2–6,598 μg/g for FB₁ and FB₂, respectively. On culture of asparagus spear,48 strains (96%) produced fumonisins in the range 0.2–781.6 μg/g and no detected to 40.3 μg/g for FB₁ and FB₂, respectively. All of F. proliferatum strains produced much higher levels of FB₁, FB₂ and total fumonisins (FB₁ + FB₂) in maize grain culture than in asparagus spear culture. Meanwhile, fumonisin B₃ (FB₃) was identified in all maize culture extracts and most of asparagus spear culture extracts. This is the first study carried out the fumonisin-producing ability of F. proliferatum strains isolated from asparagus in China. The information obtained is useful for assessing the risk of fumonisins contamination in asparagus spear. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users.     

Zinc deficient diet exacerbates the testicular and epididymal damage in type 2 diabetic rat: Studies on oxidative stress-related mechanisms

Zinc (Zn) is one of the most important trace elements in the body and is required for insulin secretion and release. Zn is also required for the growth and development of the reproductive system. Alteration in the Zn levels can cause moderate to severe damage to various organs, including the reproductive system. Most of type 2 diabetic patients have altered Zn levels/signaling. So, here we investigated the role of Zn-deficient diet (ZDD) in type 2 diabetes. Type 2 diabetes in the rat was induced by the combination of high-fat diet (HFD) and a single low dose of streptozotocin (STZ, 35 mg/kg, i.p.). Control animals were fed normal pellet diet throughout the study, while ZDD was given for four consecutive weeks to the diabetic rats, which were earlier kept on HFD for 16 weeks. The present findings showed that ZDD further decreased the serum Zn, plasma insulin and serum testosterone levels, whereas it increased cholesterol, triglycerides, BUN, %HbA1c in diabetic rats. Oxidative stress in testes was increased by ZDD as evidenced by decreased glutathione, catalase and SOD1 levels. ZDD-induced several abnormalities in sperm head morphology, altered sperm decondensation, sperm chromatin and protamine content, along with significant histopathological alterations in testes and epididymis. Further, ZDD altered protein levels of MT, MTF-1, Keap1, Nrf2, Nf-κB, GPX4 and GPX5 levels in the testes and epididymis of diabetic rat. The present results demonstrated that dietary Zn deficiency could exacerbate type 2 diabetes-induced germ cell damage.     

Semen changes in boars after experimental infection with porcine reproductive and respiratory syndrome (PRRS) virus

Eleven boars seronegative to porcine reproductive and respiratory syndrome virus (PRRSV) were trained for semen collection: five boars were inoculated intranasally with 6 x 10(6)TCID(50)/ml of PRRSV (Group A); four boars were inoculated intranasally with 6 x 10(4)TCID(50)/ml (Group B); and two boars were used as uninfected control (Group C). Semen samples were collected at 7-d intervals from 49 d prior to experimental inoculation with PRRSV to 70 d after inoculation, and were examined for sperm volume, sperm concentration, sperm morphology, sperm motility and for the presence of PRRSV. The infection in boars was demonstrated by the reisolation of PRRSV from the serum of all inoculated boars. Rectal temperatures and general health of the boars were clinically normal throughout the trial. Differences were observed in the quality of semen collected from boars after experimental infection with PRRSV. This infection induced a significant decrease in sperm motility and in spermatozoa with normal acrosomes. Of the semen samples tested for virus isolation in swine alveolar macrophages PRRSV was only isolated in 1 boar from Group B. The virus was detected in an additional semen sample in Group A by the production of an antibody titer in a biological assay. All attempts to detect PRRSV by RT-PCR in semen samples were unsuccessful. Nevertheless, from our study it is possible to suggest that the PRRSV can occasionally be transmitted in the semen during the initial phase of the disease.     

Combined effect of DHA and alpha-tocopherol enrichment on sperm quality and fertility in the turkey

The aim of the present study was to characterize the dietary effects of n-3 LC-PUFA and alpha-tocopheryl acetate (vE) on the quality, phospholipid fatty acid composition, alpha-tocopherol content (alpha-T) and in vitro susceptibility to lipid peroxidation in turkey semen. Fertility of fresh semen was also evaluated. Male turkeys were randomly divided and fed either a control diet or a fish oil and vE rich diet (FO diet) from 40 to 60 weeks of age. The FO diet increased the proportion of n-3 fatty acids in spermatozoa and as a consequence the (n-3)/(n-6) ratio also increased. These changes did not affect the proportion of n-9 PUFAs, particularly of C22:3n-9, in semen. The sperm content of alpha-T was dependent by the dietary supplementation of the vitamin and the sperm content was more than doubled supplying 120 mg kg(-1) of feed to the males compared to the 60 mg kg(-1) of feed in the control diet. In agreement with the major content of alpha-T in spermatozoa collected from the FO group were significantly less susceptible to in vitro induced oxidation. The reproductive capacity of the male breeders was not affected by the diet; however the result is considered of some relevance for field conditions where even very small changes have economic interest being applied to large bird population.     

Semen quality of postpubertal boars during increasing and decreasing natural photoperiods

The present study analyses the effects of increasing and decreasing photoperiods on the semen quality of 20 selected postpubertal Landrace boars. The boars were exposed, throughout 75 days, to increasing and decreasing photoperiods of natural light, a constant temperature of 21 +/- 1 degrees C and 60-70% of humidity, fed with a nutritious diet and, submitted to a rhythm of semen collection of twice a week. During the last 2 weeks of each treatment, semen samples were analysed and the parameters measured were: ejaculate volume and pH, sperm concentration, sperm production and the number of semen doses per ejaculate, sperm vitality, sperm motility, osmotic resistance of spermatozoa and sperm morphology. The comparative analysis between increasing and decreasing photoperiods indicated that the semen quality of boars exposed to a decreasing photoperiod was reduced as a consequence of decreases in sperm concentration, sperm production and the number of semen doses. There was no difference between increasing and decreasing photoperiods in terms of sperm vitality and sperm motility, nor in the osmotic resistance of spermatozoa to isotonic and hypotonic media. The analysis of sperm morphology showed significantly lower frequencies of mature and immature spermatozoa with a distal cytoplasmic droplet, and significantly higher frequencies of immature spermatozoa with a proximal droplet in boars exposed to the decreasing photoperiod. These results indicate that the sperm quality of the selected boars decreased during decreasing photoperiods, in comparison with increasing photoperiods, mainly due to impaired testicular function.     

Major proteins of boar seminal plasma as a tool for biotechnological preservation of spermatozoa

Boar seminal plasma is a complex mixture of secretions from the testes, epididymides, and the male accessory reproductive organs which bathe the spermatozoa at ejaculation. The seminal plasma contains factors, mostly proteins, which influence the spermatozoa, the female genital tract, and the ovum. In boars, most of the proteins belong to the spermadhesin family and bind to the sperm surface. Spermadhesins are multifunctional proteins with a wide range of ligand-binding abilities to heparin, phospholipids, protease inhibitors and carbohydrates; the family can be roughly divided into heparin-binding (AQN-1, AQN-3, AWN) and non-heparin-binding spermadhesins (PSP-I/PSP-II heterodimer). These proteins have various effects promoting or inhibiting sperm functions including motility, oviduct binding, zona binding/penetration, and ultimately fertilization. The complexity of the environmental signals that influence these actions have implications for the uses of these proteins in vivo and in vitro, and may lead to uses in improving sperm storage.     

Effects of exposing boars to different artificial light regimens on semen plasma markers and "in vivo" fertilizing capacity

This study was designed to assess the effects of exposing boars to an artificial photoperiod on semen quality in terms of sperm concentration, sperm vitality, sperm motility and acrosome integrity. We also determined biochemical semen plasma variables, such as total protein concentration, phosphorylated tyrosine residues and fructose, glucose and sorbitol contents, along with their effects on the fertility, prolificacy and libido of the boars. Three groups of 10 males were kept for 3 months under experimental conditions of 24, 12 and 0 h of artificial light, and a constant temperature of 21 +/- 1 degrees C and 60-75% humidity. The animals were fed a nutritious diet and subjected to semen collection twice per week. Semen samples were analyzed throughout the entire experimental period. Our results indicate that, while the extreme photoperiods (0 and 24 h of light) affected semen quality in terms of sperm concentration, acrosome integrity and semen volume, its fertilizing capacity was only significantly reduced under conditions of absolute darkness. Sperm motility was found to be a poor indicator of fertilizing ability, while other sperm factors, such as acrosome integrity or other functional variables seemed to behave better. The photoperiod was found to affect the production of accessory sex gland secretions more than their composition. In addition, light effects on fertility, prolificacy and libido seemed to be achieved through independent mechanisms.     

Reproductive toxicity assessment of lasofoxifene, a selective estrogen receptor modulator (SERM), in male rats

BACKGROUND: Lasofoxifene is a nonsteroidal selective estrogen receptor modulator (SERM) with greater than 100-fold selectivity against all other steroid receptors and is a potentially superior treatment for postmenopausal osteoporosis. The purpose of this study was to evaluate the effects of lasofoxifene on male reproduction in rats in light of the known effects of estrogen modulating compounds on male reproductive ability. METHODS: Lasofoxifene was administered to adult male rats at doses of 0.1, 1, 10, and 100 mg/kg for 66-70 consecutive days. After 28 days of dosing, male rats were cohabited with untreated female rats. Female rats were euthanized on gestation day 14 and a uterine examination was carried out for evaluation of reproductive parameters and embryo viability. Male rats were euthanized after 66-70 days of dosing and epididymal sperm motility and concentration were assayed. The testes, epididymides, prostate, and seminal vesicles were weighed and microscopically examined. RESULTS: The duration of cohabitation was increased for 100 mg/kg males by 0.7 days. The number of males copulating and the number of implantation sites produced per copulation were reduced in the 10 and 100 mg/kg groups. Weights of the seminal vesicles and epididymides were reduced for all groups, although the testes weight and epididymal sperm motility and concentration were not affected by treatment. There were no microscopic findings in the male reproductive tissues. CONCLUSION: The changes in male fertility and reproductive tissue weights after exposure to lasofoxifene are consistent with those previously described for estrogen receptor-modulating compounds.