Sperm subpopulations influence the pregnancy rates in cattle

This study aimed to study the characteristics and subpopulations of spermatozoa from bulls with low and high reproductive performance based on pregnancy rates. Based on historical records of pregnancy rate from four farms, 24 bulls were selected. Two groups were established, with low pregnancy rates (n = 12; LOW), including bulls that presented pregnancy rates <52.27% (33.33% to 51.81%); and a group with high pregnancy rates (n = 12; HIGH), with pregnancy rates >52.27% (52.27% to 69.64%), after fixed-time artificial insemination (FTAI). The thawed sperm straws were analysed to sperm kinetics, morphology, plasma membrane integrity and sperm subpopulations. The LOW group exhibited a higher proportion of static cells (p < .05). In contrast, the HIGH group showed greater percentages for membrane integrity and total and progressive motility, and cells with fast and medium velocity (p < .05). In the cluster procedures, four sperm subpopulations were established. The low-fertility bulls presented the highest percentage of subpopulation 2 (41.46%), characterized by slow and progressive spermatozoa. The high-fertility bulls exhibited the highest percentage of subpopulation 3 (37.17%), characterized by fast and nonlinear spermatozoa. Results from this study indicated that bulls with greater percentages of fast and nonlinear spermatozoa seem to have greater fertilization capacity and the subpopulations analysis can be considered a tool to identify ejaculates with high fertility.     

Culture system and long-term storage of culture media in the in vitro production of bovine embryos

The optimum culture system for in vitro matured and fertilised oocytes still remains to be clarified. Culture media (CM) for mammalian embryos are routinely prepared fresh for use and preserved under refrigeration during one or two weeks. The purposes of this work were (1) to compare the efficiency of a synthetic oviduct fluid (SOF) with two different bovine serum albumin (BSA) concentrations (3 and 8 g/L) for the in vitro production of bovine blastocysts, (2) to test the effect of timing on adding fetal calf serum (FCS) to the SOF, and (3) to evaluate the effects on bovine embryo development of freezing and lyophilisation as procedures for preserving the SOF. Supplementation of SOF with 3 g/L BSA increased Day-7 blastocyst expansion rates (18.3 ± 1.6 vs. 14.4 ± 0.7; P < 0.05), although no differences in hatching rates were found. Addition of FCS to SOFaa (SOF with amino acids) medium supplemented with sodium citrate (SOFaaci) at 48 and at 72 h post-insemination (PI) allowed obtaining higher Day-6 embryo development rates than when FCS was added at 18 or 96 h PI (Day-6 morulae + blastocyst rate: 30.0 ± 1.1, 40.8 ± 1.1, 43.9 ± 2.3 and 39.3 ± 0.5 for FCS addition at 18, 48, 72 and 96 h, respectively). Hatching rates were significantly improved when serum was added at 72 h PI. Finally, both refrigeration and lyophilisation appeared as useful cryopreservation procedures for SOFaaci, although a significant loss of its ability to support embryo development, compared to the control fresh culture medium, was observed.     

Chemical markers for the evaluation of raw material hygienic quality in egg products

The aim of this research was to study uracil and lactic and acetic acids as chemical markers for hygienic quality evaluation of raw material in liquid pasteurized egg products. Uracil, absent in sound whole eggs, was formed in raw and pasteurized egg products as a consequence of high microbial contamination (>10(6) cfu/g) after a sufficient lag time, remaining stable at 4 degrees C but disappearing after 7 days of storage at 25 degrees C. Both lactic and acetic acids, starting from initial values of 1-7 mg/kg dry matter, presented trends similar to that of uracil; however, acetic acid never decreased during the storage of raw egg products. With few exceptions, all three metabolites were produced by Enterobacter cloacae, Escherichia coli, Morganella morganii, Serratia liquefaciens, Aeromonas hydrophyla, Pseudomonas fluorescens, Enterococcus avium, and Enterococcus faecalis, separately inoculated in whole egg samples. Uracil seems to be the most sensible marker, with a suggested limit corresponding to the detectable level.     

Changes in Gut Microbiota Linked to a Reduction in Systolic Blood Pressure in Spontaneously Hypertensive Rats Fed an Extra Virgin Olive Oil-Enriched Diet

Fat type in diet is responsible for specific changes in gut microbiota (GM). Extra virgin olive oil (EVOO) has been shown to be beneficial for blood pressure and to produce effects on GM. To analyze the cause-effect relationship between intestinal microbial changes and blood pressure, we studied the effect of EVOO on fecal microbiota and systolic blood pressure (SBP) levels in spontaneously hypertensive rats (SHR). SHR were fed either an enriched EVOO diet or a standard diet for a period of 12 weeks. At the end of the experimental period, the microbial profiles in the feces were studied in both groups by using PCR-denaturing gradient gel electrophoresis. Real-time PCR was used to quantify the selected bacterial groups. The results demonstrated significant differences when using Lactobacillus (p<0.05), clostridia XIV (p<0.01) and universal (p<0.05) primers. A significant (r=?0.475; p=0.04) inverse correlation between the abundance of clostridia XIV and SBP, which depends on the type of diet, was also observed. Finally, the results suggested an increase in the microbial diversity of the feces of the animals fed the EVOO diet. These results strongly connect the pattern of GM in SHR fed a diet enriched with EVOO to the lower levels of SBP observed in these animals at the end of the feeding period.     

Antioxidative activity of amino phospholipids and phospholipid/amino Acid mixtures in edible oils as determined by the Rancimat method

Phosphatidylethanolamine (PE), phosphatidylcholine (PC), lysine (Lys), and mixtures of them were tested for antioxidative activity in refined olive oil by the Rancimat method to investigate the role of the chemical reactions produced in the Rancimat vessel on the induction periods (IPs) obtained. PE and Lys, but not PC, increased the IPs of the oil when tested alone. In addition, PE/Lys and PC/Lys mixtures, but not PC/PE mixtures, exhibited a synergistic effect. All these results can be understood considering the in situ formation of oxidized lipid/amino compound reaction products with antioxidative activities. Thus, the formation of pyrroles could be detected after derivatization with p-(dimethylamino)benzaldehyde, and some of these compounds could be unambiguously identified by GC-MS after their conversion into volatile derivatives. In addition, the formed products contributed to the color developed, and a correlation was observed between the Rancimat IPs obtained and the yellowness index of the oxidized oils recovered from the Rancimat. Furthermore, the differences observed in the antioxidative activities of PE, PC, Lys, and their mixtures could be explained according to the lipophility and hydrophility of the oxidized lipid/amino compound reaction products formed. All these results suggest that chemical reactions are being produced in the Rancimat vessel and the Rancimat IPs obtained are a consequence of the antioxidative activities of the products formed in these reactions. Furthermore, Rancimat may be a valuable tool for testing antioxidative activities of antioxidants produced during food processing if favorable conditions for antioxidant formation are employed.     

Fourteen years of applying zero and conventional tillage,crop rotation and residue management systems and its effect on physical and chemical soil quality

Soil management systems may negatively affect the quality of the soil. Policymakers and farmers need scientific information to make appropriate land management decisions. Conventional (CT) and zero tillage (ZT) are two common soil management systems. Comparative field studies under controlled conditions are required to determine the impact of these systems on soil quality and yields. The research presented studied plant and soil physical and chemical characteristics as affected by different agricultural management practices, i.e. ZT and CT, cropped with continuous wheat or maize in monoculture (M) or in a yearly rotation (R) of these two crops, either with residue retention (+r) or without residues retention (?r), in an experimental field in the Transvolcanic Belt of Mexico after 14 years. The dominant factors defining soil quality were organic C, total N, moisture, aggregate stability, mechanical resistance, pH and EC. The principal component combining the variables organic C, total N, aggregate stability and moisture content showed the highest correlations with final yield (R = 0.85 for wheat and 0.87 for maize).After 14 years of continuous practice, ZTM + r and ZTR + r had the best soil quality and produced the highest wheat and maize yields of average 2001–2004 (6683 and 7672 kg ha^?1 and 5085 and 5667 kg ha^?1, respectively). Removing the residues, i.e. treatments ZTM ? r with maize (average 2001–2004: 1388 kg ha^?1) and ZTR ? r and CTR ? r with wheat (average 2001–2004: 3949 and 5121 kg ha^?1), gave the lowest yields and less favourable soil physical and chemical characteristics compared to the other practices. It was found that zero tillage with residue retention is a feasible management technology for farmers producing maize and wheat in the agro-ecological zone studied, resulting in a better soil quality and higher yields than with the conventional farmer practice (maize monoculture, conventional tillage and residue removal).     

Solar Photocatalysis Using Fixed-Film TiO<Subscript>2</Subscript> for Microcystins from Colonial <Emphasis Type="Italic">Microcystis aeruginosa</Emphasis>

Microcystins (MCs) are endotoxins produced by cyanobacteria in freshwaters globally. With known potential for human health risks, rapid and effective treatment methods are needed for MCs. Previous studies have shown photocatalysis can achieve rapid half-lives with UV lamps and slurries of TiO₂. In this experiment, rates and extents of solar photocatalysis of MCs were measured using bench-scale reactors with fixed films of TiO₂ for solutions with a range of cellular:aqueous MC ratios. Since cellular MCs can be removed physically, photocatalysis rates were measured following sand filtration to discern the extent of MC removal post-filtration. Since UV energy drives photocatalysis using TiO₂, rates of removal were calculated as a function of cumulative UV insolation and time. For water containing < 10% aqueous MC, filtration removed 90% of total MC, and the subsequent photocatalysis half-life was 0.37 MJ/m² (or 111 min). For water with ~?50% aqueous MCs, filtration removed 52% of the total MCs, and the average half-life for photocatalysis was 0.38 MJ/m² (or 138 min). For the >?90% aqueous MC treatment, filtration removed 0% MCs, and the photocatalysis half-life for MCs was 0.37 MJ/m² (or 135 min). Previous studies have used clarified waters; however, results from this study are likely representative of scenarios with waters containing confounding water characteristics and use of solar light for UV, as anticipated in developing countries with less advanced water treatment methods. Photocatalysis is a rapid and effective process for decreasing concentrations of MCs and could be useful for mitigating risks from MC exposures in drinking water.     

Chemical conversion of phenylethylamine into phenylacetaldehyde by carbonyl-amine reactions in model systems

The chemical conversion of phenylethylamine into phenylacetaldehyde in the presence of lipid oxidation products (LOPs) was studied to investigate the possibility that biogenic amines can be converted into Strecker aldehydes upon processing. Model systems of phenylethylamine and methyl 13-hydroperoxyoctadeca-9,11-dienoate (HP), 2,4-decadienal (DD), 4,5-epoxy-2-heptenal (EH), 4,5-epoxy-2-decenal (ED), 4-oxo-2-hexenal (OH), 4-oxo-2-nonenal (ON), or 4-hydroxy-2-nonenal (HN) were heated for 1 h at 180 °C and pH 3. Although HN and EH did not produce more phenylacetaldehyde than when phenylethylamine was heated alone, all other lipid oxidation products assayed increased the amount of phenylacetaldehyde produced by 300-900%, with ON being the most reactive compound for this reaction. The reaction was mainly produced at acidic pH values (<6) and was dependent upon the concentration of the LOPs involved, and the phenylacetaldehyde produced increased linearly as a function of the time and temperature. The E(a) values for the reactions between phenylethylamine and DD and ON were 54.8 and 53.8 kJ/mol, respectively. The reaction is proposed to take place by the formation of an imine between the phenylethylamine and the LOPs, which is later converted into another imine by an electronic rearrangement. This new imine is the origin of phenylacetaldehyde by hydrolysis. These results show a new pathway for Strecker aldehyde formation. This route provides a potential way to reduce biogenic amine content in foods when they can be thermally processed before consumption.     

Rapid impact of Impatiens glandulifera control on above‐ and belowground invertebrate communities

The annual plant Impatiens glandulifera (Himalayan balsam) is the most widespread invasive non‐native weed in the British Isles. Manual control is widely used, but is costly and laborious. Recently, biological control using the rust fungus Puccinia komarovii var. glanduliferae has been trialled. We designed an experiment to assess the impact of these control methods on invertebrate communities in relation to unmanaged and uninvaded habitats, and to determine whether mycorrhizal inoculation aided post‐control recovery of these communities. Sixty invaded and twenty uninvaded field soil blocks were transplanted to the experiment site, where a mycorrhizal inoculum was added to half of all blocks. Biological and mechanical control treatments were applied to twenty invaded blocks independently; the twenty remaining invaded blocks were left intact. Above‐ and belowground invertebrate samples were collected from the blocks at the end of the growing season. Overall, aboveground invertebrate abundance increased with the removal of I. glandulifera, and several groups showed signs of recovery within one growing season. The effect of mechanical control was more variable in belowground invertebrates. Biological control did not affect aboveground invertebrate abundance but resulted in large increases in populations of belowground Collembola. Our experiment demonstrates that mechanical removal of I. glandulifera can cause rapid increases in invertebrate abundance and that its biological control with P. komarovii var. glanduliferae also has the potential to benefit native invertebrate communities.