An intramammary implant in the prevention of infectious mastitis in cows

A sterile polyethylene device was introduced in the milk cistern of two mammary quarters of forty dairy cows. The cows were divided into three groups according to the length of exposure of the device in the cistern (3 days, 14 days, 365 days). The somatic cell counts were studied for a year in the first 10 ml fraction of milk and an increase in the somatic cell counts was found in the quarters having the intramammary device, as compared with the control quarters (having no devices). This difference was marked during lactation and prior to the onset of drying off. For the reduction in the frequency of occurrence of new natural intramammary infections, the activity of the device against S. aureus was limited and no activity against S. agalactiae was proved. The proportions of polymorphonuclears, round-cell elements and macrophages were histologically studied and compared for the udder quarters with and without the intramammary body in correlation with the time of exposure of the device to the milk cistern milieu. The most marked differences in favour of the udder quarters with the intramammary device were recorded in the alveoli containing more cells with a significant proportion of polymorphonuclear leucocytes. Small differences were found in the interstitial and subepithelial zone of the milk cistern. The activity of acid and alkaline phosphatase and adenosine triphosphatase was histochemically determined in the tissue structures of the udder and was found not to change under the influence of the device. Leucocytes and macrophages adhering to the surface of the body were observed under scanning electron microscope.     

Long-term animal impact modifies potential production of N<Subscript>2</Subscript>O from pasture soil

At cattle overwintering areas, inputs of nutrients in animal excrements create conditions favourable for intensive microbial activity in soil. During nitrogen transformations, significant amounts of N₂O are released, which makes overwintering areas important sources of N₂O emission. In previous studies, however, increasing intensity of long-term cattle impact did not always increase emissions of N₂O from the soil: in some cases, N₂O emissions from the soil were lower at the most impacted area than at the moderately impacted one. Thus, the relationships between the level of long-term animal impact and potential production of N₂O from soil by denitrification were investigated in field and laboratory experiments. Field measurements indicated that the production of N₂O after glucose and nitrate amendments was greater in severely and moderately impacted locations than in an unimpacted location, while differences between the severely and moderately impacted locations were not significant. In laboratory experiments, the potential production of N₂O (measured as anaerobic production of N₂O after addition of glucose and nitrate) was highest in the moderately impacted soil. Surprisingly, potential N₂O production was lower in the most impacted than in the moderately impacted soil, and the net N₂O production in the highly impacted soil was further decreased by a significant reduction of N₂O to N₂. The expected stimulating effect of an increasing ratio of glucose C to nitrate N on the reduction of N₂O to N₂ during denitrification was not confirmed. The results show that cattle increase the denitrification potential of the soil but suggest that the denitrification potential does not increase indefinitely with increasing cattle impact.     

Genetic studies in tench (Tinca tinca L.): high incidence of spontaneous triploidy

A high incidence of spontaneous triploidy was found in tench broodstock hormonally treated to induce spawning but without positive response. Triploidy was also observed in random samples of fingerlings from four tench lines. Triploidy was evaluated by counting Ag-stained NORs in erythrocyte nuclei and was confirmed in 62.5% of the broodstock and in a range from 0.00% to 34.62% in fingerlings. Discrimination of tench diploids and triploids based on differences in shape and length of pelvic fins was tested in the broodstock and also in stocks of earlier artificially induced triploid tench by means of the above-mentioned cytogenetic approach and shown to be a rapid method with a high accuracy (96.43%). Natural disposition for egg overripening is one of the possible causes of highly frequent spontaneous triploidy in the analyzed samples. Genetic predisposition, i.e. occurrence of a recessive allele responsible for the failure of the 2nd polar body extrusion when homozygous, was hypothesized as another possible cause of spontaneous triploidy, based on analysis of the relationships among the tench lines.     

Effect of dietary microbially produced gamma‐linolenic acid and plant extracts on enzymatic and non‐enzymatic antioxidants in various broiler chicken organs

Plant extracts and fungal fermented feed with gamma‐linolenic acid‐rich microbial oils are perspective additives for use in animal nutrition as appetite and digestion stimulants, stimulants of physiological functions, for the prevention and treatment for certain pathological conditions, and as antioxidants. The activity of antioxidant enzymes and the level of reduced glutathione were measured in the plasma and in liver, heart and kidney mitochondria after 42 days of feeding broiler chickens both regular and combination diets. These were selected based on our previous experience. The administration of agrimony and gamma‐linolenic acid resulted in a significant decrease in superoxide dismutase activity in all four bodies in contrast to plant extracts. We conclude that the decrease in activity is due to decreased production, and hence dismutation, of superoxide radicals to peroxides followed by lower activity of glutathione peroxidase, which was not seen in the case of only plant extract administration. Generally, higher glutathione reductase activity would be in response to increased demands on reduced glutathione as a cofactor for the reaction catalysed by glutathione peroxidase and the utilization of glutathione itself. However, measured levels of reduced glutathione showed no change. The results argue against any oxidative stress conditions. The application of agrimony extract appears to be suitable for the antioxidant effect against peroxidation of gamma‐linolenic acid. As the efficacy of measuring the effects of diets on the oxidative stability of meat caused by selected antioxidant enzymes is rather low, additional data from the experiment will be processed to clearly assess the influence of this combination of diets.     

Inhibition of cholesterol oxidation products (COPs) formation in emulsified porcine patties by phenolic-rich avocado (Persea americana Mill.) extracts

The effect of phenolic-rich extracts from avocado peel on the formation of cholesterol oxidation products (COPs) in porcine patties subjected to cooking and chill storage was studied. Eight COPs (7α-hydroxycholesterol, 7β-hydroxycholesterol, 7-ketocholesterol, 20α-hydroxycholesterol, 25-hydroxycholesterol, cholestanetriol, 5,6β-epoxycholesterol, and 5,6α-epoxycholesterol) were identified and quantified by GC-MS. The addition of avocado extracts (～600 GAE/kg patty) to patties significantly inhibited the formation of COPs during cooking. Cooked control (C) patties contained a larger variety and greater amounts of COPs than the avocado-treated (T) counterparts. COPs sharply increased in cooked patties during the subsequent chilled storage. This increase was significantly higher in C patties than in the T patties. Interestingly, the amount of COPs in cooked and chilled T patties was similar to those found in cooked C patties. The mechanisms implicated in cholesterol oxidation in a processed meat product, the protective effect of avocado phenolics, and the potential implication of lipid and protein oxidation are thoroughly described in the present paper.     

Spin rate of asteroid (54509) 2000 PH5 increasing due to the YORP effect

Radar and optical observations reveal that the continuous increase in the spin rate of near-Earth asteroid (54509) 2000 PH5 can be attributed to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, a torque due to sunlight. The change in spin rate is in reasonable agreement with theoretical predictions for the YORP acceleration of a body with the radar-determined size, shape, and spin state of 2000 PH5. The detection of asteroid spin-up supports the YORP effect as an explanation for the anomalous distribution of spin rates for asteroids under 10 kilometers in diameter and as a binary formation mechanism.     

Parasitoid complex of alfalfa aphids in an IPM intensive crop system in northern Catalonia

Alfalfa aphids were monitored and aphid parasitism was determined in three crop-growing seasons (2007–2009) in commercial alfalfa fields in valleys close to the Pyrenees, where an intensive arable crop rotation is practised under non-tillage and an integrated pest management system. Acyrthosiphon pisum, Therioaphis trifolii, and Aphis craccivora were the aphid species colonizing alfalfa fields but their occurrence varied between years. Thirteen Aphidiinae parasitoid species and four Aphelinidae from the genus Aphelinus sp. were recorded. Aphidius ervi was the prevalent parasitoid species associated with A. pisum but Praon barbatum was also noticeable, especially during the first year. Trioxys complanatus and P. exsoletum were the only species associated with T. trifolii. Lysiphlebus fabarum was the prevalent parasitoid species associated with A. craccivora. The occurrence of Lysiphlebus testaceipes parasitizing A. craccivora on alfalfa is a new record for the study region because this parasitoid species had only been previously found on weeds. Only A. pisum and A. craccivora were parasitized by Aphelinus sp. Whereas A. abdominalis and A. semiflavus were associated with A. pisum, A. chaonia, and Aphelinus sp. nr. albipodus were associated with A. craccivora. Associations between aphid species and Aphidiinae or Aphelinidae parasitoid species emphasize that individual aphid species also possess individual parasitoid complexes (guilds) which do not interfere with each other in alfalfa. Alloxysta victrix, A. macrophadna, Alloxysta spp., Asaphes suspensus, A. vulgaris, Dendrocerus aphidum, Pachyneuron aphidis and Syrphophagus aphidivorus were the hyperparasitoids associated with aphid–parasitoid complexes. Our study showed A. ervi, T. complanatus, P. exsoletum, and L. fabarum as potential candidate species which could provide biological control of their respectively aphid hosts in alfalfa.