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21.
Alterations in neutrophil phagocytosis and lymphocyte blastogenesis in dairy cows around parturition 总被引：2，自引：0，他引：2
A M Saad C Concha G Astr?m 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1989,36(5):337-345
The bovine blood neutrophil phagocytosis and the blood and milk lymphocyte proliferative response upon stimulation with Phytohaemagglutinin, Concanavalin A and Pokeweed mitogens was studied from 3 weeks prior to calving until 3 weeks after calving. Neutrophil phagocytosis and the total and differential blood leukocyte counts were performed by flow cytometry. A gradual increase in the percentage of phagocytized bacteria and the average number of bacteria per phagocyte was observed before calving followed by a sharp fall on the first postpartum. This was followed by a steady increase in the above parameters reaching the highest levels at two weeks postpartum. There was a gradual increase in the number of neutrophils in blood as calving approached followed by a sharp decrease after calving. The number of lymphocytes in blood dropped before calving, being at the lowest level on the day before calving. The proliferative response of blood and milk lymphocytes upon stimulation with the three mitogens was low during the week preceding parturition with the lowest value on the day before calving. The response of blood lymphocytes returned to a higher level the second week after calving while that of milk lymphocytes remained at a low level during the first and the second postpartum weeks. 相似文献
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Antonio RUIZ-NAVARRO Manuel DELGADO-BAQUERIZO Concha CANO-D&#;AZ Carlos GARC&#;A Felipe BASTIDA 《土壤圈》2023,(6):828-837
Phosphorus (P) limitation in the coming decades calls for the utilization of alternative fertilizers in agriculture. Struvite is a promising P source, but its potential role as a fertilizer is dependent on different physical, chemical, and biological properties, which are very heterogeneous in soil, complicating the prediction of the best soil conditions for its application. Here, we evaluated the solubility of struvite in soil, its redistribution into P fractions, and its potential abiotic and biotic drivers in 62 globally distributed soils with contrasting properties through an incubation assay. We found that after 40 d, about 35% of struvite P was redistributed into soil fractions more accessible to plants and microbes. Phosphorus redistribution from struvite was driven by a complex suite of soil physical, chemical, and microbial properties as well as environmental factors that varied across soils. Soil texture played a critical role in determining the redistribution of P in struvite-amended soils in soluble (H2O extraction), labile (NaHCO3 extraction), and moderately labile (NaOH extraction) fractions. In addition, the soil solution cation concentration was one of the most important drivers of available struvite-derived P fractions. The great importance of texture and cations in determining struvite-derived P fractions in soil was contrasted with the relatively minor role of pH. At the microbial level, the number of bacterial operational taxonomic units (OTUs) from the unfertilized soils that correlated with struvite-derived P fractions was higher than that of fungi. The number of OTUs that correlated with the struvite-derived soluble P fraction was dominated by fungi, whereas the number of OTUs that correlated with the struvite-derived labile P fraction was dominated by bacteria. Overall, this study provided a predictive framework for the potential use of struvite as a P fertilizer in contrasting soils. 相似文献
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Luis D. Jimnez‐Martínez Carlos A. lvarez‐Gonzlez Erick De la Cruz‐Hernndez Dariel Tovar‐Ramírez Mario A. Galaviz Susana Camarillo‐Coop Rafael Martínez‐García Bartolo Concha‐Frías Emyr Pea 《Aquaculture Research》2019,50(1):162-172
The tropical gar (Atractosteus tropicus) is an economically and socially important freshwater fish species from southeastern Mexico, with high aquaculture potential. This study determined the expression of acetyl‐CoA carboxylase (ACC1), fatty acid synthase (FAS), and carnitine palmitoyl transferase 1 (CPT1C) in several tissues of adult specimens, as well as in early ontogeny stages of tropical gar. Partial sequences of all genes were obtained for brain, liver, muscle, mesenteric adipose, kidney, testis, gill, and heart in males. Specific qPCR primers were used to compare the expression between tissues and also during larviculture, starting with embryos (0 days after hatching, [DAH]), and at 5, 10, 15, 20, 25, and 30 DAH. Mesenteric adipose tissue, liver, and muscle showed maximum FAS, ACC1, and CPT1C expression. Additionally, the highest expression of lipogenic genes was detected in embryos (0 DAH), decreasing between 5 and 10 DAH, then increasing at 15 DAH, and ultimately decreasing again from 20 DAH onwards. Based on these results, it can be concluded that genes encoding ACC1, FAS, and CPT1C are expressed differentially across tissues of tropical gar adults, and are regulated during larval development. 相似文献
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The selection by sheep (six Coopworth ewe hoggets, 44·3 ± 4·6 kg live weight) and goats (six Saanen/Anglo‐Nubian yearling males, 38·1 ± 3·8 kg live weight) for perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) and for sward height was measured in two experiments involving paired turves. Pairs of turves with herbage of differing height and of either the same or different plant species were offered. One sward (fixed height species, FHS) was always offered at 130 mm and the other (variable height species, VHS) at 130, 90 or 50 mm. Turves (450 mm × 220 mm) were cut to a soil depth of 100–150 mm from areas of perennial ryegrass and white clover regrown to the desired height after previously being cut to 30 mm. Each turf in a pair was weighed (±1 g) before and after grazing by penned animals maintained on a barley‐based pelleted diet. The number of prehending bites taken from each turf was recorded over a grazing period (128 ± 12 s). Bite mass, bite rate and intake rate were calculated. As the sward height of the VHS turf declined, an increasing proportion of the diet was selected from the 130 mm turf. When averaged over all height contrasts, both animal species selected a higher proportion (0·776 ± 0·026) of their diet from 130‐mm white clover than from 130‐mm perennial ryegrass (0·591 ± 0·018) turves. On average, goats selected a higher proportion (0·721 ± 0·022) of their dry‐matter (DM) intake from the 130‐mm turf than sheep (0·646 ± 0·019), but the effect was not consistent. In contrasts with perennial ryegrass as the VHS (and both perennial ryegrass and white clover as FHS), the proportion of the diet selected from the 130‐mm turf was very similar for both animal species. However, with white clover as the VHS (and both perennial ryegrass and white clover as FHS), goats selected a higher proportion of their intake from the 130‐mm turf to the extent that in the 130‐mm perennial ryegrass/50‐mm white clover contrast sheep showed as strong selection for 50‐mm white clover as goats did for 130‐mm perennial ryegrass. This lesser selection of goats for white clover as its height in a sward declines is likely to contribute to the higher white clover content observed in swards grazed by goats. Bite mass was greater on white clover (246 ± 5 mg DM bite–1) than on perennial ryegrass (173 ± 5 mg DM bite–1) and was greater for goats (255 ± 6 mg DM bite–1) than for sheep (195 ± 5 mg DM bite–1). Bite rate was greater on perennial ryegrass (45·9 ± 1·0 bites min–1) than on white clover (39·9 ± 1·0 bites min–1) and was greater for sheep (45·5 ± 1·1 bites min–1) than for goats (42·5 ± 1·1 bites min–1). Apparent intake rate by both sheep and goats was lower (mean, 5·0 ± 0·29 g DM min–1) on 130 mm perennial ryegrass/white clover than on 130 mm perennial ryegrass/perennial ryegrass (7·0 ± 0·27 g DM min–1), but was higher (9·62 ± 0·29 g DM min–1) on 130‐mm white clover/perennial ryegrass than on 130‐mm white clover/white clover (8·2 ± 0·29 g DM min–1) combinations. 相似文献
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Figuerola J Jiménez-Clavero MA López G Rubio C Soriguer R Gómez-Tejedor C Tenorio A 《Veterinary microbiology》2008,132(1-2):39-46
The rapid range expansion of West Nile Virus has raised interest in understanding the population dynamics and dispersal patterns of emerging infectious diseases by wildlife. We analyzed different ecological and evolutionary factors related to West Nile Virus neutralizing antibody prevalence in 72 bird species sampled in southern Spain. Prevalence of antibodies reached its maximum during the autumn and winter in comparison to summer months. Prevalence of antibodies was directly related to body mass and migratory behaviour. The greater prevalence of antibodies observed in summer migrants can be explained, among other factors, by the diversity of localities involved in their life cycles or the geographic areas visited during their migrations. Greater prevalence in larger species was explained by their longevity because the relationship was already significant when analyzing only first year birds, and probably also involved a high attraction to vectors by larger hosts. Coloniality and winter gregarism were unrelated to the prevalence of antibodies against this highly host generalist pathogen. Evolutionary relationships between species were unrelated to differences in the prevalence of antibodies. Our results suggest larger species as good candidates for easy, faster and cheaper monitoring of local, seasonal and annual changes in WN virus serology. 相似文献
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A crude ginseng extract (GS) and the purified ginsenoside R(b1) (R(b1)) were evaluated for their adjuvant effects in dairy cattle at immunisation with ovalbumin (OVA) and/or a Staphylococcus aureus bacterin used for prevention of bovine mastitis. To evaluate a suitable dose of GS as an adjuvant, 36 lactating cows were randomly divided into six groups. The cows were inoculated twice intramuscularly with a 2-week interval, with saline solution, OVA in saline, or OVA in combination with 4, 16 or 64 mg GS, or Al(OH)(3). The level of specific antibodies to OVA in serum and milk whey was measured before immunisations and 1-5 weeks after the second immunisation. The antibody response in serum was significantly higher in animals immunised with OVA and GS than in animals immunised with OVA alone. A significant increase in milk antibody titres compared with OVA only was only found 2 weeks after the second immunisation in the group immunised with OVA and 4 mg GS. In the second part of the study, 18 heifers were randomly divided into three groups and were immunised twice intramuscularly with a two week interval, with the S. aureus bacterin (control), or with the bacterin in combination with 4 mg GS or 1mg R(b1). The specific antibody response to S. aureus and the lymphocyte proliferation after stimulation with PWM, concanavalin A (Con A) or a specific S. aureus antigen was evaluated in blood samples taken before and after immunisations as specified above. Addition of R(b1) resulted both in significantly higher antibody production and lymphocyte proliferation in response to PWM, Con A and S. aureus antigens than in the control group. Addition of GS induced a significantly higher lymphocyte proliferation in response to PWM and Con A than the control, but had no additional effect on the antibody production. In conclusion, both GS and R(b1) were safe adjuvants, and R(b1) had the strongest adjuvant effects, when used for immunisation against S. aureus in dairy cattle. Field trials are warranted to test the ability of GS and R(b1) to enhance the efficacy of mastitis vaccines in protection against intramammary infections. 相似文献
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This research investigated the impact of semolina dough formulation (percentage of sourdough [SD] addition and presence of yeast [Y] or common wheat gluten [G]) added singly and in combination on the sensory and physicochemical profiles of fresh and stored sourdough‐started durum breads, particularly Moddizzosu type. Main distinctive features of breads were identified, and optimal amounts of SD addition in presence of either yeast or gluten were used to achieve high‐quality fresh and stored soured durum breads made with semolina and remilled semolina at a ratio of 80:20. Common features of durum breads included color parameters and crumb grain characteristics of either fresh or stored samples. Increasing SD significantly increased scores for overall acceptability. In yeasted costarted samples, a linear promotion of both aroma and taste intensity resulted from increasing amounts of SD, whereas the opposite trend was observed for unyeasted breads. Higher values for degree of acidification, specific volume, crumb cohesiveness, resilience, and springiness but lower pH, moisture content, crumb hardness, and chewiness in durum samples were achieved with increased SD. The presence of Y counteracted acidification, harmonized volume increase, hardness, cohesiveness, springiness, and resilience, minimizing the effects of the SD added. Y and G acting singly as crumb softeners when added together to soured durum breads started with SD at a dose >10% provided lower and slower crumb firming kinetics. Breads with especially slow retrogradation kinetics corresponded to yeasted started samples with or without added gluten, regardless the presence or absence of SD. In unyeasted soured breads, the dose of SD slightly decreased the rate and extent of amylopectin retrogradation, irrespective of gluten addition. 相似文献
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At least two age-dependent proteins were detected in nasal secretion (NS) of young calves by crossed immunoelectrophoresis. One of them was identified as fetuin. The other one was not identified. The concentration of fetuin in NS was found to increase in cases where a sample of NS had been obtained at birth and a second sample taken within 11 days. Thereafter a decrease was always found towards day 15 or 30. 相似文献