Identification and quantification of benzimidazole resistance polymorphisms in Haemonchus contortus isolated in Northeastern Brazil     

Jessica Maria Leite dos Santos  Jomar Patrício Monteiro  Wesley Lyeverton Correia Ribeiro  Iara Tersia Freitas Macedo  Ana Lourdes Fernandes Camurça-Vasconcelos  Luiz da Silva Vieira  Claudia Maria Leal Bevilaqua 《Veterinary parasitology》2014,199(3-4):160-164

Haemonchus contortus is the most prevalent nematode in Brazil. The objective of this study was to select 6 populations of H. contortus of known or suspected benzimidazole resistance status and characterize these using quantitative real-time polymerase chain reaction (qPCR) for single nucleotide polymorphisms (SNPs) F200Y, F167Y and E198A in the β-tubulin isotype 1 gene. qPCR was performed using DNA from a pool of 10 adult male H. contortus from a single animal per farm. Faecal egg count reduction test (FECRT) and egg hatch test (EHT) were used to determine the resistance status. Samples were obtained from 6 farms located in 5 counties in the Ceará State: Tauá, Boa Viagem, Quixadá, Santa Quitéria and Solonópole. The inbred-susceptible-Edinburgh (ISE) isolate was used as reference for comparative purposes in the qPCR. Benzimidazole resistance was detected by FECRT on all farms with efficacy values ranging from 0 to 51%. EC50 values as determined by EHT were all above 1.49 μg/ml. High frequencies of the resistant SNPs F200Y and F167Y alleles were detected but no resistance was detected at SNP E198A. Our results suggest that the SNPs F167Y and F200Y are both important for benzimidazole resistance in the studied populations.  相似文献   

Faecal nitrogen excretion as an approach to estimate forage intake of wethers     

G. V. Kozloski  L. Oliveira  C. H. E. C. Poli  E. B. Azevedo  D. B. David  H. M. N. Ribeiro Filho  S. G. Collet 《Journal of animal physiology and animal nutrition》2014,98(4):659-666

Data from twenty‐two digestibility trials were compiled to examine the relationship between faecal N concentration and organic matter (OM) digestibility (OMD), and between faecal N excretion and OM intake (OMI) by wethers fed tropical or temperate forages alone or with supplements. Data set was grouped by diet type as follows: only tropical grass (n = 204), only temperate grass (n = 160), tropical grass plus supplement (n = 216), temperate grass plus supplement (n = 48), tropical grass plus tropical legume (n = 60) and temperate grass with ruminal infusion of tannins (n = 16). Positive correlation between OMD and either total faecal N concentration (Nfc, % of OM) or metabolic faecal N concentration (Nmetfc, % of OM) was significant for most diet types. Exceptions were the diet that included a tropical legume, where both relationships were negative, and the diet that included tannin extract, where the correlation between OMD and Nfc was not significant. Pearson correlation and linear regressions between OM intake (OMI, g/day) and faecal N excretion (Nf, g/day) were significant for all diet types. When OMI was estimated from the OM faecal excretion and Nfc‐based OMD values, the linear comparison between observed and estimated OMI values showed intercept different from 0 and slope different from 1. When OMI was estimated using the Nf‐based linear regressions, the linear comparison between observed and estimated OMI values showed neither intercept different from 0 nor slope different from 1. Both linear comparisons showed similar R² values (i.e. 0.78 vs. 0.79). In conclusion, linear equations are suitable for directly estimating OM intake by wethers, fed only forage or forage plus supplements, from the amount of N excreted in faeces. The use of this approach in experiments with grazing wethers has the advantage of accounting for individual variations in diet selection and digestion processes and precludes the use of techniques to estimate forage digestibility.  相似文献   

Effects of antiproteolytic agents on corneal epithelial viability and matrix metalloproteinase‐2 and metalloproteinase‐9 activity in alkali‐burned corneas of rats     

Dunia Y. Trujillo Piso  Alexandre P. Ribeiro  Miguel L. Silva  Patrícia J. Guimarães  Adriana Morales  Bianca C. Martins  Ivan M. Padua  Roberta Renzo  Alexandre L. Andrade  Ricardo R. Uscátegui  José L. Laus 《Veterinary ophthalmology》2014,17(1):23-31

  相似文献   

Short-term changes in the soil carbon stocks of young oil palm-based agroforestry systems in the eastern Amazon     

Walmir Ribeiro de Carvalho  Steel Silva Vasconcelos  Osvaldo Ryohei Kato  Carlos José Bispo Capela  Débora Cristina Castellani 《Agroforestry Systems》2014,88(2):357-368

The current expansion of the oil palm (Elaeis guineensis Jacq.) in the Brazilian Amazon has mainly occurred within smallholder agricultural and degraded areas. Under the social and environmental scenarios associated with these areas, oil palm-based agroforestry systems represent a potentially sustainable method of expanding the crop. The capacity of such systems to store carbon (C) in the soil is an important ecosystem service that is currently not well understood. Here, we quantified the spatial variation of soil C stocks in young (2.5-year-old) oil palm-based agroforestry systems with contrasting species diversity (high vs. low); both systems were compared with a ~10-year-old forest regrowth site and a 9-year-old traditional agroforestry system. The oil palm-based agroforestry system consisted of series of double rows of oil palm and strips of various herbaceous, shrub, and tree species. The mean (±standard error) soil C stocks at 0–50 cm depth were significantly higher in the low (91.8 ± 3.1 Mg C ha^?1) and high (87.6 ± 3.3 Mg C ha^?1) species diversity oil palm-based agroforestry systems than in the forest regrowth (71.0 ± 2.4 Mg C ha^?1) and traditional agroforestry (68.4 ± 4.9 Mg C ha^?1) sites. In general, no clear spatial pattern of soil C stocks could be identified in the oil palm-based agroforestry systems. The significant difference in soil carbon between the oil palm area (under oil palm: 12.7 ± 2.3 Mg C ha^?1 and between oil palm: 10.6 ± 0.5 Mg C ha^?1) and the strip area (17.0 ± 1.4 Mg C ha^?1) at 0–5 cm depth very likely reflects the high input of organic fertilizer in the strip area of the high species diversity oil palm-based agroforestry system treatment. Overall, our results indicate a high level of early net accumulation of soil C in the oil palm-based agroforestry systems (6.6–8.3 Mg C ha^?1 year^?1) that likely reflects the combination of fire-free land preparation, organic fertilization, and the input of plant residues from pruning and weeding.  相似文献   

Evaluation of the effect of ketoprofen on experimentally induced ephemeral fever in dairy heifers   总被引：1，自引：0，他引：1  

DC FENWICK  RCW DANIEL 《Australian veterinary journal》1996,74(1):37-41

Objective To evaluate ketoprofen for the therapy of ephemeral fever.
Design A blind controlled clinical trial.
Animals Sixteen cattle (one immature Holstein bull, eight Holstein and seven Jersey heifers).
Procedure Ephemeral fever was induced by the intravenous injection of blood leucocyte layer from a clinical case. Ketoprofen solution or a coded placebo was injected intramuscularly at the rate of 3 mg/kg daily for three days.
Results Ketoprofen reversed locomotor dysfunctions significantly compared with controls, but did not have any effect on rectal temperatures, leucocyte counts, plasma fibrinogen concentrations, ionised Ca-concentrations or the presence of dyspnoea.
Conclusion Ketoprofen is a safe and effective drug for the treatment of locomotor symptoms of milk fever, but has no effect on the duration of clinical respiratory abnormalities.  相似文献   

Horse resistance to natural infestations of Anocentor nitens and Amblyomma cajennense (Acari: Ixodidae).     

L M F Borges  P R Oliveira  C L M Lisboa  M F B Ribeiro 《Veterinary parasitology》2002,104(3):265-273

The objective of this study was to investigate some aspects of horse resistance to natural infestations of Anocentor nitens and Amblyomma cajennense over a 2-year period. Free-living stages of A. nitens were used to evaluate the influence of season of the year on horse resistance. Every 2 weeks, 10 selected engorged females, weighing 150-329 mg, were removed from naturally infested horses and were individually placed into glass tubes closed with a cotton stopper, and maintained in an incubator. The biological parameters evaluated varied according to the season of the year, i.e., reproductive efficiency, maximum larval survival (MLS) and egg-hatching rates were significantly lower in spring/summer than in fall/winter. At 14-day intervals, females of A. nitens and A. cajennense were counted on each side of the body of five mares. A comparison between the animal with the lowest infestation and the animal with the highest infestation showed greater differences in animals infested with A. nitens than those infested with A. cajennense. Ten animals were found to carry 64.9% of the total parasite burden of A. cajennense and 88.6% of the highest infestations of A. nitens females. A seasonal variation on intensity of horse resistance to A. nitens was observed during the study. However, this was not observed for A. cajennense. Cross-resistance was observed in animals with the highest total number of A. cajennense and the highest number of A. cajennense adults (r=0.817), larvae (r=0.756), and A. nitens females (r=0.799). These results led to the conclusion that changes in horse resistance to A. nitens occur seasonally. As far as the total population of A. cajennense and the female stage of A. nitens are concerned, horses develop cross-resistance.  相似文献   

Implications of the number of years assessment on recommendation of common bean cultivars          下载免费PDF全文

Ricardo Augusto Diniz Cabral Ferreira  Magno Antonio Patto Ramalho  Fernando Henrique Ribeiro Barrozo Toledo  Angela de Fátima Barbosa Abreu 《Plant Breeding》2015,134(5):599-604

In the common bean crop in Brazil, the requirement of the value for cultivation and use trials is that these experiments must be conducted over two years in three locations per region. Information in regard to the necessary number of years to ensure precision in cultivar recommendation and the influence of evaluated years in the estimation of the GE interaction are still scarce. Using grain yield of five check varieties assessed over 11 years in three sowing seasons per year, the aims of this study are as follows: to measure the relative contribution of the GE interaction, evaluating the implication of the number of years in the estimates of the GE interaction, and infer how many years are needed to ensure precision in cultivar recommendation. For instances, analysis of variance was carried out involving all environments and also combinations of years. The results showed that the GE interaction was greater than all other cross‐effects involving lines. The use of at least two years allows good coincidence in cultivar recommendation compared to the whole period. Increasing the evaluation time is a good strategy, especially when it is difficult to grow three different sowing seasons.  相似文献   

Nitrogen dynamics during ecosystem development in tropical forest restoration     

Nino Tavares Amazonas  Luiz Antonio MartinelliMarisa de Cássia Piccolo  Ricardo Ribeiro Rodrigues 《Forest Ecology and Management》2011,262(8):1551-1557

We considered whether ecological restoration using high diversity of native tree species serves to restore nitrogen dynamics in the Brazilian Atlantic Forest. We measured δ¹⁵N and N content in green foliage and soil; vegetation N:P ratio; and soil N mineralization in a preserved natural forest and restored forests of ages 21 and 52 years. Green foliage δ¹⁵N values, N content, N:P ratio, inorganic N and net mineralization and nitrification rates were all higher, the older the forest. Our findings indicate that the recuperation of N cycling has not been achieved yet in the restored forests even after 52 years, but show that they are following a trajectory of development that is characterized by their N cycling intensity becoming similar to a natural mature forest of the same original forest formation. This study demonstrated that some young restored forests are more limited by N compared to mature natural forests. We document that the recuperation of N cycling in tropical forests can be achieved through ecological restoration actions.  相似文献   

A case study of <Emphasis Type="Italic">Eucalyptus globulus</Emphasis> fingerprinting for breeding     

Maria Margarida Ribeiro  Leopoldo Sanchez  Carla Ribeiro  Fátima Cunha  José Araújo  Nuno M. G. Borralho  Cristina Marques 《Annals of Forest Science》2011,68(4):701-714

• Introduction  

Tree genetic improvement programs usually lack, in general, pedigree information. Since molecular markers can be used to estimate the level of genetic similarity between individuals, we genotyped a sample of a Portuguese Eucalyptus globulus breeding population—a reference population of 125 individuals—with 16 microsatellites (SSR).  相似文献   

Can Non-fumigant Nematicides Be an Alternative to Fumigation on Carrot Fields?     

Andre Luiz Biscaia Ribeiro da Silva  Daniel Tucker Price  Abolfazl Hajihassani  Juan Carlos Diaz-Perez  Elizanilda Ramalho do Rego 《Communications in Soil Science and Plant Analysis》2020,51(13):1826-1833

ABSTRACT

Root-knot nematodes (RKN; Meloidogyne spp.) cause enormous yield reductions in vegetable crops. While nematicides are the most effective method for controlling RKN in carrot (Dacatus carota), the efficacy of non-fumigant nematicides, compared to fumigants, is still not fully understood. The objective of this study was to evaluate the effect of 1,3-dichloropropene, a fumigant nematicide, and fluensulfone, a non-fumigant nematicide, on RKN control and yield of fresh market and processing carrot. Field experiments were conducted in a commercial farm in Lenox, GA. A randomized complete block design (r = 4) was used in a factorial arrangement of 3 nematicide treatments and 2 carrot cultivars. Nematicide treatments were the application of 1,3-dichloropropene, fluensulfone, and untreated control. Carrot cultivars were Baltimore (fresh marketing) and Belgrado (processing). In general, RKN population was low early season, averaging 0.8 RKN 100 cm^?3 of soil. RKN populations increased with crop development and there were significant differences among nematicide treatments. At harvest, RKN populations were lower for fluensulfone (1.1 RKN 100 cm^?3 of soil) and 1,3-dichloropropene (3.2 RKN 100 cm^?3 of soil) compared to Control (26.4 RKN 100 cm^?3 of soil); however, fluensulfone (91,278 kg ha^?1) had higher yield than 1,3-dichloropropene (64,154 kg ha^?1) and Control (61,908 kg ha^?1). Carrot cultivars were similar for RKN population and yield. Overall, the non-fumigant nematicide was more beneficial for carrot production than the fumigant nematicide.  相似文献