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991.
The aims were (a) to quantify the number of Duddingtonia flagrans chlamydospores per gram of faeces (CPG) recovered from sheep administered with different oral doses and, (b) to describe the relationship between CPG and eggs per gram of faeces (EPG) on the efficacy to reduce Haemonchus contortus infective larvae. Three doses of chlamydospores per kg BW were orally administered during seven days: (T1) non treated control group, (T2) 1 × 106, (T3) 2.5 × 106 and (T4) 5 × 106. Three lambs, infected with H. contortus, were used per group. Faeces were obtained from the rectum of each lamb during the fungal administration period (days 0–6) and for six days after that period. Four coproculture replicates were made from each animal in days 2, 4, 6, 8 and 10. A higher chlamydospore dose produced higher CPG in faeces (p < 0.05), but a clear dose dependent effect was not found either in the larvae reduction or in the CPG:EPG ratio. When ratios were re-analyzed, independently of the treatment groups of origin, a better efficacy was obtained with a ratio from 5 to 10 CPG:EPG and a higher ratio (>10 per egg) showed a lower reduction efficacy (p < 0.05). The binomial analysis showed that for each unit of increment in CPG:EPG ratio there was a reduction of larvae number until a point (between 5 and 10 CPG:EPG) where no further reduction was detected. The surface response test indicated that the number of larvae was reduced by CPG until possible saturation. The highest CPG:EPG ratios did not necessarily improve efficacy of D. flagrans.  相似文献   
992.
Francisella tularensis, a small Gram-negative facultative intracellular bacterium, is the causative agent of tularaemia, a severe zoonotic disease transmitted to humans mostly by vectors such as ticks, flies and mosquitoes. The disease is endemic in many parts of the northern hemisphere. Among animals, the most affected species belong to rodents and lagomorphs, in particular hares. However, in the recent years, many cases of tularaemia among small monkeys in zoos were reported. We have developed a real-time PCR that allows to quantify F. tularensis in tissue samples. Using this method, we identified the spleen and the kidney as the most heavily infected organ containing up to 400 F. tularensis bacteria per simian host cell in two common squirrel monkeys (Saimiri sciureus) from a zoo that died of tularaemia. In other organs such as the brain, F. tularensis was detected at much lower titres. The strain that caused the infection was identified as F. tularensis subsp. holarctica biovar I, which is susceptible to erythromycin. The high number of F. tularensis present in soft organs such as spleen, liver and kidney represents a high risk for persons handling such carcasses and explains the transmission of the disease to a pathologist during post-mortem analysis. Herein, we show that real-time PCR allows a reliable and rapid diagnosis of F. tularensis directly from tissue samples of infected animals, which is crucial in order to attempt accurate prophylactic measures, especially in cases where humans or other animals have been exposed to this highly contagious pathogen.  相似文献   
993.
如何使母猪与公猪的接触效果取得最佳化,以使母猪的人工授精能够获得良好效果. 猪人工授精技术的应用使全球养猪生产对公猪的需求量大大减少.但是臆断在猪群水平上无公猪存在的任何情况下就能获得高效的人工授精结果,那就错了.不应忽视与公猪接触有关的因素对母猪良好的刺激反应所产生的作用,应融入可获得成功的人工授精的具体操作之中.  相似文献   
994.
We carried out an inter-laboratory trial to compare the serological tests commonly used for the detection of specific Neospora caninum antibodies in cattle in Ibero-American countries. A total of eight laboratories participated from the following countries: Argentina (n = 4), Brazil (n = 1), Peru (n = 1), Mexico (n = 1), and Spain (n = 1). A blind panel of well-characterized cattle sera (n = 143) and sera representative of the target population (n = 351) was tested by seven in-house indirect fluorescent antibody tests (IFATs 1–7) and three enzyme-linked immunosorbent assays (ELISAs 1–3; two in-house and one commercial). Diagnostic performance of the serological tests was calculated and compared according to the following criteria: (1) the “Pre-test information,” which uses previous epidemiological and serological data; (2) the “Majority of tests,” which classifies a serum as positive or negative according to the results obtained by most tests evaluated. Unexpectedly, six tests showed either sensitivity (Se) or specificity (Sp) values lower than 90%. In contrast, the best tests in terms of Se, Sp, and area under the ROC curve (AUC) values were IFAT 1 and optimized ELISA 1 and ELISA 2. We evaluated a high number of IFATs, which are the most widely used tests in Ibero-America. The significant discordances observed among the tests regardless of the criteria employed hinder control programs and urge the use of a common test or with similar performances to either the optimized IFAT 1 and ELISAs 1 and 2.  相似文献   
995.
The aim of this study was to evaluate the effect of supplementation of pig diets in the growth and termination phases with different calcium sources. In experiment I, 36 whole males were distributed in randomized blocks in six groups, with six replications. A basal diet was formulated to meet the animals’ nutritional requirements except for calcium (0.09%), and the sources evaluated (calcitic limestone, monodicalcium phosphate, calcinated bone flour, and oyster flour) replaced the basal diet to provide 0.59% of total calcium. To determine the endogenous calcium, a diet containing low calcium (0.019%) was given simultaneously to another group of animals. Feces and urine were collected for determination the coefficients of apparent and true digestibility. In experiment II, 160 piglets were distributed in randomized blocks in four treatments, with five replications and four animals per experimental unit. Carcass and performance parameters, calcium concentration in bone and serum, and bone parameters were evaluated. The data were submitted to analysis of variance and factorial. The calcium source did not influence the digestibility coefficients determined by total collection (P > 0.05). The digestibility of Ca from oyster flour estimated by collection with an indicator was higher than that from the other sources (P < 0.05). Calcium sources did not interfere in the evaluated parameters (P > 0.05). The sources studied in this work can be used to supplement growing pigs’ diets.  相似文献   
996.
Evaluating phenotypic diversity makes it possible to identify discrepancies in aptitudes among animals of different genetic bases, which is an indicator of adaptive or selective differences between populations. The objective of this work was to evaluate the morphofunctional diversity of 452 male and female adult equines (Arabian, Quarter Mile, Pantaneiro, and Criollo breeds, and undefined crossbreeds of horses and mules) raised in the Pantanal biome (Brazil). Linear measurements were performed to estimate conformation indexes. Initially, a discriminant analysis was performed, regardless of the animal’s size, followed by factor analysis. The factors were characterized and used as new variables. The diversity among equines and their relationship with the factors were evaluated using multivariate analysis. The factors were classified according to their decreasing importance: balance, rusticity, and robustness for the measurement factors; and load, ability, conformation, and equilibrium for the index factors. The genetic groups of equines have well-defined morphofunctional characteristics. The main differences are based on the rusticity and ability typologies in relation to those based on performance. Equines introduced to the Pantanal biome presented a more robust and compact body with good conformation. As a result, these horses may have superior athletic performance during equestrian activities when compared to the Pantaneiro local breed. However, this biotype may represent less rusticity (less adaptive capacity). Therefore, the regional breed can be equal or better in equestrian activities than breeds introduced to the Pantanal biome. Thus, breeders may cross horses from local breeds as an alternative to those introduced. Undefined crossbred male equines presented a different profile from the Pantaneiro breed, which may indicate little use of crossbreeds in breeding.  相似文献   
997.
Parasitic agents have been associated with keratitis, but a diagnosis of parasitic keratitis has not been commonly made in domestic animals. The purpose of this study was to describe the clinical and histopathological findings in seven dogs with chronic keratitis caused by microfilariae diagnosed in Brazil. All dogs presented with superficial corneal opacities of varying degrees affecting the perilimbal and central regions of the cornea, with other opaque areas appearing as crystalline deposits and corneal vascularization. The lesions were bilateral and were associated with mild‐to‐moderate conjunctival hyperemia. There was no history of blepharospasm or pruritus, and no subjects presented with epithelial erosions. Corneal biopsy revealed free microfilariae in the corneal stroma, with varying degrees of inflammation and collagen fiber destruction. The microfilariae were also found in skin lesions by skin snip technique. No adult worms were found in these dogs, and no dogs were on heartworm preventative before diagnosis. Monthly doses of oral ivermectin improved ocular and dermal lesions. One dog showed complete remission with the treatment. The species of the microfilariae was not identified.  相似文献   
998.
Aspergillosis is an infectious, non‐contagious fungal disease of clinical importance in flamingo collections. Itraconazole is an antifungal drug commonly used in the treatment and prophylaxis of avian aspergillosis. Studies have shown that dosage regimes in birds vary based on different itraconazole presentation and administration methods. This investigation used a population pharmacokinetic approach to study itraconazole in lesser flamingos. Itraconazole was administered orally at 10 mg/kg to 17 flamingos. A sparse blood sampling was performed on the subjects, and samples were collected at 1, 2, 3, 5, 8, 12, 16, 21, and 24 hr post‐drug administration. Twelve flamingos were sampled three times, three birds bled twice and two sampled once. Itraconazole in plasma was quantified using high‐pressure liquid chromatography (HPLC). A one‐compartment pharmacokinetic model with first order absorption was fitted to the data using nonlinear mixed effects modeling (NLME) to determine values for population parameters. We identified a long half‐life (T½) of more than 75 hr and a maximum plasma concentration (CMAX) of 1.69 µg/ml, which is above the minimal inhibitory concentrations for different aspergillus isolates. We concluded that plasma drug concentrations of itraconazole were maintained in a population of flamingos above 0.5 ug/ml for at least 24 hr after a single oral dose of 10 mg/kg of itraconazole solution.  相似文献   
999.

Nitrogen (N) plays an important role in small-scale dairy systems, both in production costs and as an indicator of environmental impact. The objective of this study was to quantify nitrogen inputs and outputs to identify areas for improvement in nitrogen utilisation efficiency (NUE). Evaluation was in 12 small-scale dairy farms with different feeding strategies. Six followed the traditional cut and carry of irrigated temperate pastures (CUT), and six have implemented grazing of pastures (GRZ), quantifying N inputs and outputs from May 2016 to April 2017. Data were analysed by ANOVA following a split-plot model with season (rainy or dry) as main plots and feeding strategy (CUT or GRZ) as split-plots, with results in kilograms N per hectare and kilograms N per cow. There were differences (P < 0.05) between seasons and strategies in N inputs from purchased N fertilisers and purchased feeds as concentrates and roughages, showing different N inputs and outputs whether in CUT or GRZ strategies. There were also significant interactions between seasons and strategies as in the sale of animals, where GRZ sell throughout the year, while CUT sell at the beginning of the dry season. N balance ranged from 33.9 to 183.0 kg N/ha, and 37.8 to 111.0 as kilograms N per cow with an interaction (P < 0.05) between season and strategies. There was a larger N surplus in GRZ during the rainy season from fertiliser inputs, which reduced N utilisation efficiency (NUE). Mean NUE in kilograms N per hectare and kilograms N per cow was 19%, with the higher efficiency for GRZ in the dry season. Farms with the best NUE had lower use of fertilisers and purchased feeds.

  相似文献   
1000.
The aim of this work was to investigate the methylation and hydroxymethylation status of mesenchymal stem cells (MSC) from amniotic fluid (MSC‐AF), adipose tissue (MSC‐AT) and fibroblasts (FIB‐control) and to verify the effect of trichostatin A (TSA) on gene expression and development of cloned bovine embryos produced using these cells. Characterization of MSC from two animals (BOV1 and BOV2) was performed by flow cytometry, immunophenotyping and analysis of cellular differentiation genes expression. The cells were used in the nuclear transfer in the absence or presence of 50 nM TSA for 20 hr in embryo culture. Expression of HDAC1, HDAC3 and KAT2A genes was measured in embryos by qRT‐PCR. Methylation results showed difference between animals, with MSC from BOV2 demonstrating lower methylation rate than BOV1. Meanwhile, MSC‐AF were less hydroxymethylated for both animals. MSC‐AF from BOV2 produced 44.92 ± 8.88% of blastocysts when embryos were exposed to TSA and similar to embryo rate of MSC‐AT also treated with TSA (37.96 ± 15.80%). However, when methylation was lower in FIB compared to MSC, as found in BOV1, the use of TSA was not sufficient to increase embryo production. MSC‐AF embryos expressed less HDAC3 when treated with TSA, and expression of KAT2A was higher in embryos produced with all MSC and treated with TSA than embryos produced with FIB. The use of MSC less methylated and more hydroxymethylated in combination with embryo incubation with TSA can induce lower expression of HDAC3 and higher expression of KAT2A in the embryos and consequently improve bovine embryo production.  相似文献   
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