Lupine induced "crooked calf disease" in Washington and Oregon: identification of the alkaloid profiles in Lupinus sulfureus, Lupinus leucophyllus, and Lupinus sericeus

Several lupines (Lupinus spp.) present on western U.S. rangelands contain alkaloids that are teratogenic to livestock and cause congenital birth defects in calves (crooked calf disease). Periodically, large losses of calves due to lupine-induced "crooked calf disease" occur in northern Oregon and eastern Washington state. Five lupine populations from this area representing three species (L. leucophyllus, L. sulfureus, and L. sericeus) were evaluated taxonomically and by gas chromatography/mass spectrometry, and the major alkaloids in each lupine species were identified. The teratogenic alkaloid anagyrine was present in both of the lupine species responsible for the high outbreaks in east-central Washington and northeastern Oregon. However, the alkaloid profiles of the two lupines identified as L. leucophyllus were dissimilar, as were the alkaloid profiles of the two lupines identified as L. sulfureus. Botanical classification is not sufficient to determine potential teratogenicity, and it must be followed by chemical characterization to determine risk to livestock.     

Timing and order of different insecticide classes drive control of Drosophila suzukii; a modeling approach

The spotted-wing drosophila, Drosophila suzukii Matsumura, is an invasive pest causing significant damage to soft skinned fruits. Control of D. suzukii is critical since there is no tolerance for infested fruit in the market. While most insecticides control one or more D. suzukii life-stages (e.g., egg, larvae, and adult), the impact of insecticides that are toxic to immature stages  is unclear on the subsequent generation of a field population. Insecticides were applied at field recommended rates on cherries and blueberries in the laboratory to determine immature D. suzukii mortality. Spinetoram, cyantraniliprole, malathion, methomyl, spinosad, and phosmet resulted in relatively high mortality of all immature life stages. Zeta-cypermethrin, cyclaniliprole, and fenpropathrin resulted in lower mortality of egg and all larval instars. Malathion was also applied to lowbush blueberries with different fruit sizes (small, medium, and large) in the laboratory and there was no statistical difference in mortality rates depending on fruit sizes. Mortality data from the laboratory experiments were used to parameterize a refined D. suzukii population model. The model revealed that the timing and order of different insecticide classes are important to control D. suzukii population. Model runs that included early applications of more effective insecticides resulted in high immature mortality and greater reduction of D. suzukii populations compared to treatments applied later.

     

作物-土壤氮循环对大气CO2浓度和温度升高响应的研究进展

在地球化学元素循环中,氮素是最重要、最活跃的营养元素之一。农田生态系统中的氮素很大程度上决定农作物的产量和品质。然而,在全球气候变化背景下,随着大气CO₂浓度和温度升高,作物-土壤氮循环的变化可能显著影响农田生态系统中的作物生产。因此,研究作物-土壤氮循环对大气CO₂浓度和温度升高的响应,能够为科学合理地预测未来气候条件下,农田生态系统中作物的氮素需求,以及保障农作物产量的稳定供应提供理论依据,对于全面认识全球气候变化背景下的农田生态系统氮素循环过程及土壤可持续利用具有重要意义。本文综述了大气CO₂和温度升高对作物氮素吸收和分配,以及与氮有效性密切相关的土壤氮转化的影响,并系统总结了二者对作物-土壤氮循环过程产生的交互作用。总结以往研究发现,在大气CO₂浓度升高条件下,作物的蒸腾作用减弱,但光合作用增强,生物量加大,根系分支和根表面积增加,豆科作物的根瘤固氮能力提高,因此整体上促进作物对氮的吸收,并且增加作物向籽粒中分配氮的比例,但作物的平均氮浓度降低。此外,高CO₂浓度提高了土壤酶活性,增强了土壤有机氮矿化作用、硝化及反硝化作用,加速了土壤氮转化。升温和CO₂浓度升高对作物-土壤氮循环产生正向或负向的交互作用,主要表现在：高温和高CO₂浓度对作物的生物量、光合作用、地下部氮分配、根系分支以及根表面积具有协同促进作用,升高温度减轻了高CO₂浓度对作物蒸腾作用和作物氮浓度的抑制作用。然而,升温抑制了高CO₂浓度对作物向籽粒中氮分配、氮吸收以及产量的促进作用;升温虽然能进一步增强高CO₂浓度对土壤酶活性和有机氮矿化的促进作用,但是对于土壤硝化和反硝化作用,二者的交互作用以及相关的分子机制尚不明确。大气CO₂升高和温度升高对土壤微生物,以及微生物与作物之间的耦合关系的研究比较薄弱,特别是由微生物主导的氮循环过程及其对全球气候变化的反馈机制是未来研究的重点。本文提出利用16S rRNA、DGGE、T-RFLP、qPCR、RT-PCR技术、蛋白组学以及稳定性同位素探针原位研究技术,可以将复杂环境中微生物物种组成及其生理功能进行耦合分析,揭示大气CO₂浓度与温度对作物-土壤氮循环过程的交互作用机理,增强对气候变化下农田生态系统氮素循环响应的预测能力,为农田生态系统有效地适应气候变化提供科学的理论依据。     

An investigation of the effects of ketoprofen following rumen fistulation surgery in lactating dairy cows

Post-operative pain management following rumen surgery is not common practice. We examined the effect of providing the pain medication ketoprofen to dairy cattle following the first stage of a rumen cannulation surgery, which involves an incision in the body wall and exteriorizing and clamping the rumen. The results of this study provide clear evidence that the first stage of the surgery was painful and ketoprofen at the time of and 24 h following surgery, alleviated some, but not all, of the post-surgical pain. Pain mitigation should be included when performing flank surgery in cattle.     

Risk factors for bovine mastitis in the Central Province of Sri Lanka

A study of the risk factors associated with mastitis in Sri Lankan dairy cattle was conducted to inform risk reduction activities to improve the quality and quantity of milk production and dairy farmer income. A cross-sectional survey of randomly selected dairy farms was undertaken to investigate 12 cow and 39 herd level and management risk factors in the Central Province. The farm level prevalence of mastitis (clinical and subclinical) was 48 %, similar to what has been found elsewhere in South and Southeast Asia. Five cow level variables, three herd level variables, and eight management variables remained significant (p?相似文献   

Atypical fibrosarcoma in the skin of a Roborovski hamster (Phodopus roborovskii)

A 2.5‐year‐old intact male Roborovski hamster (Phodopus roborovskii) was presented with a large subcutaneous mass overlying the abdomen, affecting the animal's ambulation and access to different compartments of the cage through narrow tubing. Ultrasound examination delineated a well‐circumscribed mass in the subcutis of the caudoventral abdominal region. The mass was surgically excised and on cytologic examination showed, in a background of blood, a small population of individually arranged oval to spindle‐shaped cells that exhibited a moderate degree of anisokaryosis, coarsely stippled chromatin, one or more prominent nucleoli, and lightly basophilic well‐defined cytoplasmic processes. Histologically, the mass was composed of interlacing streams and bundles of pleomorphic spindle cells (ganglion‐like cells) with variable amounts of collagenous stroma. The neoplastic cells exhibited moderate features of malignancy. These cells stained intensely with vimentin, but not with any other markers, including antibodies to cytokeratin AE1/AE3, S100 protein, desmin, smooth muscle actin, synaptophysin, neurofilament, and androgen receptor. Based on histologic features, the mass was diagnosed as an atypical fibrosarcoma. This is the first report of an atypical fibrosarcoma in a Roborovski hamster and one of few reports of atypical fibrosarcoma in domesticated hamsters overall.     

Effect of rider experience and evaluator expertise on subjective grading of lameness in sound and unsound sports horses under saddle

The primary objective of this study was to investigate whether rider experience influences the assessment and grading of lameness in horses based on under-saddle gait analysis. Thirteen adult sports horses in active training were included in the study. After a baseline lameness and neurologic examination by the principal investigators, horses were videotaped while being ridden by an experienced and a less experienced rider. A 3-minute video was made for each horse and rider and 26 videos were randomly ordered and compiled on a DVD. Veterinarians with different levels of experience in evaluating lameness and veterinary students viewed the DVD and assigned a lameness score to each horse/rider combination. In a model accounting for the expertise of the evaluator, there was no difference in overall lameness scores between experienced and less experienced riders. This result was consistent for both sound and unsound horses. The overall lameness scores reported by specialists and students, however, differed significantly. The lameness score reported by the study participants while the horse was ridden was significantly associated with the subjective baseline lameness assessment reported by the principal investigators for the same limb when the horse was not under saddle. Additional work is necessary to determine whether riders with even lower skill levels would further alter the balance and motion pattern of the horse and have more influence on subjective grading of lameness.