不同措施对滨海盐渍土壤呼吸、电导率和有机碳的影响

在苏北滩涂围垦区的轻度和中度盐渍土上,通过田间试验,研究了不同农田管理措施(传统耕作、施用有机肥、氮肥增施、秸秆还田和免耕)对土壤盐分、呼吸和有机碳等的影响。结果表明,0~40cm土层平均电导率在玉米种植季明显升高,小麦种植季出现小幅降低,轻度盐渍土的电导率为4.57~8.20 d S m~(~(-1)) ,中度盐渍土为4.89~10.13 d S m~(~(-1)) ,处理之间秸秆还田最低,免耕最高,秸秆还田和施用有机肥有效减少了土壤盐分含量。与中度盐渍土相比,轻度盐渍土的呼吸强度较高,在夏玉米和冬小麦种植季节分别高约16%和18%。有机肥、氮肥增施、秸秆还田处理的土壤呼吸均高于对照,而免耕较低。两组试验的土壤有机碳和微生物生物量碳均有缓慢增加,其中施用有机肥和秸秆还田可以大幅提高其含量。轻度盐渍土壤代谢熵高于中度盐渍土,总体上对照最高,免耕最低。     

Metabonomic study of the biochemical profiles of heterozygous myostatin knockout swine

Myostatin is a transforming growth factor-βfamily member that normally acts to limit skeletal muscle growth. Myostatin gene(MSTN) knockout(KO) mice show possible effects for the prevention or treatment of metabolic disorders such as obesity and type 2 diabetes.We applied chromatography and mass spectrometry based metabonomics to assess system-wide metabolic response of heterozygous MSTN KO(MSTN+/–) swine. Most of the metabolic data for MSTN+/–swine were similar to the data for wild type(WT) control swine. There were, however,metabolic changes related to fatty acid metabolism,glucose utilization, lipid metabolism, as well as BCAA catabolism caused by monoallelic MSTN depletion.The statistical analyses suggested that:(1) most metabolic changes were not significant in MSTN+/–swine compared to WT swine;(2) only a few metabolic properties were significantly different between KO and WT swine,especially for lipid metabolism. Significantly, these minor changes were most evident in female KO swine and suggested differences in gender sensitivity to myostatin.     

Phenotypical and genotypical characterization of Shewanella putrefaciens strains isolated from diseased freshwater fish

Between 2007 and 2012, a variety of disease outbreaks most often characterized by skin disorders were observed among different species of freshwater fish in Poland. In most cases, the clinical signs included focally necrotized gills, necrotic skin lesions or ulcers. Internally, haemorrhages, oedematous kidney and abnormal spleen enlargement were generally noted. The disorders were accompanied by increased mortality. Most of the problems concerned cultured common carp Cyprinus carpio L. and rainbow trout Oncorhynchus mykiss (Walbaum). Fish have been examined from a number of these farms, and additionally, the wild and ornamental fish with similar clinical signs of diseases were also tested. Bacteria were isolated consistently from lesions and internal organs. They had characteristic orange-pigmented colonies which grew in pure culture or constituted 55–95% of total bacterial flora. One hundred and eighteen isolates were collected and biochemically identified as Shewanella putrefaciens group, and this was confirmed by sequencing. Challenge tests confirmed the pathogenicity of these bacteria. This is the first report characterizing and describing S. putrefaciens as a pathogen of different species of freshwater fish in Europe.     

Correlation of Plasma Insulin Concentration with Laminitis Score in a Field Study of Equine Cushing's Disease and Equine Metabolic Syndrome

This study aimed to investigate endocrinologic test values and the response to treatment of two commonly encountered causes of endocrinopathic laminitis, equine Cushing's disease (ECD) and equine metabolic syndrome (EMS), in a veterinary practice setting. In particular, the study aimed to determine whether insulin concentration correlated to the severity of clinical laminitis in horses with EMS or ECD. Twenty-five horses were included in the study and assigned to one of three groups: ECD (n = 6), EMS (n = 10), and controls (n = 9). Blood samples were collected at an initial visit and then at regular intervals for the next 12 months. Plasma concentrations of adrenocorticotropin (ACTH), cortisol, and insulin and serum concentrations of glucose and total thyroxine (T4) were obtained. Horses with ECD had significantly higher plasma ACTH concentrations than EMS horses or controls. Horses with EMS and ECD both had significantly higher plasma insulin concentrations than control horses, which was correlated with the Obel grade of laminitis (r = 0.63). After treatment, there was a trend for a reduction in plasma ACTH concentration in horses with ECD. A program of diet and exercise for horses with EMS resulted in reductions in both plasma insulin concentrations and bodyweight, which was variable, depending on the individual. There was a significant correlation between the change in plasma insulin concentration and Obel grade of laminitis (r = 0.69). This study has highlighted the importance of baseline plasma insulin concentration as a potential indicator of the susceptibility of horses to laminitis and the response to a program of diet and exercise.     

The stimulatory effect of insulin-like growth factor-1 on the proliferation, differentiation, and mineralisation of osteoblastic cells from Holstein cattle

This study investigated the effect of exogenous insulin-like growth factor (IGF)-1 on the proliferation and differentiation of osteoblastic cells from Chinese Holstein cattle and the resultant bone nodule formation and mineralisation in vitro. The osteoblastic cells were isolated and cultured, then identified using Giemsa and alkaline phosphatase (ALP) staining methods. The effect of different concentrations of IGF-1 on cell growth was assessed by MTT assay. The ALP activity and osteocalcin (OC) concentration in the osteoblastic cells were measured by a colorimetric assay and a radioimmmunoassay, respectively. Calcium nodules were observed using alizarin red S stain, while the content of matrix calcium was determined by atomic absorption spectrophotometry. Cell proliferation in the cultures was stimulated by IGF-1 at concentrations ranging from 1 to 200 ng/mL, with the maximum effect observed at 100 ng/mL. This effect was observed from day 1 and peaked at day 5, but decreased at day 7. At concentrations of 10 ng/mL and 100 ng/mL, IGF-1 significantly induced ALP activity, OC level, matrix calcium content, and nodule formation of the osteoblastic cells by 20–180% (P < 0.05 or P < 0.01), compared to controls. The results suggested that IGF-1 is an anabolic agent for the proliferation, differentiation, mineralisation and calcium content of dairy cow osteoblasts, and could therefore act as a potential treatment for the metabolic bone diseases in these animals.     

Interrelationship of growth hormone AluI polymorphism and hyperketonemia with plasma hormones and metabolites in the beginning of lactation in dairy cows

A polymorphic site of the growth hormone gene (AluI polymorphism) that results in an amino acid change at position 127 of the protein chain (leucine, L to valine, V) has been linked to differences in circulating metabolites and metabolic hormones of calves and bulls and to milk yield traits of lactating cows. Our objective was to investigate the interrelationship of this polymorphism with plasma concentrations of β-hydroxybutyrate, insulin, IGF-I and leptin in postpartum dairy cows. Blood samples were taken from clinically healthy, spring-calving, group-fed Holstein-Friesian cows (n = 257; 7 large-scale farms) 4–13 days after calving. Of all herds, 100 cows had plasma β-hydroxybutyrate levels above 1.2 mmol/l and 157 cows were normoketonemic. The proportion of valine carriers and LL cows was not different within groups of normo- and hyperketonemic animals. Genotype was not associated with plasma β-hydroxybutyrate, insulin, IGF-I and leptin levels either in all of the herds or in the two with the highest proportion of the valine allele carriers (n = 28, 72%). We found significantly lower insulin, IGF-I and leptin concentrations in the presence of hyperketonemia compared to normoketonemic cows. There were strong negative correlations between BHB and the other blood parameters, while insulin, IGF-I and leptin were positively related to each other. In conclusion, in the first two weeks after calving we could not demonstrate any effect of AluI polymorphism on plasma concentrations of β-hydroxybutyrate and metabolic hormones studied. Hyperketonemia was associated with a significant decrease in insulin, IGF-I and leptin blood levels. We infer that cows homozygous for the leucine allele or carrying the valine allele may have a similar endocrine and metabolic response to the challenge of increased nutrient demand early postpartum and that the presence of hyperketonemia is mainly linked to the hormonal and metabolic changes occurring at the onset of lactation.     

舍饲山羊营养盈缺分析

对33只不同品种及不同生理阶段的舍饲山羊测定日采食量,并参照美国NRC(1981)山羊营养需要标准进行营养盈缺分析,结果表明:山羊日粮代谢能为9.35～10.20 MJ/kg时,山羊干物质采食量占体重百分比为2.3 %～3.7 %,接近或高于标准.山羊每日摄入的粗蛋白质、钙和磷数量明显超过标准;公羊、空怀母羊日摄入代谢能高于标准,而妊娠母羊、哺乳母羊和波杂育成羊日摄入代谢能水平接近NRC标准或缺乏.     

环境内分泌干扰物对睾丸间质细胞功能的影响

近年来,环境内分泌干扰物(environmental endocrine disrupting chemicals,EDCs)对雄性动物的生殖毒性引起了广泛的关注。大量资料显示EDCs可引起雄性生殖发育障碍,如隐睾、尿道下裂、睾丸癌、精液品质不良等。作者就几种典型的EDCs对睾丸间质细胞分泌睾酮的影响机制作一综述。     

吉林市左家镇母牛繁殖障碍的原因调查及防治对策

通过一年多临床实践及走访调查,对吉林市左家镇引起母牛繁殖障碍的常见原因做出了较为全面的了解,并且通过临床防治总结出较为科学有效的防治对策。     

多效唑对斑马鱼体内解毒代谢酶和抗氧化酶活性的影响

[目的]探讨多效唑对水生生物在组织水平的毒性效应及其致毒机制。[方法]采用生物化学方法测定了多效唑不同浓度暴露下对斑马鱼(Brachydanio rerio)体内2种解毒代谢酶和2种抗氧化酶活性的影响。[结果]雄性斑马鱼比雌性更容易受到多效唑的胁迫,各种酶在斑马鱼体内的变化规律不同。多效唑对雄鱼超氧化物歧化酶(SOD)表现为激活-抑制-恢复,对雌鱼SOD表现为先抑制后激活但影响不显著;对雌鱼过氧化物酶(POD)表现为抑制,对雄鱼POD的抑制在后期才有所表现;对雌鱼羧酸酯酶(Car E)表现为高浓度抑制低浓度激活,后期恢复,对雄鱼Car E整体表现为激活;而对雄鱼谷胱甘肽S-转移酶(GST)则表现为高浓度中后期产生抑制,对雌鱼GST未表现出明显的抑制或激活效应。[结论]雄鱼体内Car E的活性在多效唑较低浓度下最先做出应激反应,可作为污染物早期预警的生物标志物。