快速检测动物饲料中植酸酶活性的改进方法

当前饲料中植酸酶活性直接的比色测定存在高P和其它因素的干扰。我们的目的是研究一个快速、可靠的旋转柱法(slaincolumnmethod)来精确地测定饲料成分中或配合饲料中植酸酶活性。饲料样本在0．2M柠檬酸盐缓冲液中,pH值5．5、室温条件下搅拌萃取30min．用一个注射滤过器去掉浮在表面的小部分油层．然后把滤出液放到一个旋转柱中．目的是在植酸酶活性化验之前移走游离的磷酸盐。     

Therapeutic Efficacy of Zinc Sulphate Used in Clustered Model Treatment in Alleviating Zinc Deficiency in Cattle and Its Effect on Hormones,Vitamins and Production Parameters

A survey was conducted in 10 districts of northern India. Significant deficiency of zinc was observed in soil, fodders and (cattle) serum samples. The animals showed typical signs of zinc deficiency, namely stiff gait, swelling of hocks and knees, subcutaneous fluid accumulation, rough coat, etc. of variable intensity. A clustered model therapeutic trial was conducted and zinc-deficient cattle were divided into three groups. Group A was provided with mineral mixture containing zinc sulphate. Group B was given mineral mixture without zinc sulphate and group C was given no mineral mixture. Significant improvement (p < 0.01) was observed in the haemoglobin (Hb), total white blood cells (WBC) and total erythrocyte count (TEC) levels at the 7th day of treatment in the animals of group A. Significant improvement in enzyme serum alkaline phosphatase (SAP) was observed in group A animals at the 7th day, while improvement in asparatate aminotransferase (AST), alanine aminotransferase (ALT) and ceruloplasmin (Cp) was observed after 21 days of treatment. Regarding hormones, significant improvement was observed in thyroxine (T₃) and triiodothyronine (T₄), oestrogen and progesterone in group A animals within 14 days of treatment. The values of vitamin A showed a highly significant (p < 0.01) improvement within 7 days of treatment in group A animals and that of vitamin E on the 21 st day of treatment. The milk yield of lactating cattle and body weight of growing calves in group A showed highly significant (p < 0.01) increases at about 14 and 30 days, respectively. It is concluded that zinc sulphate supplementation is highly effective in alleviating zinc deficiency and improving various biochemical and production parameters in cattle. The clustered model treatment provides a better indicator of the most limiting element under field conditions where simultaneous deficiency of various minerals is prevalent.     

肉鸡肠毒综合征的病因分析及防治

近几年来，在我国商品肉鸡饲养发达地区的肉鸡群中，普遍存在着一种以腹泻、粪便中含有没消化好的饲料、采食量明显下降、生长缓慢或体重减轻、色素沉着障碍、脱水和饲料报酬下降为特征的疾病。目前，此种疾病普遍流行，虽然死亡率不高，但造成的隐性经济损失巨大，而且往往被肉鸡饲养户错误地认为是一般的消化不良，或被兽医临床工作者认为是单一的小肠球虫感染。我们根据几年来的跟踪调查和实验室分析研究以及药物治疗的情况综合分析认为，此病是由多病因导致的一种综合征．我们暂且将此病定名为“肉鸡肠毒综合征”。     

Effect of breed and gender on bovine liver cytochrome P450 3A (CYP3A) expression and inter-species comparison with other domestic ruminants

The cytochrome P450 (P450) superfamily represents a group of relevant enzymes in the field of drug metabolism and several exogenous or constitutional factors contribute to regulate its expression. Cattle represent an important source of animal-derived food-products and studies concerning the P450 expression are needed for the extrapolation of pharmacotoxicological data from one species to another and for the evaluation of the consumer's risk associated with the consumption of harmful residues found in foodstuffs. In the present study, possible breed-, gender- and species-differences in P4503A (the P450 subfamily more expressed in the human liver) expression were studied in vitro in Piedmontese (PDM) and Limousin (LIM) meat cattle breeds of both sexes and in domestic Ruminants (cattle, sheep and goats). Cytochrome P450 and P4503A contents as well as CYP3A-dependent drug metabolising enzymes (DME) were measured in liver microsomes. Significant lower levels of P450 (P < 0.001) and P4503A (P < 0.05) contents were observed in PDM vs. LIM of both sexes; the P4503A-dependent DME activities were significantly (P values ranging from 0.05 up to 0.001) higher in PDM cattle, particularly in males. A gender-effect in DME activities was noticed (P < 0.05) only in PDM male cattle. With regards to the species, the expression of both P4503A apoprotein and some of the related DME activities were more pronounced in sheep (P < 0.01 vs. cattle) and in goats (P < 0.05 vs. sheep; P < 0.01 vs. cattle) than in cattle. The significant differences in P4503A expression observed in LIM and PDM cattle are consistent with previously published data on strain- and breed-differences pointed out in rats and men. As far as a possible sex-effect is concerned, no clear-cut evidence is likely to be drawn. Finally, P4503A expression was more relevant in small ruminants.     

Evaluation of cardiac lesions and risk factors associated with myocarditis and dilated cardiomyopathy in southern sea otters (Enhydra lutris nereis)

OBJECTIVE: To describe cardiac lesions and identify risk factors associated with myocarditis and dilated cardiomyopathy (DCM) in beach-cast southern sea otters. ANIMALS: Free-ranging southern sea otters. PROCEDURE: Sea otters were necropsied at the Marine Wildlife Veterinary Care and Research Center from 1998 through 2001. Microscopic and gross necropsy findings were used to classify sea otters as myocarditis or DCM case otters or control otters. Univariate, multivariate, and spatial analytical techniques were used to evaluate associations among myocarditis; DCM; common sea otter pathogens; and potential infectious, toxic, and nutritional causes. RESULTS: Clusters of sea otters with myocarditis and DCM were identified in the southern aspect of the sea otter range from May to November 2000. Risk factors for myocarditis included age, good body condition, and exposure to domoic acid and Sarcocystis neurona. Myocarditis associated with domoic acid occurred predominantly in the southern part of the range, whereas myocarditis associated with S. neurona occurred in the northern part of the range. Age and suspected previous exposure to domoic acid were identified as major risk factors for DCM. A sample of otters with DCM had significantly lower concentrations of myocardial L-carnitine than control and myocarditis case otters. CONCLUSIONS AND CLINICAL RELEVANCE: Cardiac disease is an important cause of death in southern sea otters. Domoic acid toxicosis and infection with S. neurona are likely to be 2 important causes of myocarditis in sea otters. Domoic acid-induced myocarditis appears to progress to DCM, and depletion of myocardial L-carnitine may play a key role in this pathogenesis.     

Identification of viral pathogens in aborted fetuses and stillborn piglets from cases of swine reproductive failure in Spain

The objective of the present study was to determine the presence of recognised abortifacient viruses such as porcine reproductive and respiratory virus (PRRSV), Aujeszky's disease virus (ADV), porcine parvovirus (PPV) and porcine circovirus type 2 (PCV2), in tissues from aborted fetuses and stillborn neonates in cases of late reproductive failure in swine. A total of 293 specimens (fetuses aborted in the last third of gestation and stillborn piglets) from 100 different cases of late-term abortions and premature farrowing from 15 different Spanish provinces were studied. PRRSV was detected in 9/100 cases by RT-PCR. Only 1/100 cases analysed (corresponding to a late-term aborted fetus with a negative PRRSV RT-PCR result) was positive for PCV2 by PCR. Neither ADV (monitored by viral isolation plus antigen detection) nor PPV (monitored by ELISA antigen capture test) infection was identified. The results suggest that PRRSV is one of the most important infectious agents, if not the most relevant one, associated with fetal infection leading to abortion or premature farrowing in Spain. Moreover, other viral pathogens such as ADV, PPV and PCV2 seem to have a minor impact on reproductive disease.     

Leptin expression in ruminants: nutritional and physiological regulations in relation with energy metabolism

Leptin, mainly produced in adipose tissue (AT), is a protein involved in the central and/or peripheral regulation of body homeostasis, energy intake, storage and expenditure, fertility and immune functions. Its role is well documented in rodent and human species, but less in ruminants. This review is focused on some intrinsic and extrinsic factors which regulate adipose tissue leptin gene expression and leptinemia in cattle, sheep, goat and camel: age, physiological status (particularly pregnancy and lactation) in interaction with long-term (adiposity) and short-term effects of feeding level, energy intake and balance, diet composition, specific nutrients and hormones (insulin, glucose and fatty acids), and seasonal non-dietary factors such as photoperiod. Body fatness strongly regulates leptin and its responses to other factors. For example, leptinemia is higher after underfeeding or during lactation in fat than in lean animals. Physiological status per se also modulates leptin expression, with lactation down-regulating leptinemia, even when energy balance (EB) is positive. These results suggest that leptin could be a link between nutritional history and physiological regulations, which integrates the animal's requirements (e.g., for a pregnancy-lactation cycle), predictable food availability (e.g., due to seasonal variations) and potential for survival (e.g., body fatness level). Reaching permissive leptin thresholds should be necessary for pubertal or postpartum reproductive activity. In addition to the understanding of leptin yield regulation, these data are helpful to understand the physiological significance of changes in leptin secretion and leptin effects, and how husbandry strategies could integrate the adaptative capacities of ruminant species to their environment.     

Pharmaceutical and nutraceutical management of canine osteoarthritis: present and future perspectives

Osteoarthritis (OA) is one of the most common chronic musculoskeletal diseases and causes of lameness in the dogs. The osteoarthritic disease process involves the entire synovial joint, encompassing the synovium, cartilage and underlying bone. Joint failure results from an abnormal mechanical strain causing damage to normal tissue or failure of pathologically impaired articular cartilage and bone under the influence of normal physiological strain or a combination of both. In both cases, the end point is cartilage loss and joint impairment. Osteoarthritic chondrocytes show an altered phenotype characterised by an excess production of catabolic factors, including metalloproteinases and reactive oxygen species. These factors constitute potential therapeutic targets and some new drugs and nutraceuticals have been proposed to promote the return to homeostasis. Until now, the therapeutic management of OA in dogs has been dominated by nonsteroidal anti-inflammatory drugs, but some new compounds, including diacerhein, with potential structure-modifying effects, are already used to treat OA in humans and could be helpful to manage OA in the dog. In addition, novel nutraceuticals, such as avocado/soybean unsaponifiable substances, have shown symptomatic effects in knee OA in humans, and could offer an alternative to prevent OA progression. This paper provides an overview of recent discoveries in the pathophysiology and in the therapeutic management of osteoarthritis in dogs.     

Evaluation of xylazine and ketamine for total intravenous anesthesia in horses

OBJECTIVE: To evaluate the use of xylazine and ketamine for total i.v. anesthesia in horses. ANIMALS: 8 horses. PROCEDURE: Anesthetic induction was performed on 4 occasions in each horse with xylazine (0.75 mg/kg, i.v.), guaifenesin (75 mg/kg, i.v.), and ketamine (2 mg/kg, i.v.). Intravenous infusions of xylazine and ketamine were then started by use of 1 of 6 treatments as follows for which 35, 90, 120, and 150 represent infusion dosages (microg/kg/min) and X and K represent xylazine and ketamine, respectively: X35 + K90 with 100% inspired oxygen (O2), X35 + K120-(O2), X35 + K150-(O2), X70 + K90-(O2), K150-(O2), and X35 + K120 with a 21% fraction of inspired oxygen (ie, air). Cardiopulmonary measurements were performed. Response to a noxious electrical stimulus was observed at 20, 40, and 60 minutes after induction. Times to achieve sternal recumbency and standing were recorded. Quality of sedation, induction, and recovery to sternal recumbency and standing were subjectively evaluated. RESULTS: Heart rate and cardiac index were higher and total peripheral resistance lower in K150-(O2) and X35 + K120-air groups. The mean arterial pressure was highest in the X35 + K120-air group and lowest in the K150-(O2) group (125 +/- 6 vs 85 +/- 8 at 20 minutes, respectively). Mean Pa(O2) was lowest in the X35 + K120-air group. Times to sternal recumbency and standing were shortest for horses receiving K150-(O2) (23 +/- 6 minutes and 33 +/- 8 minutes, respectively) and longest for those receiving X70 + K90-(O2) (58 +/- 28 minutes and 69 +/- 27 minutes, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Infusions of xylazine and ketamine may be used with oxygen supplementation to maintain 60 minutes of anesthesia in healthy adult horses.     

不同饲喂方式对断奶仔猪生长性能以及营养物质消化率的影响

选择28日龄断奶、平均体重（8．06±0．44）kg的仔猪36头,按体重相近、性别一致的原则随机分为2个处理,每个处理6个重复,每个重复3头猪。试验期28d,饲喂相同的饲粮,但处理1为自由采食,处理2为限制采食（每天上午8：00-10：00和下午5：00-7：00）,考察不同饲喂方式对断奶仔猪生长性能和营养物质消化率的影响。试验结果表明：①与限制采食相比,整个试验期断奶仔猪在自由采食条件下的日采食量和日增重分别提高28．0％（P〈0．05）和11．9％（P〈0．05）;②自由采食比限制采食经济效益提高6.41％;③采食量为断奶仔猪阶段首要考虑因素,因此建议规模猪场采用自由采食。本试验结论表明,自由采食可以提高断奶仔猪的日采食量和日增重,但降低了仔猪的饲料转化率。