日粮营养代谢与基因表达的研究进展

动物日粮营养代谢能够影响基因的表达,研究表明:通过改变日粮的营养水平可以调节动物体内相关基因的表达,从而使动物处于最佳的生长状态。本文就碳水化合物、脂肪和脂肪酸、蛋白质等营养素对基因表达的调控进行了综述。     

氨基酸在反刍动物中应用研究进展

由瘤胃合成的微生物蛋白(M CP),过瘤胃蛋白(R U P)和内源蛋白(EC P)提供的各种氨基酸(A A)是反刍动物体组织和乳蛋白合成的原料。少量吸收后的A A为机体合成其它代谢前体物所必需。因此A A营养对反刍动物营养研究很重要。随着各国新蛋白体系的相继建立,使反刍动物A A营养逐渐向     

日粮营养代谢与基因表达的研究进展

动物日粮营养代谢能够影响基因的表达,研究表明:通过改变日粮的营养水平可以调节动物体内相关基因的表达,从而使动物处于最佳的生长状态.本文就碳水化合物、脂肪和脂肪酸、蛋白质等营养素对基因表达的调控进行了综述.     

黄芪多糖对氢化可的松氧化应激状态下肉仔鸡生长性能、脏器指数及抗氧化能力的影响

本试验旨在研究黄芪多糖(APS)对氢化可的松诱导的肉仔鸡氧化应激模型生长性能、脏器指数和抗氧化能力的影响。选用1日龄的爱拔益加(AA)肉仔鸡256只,按试验要求随机分为4组,每组8个重复,每个重复8只鸡。对照组(A组)和模型组(B组)饲喂不添加APS的基础饲粮,试验1组(C组)和试验2组(D组)饲喂在基础饲粮中分别添加0.4%和0.8%APS的试验饲粮。试验预试期7 d,从第8天开始除A组(饮用蒸馏水)外,其余各组均在饮水中添加20 mg/L氢化可的松造模,连续5 d;同时C组和D组饲喂添加APS的试验饲粮至第21天。结果表明:通过在饲粮中添加APS,可改善肉仔鸡的氧化应激状态,促进动物生长,C、D组14日龄的体重和1～14日龄的平均日增重均极显著高于A、B组(P<0.01),D组21日龄的体重和1～21日龄的平均日增重均显著高于B组(P<0.05);与B组相比,APS显著提高了14日龄氧化应激状态下肉仔鸡C组的脾脏指数、C组和D组的胸腺指数(P<0.05),但对21日龄脏器指数(D组肝脏指数、C组和D组脾脏指数除外)的影响均不显著(P>0.05);与B组相比,APS还可极显著降低D组14日龄肝脏和21日龄血清中丙二醛的含量(P<0.01),并能显著提高C组21日龄肝脏中总超氧化物歧化酶的活性(P<0.05)。结果提示,APS具有缓解氢化可的松产生的氧化应激,促进动物生长、脏器指数和抗氧化能力的作用。     

β-胡萝卜素和维生素A对反刍动物繁殖作用的影响

动物的繁殖性能是考察和利用种用动物的一个重要参数,影响动物繁殖性能的因素主要有遗传力、营养和环境因素。在营养因素中,维生素A和胡萝卜素对动物繁殖性能的影响不容忽视,本文主要介绍了β-胡萝卜素和维生素A对反刍动物繁殖作用的影响。     

母猪大围产期营养抗病保健管理关键技术

动物营养与疾病、生产力之间存在着非常紧密的联系。动物营养状况的好坏直接影响动物的生产性能和对疾病的抵抗力,而机体的健康状态又决定了动物的营养需求模式。笔者通过对母猪大围产期营养需求进行分析,指导养殖者合理使用生殖营养、免疫营养和肠道营养,通过提升母源免疫力来保护仔猪的健康,开启母猪抗病营养保健的全新模式,为动物生产少用甚至不用抗生素开辟了新的途径。     

维生素A在反刍动物日粮营养中的作用和需要量

维生素A是动物生长发育所必需的营养因子。本文围绕反刍动物营养中对维生素A的需要量和吸收代谢特点、类胡萝卜素消化和吸收进行综述,总结了维生素A在反刍动物日粮中的需要量,旨在为反刍动物的维生素A合理利用提供参考。     

鲁西地方黑猪的耐粗饲性研究

为探讨鲁西地方黑猪对低营养水平日粮的耐受能力,研究设计3种不同营养水平的日粮A、B和C,并以长白猪和大白猪为对照,进行饲养试验。结果表明:A、B和C组间鲁西地方黑猪的日增质量和料重比差异不显著;而长白猪和大白猪,A组与B组,B组与C组间差异显著,A组与C组间差异极显著。表明增加粗纤维含量(9.2%~11.2%)对鲁西地方黑猪的肥育性能无显著影响,表现了良好的耐粗饲性。     

断奶日龄对仔猪胰腺和肠道淀粉酶和胰糜蛋白酶比值的影响

将 12窝三元杂交仔猪随机分为 4组 ,分别于 17、2 1、2 8和 35日龄断奶 ,测定了各组仔猪断奶前后胰腺组织和空肠食糜以及粘膜中的淀粉酶 (A)和胰糜蛋白酶 (C)的相对活性 ,分析了A C比值在断奶前后的变化动态。结果表明 :胰腺A C在哺乳期基本保持稳定 ,各组A C比值在断奶后 12小时为最低值 ,随后逐渐升高 (P <0 .0 5 ) ,并且 2 8和 35日龄断奶仔猪该值升高的速度快于 17和 2 1日龄断奶组。而空肠A C值除了哺乳期与胰腺的相似外 ,断奶后各组基本无明显回升。     

抗氧化维生素的营养需要对畜禽免疫力的影响

营养因素对机体免疫反应的影响已引起人们的重视。作为一类重要营养因素的抗氧化维生素,不仅是动物机体所必需的营养物质,参与多种代谢活动和生理活动,还可以对机体的免疫反应、免疫机能、免疫效果产生影响。本文综述了类胡萝卜素、维生素A、E、C等抗氧化维生素的主要营养作用,着重分析了它们的免疫学功能与作用。     

Fungal phytases: characteristics and amelioration of nutritional quality and growth of non‐ruminants

Fungal phytases are histidine acid phosphatases, a subclass of acid phosphatases, which catalyse the hydrolysis of phytic acid resulting in the release of phosphate moieties and thus mitigate its antinutritional properties. The supplementation of feed with phytases increases the bioavailability of phosphorus and minerals in non‐ruminant animals and reduces the phosphorus pollution due to phosphorus excretion in the areas of intensive livestock production. Although phytases are reported in plants, animals and micro‐organisms, fungal sources are used extensively for the production of phytases on a commercial scale. Phytases have been produced by fungi in both solid‐state fermentation (SSF) and submerged fermentation (SmF). The fungal phytases are high molecular weight proteins ranging from 35 to 500 kDa. They are optimally active within pH and temperature ranges between 4.5 and 6.0, and 45 and 70 °C respectively. Phytate degradation leads to amelioration in the nutritional status of foods and feeds by improving the availability of minerals, phosphorus and proteins in non‐ruminant animals and human beings and thus mitigates the environmental phosphorus pollution. Our article focuses on the role of fungal phytases in improving nutritional value of foods and feeds with concomitant increase in growth of non‐ruminant animals and mitigating environmental phosphorus pollution.     

反刍动物硒营养研究进展

本文叙述了硒的营养学功能,硒的来源以及硒在反刍动物日粮中应用的现状,比较了有机硒和无机硒的特点,最后对在反刍动物日粮中应用硒的注意事项做了强调。     

Influence of Veterinary Care on the Urinary Corticoid: Creatinine Ratio in Dogs

Physical and emotional stresses are known to increase the production and secretion of glucocorticoids by the adrenal cortex in both humans and experimental animals. The urinary corticoid: creatinine (C:C) ratio is increasingly used as a measure of adrenocortical function. In this study we investigated whether a visit to a veterinary practice for vaccination, a visit to a referral clinic for orthopedic examination, or hospitalization in a referral clinic for 1.5 days resulted in increases of the urinary C: C ratio in pet dogs. In experiment 1, owners collected voided urine samples from 19 healthy pet dogs at specified times before and after taking the dogs to a veterinary practice for yearly vaccination. In experiment 2, 12 pet dogs were evaluated in a similar way before and after an orthopedic examination at a referral clinic. In experiment 3, 9 healthy pet dogs were hospitalized for 1.5 days and urine samples were collected before, during, and after this stay. Basal urinary C:C ratios in all experiments ranged from 0.8 to 8.3 × 10^-6. In experiment 1, the urinary C:C ratio after the visit to the veterinary practice ranged from 0.9 to 22.0 × 10^-6. Six dogs had a significantly increased urinary C:C ratio (responders), but in 5 of these dogs the ratio was ≤10 × 10^-6 In experiment 2. 8 of 12 dogs responded significantly with urinary C:C ratios ranging from 3.1 to 27.0 × 10^-6. In experiment 3, 8 of 9 dogs had significantly increased urinary C:C ratios, ranging from 2.4 to 24.0 × 10^-6, in some or all urine samples collected during hospitalization. In 4 dogs urinary C:C ratios 12 hours after hospitalization were still significantly higher than the initial values. Thus, a visit to a veterinary practice, an orthopedic examination in a referral clinic, and hospitalization can be considered stressful conditions for dogs. A large variation occurs in response, and in individual dogs the increases in urinary C:C ratios can exceed the cutoff level for the diagnosis of hyperadrenocorticism. Therefore, urine samples for measurement of the C: C ratio in the diagnosis of hyperadrenocorticism should be collected in the dog's home environment, to avoid the influence of stress on glucocorticoid secretion.     

Nutritional and clinicopathological effects of post operative parenteral nutrition following small intestinal resection and anastomosis in the mature horse

REASONS FOR PERFORMING STUDY: There is an absence of data describing the nutritional requirements and nutritional status of horses following surgery for colic; furthermore, the potential effect of parenteral nutrition (PN) on improving nutritional status in such cases is unknown. HYPOTHESIS: Post operative colic cases suffer from a potentially detrimental negative energy balance and the PN formulation developed in this study would lead to clinicopathologically detectable improvements in the subjects' nutritional status. METHODS: Several clinicopathological variables, some known to be associated with nutritional status, were compared in 2 groups of horses in the post operative period following colic surgery; Group N (n = 15) were treated with PN and Group C (n = 15) were starved routinely. RESULTS: Group N had significantly lower serum concentrations of triglycerides, total bilirubin, albumin and urea and significantly higher serum concentrations of glucose and insulin compared with Group C in the post operative period. CONCLUSIONS: The control group of horses demonstrated significant clinicopathological evidence of starvation and the described PN protocol resulted in a demonstrably improved nutritional status in the treated horses. POTENTIAL RELEVANCE: Further study is required to investigate clinical benefits and possible harmful side effects of post operative parenteral nutrition before the technique can be advocated for widespread use in practice.     

大豆黄酮在反刍动物生产中的应用

大豆黄酮在反刍动物生产中的应用主要体现在能够促生长、提高泌乳量、改善乳成分,提高其营养价值、增强机体免疫力及改善山羊绒毛质量等。作者综述了大豆黄酮的提取、来源、吸收、代谢及在反刍动物生产中的应用研究现状,为大豆黄酮在反刍动物生产中应用研究提供参考依据。     

Metabolism, excretion, pharmacokinetics and tissue residues of phenylbutazone in the horse

The pharmacokinetics, metabolism, excretion and tissue residues of phenylbutazone (PBZ) in the horse were studied following both intravenous and oral administration of the drug at a dose rate of 4.4 mg/kg. A 72-hour blood sampling schedule failed to demonstrate a third exponential phase; the plasma disposition following intravenous injection being described by a two compartment open model, with the following elimination phase parameters: beta = 0.13h-1, t1/2 beta = 5.46h, Vdarea = 0.141 1/kg and C1B = 17.9 ml/kg/h. The hydroxylated metabolites oxyphenbutazone (OPBZ) and gamma-hydroxyphenylbutazone (OHPBZ) were present in detectable concentrations in plasma for 72 and 24 h, respectively. After 36 h OPBZ concentrations exceeded plasma PBZ concentrations. In urine the principal metabolites were OPBZ and OHPBZ but smaller concentrations of another compound, probably gamma-hydroxyoxyphenbutazone (OHOPBZ), were also detected. The percentages of the administered dose recovered from urine were 30.7, 39.0 and 40.3 after 24, 48 and 72 h from the time of injection. Recovery of PBZ and its metabolites from urine was significantly reduced in the first 24 h after oral dosing when the horses had free access to hay, probably as a result of markedly delayed absorption, but this did not occur in animals deprived of food for a few hours before and after dosing. Determination of approximate values of urine/plasma (U/P) concentration ratios for PBZ and its metabolites relative to endogenous creatinine U/P concentration ratio suggested that PBZ was filtered in small amounts only because of the high degree of plasma protein binding and then excreted by diffusion trapping in the alkaline urine. Much higher U/P ratios were obtained for the hydroxylated derivatives, and one at least (OHPBZ) was secreted into urine.     

The Effect of Experimental Cystitis and Iatrogenic Blood Contamination on the Urine Protein/Creatinine Ratio in the Dog

The effect of experimentally induced cystitis and iatrogenic blood contamination on the urine protein/creatinine ratio (U P/C) was evaluated in 17 dogs. Before they were included in the study, all dogs were judged to be healthy on the basis of physical examination, serum concentrations of urea nitrogen and creatinine, complete urinalysis, and a U P/C less than 0.4. A single urine sample was contaminated with increasing quantities of canine fresh whole blood (PCV = 42%; total protein = 6.2 g/dl). When added blood was equal to or greater than 25% of the total urine sample volume, the U P/C exceeded 3.5, a finding consistent with nephrotic range proteinuria. When added blood was 10% of the total urine sample volume, the U P/C was less than 1.8. Eleven Beagles underwent routine laparotomy during which a cystotomy was done. The median U P/Cs on postoperative days 1 and 2 were significantly increased compared with preoperative values (P less than 0.05); no U P/C exceeded 2.0. Renal biopsies performed on postoperative day 3 eliminated renal proteinuria as a source of urine protein. Five dogs had bacterial cystitis experimentally induced. At 72 and 96 hours after bacterial inoculation, the median U P/Cs were significantly increased (P less than 0.05); individual values ranged from 1.5 to 40.8. Renal biopsies performed between 5 and 6 days after inoculation eliminated renal proteinuria as a source of urine protein. Cytologic evaluation of urine sediment in each group did not correlate with the magnitude of the increase in the U P/C. The U P/C significantly increased in each model of lower urinary tract inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)     

羟脯氨酸在反刍动物营养研究中的应用

论述了羟脯氨酸在动物体内的重要生理功能与独特的生物活性,及尿、血清中羟脯氨酸含量的变化与机体内代谢指标的关系.重点阐述了羟脯氨酸的排出量与反刍动物营养状况中的研究进展.     

REVIEWS: Conjugated Linoleic Acid: Historical Context and Implications

Conjugated linoleic acids (CLA) are implicated as anti-carcinogenic, anti-atherosclerosis, and anti-inflammatory agents in a variety of experimental model systems. However, evidence of dietary CLA protection against human mammary cancer risk is mixed and comes from European countries where the death rate from mammary cancer is relatively scarce. Unfortunately, epidemiological data are inconclusive, especially from retrospective studies. Prospective human study evidence will take more time. European values as great as 1.9% CLA in the fat of milk products from grass-fed ruminants has been reported; ordinary monogastric meat and egg products contain substantially less CLA in fat (0.3%). It is now recognized that the principle CLA in ruminant meat and milk is the natural diene, cis (c)-9, trans (t)-11 isomer (rumenic acid) of C18:2 (octadecadienoic acid). Another isomer, C18:2 t-10, c-12, also contributes to the unique biological activity of CLA, but does not readily accumulate in ruminant lipids and is found only in commercial preparations of mixed CLA isomers. Evidence in humans suggested that the role of the dietary mixed isomer CLA in the loss of body fat mass (BFM) was only modest compared with the results from animal model studies, and urine metabolites of prostaglandin F_2α (PGF_2α), indicative of lipid oxidation stress, have been elevated during supplementation. In addition, the fatty acid C18:1 t-11 (vaccenic) is now believed to be the principle precursor of endogenous c-9, t-11 CLA in both ruminants and monogastrics. This finding helps explain the discrepancy between measured c-9, t-11 CLA originating from the rumen and that secreted in cow’s milk. Manipulation of ruminant meat and milk by feeding marine or vegetable oils is clearly associated with increases in vaccenic acid as well. This relationship requires a re-examination of human foods for vaccenic acid content and quantitative measures of CLA endogenous synthesis in humans as well to formulate dietary strategies to capture CLA’s potential protective health benefits.     

Comparison of Multistix PRO dipsticks with other biochemical assays for determining urine protein (UP), urine creatinine (UC) and UP:UC ratio in dogs and cats

BACKGROUND: Urine protein: urine creatinine (UP:UC) ratio determined from the quantitative measurement of protein and creatinine in a single urine sample is the best feasible assessment of clinically significant proteinuria in dogs and cats. A dipstick that measures urine protein, urine creatinine, and UP:UC ratio has been used in human medicine and could have application for veterinary practice. OBJECTIVE: The objective of this study was to compare the Multistix PRO dipstick (Bayer Corporation, Elkhart, IN, USA) to other biochemical methods for determination of urine protein and creatinine, and UP:UC ratio in canine and feline urine. METHODS: A complete urinalysis, including sulfosalicylic acid (SSA) precipitation, was performed on urine samples submitted to our laboratory between February and April 2003 from 100 dogs and 49 cats. Urine protein and creatinine concentrations were determined by the Multistix PRO dipstick using a Clinitek 50 analyzer (Bayer) and compared with the results of SSA precipitation and quantitative biochemical analysis. The UP:UC ratios from the dipstick results (calculated by the Clinitek 50 and also manually) were compared with those calculated from quantitative values. Pearson product-moment correlation analysis and diagnostic sensitivity and specificity (using quantitative results as the gold standard) were determined. RESULTS: For both canine and feline urine, protein and creatinine concentrations determined by the Multistix PRO correlated closely with quantitative concentrations for protein (dogs r = .78, P = .0001; cats r = .87, P = .0001) and creatinine (dogs r = .78, P = .0001; cats r = .76, P = .0001). The Multistix PRO was more sensitive and less specific than SSA precipitation for diagnosing clinically significant proteinuria. UP:UC ratios obtained by manual calculation of dipstick results correlated best with quantitative UP:UC ratios in dogs, and had higher specificity but lower sensitivity for the diagnosis of proteinuria. In cats, UP:UC ratios determined by the dipstick method did not correlate (r = -.24, P = .0974) with quantitative values. CONCLUSIONS: The Multistix PRO, with manual calculation of UP:UC, may be a good alternative for the diagnosis of clinically significant proteinuria in dogs, but not cats. Dipstick creatinine concentration should be considered as an estimate.