Biological efficacy and absorption of DL‐methionine hydroxy analogue free acid compared to DL‐methionine in chickens as affected by heat stress

1. The net absorption and the biological efficacy of DL‐methionine and of DL‐methionine hydroxy analogue free acid (MHA‐FA) were evaluated in chickens under heat stress.

2. In a growth assay, finishing broilers 21 to 42 d of age were fed on diets containing graded amounts of the two supplements; the basal diet was composed of practical ingredients.

3. From slope‐ratio analysis, equimolar efficacy of MHA‐FA relative to DL‐methionine was determined to be 83% (confidence limits 61 to 115%) from weight gain responses, and 67% (47 to 91%) from food conversion responses. This indicates that the relative efficacy of MHA‐FA is close to previous estimates of about 75% obtained under thermoneutral conditions.

4. In a balance study with caecectomised cockerels, net absorption (intake—excretion in faeces and urine) of DL‐methionine and of MHA‐FA, respectively, were determined to be 97.2 and 90.8%. The net absorption of MHA‐FA was significantly lower than that of DL‐methionine.     

Effect of dietary DL‐ethionine on growth and liver metabolism

1. The effects of DL‐ethionine, given in the diet or by injection, on growth, hepatic glycogen and lipids, and the activities of some cytoplasmic NAD‐linked dehydrogenases and NADPH‐producing enzymes were investigated.

2. Growth virtually ceased after feeding ethionine for 2 d.

3. Ethionine induced an accumulation of lipid, decreased the activities of malic enzyme and isocitrate dehydrogenase and increased the activity of lactate dehydrogenase.

4. The concentration of glycogen in the liver of ethionine‐fed chickens increased for 3 d in spite of a decrease in food intake, but then decreased.     

Comparison of DL‐methionine and methionine hydroxy analogue‐free acid in broilers by using multi‐exponential regression models

1. Methionine hydroxy analogue‐free acid (MHA‐FA) was evaluated for biopotency compared to DL‐methionine in a practical diet for broiler chicks.

2. Both methionine sources were added at equimolar concentrations of 0.03, 0.07, 0.11, 0.15, 0.20 and 0.25% to the diet.

3. A non‐linear multi‐exponential regression model was used to describe the weight gain and food conversion response to supplemental sources of methionine.

4. Compared with DL‐methionine on an equimolar basis, bioefficacy of MHA‐FA was calculated at 73% from weight gain and 68% from food conversion data, respectively. This corresponds to an efficiency of Alimet® between 60 and 64% relative to DL‐methionine on a weight for weight basis.     

DL—蛋氨酸含量的测定方法

<正> 1.测定原理蛋氨酸含量的测定可用间接碘量法进行,其化学反应的关系式简化如下:DL—蛋氨酸+碘 pH6.5PHO DL—蛋氨酸—碘(加合物)2.化学试剂的配制2.1 磷酸盐缓冲液/碘化钾溶液准确称取149.54克磷酸二氢钾和205.66克磷酸氢二钾,溶于盛有蒸馏水的容量瓶中,稀释至2升后加入27.00克碘化钾,溶液的 pH 值用酸度计检查,调节为6.5。2.2 淀粉指示剂取1.25克可溶性淀粉于小研钵中,加水少许研成糊状,然后徐徐倾入50毫升沸蒸馏水中。煮沸2分钟,冷却后加入1克碘化钾,搅拌溶解。倾出清液贮于小口瓶中备用。     

DL─蛋氨酸生产现状及预测

１蛋氨酸用途氨基酸是形成蛋白质所需的主要原料。植物和微生物可以利用其自身的生物功能生成各种已知的氨基酸,而畜禽类则不能合成诸如蛋氨酸、赖氨酸等氨基酸,这些动物体内不能自身合成而必须从饲料中摄取的氨基酸称为必需氨基酸。ＤＬ－蛋氨酸是动物机体内主要甲基供体,对动物体生理代谢有很强的调节作用。它对于鸡等家禽类是第一必需氨基酸,对于猪等畜类是继赖氨酸后的第二必需氨基酸。为了弥补饲料中天然必需氨基酸的不足,提高饲料蛋白质的生物学价值,必须科学地加入蛋氨酸等必需氨基酸,以使畜禽有较高的饲料转化率和较好的生长…     

果用桑品种DL—1的育成

桑果以其独特的色泽口感和丰富的营养价值深受消费者喜爱.云南有丰富的桑属(Morus)植物种质资源,桑属植物19个种及变种中云南有12个种的分布.从1990至2000年,云南省蚕桑研究所利用野生的长果桑(M.laevigata Wall.)、广东桑(M.atropurpurea Roxb.)、白桑(M.alba Linn.)、滇桑(M.yunnanensis Koidz.)等资源进行杂交育种选育产果专用桑品种,于1998年在单株选择中选出果形整齐、口感好、成熟整齐、叶型小、果实产量高的单株DL-1号,经近年的观察遗传性状稳定,是一个值得在水果产业上推广的新品种.本文介绍DL-1号的选育经过、生物学特性及性状、品质初分析、产果量对比、丰产栽培技术、开发前景探讨.     

Crimidine (2‐chloro‐4‐(dimethylamino)‐6‐methylpyrimidine) poisoning in a dog due to ingestion of the rodenticide Castrix®

The diagnosis and treatment of a case of crimidine poisoning in a dog are described. Presenting signs were seizures and vomiting. The vomitus contained a purple coloured cereal grain. The signs and grain colour were suggestive for a rodenticide with convulsive effects The diagnosis of crimidine poisoning was made by thin layer chromatography and was later confirmed by finding the source of the poison. Except for the administration of Vit B6, the specific antidote for crimidine, general treatment principles for poisoning were followed. The treatment of crimidine poisoning is time consuming and requires intensive care facilities.     

Sphericity Index and E‐Point‐to‐Septal‐Separation (EPSS) to Diagnose Dilated Cardiomyopathy in Doberman Pinschers

Background

E‐point‐to‐septal‐separation (EPSS) and the sphericity index (SI) are echocardiographic parameters that are recommended in the ESVC‐DCM guidelines. However, SI cutoff values to diagnose dilated cardiomyopathy (DCM) have never been evaluated.

Objectives

To establish reference ranges, calculate cutoff values, and assess the clinical value of SI and EPSS to diagnose DCM in Doberman Pinschers.

Animals

One hundred seventy‐nine client‐owned Doberman Pinschers.

Methods

Three groups were formed in this prospective longitudinal study according to established Holter and echocardiographic criteria using the Simpson method of disk (SMOD): control group (97 dogs), DCM with echocardiographic changes (75 dogs) and “last normal” group (n = 7), which included dogs that developed DCM within 1.5 years, but were still normal at this time point. In a substudy, dogs with early DCM based upon SMOD values above the reference range but still normal M‐Mode measurements were selected, to evaluate if EPSS or SI were abnormal using the established cutoff values.

Results

ROC‐curve analysis determined <1.65 for the SI (sensitivity 86.8%; specificity 87.6%) and >6.5 mm for EPSS (sensitivity 100%; specificity 99.0%) as optimal cutoff values to diagnose DCM. Both parameters were significantly different between the control group and the DCM group (P < 0.001), but were not abnormal in the “last normal” group. In the substudy, EPSS was abnormal in 13/13 dogs and SI in 2/13 dogs.

Conclusions and Clinical Importance

E‐point‐to‐septal‐separation is a valuable additional parameter for the diagnosis of DCM, which can enhance diagnostic capabilities of M‐Mode and which performs similar as well as SMOD.     

N‐Terminal Pro‐C‐Natriuretic Peptide and Cytokine Kinetics in Dogs with Endotoxemia

Background

Serum N‐terminal pro‐C‐natriuretic peptide (NT‐proCNP) concentration at hospital admission has sufficient sensitivity and specificity to differentiate naturally occurring sepsis from nonseptic systemic inflammatory response syndrome (SIRS). However, little is known about serum NT‐proCNP concentrations in dogs during the course of sepsis.

Objective

To determine serum NT‐proCNP and cytokine kinetics in dogs with endotoxemia, a model of canine sepsis.

Samples

Eighty canine serum samples.

Methods

Eight healthy adult Beagles were randomized to receive Escherichia coli lipopolysaccharide (LPS, 5 μg/kg) or placebo (0.9% NaCl) as a single IV dose in a randomized crossover study. Serum collected at 0, 1, 2, 4, and 24 hours was stored at −80°C for batch analysis. Serum NT‐proCNP was measured by ELISA and 13 cytokines and chemokines by multiplex magnetic bead‐based assay.

Results

Serum NT‐proCNP concentrations did not differ significantly between LPS‐ and placebo‐treated dogs at any time. When comparing serum cytokine concentrations, LPS‐treated dogs had higher interleukin‐6 (IL‐6), IL‐10, TNF‐α and KC‐like at 1, 2, and 4 hours; higher CCL2 at 1, 2, 4, and 24 hours; and higher IL‐8 and CXCL10 at 4 hours compared to placebo‐treated dogs. There were no differences in serum GM‐CSF, IFN‐γ, IL‐2, IL‐7, IL‐15 or IL‐18 between LPS‐ and placebo‐treated dogs.

Conclusions and Clinical Importance

Serum NT‐proCNP concentration does not change significantly in response to LPS administration in healthy dogs. Certain serum cytokine and chemokine concentrations are significantly increased within 1–4 hours after LPS administration and warrant further investigation as tools for the detection and management of sepsis in dogs.     

A purified diet for one‐day‐old chicks

1. In each of four experiments 140 or 160 1‐d‐old broiler chicks were fed for 14 d on diets based on crystalline amino acids and other purified ingredients. The basal diet was a purified diet found suitable for 7‐d‐old chicks.

2. Growth was poorer with the basal diet than with a practical diet and it was not improved by an increase in the concentration of vitamins or supplementation with isolated soy protein, water or liver.

3. An increase in the amount of mineral mixture or of magnesium alone gave a significant improvement in growth, so that it approximated that obtained with the practical diet. Food conversion efficiency was significantly better with the mineral‐supplemented than with the practical diet.

4. The basal purified diet supplemented with magnesium to provide 684 mg Mg per kilogram was satisfactory for the early growth; chicks fed on this diet did not respond to sources of “unidentified factors” such as fresh or freeze‐dried liver and soy‐protein.     

ALIMET、MHA 和 DL—蛋氨酸测定方法

一、试剂和仪器(一)酸性溶剂1.50∶10∶3=醋酸∶H_2O∶浓盐酸。2.配制10升:7500毫升醋酸,1500毫升水,450毫升盐酸混合。(二)0.5N溴化物/溴酸盐滴定1.配制1升:在1升的容量瓶中加入14克溴酸钾(KBrO_3)和溴化钾(KBr),加水定容到1升。2.用0.5N的硫代硫酸钠作对照来标定。——精确移取25毫升溴化钾/溴酸钾溶液到125毫升的三角瓶中。     

Vaccine‐Associated Leptospira Antibodies in Client‐Owned Dogs

Background

Long‐term microscopic agglutination test (MAT) results after vaccination with 4‐serovar Leptospira vaccines are not available for all vaccines used in client‐owned dogs.

Hypothesis/Objectives

To determine antibody responses of client‐owned dogs given 1 of 4 commercially available Leptospira vaccines.

Animals

Healthy client‐owned dogs (n = 32) with no history of Leptospira vaccination for at least the previous year.

Methods

Dogs were given 1 of 4 Leptospira vaccines on week 0 and then approximately on week 3 and week 52. Sera were collected before vaccine administration on week 0 and then within 3 days of week 3, within 2 days of week 4, and approximately on weeks 7, 15, 29, 52, and 56. Antibody titers against Leptospira serovars bratislava, canicola, grippotyphosa, hardjo, icterohemorrhagiae, and pomona and were determined by MAT.

Results

When compared among vaccines, MAT results varied in maximal titers, the serovars inducing maximal titers, and the time required to reach maximal titers. Each vaccine induced at least some MAT titers ≥1 : 800. Most dogs were negative for antibodies against all serovars 1 year after vaccination, and anamnestic responses were variable.

Conclusions and Clinical Importance

Dogs vaccinated with Leptospira vaccines have variable MAT titers over time, and antibodies should not be used to predict resistance to Leptospira infection. MAT titers ≥1 : 800 can develop after Leptospira spp. vaccination, which can complicate the clinical diagnosis of leptospirosis.     

DLMO──DL型嗜中温发酵剂

ＤＬＭＯ──ＤＬ型嗜中温发酵剂天津中芬乳品研究培训中心魏洁ＤＬ嗜中温发酵剂（ＣＭｅｓｐｈｉｌｉｃＣｕｌｔｕｒｅ）是一种在１８～２２℃最适宜生长的产酸、产香、产ＣＯ＿２的高浓缩混合菌种的发酵剂。它由以下４种菌种组成：乳酸链球菌、乳脂链球菌、丁二酮乳酸链...     

DL—蛋氨酸与DL—蛋氨酸羟基类似物在肉仔鸡日粮中的生物效价的比较

目前在配合饲料中,蛋氨酸饲料添加剂有两种类型:一种是 DL-蛋氨酸;另一种是DL-蛋氨酸羟基类似物。纯度在99%以上的 DL-蛋氨酸呈结晶状。DL 一蛋氨酸羟基类似物通常为游离酸(DL-MHA-FA),商品名为艾丽美(Alimet)。它是一种含有88%的蛋氨酸羟基类似物的游离酸水溶液。值得     

Utilisation of U‐14C‐lysine by young turkeys

1. U‐¹⁴C‐lysine was administered by tube into the crop to turkey poults fed on assay diets (maize + sesame + maize gluten meal) containing varying concentrations oflysine, and partition of the label into body components, carbon dioxide, and excreta was measured.

2. Deposition of ¹⁴C label into breast and heart muscles responded positively to dietary lysine concentration. There was no apparent relationship between dietary lysine intake and deposition of label into carbon dioxide or excreta.

3. Efficiency of lysine retention, above maintenance, was estimated to be 0.523 ± 0.034.

4. Turkeys exhibited variable metabolic efficiency in the use of lysine as indicated by loss of U‐¹⁴C‐lysine label to expired carbon dioxide and to excreta by individual turkeys.     

添加剂级DL—蛋氨酸含量的快速测定

<正> 蛋氨酸属于必需氨基酸,它维持畜禽机体的氮平衡,是畜禽不可缺少的营养物质。但是,由于一般化验室缺少氨基酸自动分析议,使一部分人钻空子,出售假蛋氨酸,坑害用户。这里推荐一种蛋氨酸含量的快速测定方法,供同行参考。此法操作简便,分析时间短,所用仪器、药品简单,适合饲料厂家和一般饲料分析室采用。本站两年来应用此法成功地为用户检出多批掺假蛋氨酸。     

Agreement of Serum Spec cPL with the 1,2‐o‐Dilauryl‐Rac‐Glycero Glutaric Acid‐(6′‐methylresorufin) Ester (DGGR) Lipase Assay and with Pancreatic Ultrasonography in Dogs with Suspected Pancreatitis

Background

Spec cPL is the most sensitive and specific test for diagnosing pancreatitis in dogs. Its results have not been compared to those of the 1,2‐o‐dilauryl‐rac‐glycero‐3‐glutaric acid‐(6′‐methylresorufin) ester (DGGR) lipase assay or those of abdominal ultrasonography.

Objectives

To investigate agreement of Spec cPL with DGGR lipase activity and pancreatic ultrasonography in dogs with suspected pancreatitis.

Animals

One hundred and forty‐two dogs.

Methods

DGGR lipase activity (reference range, 24–108 U/L) and Spec cPL were measured using the same sample. The time interval between ultrasonography and lipase determinations was <24 hours. The agreement of the 2 lipase assays at different cutoffs and the agreement between pancreatic ultrasonography and the 2 tests were assessed using Cohen''s kappa coefficient (κ).

Results

DGGR lipase (>108, >216 U/L) and Spec cPL (>200 μg/L) had κ values of 0.79 (95% confidence interval [CI], 0.69–0.9) and 0.70 (CI, 0.58–0.82). DGGR lipase (>108, >216 U/L) and Spec cPL (>400 μg/L) had κ values of 0.55 (CI, 0.43–0.67) and κ of 0.80 (CI, 0.71–0.9). An ultrasonographic diagnosis of pancreatitis and DGGR lipase (>108, >216 U/L) had κ values of 0.29 (CI, 0.14–0.44) and 0.35 (CI, 0.18–0.52). Ultrasonographically diagnosed pancreatitis and Spec cPL (>200, >400 μg/L) had κ values of 0.25 (CI, 0.08–0.41) and 0.27 (CI, 0.09–0.45).

Conclusions and Clinical Importance

Although both lipase assays showed high agreement, agreement between ultrasonography and lipase assays results was only fair. Because lipase results are deemed more accurate, ultrasonography results should be interpreted carefully.