肉鸡饮服“必补-18”的抗应激效果研究(Ⅱ)

本文研究了“必补＿１８”对应激条件下肉鸡的影响。结果表明：“必补＿１８”显著改善了０～３周龄肉鸡的增重、饲料转化率，显著提高了血清γ＿球蛋白水平和成活率，采食量未见有显著改变。５～８周龄肉鸡经历高温３２℃一周，其增重、饲料转化率和采食量均显著下降（Ｐ＜０．０１），饮服“必补＿１８”显著提高了增重和饲料转化率（Ｐ＜０．０１），采食量未见有差异，高温一周过程中，３２℃１６小时血浆皮质酮，Ｔ３先显著下降（Ｐ＜０．０１）、Ｔ４显著升高（Ｐ＜０．０１），３２℃１２０小时时，血浆皮质酮、Ｔ３回升且显著高于常温组（Ｐ＜０．０５），Ｔ４较１６小时显著下降（Ｐ＜０．０１）但仍高于常温组（Ｐ＜０．０５）。在高温条件下饮服“必补＿１８”血浆皮质酮、Ｔ３和Ｔ４呈现与高温对照组同样规律的变化，但这种变化得到显著缓解（Ｐ＜０．０５）     

高温条件下复合抗应激剂对肉鸡的影响

本文研究了高温条件下复合抗应激剂对肉鸡的影响。结果表明：经历３２ ℃一周的５ ～８ 周龄肉鸡采食量、增重、饲料转化率均显著下降（Ｐ＜ ０ ．０１） ，饮服复合抗应激剂显著改善增重和饲料转化率（Ｐ＜ ０ ．０１） ， 采食量未见明显改变，饲料转化率达到常温水平。３２ ℃１６ 小时血浆皮质酮、Ｔ３ 显著下降（Ｐ＜ ０ ．０１） 、Ｔ４ 显著升高（Ｐ＜ ０ ．０１） ；３２ ℃１２０ 小时血浆皮质酮、Ｔ３ 升高并超出常温组（Ｐ＜ ０ ．０５） 、Ｔ４ 较１６ 小时下降但仍高出常温组（Ｐ＜ ０ ．０５） 。饮服复合抗应激剂时血浆皮质酮、Ｔ３ 、Ｔ４ 显现相同变化规律，但这种变化得到显著缓解     

铜,锌,锰,硒对肉鸡繁殖性能和生殖激素影响的研究

铜、锌、锰、硒四种元素以一定饲料浓度添加进试验鸡的基础日粮中，定期统计开产日龄、产蛋数量、开产后每周料／蛋比、蛋的受精率和孵化率；检测血浆中性激素浓度以及在卵产出周期中的变化结果：第二组开产日龄最早，比其它组提前１６－２０天，且产蛋数为最多，开产后每周料／蛋比最小，显著低于对照组，差异显著（Ｐ＜０．０５）。蛋的受精率和孵化率均以第二组为好。四种元素混合后，均可促进睾酮（Ｔ）、雌二醇（Ｅ２）和孕酮（Ｐ）的分泌，提高血浆中浓度。在２４小时内血浆雌二醇的浓度基本上都在６－１２小时出现峰值，血浆孕酮的浓度大部分有二次峰值，第一峰值在６－１２小时，第二峰值在２４小时前后，而且试验组的水平显著高于对照组（Ｐ＞０．０１）。     

高温对产蛋鸡血浆促黄体激素和孕酮水平的影响

本文研究了高温对产蛋鸡血浆促黄体激素（ＬＨ）和孕酮含量的影响。结果表明，随温度升高，血浆孕酮水平先升后降，血浆ＬＨ在３５℃时显著下降；在２８℃和３０℃温度下，血浆ＬＨ和孕酮水平不低于正常水平，产蛋性能也无明显变化；在３４℃在３５℃温度下，血浆ＬＨ和孕酮水平均低于正常水平，产蛋性能急剧下降，说明血浆ＬＨ和孕酮水平下降是高温影响鸡产蛋性能的重要原因之一。     

不同限饲水平对产蛋期肉种鸭生产性能的影响

本研究旨在探讨不同限饲水平对产蛋期肉种鸭生产性能和孵化指标的影响。试验选取 ４０周龄父母代 ＳＭ３樱桃谷种鸭 ３２００只（母鸭 ２６００只,公鸭 ６００只）,随机分成 ４组,每组 ５个重复,每个重复 １６０只鸭（母鸭 １３０只,公鸭 ３０只）。以玉米 －豆粕 －小麦型配合饲料（代谢能 １１．５０ＭＪ／ｋｇ,粗蛋白质 １８．００％）为基础饲粮。Ｔ１组日饲喂料量最大,为每只鸭 ２２５ｇ,其他组依次降低 １５ｇ,分别为 ２１０（Ｔ２组）、１９５（Ｔ３组）和 １８０ｇ（Ｔ４组）,试验期 ３５ｄ。结果表明：１）当日饲喂料量由２２５ｇ下降到２１０ｇ时,公、母鸭的体增重均显著下降（Ｐ＜０．０５）,产蛋率略有上升,蛋重略有下降,但二者变化均不显著（Ｐ＞０．０５）,当日饲喂料量继续下降到 １９５和 １８０ｇ时,与日饲喂料量 ２２５ｇ时相比,公、母鸭体增重、产蛋率和蛋重均显著下降（Ｐ＜０．０５）;２）经回归分析,公、母鸭体增重、产蛋率、蛋重与日饲喂料量有显著的直线或二次曲线关系（Ｐ＜０．０５）,产蛋率与蛋重之间也有显著的二次曲线关系（Ｐ＜０．０５）;３）日饲喂料量对种鸭死淘率及种蛋合格率、受精率、健雏率、入孵蛋孵化率和受精蛋孵化率均无显著影响（Ｐ＞０．０５）。结果提示,适当限制饲喂料量可降低体增重,提高产蛋率,但过度限饲会影响生产性能。     

鲁西黄牛发情周期和产后期外周血浆孕酮水平

在鲁西黄牛母牛的发情周期和产后期（产犊至产后６０ｄ）收集颈静脉血样，用放射免疫分析法测定血浆孕酮（Ｐ４）水平。结果表明，母牛的发情周期平均为（２１．２±１．６）ｄ，发情当天（０ｄ）外周血浆孕酮水平为（０．５２±１．４）μｇ／Ｌ，在周期的９～１５ｄ，孕酮水平较高，其峰值为（４．６２±１．５６）μｇ／Ｌ（ｎ＝１５），在周期的约１８ｄ以后，孕酮水平迅速下降，至周期的２１ｄ降至发情开始时的水平；母牛产后１０．６～１３．６ｄ以后，外周血浆孕酮水平开始升高，出现黄体周期，约有一半的母牛产后第１个黄体周期为（８．４±０．５）ｄ，显著短于正常周期（２０．１±３．２）ｄ（Ｐ＜０．０１）；在短周期中，孕酮峰值为（１．５２±０．７１）μｇ／Ｌ，亦显著低于正常周期孕酮峰值（３．８４±１．２５）μｇ／Ｌ（Ｐ＜０．０５）。除短周期外，产后发情周期中的孕酮水平变化与通常的发情周期基本相同     

鸡传染性贫血病毒感染对雏鸡免疫系统的影响Ⅱ．几种细胞因子体外诱生活性动态变化

１日龄雏鸡人工感染鸡传染性贫血病毒（ＣＩＡＶ）后７、１４ｄ，脾脏Ｔ淋巴细胞ＩＬ－２活性明显降低（Ｐ＜０．０１，Ｐ＜０．０５），２１ｄ明显回升，２８ｄ显著升高（Ｐ＜０．０５），３５ｄ后降至对照水平；感染后７、１４和２１ｄ，胸腺Ｔ淋巴细胞ＩＬ－２诱生活性明显降低（Ｐ＜０．０５），２８ｄ后恢复至对照水平。感染后７、１４ｄ，脾脏淋巴细胞ＩＦＮ诱生活性明显低于对照鸡（Ｐ＜０．０５），２１ｄ后恢复至对照水平。感染后１４ｄ，胸腺淋巴细胞集落刺激因子（ＣＳＦ）诱生活性未见明显变化，２１ｄ显著升高（Ｐ＜０．０５），２８ｄ降至正常水平。     

鸡传染性贫血病毒感染对雏鸡免疫系统的影响：Ⅱ.几种细胞因子体外…

１日龄雏鸡人工感染鸡传染性贫血病毒（ＣＩＡＶ）后７、１４ｄ，脾脏Ｔ淋巴细胞ＩＬ－２活性明显降低（Ｐ＜０．０１，Ｐ＜０．０５），２８ｄ显著升高（Ｐ＜０．０５），３５ｄ后降至对照水平；感染后７、１４和２１ｄ，胸腺Ｔ淋巴细胞ＩＬ－２诱生活性明显降低（Ｐ＜０．０５），２８ｄ后恢复至对照水平。感染后７、１４ｄ，脾腺淋巴细胞集落刺激因子（ＣＳＦ）诱生活性未见明显变化，２１ｄ显著升高（Ｐ＜０．０５），２８ｄ降至     

热应激对母牛内分泌及繁殖机能的影响

通过对不同气温环境下母牛内分泌变化规律及繁殖性能的研究结果表明，热应激能明显改变母牛内分泌变化模式，能显著降低冷配母牛受胎率，产犊季节与胎衣不下发病率密切相关。当环境温度由４℃上升到２８１℃时，母牛血清中孕酮水平上升７３３３％（Ｐ＜００５），Ｔ３、皮质醇、ＬＨ和雌二醇水平则显著降低（Ｐ＜００５）；母牛受胎率下降１３１个百分点（Ｐ＜００５）；胎衣不下发病率上升２３３３个百分点（Ｐ＜００１）。这一结果说明，热应激条件下，孕酮水平增高和雌二醇水平降低是造成冷配母牛受胎率下降的主要因素。     

高温对蛋鸡甲状腺重及血浆甲状腺素的影响

本文研究了高温对产蛋鸡甲状腺重及血浆Ｔ４、Ｔ３水平的影响。结果表明，经高温处理后，产蛋鸡甲状腺重量减轻；血浆Ｔ４和Ｔ３水平随温度升高呈相反变化。一般高温（３０℃，短时间作用），血浆Ｔ４水平升高而Ｔ３水平下降；极端高温（３４－３５℃，长时间作用），血浆Ｔ４水平下降而Ｔ３水平升高，同时蛋鸡产热增加，产蛋量急剧下降，说明极端高温使血浆Ｔ３水平升高促进了产热增加，而采食量减少，从而影响产蛋的营养供给，是高温时产蛋率下降的重要原因之一。     

Effects of heparin, citrate, and EDTA on plasma biochemistry of sheep: Comparison with serum

The effects of various types of anticoagulants on plasma biochemistry were studied in man and various animals, but limited information is existing for sheep plasma biochemistry. Ten clinically healthy Baloochi breed of sheep were blood sampled in different tubes containing each anticoagulants and plain tube for harvesting plasma and serum. The concentrations of glucose, cholesterol, total bilirubin, urea, creatinine, total protein, albumin, calcium, inorganic phosphorus, and magnesium and the activity of aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatine kinase (CK) and gamma glutamyl transferase (GGT) were measured. Except for the amounts of GGT, bilirubin and inorganic phosphorus, other measured parameters were significantly lower in citrated plasma than that of serum. For corrected citrated plasma significant differences were seen for the concentrations of glucose, creatinine, calcium and the activity of ALP.Most parameters did not show any difference, but significant increase was seen for albumin concentration when heparin was used as an anticoagulant. Using EDTA as anticoagulant caused a significant difference for the concentrations of some of the measured parameters in plasma except glucose, GGT, cholesterol, albumin, bilirubin, CK, and inorganic phosphorus comparing with serum.     

Concentrations of ionized and total magnesium and calcium in healthy horses: effects of age, pregnancy, lactation, pH and sample type

Magnesium (Mg) and calcium (Ca) are the main divalent cations in the body. The free ionized fraction is the physiologically active form of both Mg and Ca. As ion-selective-electrode (ISE) analyzers are becoming widely used in veterinary practice it will be useful to establish reference intervals for horses. In the present study, reference intervals were established for ionized, total and the ratio of the ionized to total Mg and Ca concentrations in four horse groups: adults, neonatal foals, and pregnant and lactating mares, as well as in three sample types, whole blood, plasma and serum, using an ISE-analyzer. Sample pH effect was assessed.Concentration differences in both total and ionized cations were recorded for some measures between horse groups and different sample types. The most significant differences were recorded between neonatal foals and other groups. These results demonstrate the need to use specific reference intervals for horses of different physiologic status and in specific sample types.     

Adiposity,Plasma Insulin,Leptin, Lipids,and Oxidative Stress in Mature Light Breed Horses

Background

Increased blood insulin levels are associated with an increased risk of pasture‐associated laminitis in equids.

Objective

To determine the relationship between plasma insulin, leptin, and lipid levels, and measures of oxidative stress with adiposity in mature light breed horses.

Animals

300 randomly selected light breed horses, aged 4–20 years.

Methods

A random sample of horses (140 mares, 151 geldings, and 9 stallions) was drawn from the VMRCVM Equine Field Service practice client list. Evaluations occurred June 15 – August 15, 2006, with all sampling performed between 0600 and 1200 hours. Concentrate feed was withheld for at least 10 hours before sampling. Plasma was analyzed for insulin, glucose, leptin, triglycerides, nonesterified fatty acids, and measures of oxidative stress. Body condition score was determined as the average of 2 independent investigators.

Results

Overconditioned and obese horses had higher plasma insulin (P < .001) and leptin (P < .01) levels than optimally conditioned horses. Obese horses had higher triglyceride levels (P = .006) and lower red blood cell gluthathione peroxidase activities (P = .001) than optimally conditioned horses.

Conclusions and Clinical Importance

Maintaining horses at a BCS <7 might be important for decreasing the risk of pasture‐associated laminitis.     

The intravenous glucose tolerance test in water buffalo

OBJECTIVE: The response to intravenous glucose loading in the buffalo using the intravenous glucose tolerance test (IGTT) was investigated to provide a reference for intravenous glucose injection in buffaloes. METHOD: Twelve healthy, fasted, male swamp buffaloes were divided into three groups. Group I: six buffaloes were given 50% glucose at a dosage of 1 g/kg body weight via the jugular vein. Group II: three buffaloes received normal saline. Group III: three buffaloes were not injected. Blood samples were taken from the opposite vein at 60 and 10 min pre-injection (pre60 and pre10), and at 1, 5, 10, 30, 60, 120, 180, 240, 300, 360 and 420 min post-glucose injection (PGI). Plasma glucose was analyzed by the oxidase method. Insulin and glucagon were soon determined with a human radioimmunoassay kit. The insulin (pmol/l)/glucose (mmol/l) ratios (IGR) were also calculated for each sampling time. RESULTS: Mean plasma glucose, insulin and glucagon concentrations of buffaloes in groups II and III were similar at all the sampling times (p > 0.05) and the curves of the IGR for group II and group III were flat throughout. Group I Buffaloes showed an immediate 20 times increase in the mean plasma glucose concentration PGI, over the pre60 and pre10. The peak plasma insulin concentration occurred at 30 min PGI. The mean plasma glucose and insulin concentrations remained above pre-administration levels until 420 min PGI (p < 0.05). However, the mean plasma glucagon concentrations were different only at 1 and 5 min PGI sampling times. The curve of the IGR for group I showed an initial decrease at 1 min PGI, and fluctuated from 10.18 to 25.55 for the remainder of the sampling period. The correlation analysis showed that the mean plasma glucose concentration was positively correlated with insulin level (r = 0.73, p < 0.005), and significantly negatively correlated with mean plasma glucagon (r = -0.58, p < 0.05). The mean plasma insulin level did not show significant correlation with the glucagon (r = 0.06, p > 0.05). CONCLUSION: The hyperglycemia, high insulin, and protracted glucose and insulin curves, the initial decrease in the insulin/glucose ratio indicates that there was an unexpected glucose tolerance to acute intravenous glucose loading in water buffalo compared with other ruminants. The possibly suggested intravenous glucose load in buffaloes is about 5.09-8.28 mmol/l.     

Relationship between body measurements,metabolic hormones,metabolites and residual feed intake in performancetested pedigree beef bulls

The objective of this study was to examine the relationship between easily measured, potential physiological and physical indicators of feed efficiency including metabolic hormones, metabolites, ultrasonic muscle and fat measures with performance and efficiency traits in performance tested pedigree beef bulls (n = 302; initial bodyweight 493 (SD = 64) kg). Animals were offered a high energy concentrate ad libitum plus 1.5 kg fresh weight grass hay daily and individual feed intake was measured for 70 days. Blood samples were collected by coccygeal venipuncture at the start and end of the performance test period and analysed for plasma concentrations of IGF-I, insulin, leptin and various metabolites. Similarly, ultrasonic muscle and fat depths were measured at the start and end of the test period. Residual feed intake (RFI) was computed for each animal as the residuals from a multiple regression model regressing dry matter intake (DMI) on average daily gain (ADG) and mid-test BW^0.75 (MWT). Overall ADG, DMI, feed:gain (F:G) and RFI were 1.91 (SD = 0.29), 10.10 (SD = 1.31), 5.37 (SD = 0.84) and 0.00 (SD = 0.78), respectively. Residual feed intake was strongly correlated with DMI (r = 0.67) and moderately correlated with F:G (r = 0.40). Moderate positive correlations ranging from 0.3 to 0.6 were estimated between ultrasonic measures of final fat and muscle depth and their respective gains over the test period with DMI, ADG and RFI. There was no evidence of a strong association between any of the plasma analytes measured and RFI at either sampling times. However, end of test insulin was negatively correlated (r = − 0.14) with RFI. Final IGF-I concentration was negatively associated with DMI (r = − 0.14) and F:G (r = − 0.15). End of test circulating leptin concentration was positively correlated with DMI (r = 0.14) and F:G (r = 0.15). Plasma glucose concentration at the end of test was negatively related to DMI (r = − 0.21) and F:G (r = − 0.21). A positive relationship was observed between end of test plasma urea concentration and DMI (r = 0.30). Overall, the correlation coefficient estimates between the potential blood markers and measures of intake, performance and efficiency were weak and generally not different from zero. This suggests that it is unlikely that measurement of these metabolic indicators, per se, will be useful in the early identification of feed efficient animals.     

Effects of dietary Selenomethionine supplementation on growth performance,antioxidant status,plasma selenium concentration,and immune function in weaning pigs

Background

This study was designed to evaluate the efficacy of DL-selenomethionine (DL-SeMet) supplementation on growth performance, antioxidant status, plasma selenium (Se) concentration, and immune function of weaning pigs. 216 weaning pigs were randomly allocated to 6 treatments with 6 replicates each according to a complete randomized block design. Each replicate had six pigs. Diet of group one was corn-soybean basal diet without any additional Se supplement. Group 2 was supplemented with 0.3 mg/kg of Se from sodium selenite. Groups 3-6 were supplemented with 0.1, 0.3, 0.5, and 0.7 mg/kg of Se from DL-SeMet, respectively. The trial lasted for 42 days.

Results

Pigs supplemented with 0.3 and 0.7 mg/kg DL-SeMet obtained better feed gain ratio (P < 0.05). The best antioxidant ability (serum, liver, and muscle) was shown in 0.1-0.3 mg/kg DL-SeMet groups (P < 0.05). The plasma Se concentration increased as the dietary DL-SeMet level elevated. The immunity among groups was not affected.

Conclusions

DL-SeMet supplementation in the diet significantly improved the growth performance, antioxidant ability and plasma Se content of weaning pigs. DL-SeMet can replace sodium selenite in the diet of weaning pigs.     

植物乳酸杆菌对感染沙门氏菌蛋鸡血浆生化、免疫水平及沙门氏菌定植的影响

本试验旨在研究植物乳酸杆菌对感染肠炎沙门氏菌蛋鸡血浆生化、免疫水平及沙门氏菌定植的影响。将400只京红1号商品代蛋鸡随机分成4个处理组,每组5个重复,每个重复20只鸡。A组和C组饲喂基础饲粮,B组和D组在基础饲粮添加2×10~8 CFU/g植物乳酸杆菌。饲喂1周后,C组和D组连续2 d口服1×10~10CFU/m L肠炎沙门氏菌菌液,A组和B组口服等量无菌PBS溶液,饲养3周。结果表明:添加植物乳酸杆菌可显著提升总蛋白、球蛋白水平(P0.05),显著降低低密度脂蛋白和甘油三酯(P0.05);添加植物乳酸杆菌可显著增加IgM、IgG(P0.05);蛋鸡感染沙门氏菌的第14天和第21天及试验全程,添加植物乳酸杆菌显著减少盲肠食糜中肠炎沙门氏菌拷贝数(P0.05)。综上可知,日粮中添加植物乳酸杆菌可改善感染肠炎沙门氏菌蛋鸡的血浆生化指标,缓解炎症损伤,降低盲肠沙门氏菌定植数量,保障机体健康。     

Development and validation of a sensitive enzyme immunoassay (EIA) for blood plasma cortisol in female cattle,buffaloes, and goats

A highly sensitive enzyme immunoassay (EIA) that used the second antibody coating technique and the cortisol-horseradish peroxidase conjugate as a label for determination of free and total cortisol in blood plasma of dairy animals (cows, buffaloes, and goats) was developed. For biological validation of the EIA, blood samples were collected from the animals at 48 and 24 h before and 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, and 132 h after dexamethasone administration. The EIA was performed directly with 20 μL of fresh plasma (for free cortisol) and also with 20 μL of heat-treated plasma (for total cortisol) after 1:5 dilutions with PBS. Cortisol standards ranging from 0.39 to 200 pg/well/20 μL were used, and the sensitivity of the EIA procedure was found to be 0.39 pg/well/20 μL, which corresponded to 0.02 ng/mL. In comparison with RIA the EIA was at least 4 times more sensitive and required 5 times less cortisol antiserum. In female cattle, buffaloes, and goats, the total, free, and bound plasma cortisol before dexamethasone administration was significantly (P < 0.05) higher than the total, free, and bound cortisol after dexamethasone administration. It can be concluded from these studies that the direct, sensitive EIA validated for estimating the free and total cortisol concentrations was sufficiently reliable and quick for studying the dynamics of cortisol distribution in blood plasma of dairy animals.     

泌乳奶牛低血钙的诊断和治疗

选择14头有运动障碍的荷斯坦泌乳牛,测定其血浆钙（Ca）、磷（P）含量,在日粮中添加石粉饲喂半个月后,再测定其血浆Ca、P。结果显示,患牛补充石粉前低血钙率达85.32%,补充石粉后15d降至16.67%,同时血浆Ca含量极显著升高（P〈0.01）,血浆P含量显著下降（P〈0.05）,钙磷比显著升高（P〈0.05）。因此,机体钙浓度低、磷浓度高所致的钙磷比失调是引起奶牛骨软症的主要原因。石粉能有效地防治奶牛骨软症。