Bovine interleukin 2: biochemical and biological characterization

Interleukin 2 (IL-2), secreted by bovine peripheral blood mononuclear cells (PBL) on stimulation with concanavalin A (Con A), was purified and characterized by different chromatographic and electrophoretic techniques. The ability of IL-2 to support proliferation of Con A-stimulated bovine lymphoblasts was used to assay and quantitate IL-2 activity. Bovine IL-2 having an apparent MW of 27,000 eluted from a gel-filtration column; from an anion exchange column peak activity was detected at 190 mM NaCl. Binding of bovine IL-2 to phenyl-Sepharose gel and elution with 35-60% ethanediol indicated its hydrophobic nature. Studies on cross-species reactivity revealed that both buffalo and goat lymphocytes respond to cattle IL-2 and detected 35% of activity from a standard cattle IL-2 preparation. Sheep lymphocyte response to cattle IL-2 was negligible.     

Bovine interleukin 2: production and characterization

The production of bovine IL 2 was studied and IL 2 was partially characterized. PMA at 5 ng/ml + Concanavalin A at 5 micrograms/ml treatment of peripheral blood mononuclear cells gave a greater yield of IL 2 activity in the supernatants than Con A, PMA or sodium periodate treatments alone. Macrophage depletion increased yields as did the addition of indomethacin, a prostaglandin E2 inhibitor. Bovine IL 2 was sensitive to trypsin, relatively stable at pH 2-9, 2-ME resistant and sensitive to increasing molar concentrations of urea. The activity of bovine IL 2 was reduced by over 45% at 70 degrees C for 30 min and 95% at 90 degrees C for 30 min. Bovine IL 2 was more stable at 4 degrees C than at room temperature and the stability at room temperature could be improved by inclusion of 1% BSA. Bovine IL 2 eluted from DEAE-Sephadex as a broad peak with 0.1-0.2 M NaCl. Peak activity corresponded to a molecular weight of approximately 16,000 daltons on Sephadex G-100.     

Parameters of production and partial characterization of feline interleukin 2

The conditions for the production of feline interleukin 2 (IL-2) from peripheral blood leukocytes (PBL) and splenocytes by concanavalin A (Con A) stimulation are described. Feline IL-2 was quantitated by measuring DNA synthesis in the murine IL-2-dependent cell line, CTLL-20. In addition, feline IL-2 was generated for the maintenance of long-term cultures of Con A-stimulated feline PBL and for biochemical characterization. Finally, IL-2 production was evaluated from the PBL of feline leukemia virus (FeLV)-infected cats. Con A at 9.6 micrograms/ml produced a plateau of peak IL-2 activity from 24 to 48 h following stimulation. The tumor promoter, phorbol myristic acetate, stimulated feline IL-2 production and enhanced Con A-stimulated feline IL-2 production. Fetal calf serum (FCS) was not required for IL-2 production; however, FCS at 5% (v/v) allowed for maximal Con A-stimulated IL-2 production. Feline IL-2 generated from Con A-stimulated splenocytes migrated with an apparent molecular size of 13.7 to 23 kD by gel filtration chromatography and supported the proliferation of Con A-activated feline PBL at a final concentration of 0.3 to 0.9 units/ml.     

Bovine interleukin 2: production by an E-rosette-defined lymphocyte subpopulation

E-rosette-separated bovine peripheral blood lymphocyte subpopulations were examined for ability to produce interleukin 2 (IL 2). Sequential E-rosetting techniques resulted in three T-cell subpopulations and a non-T population. Separated cells were stimulated with Con A and the resulting culture supernatants were assayed for IL 2 activity on IL 2-dependent cells. The bovine T-cell subpopulation which rosetted with both neuraminidase-treated and 2-aminoethylisothiouronium bromide (AET)-treated erythrocytes was found to produce significantly more IL 2 than the other T-cell subpopulations or the non-T population. These results suggest that this population may have a T-helper cell function. IL 2-dependent cells were found to be predominately T-cells by E-rosetting, were lymphoblastoid in appearance and surface immunoglobulin negative. Conditioned media containing IL 2 were used to demonstrate cytotoxic T-cell activity against allogeneic lymphocytes in peripheral blood lymphocytes.     

二氢杨梅素对肉仔鸡血液生化指标及生长性能的影响

二氢杨梅素(dihydromyricetin,DMY)——3,5,7,3′,4′,5′-六羟基2,3双氢黄酮,是从藤茶中提取的一种天然植物添加剂,DMY具有抗氧化、清除自由基、抑菌杀菌、保肝护肝、抗炎、镇痛等功效。谢鹏等(2004)[1]首次报道的肉鸡生产试验表明,DMY具有促生长、提高免疫机能等作用,但由于D     

Relation between biochemical parameters in the blood of cows and milk production

No differences in blood samples were found out when the biochemical parameters in arterial and venous blood of dairy cows were compared before and after milking. Negative correlation coefficient (r = -0.3460) approaching the significance level was determined by comparing the values for milk yield on the day of sampling (in ascending phase of lactation) and protein content in venous blood after milking, and significant negative correlation coefficient (r = -0.3813) for daily milk yield and gamma-globulin concentration in venous blood before milking. The relationship between butterfat content on the day of milking and the values of alkaline phosphatase can be characterized by significant up to highly significant negative correlation coefficients in all three blood samples (r = -0.3232 to -0.3908).     

Serum biochemical parameters and embryo production during superovulatory treatment in dairy cattle

The objective of this study was to determine the relationship between the number of transferable embryos (TE) and various blood chemistry parameters as a reflection of the metabolic state of cows after superovulatory treatment. Forty-nine Holstein cows were subjected to superovulatory treatment for commercial embryo production. At the time of embryo harvest, individual blood samples were taken from cows for biochemical analysis. All embryos including dead ones as well as non-fertilized oocytes were counted in uterine lavage. Feed samples collected daily for a period of two weeks before embryo harvest, were analyzed for mycotoxins: vomitoxin, zearalenone and T-2 toxin. On average, cows produced 9.45 ± 5.60 embryos and oocytes of which 5.27 ± 4.20 were TE, 0.37 ± 0.80 were dead embryos and 3.82 ± 3.78 were non-fertilized oocytes. Higher concentrations of Mg and K were associated with a higher production of TE (p = 0.005 and p = 0.043, respectively) and higher activity of creatinine kinase was associated with a lower production of TE (p = 0.011).     

Serum biochemical parameters and embryo production during superovulatory treatment in dairy cattle

The objective of this study was to determine the relationship between the number of transferable embryos (TE) and various blood chemistry parameters as a reflection of the metabolic state of cows after superovulatory treatment. Forty-nine Holstein cows were subjected to superovulatory treatment for commercial embryo production. At the time of embryo harvest, individual blood samples were taken from cows for biochemical analysis. All embryos including dead ones as well as non-fertilized oocytes were counted in uterine lavage. Feed samples collected daily for a period of two weeks before embryo harvest, were analyzed for mycotoxins: vomitoxin, zearalenone and T-2 toxin. On average, cows produced 9.45 ± 5.60 embryos and oocytes of which 5.27 ± 4.20 were TE, 0.37 ± 0.80 were dead embryos and 3.82 ± 3.78 were non-fertilized oocytes. Higher concentrations of Mg and K were associated with a higher production of TE (p = 0.005 and p = 0.043, respectively) and higher activity of creatinine kinase was associated with a lower production of TE (p = 0.011).     

Effect of different selenium sources on production performance and biochemical parameters of broilers

Selenium (Se) is an essential trace element for animal and human. Supplementation of Se usually in livestock diet has been proved as effective element. This study was conducted to investigate the effect of different sources of selenium on growth performance, slaughter performance, immune trait, oxidation resistance, meat quality and selenium content in tissue of broilers to comprehensively evaluate the effect of selenium. A total of 324 1‐day‐old AA broilers were selected and randomly allocated to three treatments of six replicates with 18 broilers each. The trial period was 42 days and was divided into two periods. Our results showed that effect of different sources of selenium on growth performance, slaughter performance, the immune status, drip loss and flesh had not significant difference (p > 0.05); while the activities of serum glutathione peroxidase (GSH‐Px), total superoxide dismutase (T‐SOD), the abilities to inhibit hydroxyl radical (OH˙) and total antioxidant capacity (T‐AOC) were significantly higher in selenium yeast than sodium selenite groups, and the contents of MDA of selenium yeast groups were significantly lower than that of sodium selenite. This study demonstrated that the different sources of selenium had no obvious effect on production performance of broilers, but significantly influenced the broiler oxidation resistance.     

Effects of dietary copper supplementation on production performance and plasma biochemical parameters in broiler chickens

1. A study was conducted to estimate the effect of copper (Cu) supplementation on growth performance and biochemical profiles of blood and meat in broiler chickens.

2. A total of 240?d-old broiler chicks (Vencobb-100) were randomly divided into 12 groups, each of 20 chicks (4 treatments?×?3 replicates).

3. The basal diet (T₁) contained 215?g?kg^?1 crude protein (CP), 12·76?MJ?kg^?1 ME, 32?g?kg^?1 total calcium and 5?g?kg^?1 total phosphorus. T_2, T₃ and T₄ were formulated to contain an additional 75, 150 and 250?mg?Cu?kg^?1 diet, respectively. Copper sulphate pentahydrate (CuSO₄, 5H₂O) was used as the source of Cu.

4. Significant reductions in plasma total cholesterol and triglyceride, and an elevated concentration of HDL-cholesterol, were observed in the chickens fed with 250?mg?Cu?kg^?1 (T₄) of feed at the 3rd and 6th week of the experiment. Total cholesterol in meat decreased significantly in the birds fed with dietary Cu at 250?mg?kg^?1 (T₄) of feed.

5. Growth performance was measured in terms of live weight gain, cumulative feed intake and feed conversion ratio at the end of d 21 and d 42 of the experiment, and the result was found to be commercially beneficial for the chickens receiving 150?mg?Cu?kg^?1 (T₃) of diet. The concentration of Cu in breast muscle and liver increased significantly at the end of experiment.

6. From this study it can be concluded that supplementation with dietary Cu may be beneficial for production performance and plasma biochemical characteristics of broiler chickens.     

酵母硒对蛋鸡生产性能、血清生化指标及常规蛋品质的影响

本试验旨在研究玉米-豆粕饲粮下添加不同水平酵母硒对蛋鸡生产性能、血清生化指标及常规蛋品质的影响。试验选用1 000只280日龄的海兰褐壳蛋鸡,随机分为5组,每组5个重复,每个重复40只,分别为基础饲粮组、0.1、0.2、0.3和0.4mg/kg酵母硒添加水平组,试验期40d。结果发现,与对照组相比,饲粮添加0.3~0.4mg/kg酵母硒可显著提高产蛋率和平均蛋质量(P0.05),并显著降低料蛋比和破蛋率(P0.05);与对照组相比,饲粮添加0.3~0.4mg/kg酵母硒分别提高了血清总蛋白(P0.05)和降低了血糖含量(P0.05),各酵母硒添加组均显著提高了血清无机磷(P0.05)和钙(P0.05)水平,且以0.3mg/kg添加组钙、磷水平最高;与对照组相比,各试验组均可显著改善蛋壳强度、蛋白高度、哈氏单位和蛋黄颜色(P0.05),且以0.3mg/kg酵母硒添加组蛋壳强度、蛋白高度和哈氏单位最高,但各试验组蛋形指数和蛋壳厚度与对照组差异不显著(P0.05)。结果表明,蛋鸡饲粮中添加0.3mg/kg酵母硒效果最佳。     

不同水平互花米草提取物对泌乳奶牛生产性能和血清生化指标的影响

文章旨在研究饲粮中添加互花米草提取物对奶牛产奶性能及血清生化指标的影响。试验选取体重(550±25) kg、胎次2～3胎、泌乳期(110±24) d及泌乳(24.2±4.2) kg/d的泌乳期荷斯坦奶牛90头,采用完全随机区组设计分为6组,每组15头,进行为期60 d的饲养试验,其中预试期10 d,正试期50 d。对照组饲喂基础饲粮,处理组分别在基础饲粮中每天添加5、10、25、50 g/d和100 g/d的互花米草提取物。结果表明:整个试验期间,处理组的采食量、产奶量、乳脂率、乳蛋白率、总固形物含量、乳尿素氮含量以及血清谷丙转氨酶、谷草转氨酶、碱性磷酸酶、谷氨酰胺基转移酶、α-羟丁酸脱氢酶、乳酸脱氢酶、总蛋白、球蛋白和肌酐含量与对照组相比均无显著差异(P>0.05);5～50 g/d组乳糖率和白蛋白含量显著高于100 g/d组(P<0.05)。互花米草提取物添加量5～50 g/d组体细胞数显著低于对照组和100 g/d组(P<0.05)。50 g/d组尿素氮浓度显著高于100 g/d组(P<0.05);而该组尿酸浓度显著低于5 g/d组(P<0.05)。50 g/d组葡萄糖浓度显著高于对照组、5 g/d和10 g/d组(P<0.05)。试验条件下,饲粮中添加100 g/d范围内的互花米草提取物对奶牛产奶性能没有明显影响,但50 g/d组可以提高乳糖率和血糖浓度,降低体细胞数,是适宜的添加剂量。     

香兰素对泌乳前期奶牛产奶性能及血清生化指标的影响

本试验旨在研究香兰素对奶牛干物质采食量、产奶量、乳成分及血清生化指标的影响,为香兰素在奶牛生产上的开发应用提供科学依据。选取40头健康的荷斯坦奶牛进行配对,随机分为对照组和试验组,每组20头,在相同的条件下饲养。对照组饲喂牛场全混合日粮,试验组在对照组日粮基础上添加10 g/d香兰素,预试期7 d,试验期70 d。结果表明:日粮添加10 g/d香兰素对奶牛泌乳前期的干物质采食量、产奶性能无显著影响(P0.05);日粮中添加10 g/d香兰素对泌乳前期奶牛的乳成分无显著影响(P0.05);日粮中添加10 g/d香兰素对血清生化指标无显著影响(P0.05)。得出结论:在日粮中添加10 g/d香兰素对泌乳前期奶牛的生产性能及血清生化指标无显著影响。     

Bovine interleukin 2 (IL-2) production and activity on bovine and murine cell lines

Long-term growth of T cell cultures requires addition of Interleukin 2 (IL-2). In order to maintain bovine cultures, optimal conditions for bovine IL-2 production were defined using peripheral blood mononuclear cells (PBM). Irradiation and preculture enhanced IL-2 production possibly by reducing suppressor activity. IL-2 activity was also detected in Bovine Herpesvirus Type 1-stimulated cultures. Unlike mitogen-stimulated cultures, a wide variation in IL-2 activity was seen between supernatants produced by virus-stimulated cells from different animals indicating the clonal nature of antigen specific cells from individuals. Bovine IL-2-dependent cells used to quantitate IL-2 activity were characterized as: PNA, esterase negative, H4+ (anti Ia-like), B29+ (anti-pan T cell), and C5- (anti-monocyte). The observations that bovine IL-2 can maintain activated murine cells, CTLL-20 and HT-2, could lead to the replacement of rat IL-2 with bovine IL-2 in long-term murine cultures. Conditions described here result in large volumes of active medium.     

Change in interleukin 2 production by lymphocytes during maturation of young cats

Lymphocytes from four specific-pathogen free cats were tested for their interleukin 2 activity every week beginning when the cats were 12 weeks old and ending when they were 26 weeks old. Lymphocytes from cats 20 weeks old released significantly more interleukin 2 than those obtained from these cats at earlier ages when stimulated with calcium ionophore A23187 and phorbol myristate acetate. The change of interleukin 2 levels with maturation of young cats may represent an important difference in their level of defense to infections with various pathogens.     

Expression and characterisation of equine interleukin 2 and interleukin 4

In the present study, we describe the expression of equine IL2 and IL4. The cDNA of equine IL2 or IL4 was cloned in a mammalian expression vector, containing c-terminal myc- and six histidines His(6)-epitopes for recognition and purification of equine cytokines. The vector constructs were used for transfection of chinese hamster ovary (CHO) cells. Purified equine cytokines were characterised by western blotting. Equine IL2 was secreted with a molecular weight of approximately 17.1kDa, whereas IL4 was expressed in three different sizes of 17.1, 19.6 and 22.1kDa, probably due to different glycosylation modifications. The biological activities of both cytokines were tested by proliferation assays using leukoagglutinin (LAG) prestimulated equine PBMC. Both, equine IL2 and IL4 induced dose-dependent lymphocyte proliferation. In contrast to IL4, IL2 supported the proliferation of B cells.     

Effect of cortisol in vitro and in vivo on production of bovine interleukin 2

The influence of cortisol in vitro and in vivo on lymphocyte proliferative responses and interleukin 2 (IL2) production was evaluated in Hereford feeder calves. Cortisol, added to bovine mononuclear cell cultures, reduced (P less than 0.05) mitogen-stimulated lymphocyte proliferative responses and IL2 production. Lower IL2 activity from cortisol-treated cell cultures was not caused by a cortisol-mediated cytotoxicity or a residual cortisol effect on the IL2-indicator cell line. Calves given ACTH (1.0 IU/kg of body weight, IM) twice daily for 2 days had increased (P less than 0.001) plasma cortisol concentrations when compared with those of saline-treated controls. Leukocytosis (P less than 0.002), characterized mainly by a neutrophilia (P less than 0.007), was evident in ACTH-treated calves. Lymphocyte proliferative responses to the phytomitogens, concanavalin A, phytohemagglutinin, and pokeweed mitogen were decreased (P less than 0.05) in calves with increased plasma cortisol concentrations. Interleukin 2 production was lower (P less than 0.05) in concanavalin A-stimulated lymphocyte cultures from ACTH-treated calves. Seemingly, lower lymphocyte proliferative responses in cortisol-treated mononuclear cell cultures and in ACTH-treated calves were caused partly by lower IL2 production.     

饲粮不同蛋白质水平对半番鸭生产性能和血液生化指标的影响

本试验旨在研究低蛋白质日粮对半番鸭生产性能和血液生化指标的影响。按照组间平均体重接近原则,将360只14日龄半番鸭称重后分成3组,每组4个重复,每个重复30只。每组分别饲喂14%、16%和18%3种不同蛋白水平饲粮,饲养至70日龄屠宰,测定屠宰性能并采集血液测定生化指标。结果表明:14⁷0日龄半番鸭平均日采食量、平均日增重及料重比各组间均无显著差异(P>0.05)。70日龄半番鸭的屠宰率、半净膛率、全净膛率、胸肌率、腿肌率、腹脂率各组间差异不显著(P>0.05)。70日龄半番鸭血液的总蛋白、白蛋白、球蛋白、碱性磷酸酶、尿酸、尿素氮、甘油三酯、胆固醇、高密度脂蛋白和低密度脂蛋白含量各组间均差异不显著(P>0.05)。由此可见,14%蛋白水平的饲粮完全可以满足半番鸭的生长需要,而不影响其生产性能和血液生化指标。     

Bovine interleukin 2: regulatory mechanisms

A cDNA clone of the bovine interleukin-2 (IL-2) gene has been isolated and demonstrated to produce a functional bovine IL-2 protein when transfected into either CV-1 or COS-1 monkey cells. Homology comparisons of both the nucleotide and predicted amino acid sequences of bovine IL-2 with those of the human and mouse show extensive regions of sequence conservation between the species. The amino acid sequence of the mature bovine IL-2 protein shares about 60-63% homology with those of the human and mouse, but the 3' untranslated regions of the human and mouse gene share as much, if not greater, sequence homology with the 3' untranslated regions of the human and mouse genes. In particular, a tandemly repeated sequence (TATT), n, found in the 3' untranslated tail of the bovine IL-2 clone is also found in the 3' untranslated region of a large group of cytokine genes and other inducible genes of the lymphoid and immune response systems. This sequence may serve a specific regulatory function in the immune system.     

中草药增重剂对小尾寒羊生产性能及血液理化指标影响的研究

试验观察不同水平的纯中草药饲料添加剂对小尾寒羊的增重保健效果。结果表明 ,中草药能够显著提高小尾寒羊的增重速度 ,添加中草药 1 .5 %和 2 .0 %的组平均日增重分别比对照组提高了 61 .53 %和 65 .49% (P <0 .0 5) ;提高小尾寒羊的日粮干物质、粗蛋白质、酸性洗涤纤维、中性洗涤纤维表观消化率 ;饲料干物质转化率比对照组降低了 66.92 % ,精料转化率降低了32 .0 2 % ;血清中生长激素和胰岛素样生长因子含量随着中草药添加量的增加而呈升高趋势 ;中草药添加 1 .5 %组T3 、T4的水平高于对照组 (P <0 .0 5) ,分别比对照组提高 2 31 .48%和 2 1 8.89%。