BHK-21细胞无血清悬浮培养生产新城疫病毒

为建立基于无血清悬浮培养细胞生产新城疫病毒(NDV)的工艺,本研究首先筛选了适于NDV增殖的乳仓鼠肾细胞(BHK-21)单克隆细胞株,并将鸡胚适应的NDV在筛选获得的细胞株(BHK-v002)中传代,获得细胞适应的NDV。进一步采用单因素实验法检测病毒感染复数(MOI)、TPCK-胰酶浓度、细胞培养液的稀释比例等工艺参数对病毒效价的影响。结果显示,NDV在无血清培养的BHK-v002细胞中增殖的最适条件为:当细胞生长至约9.0×10^6个/mL时,以培养液.新鲜培养基为2:1的比例补加新鲜培养基,使细胞密度达6.0×10^6个/m L,按MOI为0.005接种NDV LaSota株,TPCK-胰酶终浓度为5μg/mL。接种病毒后96 h收获病毒液的HA效价为8.5 log2HAU/25μL,单细胞产毒量(Svy)达到1 685.9病毒颗粒/细胞,半数组织细胞感染剂量(TCID50)为7.9 log10TCID50/100μL。本研究确定了NDV LaSota株在BHK-21细胞悬浮培养中的增殖条件,建立了基于BHK-21细胞无血清悬浮培养体系中NDV的生产工艺,该工艺操作简便,易于放大,为当前ND疫苗的鸡胚生产工艺提供了候选替代方案。     

促生长散对育肥羔羊血清矿物元素含量的影响

选择育肥羔羊１２０只,随机分为试验组６０只、对照组６０只,试验组羔羊于试验正式开始后第１天——３天添加促生长散,每只羔羊每天饲喂５ｇ,于第３０天——３２天再次添加促生长散,每只羔羊每天饲喂１５ｇ,试验组和对照组羔羊分别于用药前、第一次和第二次用药后７天、１４天、２１天、２８天采血,测定血清中钙、磷、钠、钾、铁、铜元素含量。结果表明,试验组与对照组相比：血清中各矿物元素含量都有不同程度的升高。     

双倍盐MEM和传统MEM对BHK-21细胞生长和FMDV增殖的影响

采用双倍盐MEM细胞培养基与传统培养基进行了BHK-21细胞生长和FMDV增殖对比实验,实验结果表明两种培养基无明显差异,双倍盐MEM培养基工艺简单,易于质量控制,是细胞培养基选择的一个方向。     

塞尼卡病毒A在BHK-21细胞中培养条件探索

研究发现,塞尼卡病毒A(Senecavirus A,SVA)是引发猪原发性水疱病(PIVD)的主要原因,感染猪的鼻吻、蹄冠部出现水疱性病变,还可造成新生仔猪死亡.为探索SVA在BHK-21细胞中培养的适宜条件,笔者分别从同步接毒法、单层接毒法、细胞浓度、收毒时间、血清含量等方面设计试验开展研究.本试验结果为制备高效价的...     

新生牛血清促细胞生长活性检测方法的建立与应用

牛血清是医药生物技术产品中重要的原辅材料之一,做好牛血清的质量控制是提高生物制品质量的重要环节。本研究通过应用PK15、BHK21和ST三种兽用生物制品研制中常用的细胞作为载体,选用国内同等价位5个不同厂家生产的新生牛血清作为比较对象,采用细胞倍增时间测定法、细胞克隆形成率测定法、细胞三次连续传代培养法、MTT比色法和微量终点稀释法五种血清质量鉴定的方法进行比较,检测新生牛血清的促细胞生长活性,最终确定了MTT比色法作为便捷高效快速筛选新生牛血清的检测方法。     

MDCK细胞连续传代培养的生长特性研究

目的:确定引进的MDCK细胞冻存保种效果。方法:复苏从ATCC引进保种冻存的MDCK细胞(P55),连续传代至P66,分别在P57、P59、P62和P66测定细胞生长曲线,计算细胞最大增殖浓度和倍增时间进行比较。结果:保种的细胞复苏活力达95.3%,最大增殖浓度分别为107.6×104、105.5×104、97×104和102.4×104(个/ml),倍增时间分别为15.8、15、15.2和15.3(h),结论:引进的MDCK细胞保种冻存后复苏活力高,能稳定连续传代培养,可用于相关研究。     

饲喂代乳粉对羔羊生长性能和血清生化指标的影响

试验旨在研究代乳粉对早期断奶羔羊生长性能及血清生化指标的影响。将18只新生陶赛特(♂)×小尾寒羊(♀)杂交F1羔羊随机分为试验组和对照组,每组9只羔羊,试验组饲喂代乳粉,对照组随母羊哺乳。在羔羊20、40、60、80、90日龄测定体重及体尺,并在50、90日龄采集血液样品分析血清生化指标。结果表明:饲喂代乳粉组羔羊体增重显著高于母羊哺乳组(P<0.05),试验组羔羊增重比母羊哺乳组高26.47%;体高、体长及胸围差异不显著(P>0.05);50日龄时,饲喂代乳粉组羔羊白蛋白和白/球蛋白比显著低于母羊哺乳组(P<0.05),而50和90日龄时,饲喂代乳粉组碱性磷酸酶活性显著高于母羊哺乳组(P<0.05)。结论:饲喂代乳粉可提高早期断奶羔羊的生长性能,促进其生长发育。     

羔羊断奶日龄对生长和血清指标的影响

本试验主要研究断奶日龄对羔羊生长性能和血清指标的影响,以确定羔羊早期断奶的最佳时间。16只无角陶塞特(♂)×小尾寒羊(♀)杂交一代羔羊,随机分为4组,对照羔羊随母羊哺乳,A、B、C组羔羊分别在第7、17和27天断奶,饲喂代乳品。试验结果表明:早期断奶组与对照组羔羊的体重、体长、体高和胸围均差异不显著(P>0.05)。试验期间(羔羊7~47日龄),羔羊血清尿素氮(urea nitrogen,UN)含量在4.13~6.81mmol/L之间。血清葡萄糖(glucoses,GLU)含量在4.34~7.30mmol/L之间;总蛋白(total protein,TP)含量为54.60~59.37g/L;白蛋白(albumin,ALB)含量为29.97~35.06g/L;球蛋白(globulin,GLOB)含量为20.23~29.40g/L;白蛋白/球蛋白(A/G)值为1.00~1.70。羔羊47日龄时,不同断奶日龄组与对照组羔羊之间的UN、GLU、TP、ALB和GLOB含量均差异不显著(P>0.05)。试验结论,羔羊早期断奶切实可行,羔羊可在7日龄断奶,17日龄断奶效果更好。     

鸡新城疫病毒LaSota株在BHK-21细胞上增殖条件的优化

本研究旨在对鸡新城疫病毒(Newcastle disease virus,NDV)LaSota株在BHK-21细胞上的增殖条件进行优化,为实现应用细胞系生产NDV提供参考。在确定BHK-21细胞TPCK-胰酶耐受浓度的基础上,在培养基中添加不同浓度的TPCK-胰酶、新生牛血清及调节不同pH,通过对细胞培养液细胞半数感染量(TCID₅₀)的测定,确定最适胰酶浓度、血清浓度及pH;通过固定接毒量而添加不同数量细胞或固定细胞数量而接种不同量的病毒,确定最适细胞量及接毒量;将BHK-21细胞接种NDV LaSota株后,通过测定不同时间细胞上清液TCID₅₀绘制增殖曲线,确定最佳收毒时间;应用转瓶对该病毒进行扩大培养,并进行TCID₅₀、鸡胚半数感染量(EID₅₀)与血清凝集价(HA)的测定。结果显示,NDV LaSota株在BHK-21细胞上增殖的最适TPCK-胰酶浓度为3μg/mL,最适接毒量为10^6.375 EID₅₀,细胞数量为1×10~6个,培养基pH为7.2,且可用无血清培养基进行培养,BHK-21细胞接种NDV LaSota株后最佳收毒时间为34～36 h。应用BHK-21细胞采用转瓶培养的方式对NDV LaSota株进行增殖,结果显示,细胞培养液TCID₅₀值为10^7.0/0.1 mL,EID₅₀为10^7.5/0.1 mL,HA效价为1∶256。因此,应用以上条件增殖培养NDV LaSota株,完全适用于该病毒的规模化生产,且符合现行的兽医生物制品与检验制造规程。     

两种不同营养水平的代乳粉对羔羊生长性能的影响

试验选用18只10日龄公羔，随即分成A、B、C三组，A组哺喂1号（低营养水平）代乳粉，B组哺喂2号（高营养水平）代乳粉，C组随母羊自然哺乳，每隔10d测定一次体重、体尺，进行了60d的饲养试验，结果表明：30日龄前，特别是10～20日龄阶段，自然哺乳组日增重达到154g／d，而代乳粉组平均日增重仅仅76．9g／d，试验组与对照组差异极显著（P〈0．01）；20日龄时，A、B、C三组体高增加分别为2．4％、6．50％、7．36％，A、B两组分别与C组差异极显著（P〈0．01）；体长A、B两组与C组差异显著（P〈0．05）：但随着日龄的增加，消化道逐渐健全，羔羊越来越习惯于吸允代乳粉，消化吸收能力加强，尤其到试验后期（41—60d），B组表现明显的生长优势，不同日龄体重、阶段平均日增重、体高、体长、胸围、管围都明显高于A组和C组。     

Effects of supplemental safflower and vitamin E during late gestation on lamb growth, serum metabolites, and thermogenesis

Twin-bearing Targhee ewes (Exp. 1, 1 yr, n = 42) and 1,182 single- and twin-bearing whiteface range ewes (Exp. 2, n = 8 experimental units over 2 yr) were used in a 2 x 2 factorial arrangement of treatments to determine the effect of supplemental energy source and level of vitamin E supplement on lamb serum metabolites and thermogenesis (Exp. 1) and on lamb growth (Exp. 2). During late gestation, ewes were individually fed (Exp. 1) or group-fed (Exp. 2) a daily supplement. Supplements were 226 g/ewe of daily safflower seed (DM basis; SS) with either 350 IU/ewe daily (VE) or no added supplemental (VC) vitamin E; or 340 g/ewe daily of a barley-based grain supplement (DM basis; GC) and either VE or VC. One hour postpartum in Exp. 1, twin-born lambs were placed in a 0 degrees C dry cold chamber for 30 min. Lamb rectal temperature was recorded every 60 s and blood samples were taken immediately before and after cold exposure. In Exp. 2, lambs were weighed at birth, at turnout from confinement to spring range (32 d of age +/- 7; turnout), and at weaning (120 d of age +/- 7). Ewes were weighed at turnout and weaning. In Exp. 1, a level of vitamin E x energy source interaction was detected (P < 0.10) for body temperature and change in NEFA and glucose concentrations. Lambs from SSVC ewes had the lowest (P = 0.01) body temperature and had decreased (P = 0.08) NEFA concentration. The SS lambs tended to have decreased (P < 0.11) concentrations of blood urea N (BUN) and thyroxine at 0 min than did lambs born to GC ewes. After 30 min of cold exposure, SS lambs had increased and GC lambs had decreased BUN, triiodothyronine, and triiodothyronine:thyroxine concentrations (P < 0.10). In Exp. 2, kilograms of lamb per ewe at turnout and weaning and lamb survival at weaning were greater (P < 0.07) for GC than SS lambs. Based on the decreased body temperature in SSVC lambs at birth, the greater change in BUN during the cold exposure for SS than GC lambs, and the decreased survival rate for SS than GC lambs, SSVC-supplemented ewes appeared to give birth to lambs with an apparently decreased energetic capacity. This may compromise the ability of the newborn lamb to adapt to extreme environmental conditions.     

苜蓿干草长度对育肥湖羊生长性能和营养物质消化率的影响

文章旨在探讨苜蓿干草切割长度对湖羊增重性能和营养物质表观消化率的影响。试验选择60只体重和日龄相近的断奶湖羊,随机分为4组,对照组日粮中的苜蓿干草为自然长度,其余3组分别饲喂切割长度为5、15和25 mm的苜蓿干草,预饲期为10 d,正试期为90 d,在饲喂试验结束前的最后10 d开展消化试验。试验结果表明,苜蓿干草切割长度对育肥羔羊的干物质采食量具有显著影响,育肥羔羊的干物质采食量随苜蓿干草切割长度的增加而降低。苜蓿干草切割长度对育肥羔羊的平均日增重具有显著影响,以苜蓿切割长度为15 mm具有最大日增重。育肥羔羊的营养物质表观率受苜蓿干草长度的影响显著,日粮营养物质的表观消化率随苜蓿干草切割长度的增加而增加。因此,在育肥羔羊饲料配制过程中,应考虑苜蓿干草的切割长度,本试验中以苜蓿干草切割长度为15 mm具有最佳生长性能。     

Effects of zeranol on in vitro growth hormone release by lamb and rat pituitary cells

A series of experiments was conducted to evaluate the effect of zeranol on release and synthesis of growth hormone (GH) by anterior pituitary cells established in either static or continuous flow cultures. Young adult male rats, slaughter-age lambs and juvenile lambs were used as sources of pituitary cells. In static primary cell cultures, no consistent effect of zeranol at 10(-7), 10(-9) or 10(-11) M was demonstrated by either rat or ovine cells. Rat pituitaries established in perifusion culture chambers showed no repeatable response to zeranol. Dissociated cells from lambs established in perifusion culture, however, had significant increases in release of GH in response to 37% of zeranol pulse exposures. When dissociated cells from juvenile lamb pituitaries were used, up to 10-fold increases in GH release consistently were measured within minutes of exposure to zeranol.     

能量水平对妊娠后期绒山羊养分消化率及羔羊的影响

试验通过为内蒙古白绒山羊妊娠后期母羊提供不同代谢能水平的日粮,研究母羊妊娠后期日粮能量水平对初生羔羊发育状况的影响,以及日粮不同能量水平条件下妊娠母羊对养分的表观消化率。结果表明:母羊妊娠后期高能日粮和低能日粮对羔羊初生重影响显著,母羊妊娠后期高代谢能(14.3 MJ/kg)可以有效增加羔羊体尺;日粮代谢能水平会显著影响母羊妊娠后期的体增重。本试验中,日粮代谢能水平为14.3 MJ/kg时,内蒙古白绒山羊母羊妊娠后期体增重最大;高的日粮代谢能水平(14.3 MJ/kg)会增加内蒙古白绒山羊妊娠后期母羊日粮营养物质的表观消化率,尤其是粗蛋白表观消化率。     

杜泊绵羊羔羊生长发育规律的研究

杜泊羔羊体形外貌一致 ,黑头白身躯 ,肉用体型典型。初生重 :公羔 5 3kg± 0 8kg ,母羔 4 5kg± 0 9kg ;3月龄体重 :公羔 3 7 9kg± 5 3kg ,母羔 3 3 3kg± 4 4kg ;0～ 3月龄平均日增重 3 5 1g± 71g ,其中公羔 3 85g± 74g ,母羔 3 3 3g± 64g。饲料利用率高 ,哺乳期只均日耗颗粒饲料 (含 2 4%花生秧粉 ) 5 2 1g ,料重比为 1 8∶1(母乳除外 ) ;抗寒耐热 ,抗病力强 ,适应性好 ,易管理     

早期断奶对羔羊生长发育的影响

将120只10～15 日龄的德国美利奴羊(♂)×小尾寒羊(♀)杂交一代羔羊随机分为Ⅰ、Ⅱ、Ⅲ、Ⅳ组,Ⅰ组于35 日龄断奶、Ⅱ组于45日龄断奶、Ⅲ组于60 日龄断奶、Ⅳ组于90日龄断奶.结果表明:60 d体重4组间无显著差异(P>O.05);90 d体重,Ⅱ、Ⅲ、Ⅳ组极显著(P(0.01)高于Ⅰ组,Ⅱ、Ⅲ、Ⅳ组间差异不显著(P>O.05).30～60日龄日增重,Ⅱ、Ⅲ、Ⅳ组极显著高于Ⅰ组(PO.05).45日龄断奶,羔羊体质健壮,抗病能力较强,综合效益高,为最佳断奶时间.     

不同断奶日龄对羔羊育肥效果的影响

选择出生重及出生日期相近、生长发育正常的滩羊羔羊60只,随机分为4组,分别为30、45和60日龄断奶组,120日龄哺乳组为对照,各选取15只羔羊进行育肥试验,直至120日龄。结果表明:在120日龄时,试验组羔羊的体重和体尺均极显著高于对照组(P<0.01)。其中体重最高的是60日龄断奶组羔羊,为36.25 kg,日增重(75～120 d)达278.67 g,极显著高于对照组的23.27 kg和136.0 g,经济效益比对照组高出80.12元/只。     

Effects of Ca salt supplementation on milk yield and composition and on lamb growth rate of Awassi ewes

An experiment was conducted to evaluate the effect of a Ca salt supplement on lactating Awassi ewes and their lambs. Ninety Awassi ewes (average BW = 55 kg ± 1.13) were allocated into three treatment groups of 30 each; 0%, 3%, or 5% Ca salt supplemented groups. The experiment started at lambing and lasted for 60 d. During this period, milk production and composition, final body weights, total feed intake, serum cholesterol and triglycerides, weaning weights of lambs, and milk fatty acid profile were tested. Milk production and energy corrected milk increased (P < 0.05) with Ca salt level in the diet. Milk fat content was higher (P < 0.05) at 3% treatment group compared to 0% and 5% treatment groups. However, no differences were detected in content of crude protein and total solids, and milk energy value. Milk fat yield (g/d) increased (P < 0.05) as Ca salt in the diet increased. Final body weight was higher (P < 0.05) for 5% group when compared to the 0% group with no differences between the 3% group when compared to 0% and 5% groups. No differences were observed in feed intake of ewes. Metabolizable energy intake was greater (P < 0.05) for the 3% and the 5% treatment groups when compared to the 0% treatment group. Feed to milk ratio increased (P < 0.05) when increasing the level of Ca salt in the diet. Serum cholesterol was greater (P < 0.05) in the 5% treatment group than the 0% and 3% treatment groups for ewes and lambs. Serum triglyceride was similar among treatment groups in ewes whereas serum triglyceride was greater (P < 0.05) for lambs in 5% treatment group than 0% and 3% treatment groups. However, serum triglyceride was similar in ewes among treatment groups. Weaning weights and average daily gain of male lambs were higher (P < 0.05) in lambs fed Ca salt (3% and 5%) when compared to 0% treatment group. No differences were detected in weaning weights and average daily gain of female lambs among treatment groups. However, milk conversion ratio was better (P < 0.05) for the 5% group lambs than the 0% and 3% treatment groups. Ca salt reduced (P < 0.05) short and medium-chain milk fatty acids and increased (P < 0.05) content of long chain and unsaturated ones. These results of this indicate that Ca salt supplementation can improve milk production of lactating ewes, the growth rate of their lambs, and produce healthy quality value milk.