共查询到17条相似文献，搜索用时 156 毫秒
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生长激素（PST）脂质体对育肥猪生产性能的影响 总被引：3，自引：0，他引：3
选择18头体重20kg左右的太湖二元杂交小公猪，分成A、B、C3组，每组6头。A组为对照组；B组颈部肌肉注射生长激素（PST）4ml/头；C组颈部肌肉注射PST脂质体28mg/头；结果表明PST与PST脂质体对育猪的生产性能影响较为接近，与对照组相比，均可显著提高育肥猪的日增重，饲料报酬，改善猪的胴体品质，说明PST脂质体可代替PST用于生产实践。 相似文献
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本文通过逆相蒸发法制备猪生长激素（PST）脂质体，重点是探讨不同组份原料对PST脂质体化学稳定性的影响。经过试验论证，加入抗氧化剂后，包封率明显提高，而且加BHT的效果比加维生素E（VE）的效果要好。通过对大豆卵磷脂和蛋黄卵磷脂的对比实验，证明了蛋黄卵磷脂所制脂质体效果较好，通过测定酸价，丙二醛含量的变化也证明了这一点。为PST脂质体的临床应用做初步的研究。 相似文献
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猪生长激素脂质体对育肥猪缓释作用效果研究 总被引：1，自引：0，他引：1
为了解猪生长激素(pGH)脂质体对育肥猪缓释作用效果,选用体重约50 kg健康去势的长白×大约克公猪24头,随机分成4组,即对照组和3个试验组。对照组每天注射生理盐水,试验一组每天按4 mg的剂量肌肉注射pGH,试验二组每3 d注射12 mg pGH脂质体,试验三组每7 d注射28 mg pGH脂质体,试验期为21 d。结果显示:注射pGH及其脂质体能够提高猪的日增重(P<0.05)和末重,显著降低料重比(P<0.05),试验组血清中胰岛素样生长因子1(IGF-1)水平显著高于对照组(P<0.01);注射生长激素的猪血清中生长激素水平均有不同程度的升高。脂质体的缓释时间可以达到7 d,表明猪生长激素脂质体在促进猪生长发育方面的效果明显。 相似文献
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磷酸泰乐菌素脂质体的制备及体外释放动力学研究 总被引：2，自引：2，他引：0
为延长磷酸泰乐菌素在体内的作用时间,通过比较采用硫酸铵梯度法制备其脂质体制剂。以包封率为指标,分别考察磷脂与胆固醇之比、药脂比、硫酸铵浓度、孵化温度和孵化时间对包封率的影响,并在此基础上进行正交试验筛选最优处方。同时,对所得脂质体的形态、粒径及分布、包封率及体外释放动力学进行研究。结果显示,正交试验优化得到的最佳处方工艺如下,磷脂与胆固醇质量比为4∶1,药脂比为1∶10,硫酸铵浓度为300 mmol/L,体系pH值为7.0,孵化温度为50℃,孵化时间为20 m in。电镜下观察脂质体呈球形或类球形,分布均匀,平均粒径为6.526μm,且大部分在1μm~12μm之间,包封率为58.32%,体外释药符合W eibull方程(r=0.976 4)。研究证实硫酸铵梯度法制备磷酸泰乐菌素脂质体方法可行,包封率高,稳定性好,体外释药具有一定的缓释效应。 相似文献
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D G McLaren P J Bechtel G L Grebner J Novakofski F K McKeith R W Jones R H Dalrymple R A Easter 《Journal of animal science》1990,68(3):640-651
Exogenous administration of porcine somatotropin (PST) has been shown to promote growth in the pig; however, dose-response relationships and interactions with PST source and sex for animals taken to market weight have not been established clearly. The present study was conducted to determine the relationship between dosage of pituitary-derived and recombinantly manufactured PST (pPST and rPST) and growth (ADG), structural soundness, gain-to-feed ratio (G/F) and average daily feed intake (ADF). Crossbred barrows (n = 113) and gilts (n = 97) were injected with either saline, 1.5, 3.0, 6.0 or 9.0 mg/d of pPST or rPST from 57 +/- .3 to 103.5 +/- .7 kg live weight. Pigs were housed five per pen and had ad libitum access to an 18% crude protein diet for the duration of the experiment. Response curves for pPST and rPST did not differ (P greater than .20) for ADG, soundness score or ADF. Although regression coefficients for response of G/F to pPST and rPST differed (P = .05), pairwise comparisons of treatment means did not (P greater than .10). Response curves for barrows and gilts did not differ for ADG or soundness (P greater than .05). Averaged over PST source and sex, quadratic dose-responses were detected for ADG, G/F and ADF (P less than .01), but PST had no effect on soundness (P greater than .25). Exponential regression models best described the dose-response relationships, and 6.0 mg.pig-1.d-1 was predicted to result in 95% of maximal achievable response for days to 103.5 kg and G/F. At this dose, pigs were predicted to grow .15 kg/d (20%) faster during the treatment period, reach slaughter weight 11.6 d earlier, consume .56 kg/d (19%) less feed, and have a G/F .095 (36%) greater than controls. 相似文献
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The effect of multiple lipopolysaccharide (LPS) challenges in swine undergoing long-term treatment with porcine somatotropin (PST) was determined. Changes in aspartate serine transaminase (AST) occurred only at 24h following the first LPS challenge dose (P<0.05), while PST treatment moderated any change from occurring. Nonesterified free fatty acid (NEFA) levels were elevated in PST treated animals for the first 3 days following daily LPS treatment (P<0.05), while LPS treatment alone had no effect on plasma NEFA levels. Plasma urea nitrogen (PUN) levels were unchanged by LPS following the initial LPS challenge, but were decreased following the second challenge dose (P=0.014). These changes were long lasting, with a return to normal PUN levels not evident until Day 6. The PST treatment mitigated changes in PUN (P<0.05) when LPS was administered. Haptoglobin plasma levels, along with lipid peroxide production were not affected by LPS challenge or PST administration. LPS challenge reduced the levels of immunoreactive heat shock protein 70 (HSP70) throughout the entire challenge period (P<0.001). PST-LPS animals had normal levels of this protein. The results of the present study demonstrate that long-term PST treatment mitigates the adverse effects of subchronic LPS administration. 相似文献
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为分析使用棉绳采集口腔液监测猪场伪狂犬病（PR）方法的科学性,本研究拟通过实验室水平、动物试验及临床应用3个方面对使用棉绳采集口腔液监测猪场PR这一方法开展应用分析。首先对采样条件进行优化,并通过模拟试验测定棉绳对伪狂犬病病毒（PRV）的释放能力,通过动物试验测定病毒感染后检出时间,最后对临床样品进行检测分析。结果表明：使用直径为1.0 cm的棉绳,在早上喂料前采集口腔液样品,采样时间为20~30 min,可采集到更能满足试验要求的口腔液。病毒释放能力测定显示,棉绳对PRV的释放能力为50%左右,使用棉绳采集口腔液可检测到1个TCID50/0.1 mL的病毒含量。动物试验检测发现,猪群在感染后28 d中除第5天外,口腔液中病原含量均高于鼻拭子中病原含量,口腔液检测效果优于鼻拭子,且口腔液中病毒的检出时间（感染后第1天）早于血液中抗体转阳时间（感染后第7天）。临床样品检测分析结果表明,PRV疫苗免疫后也可通过口腔液检测到疫苗毒,并且存在无法通过口腔液检测感染PRV野毒后稳定猪中带毒的情况,因此口腔液检测方法应结合gE抗体检测,才可综合判断猪群是否为感染群体。综上,本研究优化了口腔液采集方法,并测定了棉绳对口腔液的释放能力和感染后检出时间,表明口腔液可作为较好的监测猪群PR的手段;口腔液监测方法需结合gE抗体检测来综合判断猪群是否为感染群体。 相似文献
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为分析使用棉绳采集口腔液监测猪场伪狂犬病(PR)方法的科学性,本研究拟通过实验室水平、动物试验及临床应用3个方面对使用棉绳采集口腔液监测猪场PR这一方法开展应用分析。首先对采样条件进行优化,并通过模拟试验测定棉绳对伪狂犬病病毒(PRV)的释放能力,通过动物试验测定病毒感染后检出时间,最后对临床样品进行检测分析。结果表明:使用直径为1.0 cm的棉绳,在早上喂料前采集口腔液样品,采样时间为20~30 min,可采集到更能满足试验要求的口腔液。病毒释放能力测定显示,棉绳对PRV的释放能力为50%左右,使用棉绳采集口腔液可检测到1个TCID50/0.1 mL的病毒含量。动物试验检测发现,猪群在感染后28 d中除第5天外,口腔液中病原含量均高于鼻拭子中病原含量,口腔液检测效果优于鼻拭子,且口腔液中病毒的检出时间(感染后第1天)早于血液中抗体转阳时间(感染后第7天)。临床样品检测分析结果表明,PRV疫苗免疫后也可通过口腔液检测到疫苗毒,并且存在无法通过口腔液检测感染PRV野毒后稳定猪中带毒的情况,因此口腔液检测方法应结合gE抗体检测,才可综合判断猪群是否为感染群体。综上,本研究优化了口腔液采集方法,并测定了棉绳对口腔液的释放能力和感染后检出时间,表明口腔液可作为较好的监测猪群PR的手段;口腔液监测方法需结合gE抗体检测来综合判断猪群是否为感染群体。 相似文献
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LJ Smith L Krugner-Higby M Clark D Ney E Dahly 《Veterinary anaesthesia and analgesia》2003,30(2):116-117
A delayed‐release formulation of liposome‐encapsulated oxymorphone was produced using a novel dehydration–rehydration technique. The purpose of this study was to (i) compare the analgesic properties of this preparation with those of repeated injections of standard oxymorphone in rats with post‐operative visceral pain and (ii) determine whether liposome‐encapsulated oxymorphone differed from standard oxymorphone in duration of the effect. Visceral pain was elicited in approximately 300 g Sprague–Dawley rats by intestinal resection performed under isoflurane anesthesia. Rats were monitored with pulse oximetry; mean anesthesia time (35 ± 10 minutes) did not differ between the groups. Rats were randomly divided into two groups: Group 1 received 1.2 mg kg?1 liposome‐encapsulated oxymorphone SC once at skin closure and 0.2 mL of saline SC every 4 hours; Group 2 received 0.2 mL liposome‐encapsulated sucrose SC once at skin closure and 0.3 mg kg?1 standard oxymorphone SC every 4 hours. In both groups, a behavioral ethogram for pain score (grooming, porphyrin staining, body position) was recorded every 4 hours for 48 hours after surgery. Observers were blinded to the treatment. Body weight, food consumption, and urine output were recorded daily for 7 days after anesthetic recovery. Data were analyzed using anova , with significance at p < 0.05. Based on the behavioral pain score, a single injection of liposome‐encapsulated oxymorphone was as effective for relief of post‐surgical visceral pain in rats as multiple (every 4 hours) injections of standard oxymorphone administered over a 48 hour period (p = 0.18). In rats, given one dose of liposome‐encapsulated oxymorphone, the mean body weight change from day 0 to day 7 was +9.4 g, whereas rats given multiple injections of standard oxymorphone had a mean body weight change of ?3.6 g over this time (p < 0.01). Mean daily food consumption was significantly less in rats given multiple injections of standard oxymorphone (p < 0.05). There was no difference between groups in urine production. In conclusion, a single dose of liposome‐encapsulated oxymorphone was effective in treating visceral pain in rats. Rats treated with liposome‐encapsulated oxymorphone had improved recovery, based on body weight changes and food consumption, compared with rats treated with multiple doses of standard oxymorphone. Liposome‐encapsulated oxymorphone offered advantages including provision of effective analgesia, prolonged dosing intervals, and minimal handling stress. 相似文献