1,25(OH)2 vitamin D concentration in the plasma of Solanum glaucophyllum intoxicated rabbits

OBJECTIVE: To test Solanum glaucophyllum calcinotic effects in adult New Zealand White rabbits in relation to cumulative dose and active principle concentration in plasma. DESIGN: An intoxication assay with controls. PROCEDURE: Rabbits were orally dosed with aqueous extracts of dry leaves of S glaucophyllum for 5, 7 or 9 days. During the experiment, body weight, calcaemia and phosphataemia were measured; retinal blood vessel calibre was observed by ophthalmoscopic examination of the ocular fundus. 1,25(OH)2 vitamin D plasma concentration was determined at the end of the experimental periods. Soft tissue calcium concentration and the presence of calcinotic lesions were studied after euthanasia. RESULTS: Toxic effects were evident in S glaucophyllum treated groups (loss of body weight, elevation of soft tissue calcium concentration, and presence of calcinotic lesions). Plasma 1,25(OH)2 vitamin D concentrations were negatively correlated with final body weight (r = -0.97; P < or = 0.001), and positively correlated with renal calcium concentration (r = 0.74; P = 0.02). There was also a significant regression of plasma 1,25 (OH)2 vitamin D concentration on the cumulative dose of S glaucophyllum (R2 = 0.87; P < or = 0.001). CONCLUSIONS: The procedure described here offers a sensitive and practical experimental model for the study of the pathogenesis of enteque seco.     

生长育肥兔复合添加剂配方筛选试验

选择年龄相近 ,健康无病 ,体重约 1kg的新西兰白兔 80只 ,根据体重、性别按组间相似的原则分为 4组 ,每组 2 0只。结果表明 ,试兔平均日增重 4组间有明显差异 ,饲料报酬和单位增重的饲料成本 ,以试验 2组和试验 3组最好 ;试验 1 ,2 ,3组试兔干物质、能量和粗蛋白质的消化率均显著高于对照组 (P <0 0 1 ) ,而试验组间无显著差异 (P <0 0 5) ,3个试验组的胴体重和屠宰率都显著高于对照组 (P <0 0 1 ) ,但以试验 2组最高 ;肌肉pH值和系水力各组之间无显著差异 (P <0 0 5)。     

Methionine promotes the development of hair follicles via the Wnt/β-catenin signalling pathway in Rex rabbits

To investigate the effect and molecular mechanism of methionine (Met) on the growth of hair follicles (HFs) in Rex rabbits. A total of 200 weaning Rex rabbits were divided into four groups and fed varying levels of Met-supplemented diets. We measured the HF density on dorsal skin and the Wnt/β-catenin pathway protein expression level. Meanwhile, whole HFs were isolated from Rex rabbit skins and cultured with Met in vitro to measure hair shaft growth. The relationship between Met and the Wnt/β-catenin signalling pathway was also characterized by using the Wnt/β-catenin signalling inhibitor, XAV-939. The results showed that the addition of dietary Met could significantly increase the HF density on dorsal skin (p < .05) and enhance the protein expression level of Wnt10b (p < .05), β-catenin (p < .05) and DSH (p < .05). Methionine stimulation could also prolong the hair shafts growth in vitro (p < .05). And inhibition of Wnt/β-catenin signalling using XAV-939 could eliminate this phenomenon. In summary, Met can increase the density of HFs on dorsal skin in vitro and prolong the hair shaft growth of HFs in vivo via the Wnt/β-catenin signalling pathway.     

Growth performance,carcass quality,biochemical and haematological traits and immune response of growing rabbits as affected by different growth promoters

The aim of the article was to study the effect of different growth promoters on growth performance, carcass quality, biochemical and haematological traits and immune response of growing rabbits. A total number of 105 male growing NZW rabbits during 35–91 days of age were randomly distributed among 7 groups fed the same basal diet and submitted to different dietary treatments: the first group was unsupplemented and used as control; the other groups were supplemented respectively with bee pollen and/or propolis at 200 mg/kg BW of each and inulin and/or mannanoligosaccharides (MOS) at 35 mg/kg BW of each. Body weight gain, daily feed intake, feed conversion ratio (FCR), biochemical and haematological blood parameters, carcass characteristics, histological studies of ileum and spleen and economical efficiency were measured. Bee pollen administered alone or with propolis significantly (p < 0.01) the body weight gain and improved FCR in respect of the control group. Inulin with MOS significantly improved just FCR than the control group. Bee pollen with propolis and MOS supplemented‐groups resulted in significantly higher (7.96 and 8.41% respectively) white blood cells compared to the control group. Plasma total cholesterol was significantly higher for the MOS group in respect of the control, bee pollen, inulin and inulin with MOS supplemented‐groups. Propolis resulted in significantly higher dressed carcass percentage than the control group and higher carcass index than only bee pollen with propolis supplemented‐group. Bee pollen, in particular if in combination with propolis, could be used as a supplement in the growing rabbits during days 35–91 of age with positive effects on growth rate and feed conversion ratio.     

乳酸菌对獭兔生长性能、肉品质及肌肉胰岛素样生长因子-1、胰岛素样生长因子1受体、生长激素受体mRNA相对表达量的影响

本试验旨在研究乳酸菌对獭兔生长性能、肉品质及肌肉胰岛素样生长因子-1(IGF-1)、胰岛素样生长因子1受体(IGF-1R)、生长激素受体(GHR)mRNA相对表达量的影响,探讨其对肉品质的调控作用及适宜用量.选取(43±2)日龄断奶、体重为(1.15±0.05)kg的健康白色獭兔80只,随机分为5组,每组4个重复,每个重复4只兔(公母各占1/2).对照组喂饮生理盐水;试验组(Ⅰ～Ⅳ组)喂饮植物乳杆菌菌液,其水平分别为104、107、1010和1013 CFU/mL.每隔1d喂饮1次,每次10 mL.预试期7d,正试期60 d.结果表明:1)与对照组相比,Ⅰ、Ⅱ组的失水率分别降低了4.49％和2.27％,差异显著(P＜0.05).各组獭兔肌肉的pH、剪切力和肉色均无显著差异(P＞0.05).2)Ⅱ组平均日增重显著高于对照组(P＜0.05),料重比显著低于对照组(P＜0.05).各组平均日采食量差异不显著(P＞0.05).3)Ⅰ组IGF-1 mRNA相对表达量显著高于其他各组(P＜0.05),Ⅱ组GHR mRNA相对表达量显著高于对照组(P＜0.05).各组IGF-1RmRNA相对表达量无显著差异(P＞0.05).由此可知,在饮水中添加乳酸菌能提高獭兔生长性能,促进肌肉IGF-1、GHR mRNA的表达,并改善肌肉的系水力.本试验条件下,乳酸菌的适宜添加水平为107 CFU/mL,推荐添加水平为104 ～ 107 CFU/mL.     

獭兔双歧杆菌的培养特性及抗菌活性研究

【目的】研究獭兔双歧杆菌的生理特性及抗菌能力。【方法】将獭兔双歧杆菌接种于特定的培养基后,观察其生长特性,并与大肠埃希菌共培养,研究其抗菌能力。【结果】獭兔双歧杆菌呈分枝状,在改良肉汤培养基中生长旺盛;耐温驯化后发现,獭兔双歧杆菌可在42℃下生长;獭兔双歧杆菌对许多药物如红霉素等敏感;獭兔双歧杆菌与大肠埃希菌共培养可抑制大肠埃希菌生长,其代谢产物也具有明显的抑菌能力。【结论】獭兔双歧杆菌在体外培养良好,具有很好的抗菌活性。     

Assessing the fate of recombinant plant DNA in rabbit’s tissues fed genetically modified cotton

Various feeding studies have been conducted with the different species of animals to evaluate the possible transfer of transgenic DNA (tDNA) from genetically modified (GM) feed into the animal tissues. However, the conclusions drawn from most of such studies are sometimes controversial. Thus, in the present study, an attempt has been made to evaluate the fate of tDNA in rabbits raised on GM cotton-based diet through PCR analysis of the DNA extracted specifically from blood, liver, kidney, heart and intestine (jejunum). A total of 48 rabbits were fed a mixed diet consisting variable proportions of transgenic cottonseeds meal (i.e. 0% w/w, 20% w/w, 30% w/w and 40% w/w) for 180 days. The presence of transgenic DNA fragments (Cry1Ac, Cry2A and CP4 EPSPS) or plant endogenous gene (Sad1) was traced in those specific tissues and organs. The presence of β-actin (ACTB) was also monitored as an internal control. Neither the transgenic fragments (459 bp of Cry1Ac gene, 167 bp of Cry2A gene and111 bp of CP4 EPSPS gene) nor cotton endogenous reference gene (155 bp of Sad1) could be detected in any of the DNA samples extracted from the rabbit's tissues in both control and transgenic groups. However, 155 bp fragment of the rabbit's reference gene (ACTB) was recovered in all the DNA samples extracted from rabbit tissues. The results obtained from this study revealed that both plant endogenous and transgenic DNA fragments have same fate in rabbit's tissues and were efficiently degraded in the gastrointestinal tract (GIT).     

Influence of multi-enzyme preparation supplemented with sodium butyrate on growth performance blood profiles and economic benefit of growing rabbits

The present study was carried out to explore the impacts of dietary supplementation of enzyme mixture with sodium butyrate on the growth performance, carcass traits, blood profile and economic benefit in two breeds of weanling rabbits adapted to survive in Egypt (New Zealand White and Rex). One-hundred and twenty weaned male rabbits (New Zealand White and Rex) of 6 weeks of age and 770.5 ± 20 g body weight were allotted randomly into four groups in a factorial arrangement. The obtained results indicated that there were non-significant differences in all growth performance traits, blood profile and economic parameters due to the breed effect. However, there were significant differences in most of carcass traits due to the breed effect except total giblets and New Zealand White breed showed the highest value of these parameters including dressing % (p < .01), forequarter and loin % (p < .001) and hindquarter % (p < .003) compared with Rex breed counterparts. The effect of the treatment and its interaction with the breed significantly (p < .05) improved body weight gain, feed consumption and carcass traits (percentage of dressing, forequarter, hind quarter and lion). However, final body weight and feed conversion ratio were not significantly influenced. Supplementing a diet with treatment significantly decreased blood triglycerides, cholesterol and the ratio between albumin and globulin (A/G ratio), while increased blood total protein and globulin. Although higher feed cost and total costs in treated groups than control ones in each breed, they showed higher total return and net return. Rex non-treated rabbit breed showed the lowest profitability measures compared with other groups. In conclusion, dietary supplementation of multi-enzyme with sodium butyrate is highly recommended in growing rabbits due to their beneficial effects on the growth performance and profitability.     

利用成年母兔耳部皮肤上皮细胞生产克隆胚胎的研究

以成年母兔耳部皮肤上皮细胞为核供体,对家兔体细胞核移植技术中融合、激活以及不同来源受体卵母细胞的选择等环节进行了研究,比较了不同电场强度对重构胚胎融合率、分裂率的影响。结果表明,200V/mm电场强度时重构胚胎的融合率(82.53%)显著高于160V/mm(59.73%),但与240V/mm(79.56%)无显著差异;200V/mm时重构胚胎的分裂率(71.43%)显著高于160V/mm(49.43%)和240V/mm(57.80%)。来源于输卵管卵母细胞组成的重构胚胎的融合率(84.71%)和裂解数与来源于卵巢大卵泡(78.75%)的无显著差异;但来源于输卵管的重构胚胎分裂率(73.68%)显著高于来源于卵巢大卵泡的(56.35%)。将646枚2~4细胞期重构胚移植到38只同期化及非同期化的受体后无幼仔出生。     

Pharmacokinetics of ketamine following a short intravenous infusion to isoflurane-anesthetized New Zealand White rabbits (Oryctolagus cuniculus)

ObjectiveTo describe the pharmacokinetics of ketamine following a short intravenous (IV) infusion to isoflurane-anesthetized rabbits.Study designProspective experimental study.AnimalsA total of six adult healthy female New Zealand White rabbits.MethodsAnesthesia was induced with isoflurane in oxygen. Following determination of isoflurane minimum alveolar concentration (MAC), the isoflurane concentration was reduced to 0.75 MAC and ketamine hydrochloride (5 mg kg^–1) was administered IV over 5 minutes. Blood samples were collected before and at 2, 5, 6, 7, 8, 9, 13, 17, 21, 35, 65, 125, 215 and 305 minutes after initiating the ketamine infusion. Samples were processed immediately and the plasma separated and stored at –80 °C until analyzed for ketamine and norketamine concentrations using liquid chromatography–mass spectrometry. Compartment models were fitted to the concentration–time data for ketamine and for ketamine plus norketamine using nonlinear mixed-effects (population) modeling.ResultsA three- and five-compartment model best fitted the plasma concentration–time data for ketamine and for ketamine plus norketamine, respectively. For the ketamine only model, the volume of distribution at steady state (Vss) was 3217 mL kg^–1, metabolic clearance was 88 mL minute^–1 kg^–1 and the terminal half-life was 59 minutes. For the model including both ketamine and norketamine, Vss were 3224 and 2073 mL kg^–1, total metabolic clearance was 107 and 52 mL minute^–1 kg^–1 and terminal half-lives were 52 and 55 minutes for the parent drug and its metabolite, respectively.Conclusions and clinical relevanceThis study characterized the pharmacokinetics of ketamine and norketamine in isoflurane-anesthetized New Zealand White rabbits following short IV infusion. The results obtained herein will be useful to determine ketamine infusion regimens in isoflurane-anesthetized rabbits.