Pathogenicity of Escherichia coli O_(123) from Rex Rabbit on White Mice

[Objective]The paper was to analyze the pathogenesis of Escherichia coli O123 from rex rabbit. [Method]E. coli O123 isolated from rabbit liver with diarrhea symptom in scale rex rabbit farm was intraperitoneally injected into 18- 22 g Kunming mice,and its pathogenicity was determined by clinical symptoms and pathological examination. [Result]When the inoculation concentration was about 8. 5 × 107 CFU /mL,Kunming mice appeared the clinical symptoms of drooping spirit,diarrhea and gathering,and the mortality reached 50%. Anatomical examination found that intestinal wall was thinning and intestinal mucosa was bleeding. [Conclusion]E. coli from rex rabbit has strong pathogenicity,and establishing animal model with Kunming mice to study its pathogenesis is of great reference significance for diagnosis and prevention of E. coli disease of rex rabbit.

Effects of Diets with Different Corn-to-Soybean Ratios on Performance of Lactational Rex Rabbits

[ Objective] To study the effects of diets with different com-to-soybean ratios on production performance of lactational Rex rabbits and select the best feed formula. [Method] A total of 80 lactational healthy Rex rabbits （similar age, body weight and delivery time） were randomly divided into five groups, 16 in each group. The Rex rabbits in group I were fed with corn-based meal diet, group II with soybean-based meal diet, group III with the developed corn-soybean meal diet, group IV with corn-soybean meal free diet, and group CK with conventional corn-soybean meal diet. During the lactation period, the changes in the lactation performance, growth rate of baby rabbits, weight and feed costs were observed. [ Result] The lactation performance of mother rabbits and the growth rate of baby rabbits in the experimental groups were similar to that in the control group. The weaning survival rate of the group III was the highest, but it was not significantly higher than that of the control group. The weaning survival rate of the other three groups was lower than that of the control group （P〈0.05）. The weight loss of mother rabbits in the group I, II and III was not significantly different from that of the control group, but the weight loss of the group IV was higher than that of the control group （ P 〈 0.01 ）. [ Conclusion] Diets with appropriate corn-to-soybean ratios not only reduce feed costs but also give the best feeding effects.

Gene Expression Patterns in Different Wool Densities of Rex Rabbit Using cDNA Microarray

This study was carried out to identify gene expression patterns in different wool densities of rex rabbit. The mid-dorsal skin samples from 8 rex rabbits were studied. They were divided into two groups according to different wool densities. Total RNA was isolated and labeled by reverse transcription reaction with Cy5-dCTP and Cy3-dCTP for cDNA probe. The cDNA probe was hybridized with cDNA microarrays containing 14 601 rabbit’s genes. The differently expressed genes were analysed with the Gene Ontology （GO） classification and the pathway analysis. Hierarchical clustering was performed to clarify genes in association with different wool densities. The 2 657 differentially expressed genes were identified. Among them, 1 103 genes were functionally known genes, 687 genes were up-regulated and 419 were down-regulated. GO analysis indicated that these altered genes were associated with metabolism, signal transduction, cell cycle, cell adhesion, cell proliferation, cell division, apoptosis, and other processes. KEGG analysis showed that 95 signal pathways associated with up-regulated genes and 87 signal pathways associated with down-regulated genes had changed significantly （P0.05）. Some important differentially expressed genes in different wool densities of rex rabbit were identified, such as MMP2, TGF-β1, TGF-β2, IGF-1, ITGB1, RPS6KB1, BMP2, ActRIIB, CDK2, and CCNA2. Hierarchical clustering analysis separated the differentially expressed genes into 5 main characteristic groups. Data from cDNA microarray experiments clearly distinguished between group A and group B. Some important genes were identified, which might be useful in further study on wool density markers of rex rabbit.

Differential Expression of CCNA2 Gene and MMP2 Gene in Skin Tissue of Rex Rabbit with Different Fur Densities

[ Objective] The paper was to search for the molecular marker highly associated with fur density of rex rabbit. [ Method ] Experimental rex rabbits were divided into dense fur group and sparse fur group. The variation rule of gene expression in skin tissue of rex rabbits with different fur densities was detected using rabbit whole gene cDNA microarray. [ Result] A total of 2 657 genes with differential expression were detected by microarray test, including 1 106 genes with known function, 687 genes with up-regulated expression and 419 genes with down-regulated expression. The expression levels of multiple genes involving in cell proliferation, differentiation, apoptosis and migration had significant changes. MMP2 gene had high expression in skin tissue of rex rabbits in dense fur group, which was 8. 195 times of gene expression in sparse fur group ; CCNA2 gene had low expression in skin tissue of rex rabbit in dense fur group, which was 0. 143 times of gene expression in spaarse fur group. [ Conclusion ] The results provide the theoretical basis and research direction for early breeding of rex rabbit in practical production.

Phenotypic and Genetic Characteristics of a Bordetella hinzii Isolated from a Rex Rabbit

A Bordetella hinzii strain, isolated from the lung of a dead breast-feeding infant rex rabbit with a respiratory infection, was used as study object to investigate its phenotypic and genetic characteristics. The strain could grow on MacConkey agar and was gram-negative, oxidase-positive, catalase-positive, short rodshaped, and it can produce alkali from malonate. Its 6S rRNA sequence was partially identical with B. hinzii （AF177667）. Animal experiments revealed nasal mucous hyperemia, tracheal congestion and bronchopneumonia in 28-day old rex rabbits. To sum up, this Bordetella hinzii isolate was deemed as a novel causative agent of respiratory disease in rex rabbit.

Effects of Different Feed Additives on Fur Production Performance of Rex Rabbit

[ Objectivel To investigate the effects of three different levels of feed additives on fur production performance of Rex rabbit. [ Method] A total of 60 healthy American strain Rex rabbits at the age of 60 d （female：male =1：1 ） were randomly divided into group I, group II and group III. The Rex rabbits in the group I were fed basal diet containing nutritional substances; those in the group II were fed basal diet containing nutdtionai substances and Chinese herbal additive; and those in the group III were fed basal diet containing nutritional substances, Chinese herbal additive and enzyme. The trial lasted for 100 d. After slaughtering, the fur area, fur thickness, wool density, wool fineness and coarse wool rate were determined. [Result] The fur production performance of group III was significantly higher than that of group I （ P 〈 0.05）. There was no significant difference between group III and group II. [ Conclusion] Supplementing Chinese herbal additive and enzyme in diet can improve the fur production performance of Rex rabbit.

Pyridoxine regulates hair follicle development via the PI3K/Akt, Wnt and Notch signalling pathways in rex rabbits

This study was conducted to evaluate the effect of pyridoxine on the development of hair follicles in Rex rabbits and the underlying molecular mechanism.Two hundred 3-month-old Rex rabbits were randomly divided into 5 groups and fed diets supplemented with 0,5,10,20,or 40 mg/kg pyridoxine.The hair follicle density on the dorsal skin and the gene and protein expression levels of components of the phosphoinositide 3-kinase(PI3 K)/protein kinase B(PKB or Akt),Wnt,Notch and bone morphogenetic protein(BMP)signalling pathways were measured.In addition,free hair follicles were isolated from Rex rabbits and cultured with pyridoxine in vitro to measure hair shaft growth.Furthermore,dermal papilla cells(DPC)were isolated from the skin of Rex rabbits and cultured with pyridoxine in vitro to measure the gene and protein expression levels of components of the PI3 K/Akt,Wnt,Notch and BMP signalling pathways.The results showed that the addition of dietary pyridoxine significantly increased the total follicle density,secondary follicle density,and secondary-to-primary ratio(S/P,P<0.05),that the growth ratio of hair stems was promoted by pyridoxine in basic culture medium,and that the growth length of tentacle hair follicles cultured in the pyridoxine group was longer than that in the control group(P<0.05).In addition,pyridoxine changed the DPC cycle progression and promoted cell proliferation,and appropriate concentrations of pyridoxine(10 and 20μmol/L)significantly inhibited cell apoptosis(P<0.05).Pyridoxine significantly affected the gene expression of components of the PI3 K/Akt,Wnt and Notch signalling pathways in the skin and DPC of Rex rabbits(P<0.05),increased the levels of phosphorylated catenin beta 1(CTNNB1)and Akt,and decreased the level of phosphorylated glycogen synthase kinase 3 beta(GSK-3β)(P<0.05).Therefore,the molecular mechanism by which pyridoxine promotes hair follicle density in Rex rabbits probably occurs through activation of the PI3 K/Akt,Wnt and Notch signalling pathways,prolonging hair follicle growth and delaying the onset of telogen.

Thickness Method for Measuring Hair Density of Rex Rabbit

[Objective] The paper was to characterize hair density by changes in hair thickness under certain pressure.[Method] Tile effects of weight of thickness tester and wafer urea at the hottom of presser foot on measurement results were studied, and the optimal measuring weight and wafer diameter was determined. The measurement results of hair thickness under the ahove condition were compared with the results of manual counting. Meanwhile, the effects of hair length and hair fineness on hair density were analyzed.[Result] The hair density obtained by manual count- ing had consistent change trend with the hair thickness measured under certain conditions. If the length and fineness of hairs were introduced for modification, the correlation between hair thickness and hair density would be better. There were little changes in hair length and finelless of rex rabbit, and their effects on hair thickness could be ignored under general condition. [Conclusion] It is completely feasible to characterize hair den- sity of rex rabbit by hair thickness under pressure.

川白獭兔和伊拉兔行为、血清生化指标和盲肠微生物菌群的比较研究

【目的】比较川白獭兔和伊拉兔行为、血清生化指标和盲肠微生物菌群的差异,并探讨行为与盲肠微生物菌群之间的潜在联系。【方法】选取健康状况良好的35日龄雄性断奶川白獭兔和伊拉兔各72只,各分为24个重复,每个重复3只兔。预饲期7d,正试期33d,试验共持续40d。宰前24h,观察川白獭兔和伊拉兔的行为。在75日龄时,进行强直不动性行为测试、新物体试验和旷场试验。将75日龄的川白獭兔和伊拉兔进行屠宰,采集血样测定血清生化指标,并采集盲肠内容物测定微生物组。【结果】川白獭兔躺、闻嗅和食粪行为频率显著高于伊拉兔(P<0.05),坐、社交行为和啃咬笼具行为频率显著低于伊拉兔(P<0.05)。川白獭兔躺和食粪行为持续时间显著长于伊拉兔(P<0.05),进食、坐和啃咬笼具行为持续时间显著短于伊拉兔(P<0.05)。川白獭兔和伊拉兔强直不动性试验和新物体试验差异均不显著(P>0.05)。在旷场试验中,川白獭兔静止不动时间、后腿直立次数显著高于伊拉兔(P<0.05),但探索时间显著低于伊拉兔(P<0.05)。在血清生化方面,川白獭兔组的血清葡萄糖含量显著低于伊拉兔(P<0.05)。川白獭兔和伊拉兔盲肠微生物Alpha多样性差异不显著(P>0.05),厚壁菌门和拟杆菌门为两个兔品种的优势菌门,拟杆菌门与食粪行为时长呈显著负相关(P<0.05)。【结论】与伊拉兔相比,川白獭兔血清葡萄糖浓度较低,此外,川白獭兔啃咬笼具行为频率低、持续时间短,提示川白獭兔的刻板行为少。

氧化应激对宰后獭兔肉肌肉品质、脂质及蛋白质氧化的影响

为研究宰后氧化应激水平变化对獭兔肉成熟过程中肌肉食用品质、脂质氧化及蛋白质氧化程度的影响。用经H_(2)O_(2)氧化剂和N-乙酰半胱氨酸(N-acetylcysteine,NAC)抗氧化剂处理后的川白獭兔肉为实验对象,测定和分析处理后成熟期间獭兔肉食用品质、脂质氧化及蛋白质氧化程度评价指标的变化。结果表明,随着成熟时间延长,H_(2)O_(2)处理组獭兔肉氧化应激水平显著高于空白组和NAC处理组(P<0.05);H_(2)O_(2)处理组pH值迅速下降,并显著低于空白组和NAC处理组(P<0.05);H_(2)O_(2)处理对肌肉色泽和保水性均产生不利影响;同时,H_(2)O_(2)介导的氧化应激显著加剧了肌肉的脂质过氧化程度,造成肌肉新鲜度下降(P<0.05);还对肌原纤维蛋白(myofibrillar protein,MP)的氧化起显著促进作用(P<0.05)。综上说明,宰后缺血缺氧环境导致獭兔肉内氧化应激水平升高,可能通过促进肌肉的脂质氧化和蛋白氧化最终导致獭兔肉食用品质的下降。

“复合酶+柠檬酸+二甲酸钾”组合添加剂对生长獭兔生产性能、养分表观消化率、血清生化指标及毛皮品质的影响

本试验旨在研究“复合酶+柠檬酸+二甲酸钾”组合添加剂对生长獭兔生产性能、养分表观消化率、血清生化指标及毛皮品质的影响。本试验选取健康的35日龄断奶獭兔204只,随机分为4个组,每组51只,单笼饲养。对照组饲喂基础饲粮,高剂量组饲喂基础饲粮+0.34%复合酶+0.30%柠檬酸+0.70%二甲酸钾,中剂量组饲喂基础饲粮+0.34%复合酶+0.23%柠檬酸+0.53%二甲酸钾,低剂量组饲喂基础饲粮+0.34%复合酶+0.20%柠檬酸+0.46%二甲酸钾。预试期5 d,正试期60 d。结果显示:1)各组獭兔的末重、平均日采食量无显著差异(P>0.05);低剂量组的平均日增重最高,料重比和死亡率最低,且与对照组差异显著(P<0.05);胴体重、半净膛屠宰率、全净膛屠宰率均以低剂量组最高,且与中剂量组有显著差异(P<0.05)。2)各组之间獭兔的干物质、淀粉、粗灰分、中性洗涤纤维和酸性洗涤纤维表观消化率差异不显著(P>0.05);低剂量组獭兔的粗蛋白质、粗脂肪表观消化率显著高于对照组(P<0.05),与高剂量组、中剂量组差异不显著(P>0.05)。3)各组之间獭兔的血清总胆固醇、无机磷、肌酐、总蛋白、白蛋白、高密度脂蛋白含量差异不显著(P>0.05);低剂量组血清甘油三酯、低密度脂蛋白含量最低,与对照组、高剂量组差异不显著(P>0.05),但显著或极显著低于中剂量组(P<0.05或P<0.01);各组之间獭兔的胸腺指数、脾脏指数、圆小囊指数差异不显著(P>0.05)。4)低剂量组獭兔肩部、臀部、腹部被毛长度及肩部被毛密度、臀部皮张厚度极显著高于对照组(P<0.01);獭兔的臀部、腹部被毛密度各组之间无显著差异(P>0.05)。综合以上结果得出,本试验条件下,生长獭兔饲粮中组合添加剂的适宜添加量为0.34%复合酶+0.20%柠檬酸+0.46%二甲酸钾。

饲粮中添加酵母菌-凝结芽孢杆菌联合发酵培养物对獭兔肠道形态、肠道通透性、盲肠发酵及微生物区系的影响

本试验旨在研究饲粮中添加酵母菌-凝结芽孢杆菌联合发酵培养物对獭兔肠道形态、肠道通透性、盲肠发酵及微生物区系的影响。选取160只35日龄体重相近的健康獭兔,随机分为4组,每组8个重复,每个重复5只。对照组饲喂基础饲粮,试验组分别饲喂在基础饲粮中添加0.01%、0.02%和0.04%酵母菌-凝结芽孢杆菌联合发酵培养物的试验饲粮,预试期7 d,正试期56 d。结果显示:1)0.02%和0.04%添加组空肠隐窝深度显著低于对照组(P<0.05),0.02%添加组空肠绒隐比显著高于对照组(P<0.05),0.04%添加组回肠绒毛高度较对照组显著提高(P<0.05)。2)0.01%和0.02%添加组血清二胺氧化酶(DAO)活性较对照组显著降低(P<0.05),各组间血清D-乳酸(D-LA)含量无显著差异(P>0.05)。3)各组间空肠、回肠和盲肠pH无显著差异(P>0.05),各组间盲肠中乙酸、丙酸、丁酸和总挥发性脂肪酸浓度及乙酸、丙酸和丁酸比例无显著差异(P>0.05)。4)0.02%和0.04%添加组Simpson指数较对照组呈提高趋势(0.05≤P<0.10)。在门水平上,疣微菌门相对丰度随酵母菌-凝结芽孢杆菌联合发酵培养物添加量的增加呈现先降低后升高的趋势(0.05≤P<0.10);0.02%添加组软壁菌门相对丰度显著高于0.01%和0.04%添加组(P<0.05),但各试验组与对照组间无显著差异(P>0.05)。在属水平上,瘤胃球菌科_UCG-014、艾克曼菌属、dgA-11_gut_group、副室杆菌属和罕见小球菌属相对丰度随酵母菌-凝结芽孢杆菌联合发酵培养物添加量的增加出现变化趋势(0.05≤P<0.10)。综上所述,饲粮中添加酵母菌-凝结芽孢杆菌联合发酵培养物可改善獭兔肠道形态,降低肠道通透性,对空肠、回肠和盲肠内pH以及盲肠发酵均无显著影响,但能够提高盲肠微生物多样性。结合前期生长性能结果,推荐添加量为0.02%~0.04%。

不同月龄獭兔皮肤组织切片的观察与研究

伴随养殖业在农村地区的大力发展,部分养殖场户已不满足于猪、牛、羊、禽等常规养殖,将目光投向小众动物养殖。,獭兔养殖逐渐走入广大养殖户视野,具有以下明显优势:一是种兽投资成本低,对于养殖户而言入行门槛较低;二是饲料成本可控,獭兔饲料中占比50%以上的成分是草粉,平均1.5~2 kg普通等级饲料就可长0.5 kg肉;三是市场周期短。獭兔一年可生仔兔6~8窝,平均每窝8只左右,经营周期短,成活率较高;四是市场销售前景看好,目标群体大。獭兔裘皮服装、毛领、编织、内胆、鞋材、衣服贴边等使用獭兔皮的品种多,皮草厂家需求缺口巨大;五是屠宰副产品价值超过其他毛皮动物。獭兔肉属于高蛋白肉、低脂肪营养保健高档肉,已逐步成为高端肉品市场新宠;六是獭兔已可作为生物实验和生物制药对象。规模养殖户可与生物制药厂家合作开发实验兔、制药原料兔等相关项目,科技附加值较高。本论文通过分别取2、4、5月龄獭兔的皮肤样本,经脱水、透明、浸蜡、包埋、切片、贴片等一系列操作流程,制成本试验所需的不同月龄獭兔皮肤组织切片,后采取HE染色法对制成的所有切片进行染色,观察比较不同时期獭兔皮肤组织形态之间存在的差异,通过分析得出最佳采皮月龄时间,从而为提高养兔效益,获得更好的兔皮质量提供一定的采皮参考依据。

日粮中锌、铜、锰和硒对生长獭兔生产性能及生化指标的影响

选用吉戎-Ⅱ生长獭兔随机分组,各组日粮中分别添加锌、铜、锰和硒,其中锌的添加量为0、40、80、120 m g/kg,硒为0、0.1、0.25、0.4、0.55、0.7 m g/kg,锰为0、5、15、25、35、45 m g/kg,铜为0、10、20、40、80、160 m g/kg。结果表明,4种元素均能影响生长獭兔的生长性能。试验所选相关酶CuZn-SOD、GPX、M n-SOD、CP的活性能较好地反映此4种元素在獭兔体内的代谢状况。肾脏、肝脏中Zn和Se的沉积量能较好地反映饲粮Zn和Se在獭兔体内的沉积情况。胫骨和被毛中锰浓度则可以作为评价锰吸收利用率的敏感指标。综合各项指标得出,吉戎-Ⅱ獭兔日粮中锰、锌、铜、硒的适宜添加量分别为35、80、40、0.25 m g/kg。

含硫氨基酸对獭兔生长及被毛发育的影响

本试验旨在通过测定生长及被毛发育相关指标,确定蛋氨酸及半胱氨酸在獭兔饲粮中的最优添加水平,并了解它们在影响獭兔生长及被毛发育方面的相互关系。选择同天出生的仔獭兔294只,以窝为单位随机分为7组,每组7个重复,每个重复6只。对照组獭兔饲喂基础饲粮(含半胱氨酸0.23%、蛋氨酸0.24%),试验组獭兔分别饲喂在基础饲粮中添加0.10%、0.25%和0.40%半胱氨酸或蛋氨酸的试验饲粮。饲养周期为初生到151日龄。结果表明:饲粮中添加含硫氨基酸提高了獭兔的150日龄体重及平均日增重,0.25%、0.40%组与对照组相比存在显著差异(P<0.05)。随着含硫氨基酸添加水平的增加,獭兔的料重比表现为下降的趋势(P>0.05),平均日采食量则表现为上升的趋势(P>0.05)。与对照组相比,0.25%和0.40%组换毛完成率和被毛密度显著或极显著提高(P<0.05或P<0.01),但0.25%与0.40%组间差异不显著(P>0.05)。从92日龄和151日龄被毛评分来看,獭兔被毛品质随含硫氨基酸添加水平的增加仅表现出提高的趋势,组间差异不显著(P>0.05)。上述各指标在蛋氨酸与半胱氨酸各对应水平间均无显著差异(P>0.05)。通过生长曲线拟合分析,在2种含硫氨基酸的添加水平内,添加水平仅改变獭兔的最大生长速度,而对成年体重的影响不大。由此得出,蛋氨酸与半胱氨酸对獭兔生长与被毛发育均具有促进作用,均以0.25%添加水平为最优,且促进效果几乎同等,等量半胱氨酸可以完全代替蛋氨酸。但是,仅通过添加含硫氨基酸不能显著地改变獭兔的表观被毛品质。

苜蓿草粉对獭兔消化率及饲用效果的影响

为探讨紫花苜蓿(Medicago sativa)草粉对獭兔饲用价值的影响,选取体重相近的56日龄獭兔108只,分别测定苜蓿草粉(alfalfa meal,AM)、玉米(Zea mays)秸秆(corn stalk,CS)和大豆(Glycine max)秸秆(soybean straw,SS)单一饲喂时的消化率,3种粗饲料源配制的配合饲料中各种营养物质的消化率,以及不同水平AM对獭兔胴体与毛皮品质的影响。结果表明:AM与CS和SS具有相似的粗饲料价值;AM对配合饲料粗蛋白质利用率的影响低于SS和CS;50%的AM有利于提高獭兔的屠宰率、肌肉系水力与毛皮强度。因此,AM优于CS和SS,饲喂50%的AM有利于獭兔商品价值的改善。

中草药饲料添加剂对獭兔肉品质的影响(英文)

1材料与方法 1．1供试动物分组设计将108只40日龄断奶獭兔（体重差异不显著）随机分成3组，每组6个重复，每重复6只。3组分别饲喂基础日粮、添加0．3％中草药添加剂的基础日粮和添加0．4％中草药添加剂的基础日粮，分别记作A、B、C。

枯草芽孢杆菌和复合酶制剂对獭兔生长性能、养分表观消化率、屠宰性能、免疫器官指数及毛皮质量的影响

本试验旨在研究饲粮中添加枯草芽孢杆菌和复合酶制剂对獭兔生长性能、养分表观消化率、屠宰性能、免疫器官指数及毛皮质量的影响。采用单因子设计,选取体重相近的健康42日龄獭兔126只,随机分为3组,每组42个重复,每个重复1只兔。对照组饲喂基础饲粮+300 mg/kg金霉素,试验Ⅰ组饲喂基础饲粮+200 mg/kg枯草芽孢杆菌+200 mg/kg复合酶制剂,试验Ⅱ组饲喂基础饲粮+400 mg/kg枯草芽孢杆菌+400 mg/kg复合酶制剂。预试期5 d,正试期41 d。结果表明:1)各组之间獭兔的末重、平均日采食量、平均日增重、料重比、腹泻率和死亡率无显著差异(P>0.05),腹泻率和死亡率均以试验Ⅰ组最低。2)对照组獭兔的粗纤维表观消化率极显著高于试验Ⅱ组(P<0.05),对照组和试验Ⅱ组獭兔的钙表观消化率极显著高于试验Ⅰ组(P<0.01)。各组之间獭兔的干物质、粗蛋白质、粗灰分、磷、中性洗涤纤维和酸性洗涤纤维表观消化率无显著差异(P>0.05)。3)各组之间獭兔的宰前活重、胴体重、半净膛率和全净膛率无显著差异(P>0.05)。4)各组之间獭兔的胸腺指数、脾脏指数和圆小囊指数无显著差异(P>0.05)。5)对照组和试验Ⅰ组獭兔的臀部被毛密度极显著高于试验Ⅱ组(P<0.01),对照组和试验Ⅰ组獭兔的肩部被毛密度显著高于试验Ⅱ组(P<0.05);对照组獭兔的腹部被毛密度极显著低于试验Ⅰ组和试验Ⅱ组(P<0.01),试验Ⅰ组极显著低于试验Ⅱ组(P<0.01)。对照组獭兔的臀部皮张厚度极显著低于试验Ⅱ组(P<0.01)。由此可见,饲粮中添加枯草芽孢杆菌和复合酶制剂对獭兔生长性能、屠宰性能、免疫器官指数无显著影响,对粗纤维和钙表观消化率及被毛密度、臀部皮张厚度有显著影响。综合考虑以上指标,獭兔饲粮中添加200 mg/kg枯草芽孢杆菌+200 mg/kg复合酶制剂效果较好。

不同被毛密度獭兔皮肤差异表达基因的研究

本研究旨在筛选4日龄不同被毛密度獭兔皮肤的差异表达基因。采用Agilent公司家兔全基因表达谱芯片对4日龄不同被毛密度獭兔皮肤组织进行差异基因筛选,并通过实时荧光定量PCR方法对部分差异显著基因进行验证。试验共筛选出188个差异基因,与低被毛密度獭兔相比,高被毛密度獭兔皮中表达上调基因72个,其中包含24个已知功能基因,表达下调基因116个,其中包含38个已知功能基因。GO(Gene ontology)分类显示,大部分差异基因参与细胞增殖、凋亡、氧化还原、脂代谢分解等生命过程。KEGG(Kyoto encyclopedia of genes and genomes)通路分析显示,差异基因主要参与Wnt信号通路、PPAR信号通路、维生素合成与代谢途径等。荧光定量PCR结果与基因芯片结果基本吻合,证实基因芯片结果可靠。结果表明,差异倍数较大的差异基因,像胰岛素样生长因子(IGF-I)、血管内皮生长因子(VEGF)和骨形态发生蛋白(BMP2)可能与獭兔被毛的形成有关;Wnt信号通路、PPAR信号通路等,以及维生素合成与代谢途径等也可能参与被毛的发育过程。

日粮能量水平对断奶至3月龄獭兔生长发育、消化代谢、血液生化和盲肠发酵的影响

本研究旨在探讨日粮不同能量水平对断奶至3月龄獭兔生长性能、营养物质消化代谢、血液生化参数和盲肠发酵的影响。选用断奶獭兔200只,随机分成5组,每组40个重复,饲喂5种不同消化能水平的日粮(9.46、9.97、10.46、10.94、11.43MJ.kg-1),预试期7d,正试期53d。通过动物饲养试验、消化代谢试验和屠宰试验对獭兔的各项指标进行研究。结果表明,在初始体质量无显著差异的情况下,平均日采食量随日粮消化能水平的提高极显著降低(P<0.01),日粮能量水平对料重比影响显著(P<0.05),其中10.46MJ.kg-1组最小;随日粮消化能水平的增加,食入氮极显著降低(P<0.01),粪氮排出显著降低(P<0.05);日粮能量水平对DE/GE和ME/GE影响显著(P<0.05),其中10.46MJ.kg-1组的DE/GE和ME/GE最高;日粮能量水平对血清中胰岛素浓度影响显著(P<0.05);盲肠氨氮浓度和丙酸比例随日粮能量水平的增加而显著增加(P<0.01或P<0.05),乙酸比例和乙丙酸比随日粮能量水平的增加而显著降低(P<0.01或P<0.05)。本试验结果表明,断奶至3月龄獭兔的适宜日粮消化能水平为10.46MJ.kg-1。