乳胶凝集试验与血清中和试验检测猪伪狂犬病血清抗体的 …

应用血清中和试验（ＳＮＴ）和伪狂犬病乳胶凝集试验（ＬＡＴ）诊断试剂盒对两种伪狂犬病是性血清、伪狂犬病病毒（ＰＲＶ）高兔血甭及６０份被检猪血清进行了ＰＲＶ抗体效价测定和相关性分析,两种方法测得的抗体效价之间呈强相关性（ｒ＝０．９６）,且ＬＡＴ效价比ＳＮＴ一般高出一个滴度;能干为自３５个猪场的４１４份猪血清进行了ＰＲＶ抗体检测,并与ＳＮＴ检测结果进行了对比,结果在ＳＮＴ检测为阳笥的１７１份血清中,ＬＡ     

应用动物模型REML法估计金华猪繁殖性状遗传参数

试验资料取自金华猪场 1 979～1 999年金华猪繁殖性能的生产记录。采用动物模型约束性最大似然法 (REML)对该猪群的遗传参数进行估计 ,测定 1 1 4 4头纯繁金华母猪的产仔哺育记录。结果表明 ,产仔数 (TNB)、产活仔数 (NBA)、初生重 (PBW)、初生窝重 (LBW)、 2 0日龄头数(NFC)、 2 0日龄窝重 (LWFC)、 2 0日龄重 (PWFC)、 60日龄头数 (NW)、 60日龄窝重 (LWW)、 60日龄重 (PWW)、乳头数 (TN)的遗传力分别为0 1 2± 0 0 9、 0 1 8± 0 1 1、 0 1 5± 0 0 9、 0 0 2± 0 0 9、 0 1 0± 0 1 1、 0 0 8± 0 1 3、 0 1 8± 0 1 0、 0 2 3± 0 1 1、 0 31± 0 1 3、 0 35± 0 1 1和 0 1 9± 0 1 0。TNB与NBA、LBW、NW、LWW的遗传相关范围为 0 66～ 0 88,TNB与PBW的遗传相关为 - 0 43。NBA与LBW、NW、LWW的遗传相关范围为 0 60～ 0 64,NBA与PBW遗传相关为 - 0 63。PBW与PWW的遗传相关为 0 51。     

Fit of Wood's function to daily milk records and estimation of environmental and additive and non-additive genetic effects on lactation curve and lactation parameters of crossbred dual purpose cattle

The objectives of this study were to estimate the environmental and additive and non-additive genetic effects on lactation curve and lactation parameters of crosses of Holstein (H), Brahman (B) and Brown Swiss (BS) in Olancho region in Honduras. The data consisted of 54,517 milk yield records from 192 dual-purpose crossbred cows lactating from 2000 to 2005 at the Universidad Nacional de Agricultura de Honduras (UNA). The lactation curve and lactation parameters of interest were the scaling factor to represent yield at the beginning of lactation (a), the factor associated with the inclining (b) and declining (c) slopes of the lactation curves, and the milk yield at initial day of lactation (MY₂₀), peak milk yield (MY_max), day at peak milk yield (t_max), and the total milk yield (TM) per lactation, respectively. The incomplete gamma function (Wood function) was used to estimate lactation curve and lactation parameters from daily milk records of H × B, H × BS and BS × B crossbred cows. The environmental, additive and non-additive genetic effects on lactation curve and lactation parameters were estimated using Dickerson and Kinghorn models. The coefficients of determination of fitness of Wood's function (R²) ranged from 80% to 97% with an average of 93%. The lactation curve of the crossbred cows was similar to those reported for dairy cows grazing in the tropics. Lactation parameters such as MY_max, t_max and TM were significantly (P < 0.05) influenced by environmental sources of variation suggesting the necessity of differential management strategies. The moderate to large positive phenotypic correlation of MY_max and TM indicate that one of the milk yield parameters could be used as a selection criterion to improve either one or both traits. Despite the fact that both genetic models showed similar patterns, the absolute value of the parameters varied. For both models, individual additive genetic breed effect for H breed were significant (P < 0.05) and contributed more to TM than the BS breed. In the Dickerson model, highly positive significant (P < 0.01) effect on TM for H×BS and BS×B crosses was found. The Kinghorn model did not show significant effects of dominance on this parameter. The estimate of recombination effect for all crosses involving B breed were negative and significant (P < 0.05) for positive correlated lactation curve parameters. Although the inclusion of non-additive effects on crossbreeding genetic effects were not all significant for lactation curve and lactation parameters, non-additive effects should be taken into account to improve the Honduran dairy cattle production management.     

钙和维生素D3对肉仔鸡肉品质和血液生化指标的影响

本试验旨在研究饲粮中添加高水平的钙和维生素D3对AA肉仔鸡肉品质和血液生化指标的影响。试验采用2×2完全随机因子设计,选用240只21日龄AA肉仔鸡,随机分成4个处理,每个处理6个重复,每个重复10只。试验期为28 d。玉米-豆粕型基础日粮中含钙0.90%、维生素D3 750 IU/kg,日粮中共设两个钙水平(0.9%,1.15%)和两个维生素D3水平(750、5000 IU/kg)。结果表明:(1)在AA肉仔鸡饲粮中单独添加1.15%的钙对肌肉嫩度影响显著(P<0.05),5000 IU/kg维生素D3对肌肉嫩度影响不显著(P>0.05),同时添加钙和维生素D3的互作效应对肌肉嫩度影响显著(P<0.05);(2)1.15%的钙显著降低胆固醇、甘油三酯、低密度脂蛋白的含量(P<0.05),显著升高了高密度脂蛋白的含量(P<0.05);(3)单独添加5000 IU/kg维生素D3显著降低了低密度脂蛋白的含量(P<0.05)。以上研究结果表明,玉米-豆粕型基础日粮中长期添加1.15%钙和5000IU/kg维生素D3能够减小肌肉剪切力,降低血液中总胆固醇和甘油三酯的含量,从而提高肉品质。     

鹅源鸭疫里默氏杆菌的分离和鉴定

为研究鹅源鸭疫里默氏杆菌的生化特性、药敏情况、血清型和致病性,从扬州郊区发病鹅场分离到1株细菌,经分离培养、染色镜检、生化特性鉴定、玻片凝集试验,确定为Ⅱ型鸭疫里默氏杆菌。对病料进行病毒分离试验,经过血凝试验和琼脂扩散试验,没有发现鹅新城疫病毒、禽流感病毒和小鹅瘟病毒。动物致病性试验结果表明,鸭疫里默氏杆菌分离菌株可以通过静脉注射、皮下注射和滴鼻3种途径感染鹅,出现100%的死亡率,说明分离株对扬州鹅具有很强的致病性,同时提示在鹅的免疫计划中也应该充分考虑到鸭疫里默氏杆菌的致病和传播。     

发酵棉粕对肉鸡生长性能、血清生化指标及免疫功能的影响

试验旨在研究发酵棉粕(FCM)替代豆粕(SBM)对AA肉仔鸡生长性能、血清生化及免疫功能的影响,并确定发酵棉粕在AA肉鸡日粮中的最适添加量。试验选择480羽1日龄AA肉鸡(44.40±1.11)g,随机分成4组,每组6个重复,以玉米豆粕基础日粮为对照组,分别用5%、10%和15%的发酵棉粕替代豆粕。结果表明:与对照组相比,添加发酵棉粕对肉鸡平均日增重(ADG)、采食量(ADFI)和饲料增重比(F/G)无显著影响;21日龄时,添加5%FCM显著提高了肉鸡的血液IgG和IgM含量及法氏囊指数(P<0.05),添加15%FCM显著降低了血清中尿素氮(UN)含量(P<0.05),此外,3个FCM处理均能提高胸腺指数(P<0.05),但对脾脏指数无影响;42日龄时,5%和10%FCM组显著降低了血清中的UN含量(P<0.05),15%FCM还提高了胸腺和法氏囊指数(P<0.05)。试验通过主成分分析,在试验范围内建立了评价FCM综合效果的参数Z,并得到1~21日龄和22~42日龄阶段,FCM的适宜添加量分别为5%和15%。     

苜蓿青饲对波尔山羊生长性能及血液生理生化指标的影响

近年来,随着苜蓿(Medicago sativa L.)产业的发展,相关草产品在奶牛饲养中得到广泛应用并日益成熟,但在山羊饲养的消化生理、营养代谢及利用方面的研究却相对缺乏。为了解不同水平苜蓿鲜草饲粮对波尔山羊生长性能及血液生理生化指标的影响,于2005年7-9月,选用3月龄、初始体重17.77±1.05 kg、遗传背景基本一致的波尔山羊(Capra hircus L.)45只,随机分为5个处理组,各组饲粮中苜蓿鲜草替代水平分别为0%(对照组)、15%(试验1组)、30%(试验2组)、45%(试验3组)和60%(试验4组)(按干物质计)。结果表明:试验1、2、3组平均日增重和料重比都优于对照组,但差异不显著;试验2组血液总蛋白和球蛋白含量极显著(P<0.01)、白蛋白含量显著(P<0.05)高于对照组,而总胆固醇、高密度酯蛋白胆固醇含量显著低于对照组(P<0.05),尽管各组血糖、尿素氮、甘油三酯及低密度酯蛋白胆固醇含量差异不显著,但试验Ⅱ组甘油三酯和低密度酯蛋白胆固醇含量均最低。因此,30%替代水平为最佳,建议在生产中应用。     

不同蛋白质水平精料对广丰山羊生长性能、屠宰性能和血清生化指标的影响

本试验旨在研究不同蛋白质水平精料对广丰山羊生长性能、屠宰性能和血清生化指标的影响.选择健康且体重相近的3月龄左右广丰山羊30只,随机分为3组,每组10只(公母各占1/2).3组山羊分别饲喂高(22.87％,H组)、中(19.07％,M组)和低(15.23％,L组)蛋白质水平的精料,粗料均为野生芒草鲜草,精粗比50:50...     

Effects of dietary supplementation with Allium mongolicum Regel extracts on growth performance,serum metabolites,immune responses,antioxidant status,and meat quality of lambs

The present study was to evaluate the effects of dried Allium mongolicum Regel (AMR) powder and its water- and fat-soluble extracts (AWE and AFE) on the growth performance, serum metabolites, immune responses, antioxidant status, and meat quality of lambs. A total of 32 male small-tailed Han lambs (5 months old; initial body weight = 34.8 ± 0.40 kg) were used in a 60-d feeding experiment after a 15-d adaptation period. The lambs were randomly divided into 4 groups (n = 8) and fed a basal diet (control, CON group), the basal diet supplemented with dried AMR powder at 10 g/d per lamb (AMR group), the basal diet supplemented with AWE at 3.4 g/d per lamb (AWE group), or the basal diet supplemented with AFE at 2.8 g/d per lamb (AFE group). Blood samples were collected on d 0, 30, and 60 in the feeding experiment (n = 8). At the end of the experiment, the lambs were sacrificed and the longissimus dorsi muscles collected. Growth performance was not significantly affected by dietary supplementation of AMR, AWE and AFE (P > 0.05). However, significantly lower albumin (P = 0.006), total protein (P = 0.006), globin (P = 0.025), and blood urea nitrogen (P = 0.024) concentrations were observed in AFE group relative to CON and AMR groups. Similarly, a significantly lower lactate dehydrogenase activity (P = 0.018) was observed in AFE group relative to AWE group, but not in other groups (P > 0.05). In addition, significantly increasing trends in glutathione peroxidase (P = 0.06) in AMR, AWE, and AFE groups were observed relative to the control group. Furthermore, significantly lower drip loss (P = 0.011) across the treatment groups and cooking loss (P = 0.048) were observed in the AMR group relative to the control group. Taken together, these results indicate that AMR and its extracts had no significant effect on lamb growth performance, antioxidant status, and immune responses, but could significantly improve meat quality without the occurrence of pathological kidney and liver lesions.     

纳罗克非洲狗尾草光合生理日变化研究

在昆明市利用Ci-310便携式光合测定仪测定了纳罗克非洲狗尾草（Setaria sphacelata stapf cv.Narok）种子田夏季光合生理参数的日变化.对大气温度、CO2浓度、相对湿度、植物气孔导度、胞间CO2浓度、蒸腾速率、瞬时水分利用率、光合有效辐射、净光合速率等参数进行分析,结果表明：纳罗克非洲狗尾草光合生理特性受环境影响呈规律性变化,光合速率、光合有效辐射、气孔导度和蒸腾速率的日变化呈双峰曲线,存在“午睡”现象.非气孔限制为引起光合“午睡”的主要原因,其中净光合速率降低为叶肉光合活性下降所致.