反刍动物饲料营养价值评定及模型应用

反刍动物饲料营养价值评定包括饲料营养成分评定和饲料营养物质可利用性评定两个方面,其中,评定反刍动物饲料营养物质可利用性的方法主要有体内法、半体内法和体外法,因各自的特点分别应用于不同的研究领域.反刍动物饲料营养价值评定模型的应用,又使这些评定方法得到进一步深入和扩展.文章综述了反刍动物饲料营养价值评定的主要方法以及几种营养价值评定模型的应用研究进展.     

反刍动物饲料营养价值评定及替代法展望

传统上评定反刍动物饲料营养价值的方法很多,但多数是评定配合饲料或者粗饲料。现在反刍动物饲料中精料的添加量日益重要,为了追求更高的经济效益有必要对精料的营养价值进行准确评定。近年来,通过消化代谢试验结合替代法评定动物饲料营养价值的报道越来越多,饲料营养价值评定模型的应用,使得一些无法直接评定的肉羊精料的评定方法有了新的方向。文章综述了反刍动物饲料营养价值评定的主要方法以及替代法评定反刍动物精料营养价值和预测模型应用于反刍动物精料原料的可实行性。     

适宜的猪饲料评定体系

饲料费用是养猪生产成本中最主要的部分.因此,获得养猪生产的最佳经济效益和最佳状态必须有一个适宜的猪饲料评定体系.这样的一个饲料评定体系既包括对猪营养需要的评定,又包括对饲料组分的有效营养成分的评定.近年来,猪饲料评定体系有了长足发展,特别是在蛋白质和能量评定方面.     

原子吸收光谱法测定饲料中镉测量不确定度的评定

测量不确定度是评定检测样品结果准确度的尺度,本文用原子吸收光谱法对饲料中镉的测量不确定度进行评定,依照JJF1059-1999《测量不确定度评定与表示》的要求,全面了解影响饲料中镉测定的不确定度。研究说明,评定中以A类评定分量占主要地位,评定不给自由度,包含因子统一取2的简化评定过程是可行的。     

青贮品质评定(一)

正品质评定是对青贮饲料收贮全过程质量优劣的监督,是提高青贮饲料利用效率的重要途径和方法(玉柱和刘长春,2012)。青贮品质评定一般分为感官评定和理化评定。感官评定在青贮饲料现场即可进行,生产实践中比较常用,但这种方法只能表观评定青贮饲料发酵的优劣;对于量化评定青贮饲料的品质以及提高青贮饲料的利用效率,必须借助于理化评定。理化评定一般需要在实验室进行,随着对青贮饲料研究的深入,理化评定也从传统的干物质、pH、有机酸总     

基于决策树算法的奖学金分析应用研究

奖学金评定的质量是当代高校学生最为敏感的问题之一。做到评定的"公平、公正、公开",并更好的鼓励先进,鞭策后进,提高学生全面素质是评定工作的关键。本文基于决策树算法,对高校学生奖学金评定相关属性数据进行分析挖掘。用具体实验发现奖学金评定中的主导因素,为教务人员提供奖学金评定规则制定的支持和帮助。     

金工实习成绩的评定与改进

本文介绍了学生金工实习成绩评定的内容,客观、公正、科学地评定学生金工实习成绩的办法。对成绩评定中不科学地方提出改进建议。通过金工实习成绩评定推动金工实习教学质量的提高。     

青贮饲料的合理调制与质量评定标准分析

本文以非常规型青贮饲料为例,对青贮饲料的调制方法进行分析,并对青贮质量评定标准加以阐述,重点介绍感官评定、PH值评定与实验室评定三项内容,力求通过本文研究,使青贮饲料调制方法更加科学有效,与质量评定标准充分符合,在促进资源高效利用的同时,获得更多的经济效益。     

家禽油脂代谢能值评定方法的研究

油脂是一种重要的家禽高能饲料原料,在整个饲料配方成本中占有很重要的比例,因此,准确评价油脂的代谢能值就显得尤为重要。油脂代谢能值的评定受诸多因素影响,导致油脂代谢能评定结果变异较大,油脂也成为代谢能最难评定的饲料原料之一。本文论述了影响油脂代谢能值评定的因素和评定方法对油脂代谢能测定结果的影响,以期为今后评定家禽油脂代谢能提供参考。     

微卫星DNA与延边黄牛肉用生长性状关系

选择与肉牛主要生产性状紧密连锁的 5个微卫星位点 ,以肉牛线性体型评分方法作为衡量肉牛生长发育的指标 ,运用最小二乘法拟合线性模型 ,分析了延边黄牛肉用生产性状与微卫星标记的关系 ,并分析了微卫星 ETH10和IDVGA4 6位点的不同基因型与肉用生产性状的关系。结果表明 ,微卫星 EHT10位点的等位基因 2 0 9对外貌线性评定中的背线性状、肌肉度线性评定中的肩部性状有正面影响 ,等位基因 2 13对外貌线性评定中的系部、肌肉度线性评定中的尻形状和细致度线性评定中的骨骼及皮肤性状有正面影响 ,而等位基因 2 15对外貌线性评定中的背线性状、肌肉度线性评定中的尻形状有负面影响 ;微卫星 IDVGA4 6位点的等位基因 2 4 9对背线、前肢和后肢等外貌线性评定性状 ,肌肉度线性评定的腰宽以及细致度线性评定的骨骼和皮肤性状有正面影响 ,等位基因 2 0 3对外貌评定性状的头部、背线 ,肌肉度评定性状腰宽以及细致度评定性状骨骼和皮肤有负面影响 ,等位基因 2 4 5对腰宽性状也起到负面影响     

玉米赤霉烯酮对后备母猪子宫和卵巢抗氧化和炎症指标及相关基因表达的影响

试验旨在研究玉米赤霉烯酮（zearalenone,ZEA）对后备母猪子宫和卵巢抗氧化和炎症指标及相关基因表达的影响。选择胎次和体重（（23.20±0.68）kg）相近的长×大二元后备母猪48头,随机分为4组,每组设12个重复,每个重复1头母猪。对照组（CON组）饲喂基础饲粮,试验组（T1、T2、T3组）饲喂在基础饲粮中分别添加200、800、1600 μg·kg^-1ZEA的试验饲粮。预试期7 d,正试期40 d。结果如下：1）与CON组相比,T3组血清T-AOC和SOD活性显著降低（P<0.05）,MDA水平显著升高（P<0.05）。2）与CON组相比,子宫组织中,T2和T3组T-AOC活性显著降低（P<0.05）,T3组SOD活性极显著降低（P<0.01）,卵巢组织中,T3组T-AOC活性、T2组GSH-Px和SOD活性显著降低（P<0.05）,T3组MDA水平显著升高（P<0.05）。3）与CON组相比,T2组血清TNF-α和IL-4水平显著升高（P<0.05）,T1~T3组血清IL-10水平显著降低（P<0.05）。4）与CON组相比,子宫组织中,T2组IL-1β水平显著升高（P<0.05）,T1和T3组IL-10水平显著降低（P<0.05）。卵巢组织中,T2组TNF-α水平显著升高（P<0.05）,T1~T3组IL-4水平显著升高（P<0.05）。5）子宫组织中,T3组Cu/Zn-SOD mRNA的相对表达显著低于CON组（P<0.05）,T2组IL-1β mRNA的相对表达显著高于CON组（P<0.05）。6）卵巢组织中,T3组GSH-Px mRNA的相对表达显著低于CON组（P<0.05）,T2组IL-1β mRNA的相对表达显著高于CON组（P<0.05）。综上所述,ZEA能通过抑制SOD和GSH-Px的表达与合成,降低后备母猪子宫和卵巢的抗氧化性能,并引起氧化应激。ZEA能通过促进TNF-α和IL-1β表达与合成引起子宫和卵巢的炎症反应,抑制IL-10的表达与合成从而抑制两组织的抗炎反应。     

Copper deficiency in sheep: An assessment of the relationship between concentrations of copper in serum and plasma

AIM: To assess the relationship between concentrations of copper in serum and plasma in sheep.

METHODS: Concentrations of Cu were measured in paired serum and heparinised plasma samples collected from 110 sheep in nine flocks. Linear regression was used to evaluate whether flock or gender had a significant effect on the association between concentrations of Cu in serum and plasma. The individual results for concentrations of Cu in serum were then compared with those from plasma, using correlation and limits of agreement plotting.

RESULTS: Concentrations of Cu in serum ranged from 7.3 to 22 (mean 14.0) µmol/L, while concentrations in plasma ranged from 9 to 27 (mean 16.3) µmol/L. On average, concentrations of Cu in serum were 2.3 µmol/L lower than in plasma. Over the range of values seen in this study, concentrations of Cu in plasma and serum were significantly correlated (r=0.89), and mean concentrations in serum were 87% of those in plasma. There was no effect of flock or gender on the relationship between concentrations of Cu in serum and plasma. Despite the significant correlation, there was marked variability between individual samples in the proportion of Cu that was lost during clotting, with the 95% limits of agreement for serum Cu ranging from 70 to 104% of the plasma concentration.

CONCLUSIONS: As in cattle, the individual variability in the loss of Cu during clotting in sheep is too great for concentration of Cu in serum to be used as a substitute for that in plasma.

CLINICAL RELEVANCE: When assessing the blood Cu pool as part of the diagnosis of Cu-responsive disease in sheep, the concentration of Cu in plasma should be measured in preference to that of serum. We suggest that a range of 4.5 to 9 µmol/L in plasma be used to define marginal Cu status in sheep.     

Age-Dependent Immunolocalization of Fibronectin and Histological Changes in the Thymus of Rats

Age-dependent variations in the immunolocalization of fibronectin (FN) in the thymus were investigated in 1-, 6-, 12- and 20-month-old male and female Swiss albino rats (Rattus rattus) at the light-microscopic level and the changes with ageing in the histological structure of the thymus were also studied. There were no significant differences in the age-dependent variations in the immunolocalization of fibronectin or in the histological structure of the thymus between male and female rats of the same age but there were increases with ageing in the fibronectin content of the thymic capsule, the connective tissue between the lobules, around blood vessels, and in the medulla and cortex of thymus. The connective-tissue content between lobules, fat cells, Hassall's corpuscles, the thickness of capsule and the ratio of the medulla to the cortex of the lobules showed age-dependent increases in the thymus of rats of both sexes. Decreases in the organ weight/body weight ratio were also observed with ageing.     

不同周龄SPF级SD大鼠胰腺自发性病变的组织学观察

研究不同周龄SPF级SD大鼠胰腺自发性病变的种类及其病变发生率,为药物安全性评价提供背景资料。收集3年安评试验中11、19、31周龄试验对照组大鼠胰腺制作病理切片,光学显微镜下观察SD大鼠胰腺病变的种类及组织形态学特点,并统计其病变发生率。结果显示,大鼠胰腺主要出现了以下病变:①单核细胞浸润:11周龄大鼠该病变的总体发生率为0.6%,其中雌性为0,雄性为1.25%;19周龄大鼠该病变的总体发生率为1.0%,其中雌性为1.0%,雄性为1.0%;31周龄大鼠该病变的总体发生率为1.0%,其中雌性为0,雄性为1.96%。②腺泡细胞空泡变性:11周龄大鼠未观察到该病变的发生;19周龄大鼠该病变的总体发生率为1.0%,其中雌性为0,雄性为2.0%;31周龄大鼠该病变的总体发生率为3%,其中雌性为2.1%,雄性为3.9%。③腺泡细胞萎缩、腺管增生:11周龄大鼠未观察到该病变的发生;19周龄大鼠该病变的总体发生率为0.5%,其中雌性为0,雄性为1.0%;31周龄大鼠该病变的总体发生率为3.0%,其中雌性为1.0%,雄性为4.9%。结果表明,SPF级大鼠胰腺可发生单核细胞浸润、腺泡细胞空泡变性、腺泡细胞萎缩及腺管增生等自发性病变,且病变发生率可随着年龄的增加而增加。     

Clinicomorphological Studies in Chicks Fed Ochratoxin A While Simultaneously Developing Coccidiosis

The progression of coccidiosis and the resultant mortality were followed in chicks fed a OTA-contaminated diet. More complex and rapid progress of coccidiosis occurred in OTA-treated chicks than in chicks fed a OTA-free diet. The concentration of total protein in the serum was significantly decreased in the chicks in the OTA-treated group, whereas this was significantly increased in chicks infected with Eimeria tenella, irrespective of additional treatment with OTA. The serum glucose concentration was significantly increased in all the chicks exposed to OTA and/or suffering from coccidiosis, as was serum retention of uric acid in all groups, most notably in those consuming OTA. OTA induced degenerative changes in, and an increase in the weight of the kidneys, liver, heart and ventriculum; there was depletion of lymphoid tissue and a decrease in the lymphoid organs' weight and body weight. Coccidiosis induced only a slight growth depression and a slight increase in the relative weight of the kidneys and liver. The intensity of the clinical signs, the impairment of kidney function, macroscopic and histopathological changes, deviations in the weight of some organs and general depression in growth were greater when chicks infected with E. tenella were also given OTA.     

Immunohistochemical study of galectin-3 in mature and immature bull testis and epididymis

Galectin-3, a member of the β-galactoside-binding protein family, has been implicated in mammalian sperm maturation. We examined galectin-3 expression in the testis and epididymis of sexually mature and immature bulls. Western blot analysis showed varying levels of galectin-3 in the bull testis and epididymis, and galectin-3 immunoreactivity was higher in the mature testis and epididymis than in immature organs. Galectin-3 was primarily localized in interstitial cells of the immature bull testis and in the peritubular myoid and interstitial cells of the mature testis. In the immature epididymis head, galectin-3 was primarily in the principal and basal cells of the epithelium. In the mature epididymis head, moderate levels of galectin-3 were detected in the sperm, while low levels were found in the stereocilia, epithelium and connective tissue. In the immature epididymis body, moderate protein levels were detected in the principal cells, while lower levels were found in the basal cells. The mature epididymis body showed moderate levels of galectin-3 immunostaining in the stereocilia and epithelium, but low levels in the connective tissue. In the immature epididymis tail, only low levels of galectin-3 staining were found in the epithelium, whereas the mature epididymis tail showed high levels of galectin-3 in the principal cells, moderate levels in the basal cells and low levels in connective tissue. These findings suggest that galectin-3 expression plays a role in the maturation and activation of sperm in bulls.     

泌乳期山羊腺垂体中ERα和ERβ的分布特点

为了获得ERα和ERβ在泌乳期参与腺垂体激素分泌的调节机理的形态学依据,试验采集泌乳初期、泌乳中期和泌乳后期山羊的腺垂体,用免疫组化SP法检测了ERα和ERβ在腺垂体的分布.结果表明,山羊腺垂体中ER两种亚型分布在腺垂体远侧部的嗜色细胞中；ERα阳性细胞数量随泌乳时间逐渐减少,泌乳初期和泌乳后期多呈胞质阳性,高峰期呈胞...     

绿色植物在大气甲烷循环中的作用

甲烷是引起气候变暖的一种重要温室气体,近年来一些研究发现陆地植物具有排放甲烷的能力,打破了植物仅为连通土壤-大气气体交换通道的原始理念,但由于其发生机理尚无法解释,也引起了人们的质疑。对绿色植物在大气甲烷循环中的作用进行了文献综述,对主要研究结果之间的差异进行了比较,同时就未来绿色植物在大气甲烷循环中的作用进行了阐述,拟为进行植物在地球甲烷循环中的功能及潜力的估测提供理论依据。     

新疆南北疆两羊场春季养殖环境指标差异比较及羔羊健康状况调查

为了解新疆南北疆地区集约化养殖场春季羊舍环境的变化及羔羊健康状况，本研究对新疆昌吉州木垒县（ML）和阿克苏地区温宿县（WS）两个典型的集约化养殖场羊舍春季环境指标：二氧化碳（CO₂）、氨气（NH₃）、硫化氢（H₂S）、甲烷（CH₄）、光照强度、温度、湿度、噪音、可吸入颗粒物（inhalable particles，PM₁₀）和总悬浮颗粒物（total suspended particulars，TSP）进行为期15 d的连续监测，采集连续5 d的24 h数据，分析其日周期变化规律，同时对两羊场羔羊健康与疾病状况进行临床观察。结果表明，木垒羊场羊舍春季噪音极显著高于温宿羊场羊舍（P<0.01），温宿羊场羊舍春季NH₃、CO₂浓度及TSP、PM₁₀浓度都极显著高于木垒羊场羊舍（P<0.01）；从环境指标日周期变化来看，木垒、温宿春季羊场羊舍温度分别约有15和24 h超过国家行业标准（NY/T 388－1999）限值范围。两羊场春季羔羊主要疾病为腹泻、咳嗽及营养不良导致的瘫痪，且温宿羊场羔羊的咳嗽率显著高于木垒羊场（P<0.05），木垒羊场羔羊的瘫痪率显著高于温宿羊场（P<0.05）。综上，两羊场羊舍除温度指标外其他环境指标参数均符合国家标准，表明两场春季羊舍环境对于羊的生长发育比较适宜，但需要对羊舍的温度进行把控从而保证动物的福利及健康需求；两羊场春季监测羊舍的断奶羔羊整体健康状况良好，但木垒羊场需加强对新生弱羔初乳获得、育肥羔羊的补饲等方面的饲养管理。此研究可为新疆地区舍饲肉羊适宜养殖环境标准制定提供一定参考，同时也为新疆肉羊养殖场的饲养管理、动物健康和福利的保障、生产水平的提高提供科学依据。     

青海藏羊不同剪毛量区段含硫量的测定

用重量法对青海藏羊不同剪毛量区段的含硫量进行了测定和统计分析 ,结果表明 ,成年公羊 3 .5 0kg区段含硫量最高 ,二岁公羊 3 .0 0kg区段含硫量最高 ,一岁公羊 0 .5 0kg区段含硫量最高 ;成年母羊 2 .5 0kg区段含硫量最高 ,二岁母羊3 .0 0kg区段含硫量最高 ,一岁母羊 2 .5 0kg区段含硫量最高。同性别年龄内剪毛量区段间含硫量差异不显著 (P >0 .0 5 )。