生鲜乳中污染物的检测

改革开放以来,我国乳制品工业在行业规模、乳制品产量、技术装备、质量安全等方面都有了根本的转变。但由于乳制品工业发展时间短,发展速度过快,基础薄弱,特别是由于奶源管理、质量控制、检测手段落后等方面的原因,质量安全问题时有发生,给消费者的生命和财产安全带来损害。按照标准GB2762-2005《食品中污染物限量》的规定,涉及生乳的标准包括铅、总汞、无机砷、铬、硒等5项指标。     

酸化饮水对断奶仔猪健康的积极影响

水的摄入对仔猪健康和生产具有重要影响,但仍是一个未充分了解的参数。提高饮水质量应该成为猪场的一个标准操作规范以改进猪群健康和生长性能。全世界猪场业主的一个共识是要建立一个可盈利的猪生产系统,但达到这个目标,每个阶段猪(母猪,仔猪,育成猪和肥育猪)生产性能水平至关重要。不同的圈舍、饲料、管理和生物安全等指标综合在一起决定了生产性能水平,但首要的是猪群的健康。     

理想蛋白质及精细饲养与泌乳期母猪繁殖性能的关系

泌乳母猪的饲养是规模化养猪的核心环节。营养供给合理与否影响母猪的产仔数、仔猪成活率与断乳重、母猪发情及使用年限,直接影响养猪的经济效益。近二十年,以降低背膘厚度为选育目标的猪育种,使母猪基因型发生改变,成熟母猪体型大、采食     

奶牛夏季高产巧管理

奶牛是耐寒怕热的家畜,其适宜的温度为10—20℃,一般环境温度在4—24℃、相对湿度60—80%时,对产奶量影响较小,25℃以上越高对产奶量的影响越大,下降幅度可达到5—10千克。主要是因为高热和高湿的环境条件会给奶牛造成严重的应激反应,减少了用于支持产奶量和维持身体所需养分的摄入量。因此,夏季奶牛的饲养管理主要任务是防     

成年马钙摄入量对磷消化率的影响

许多资料表明，当成年马钙摄入量高时磷的消化率则低，尚无资料报道当磷摄入量恒定时钙的摄入量对磷的表观消化率的影响。荷兰乌得勒支大学动物医学院Van Doom等研究饲喂6匹成年马3种钙水平日粮对磷表观消化率的影响。每天日粮中钙的饲喂水平分别为148，316，535mg／kg；磷的表观摄入量大约为125mg／kg；镁的摄入量大约为35mg／kg。     

日粮硒来源和水平影响鸡胚的硒摄入量

美国研究人员测定了日粮硒 (Se)来源 (有机或无机 )和Se水平对鸡胚Se摄入量的影响。给 12 6只产蛋鸡饲喂低Se日粮 ,16周后分作 7种日粮处理 ,饲喂低Se基础日粮及用硒酸钠或富Se酵母提供 3种水平 (0 .1、0 .2或 0 .3mg/kg)Se的日粮。饲喂 33d后收集受精卵 ,对卵不孵化或孵化 5、10、15、2 0d。然后单独测定不孵化卵卵黄和蛋白的Se ,单独测定孵化卵胚和胚外部分的Se。结果 ,日粮处理之间卵黄和蛋白的Se浓度有显著差异。与饲喂硒酸钠母鸡的卵比较 ,饲喂富Se酵母母鸡卵黄和蛋白的Se浓度较高。饲喂富Se酵母母鸡卵的胚和胚外部分Se浓度高于…     

植物性饲料磷生物学利用率的测定方法及存在问题

多年来,一直都假定植物性饲料中有1/3的磷对单胃动物具有生物学利用率。因为植物性饲料中有2/3的磷以植酸磷形式存在,而其余1/3是以非植酸磷形式存在。由于单胃动物消化道缺乏植酸     

Analysis on Dynamic Changes of Nutrient Intake and Serum Biochemical Indexes of Barn Feeding Ewes

In order to research the dynamic changes of nutrient intake and serum biochemical indexes of barn feeding ewes in different pregnant stages, and provide evidence for reasonable diet formulation and health state analysis of barn feeding goats, each 10 healthy female goats in non-pregnancy, early pregnancy and late pregnancy were randomly selected in this experiment, whose feed intake were determined;6 ill parturient ewes and each 8 healthy female goats in non-pregnancy, 1 month pregnancy, 2 months pregnancy, 3 months pregnancy, 4 months pregnancy and labor were randomly selected in this experiment, whose 7 serum biochemical indexes were determined.The results showed as follows:① In comparison to NRC(2007) goat nutritional requirements, DM, ME and CP intakes were more than the requirements in non-pregnant and early pregnant ewes, while DM, ME and CP intakes were less than the requirements in late pregnant ewes;Ca and P intakes were much more than the requirements in various stages of ewes.② From non-pregnancy, pregnancy to labor, healthy ewes' GLU content decreased (3.44 to 2.57 mmol/L) and KB content increased (14.93 to 23.55 μg/mL), while ill parturient ewes'GLU content was significantly decreased to 0.85 mmol/L(P<0.05) and KB content was significantly increased to 42.98 μg/mL (P<0.05);Healthy ewes' TP content decreased (70.55 to 59.94 g/L) and ALB content had little change (33.55 to 32.61 g/L), while ill parturient ewes' TP and ALB content both further decreased (56.79 and 29.72 g/L, respectively);Healthy ewes' Ca and P content had little change (2.21 to 2.19, 2.62 to 2.25 mmol/L, respectively), while ill parturient ewes' Ca (1.80 mmol/L, P<0.05) and P (2.17 mmol/L) content both decreased;Healthy ewes'AKP content decreased (258.57 to 104.35 U/L), but ill parturient ewes'AKP content increased (180.53 U/L).All the analysis showed that the inadequate energy intake of ewes in late pregnancy was the root cause of the decreased GLU and other serum biochemical indexes contents and the increased KB contents and the ill parturient ewes was diagnosed as pregnancy toxemia.Therefore, the ewes'diet formulation should be adjusted, different stages of ewes should be separated to feed, the energy intake of ewes in late pregnancy should be increased.     

泌乳母猪的营养需求

1提高采食量通常泌乳母猪的能量摄入量取决于母猪的自身体况,产乳量和乳组分以及体重和体组成的变化。泌乳期间的总采食量与母猪的泌乳性能、繁殖性能呈正相关。而泌乳期的采食量下降对母猪的生产性能影响很大,如发情间隔延长,受胎率降低,窝产仔数减少,产仔率降低。通常母猪养殖生产中在泌乳期都应该保持较高的采食量。2蛋白质现代母猪由于体重大、产仔数多、泌乳量高,因此需要泌乳旺期母猪日粮中提高蛋白质含量,且保     

‘温185’核桃根施氮磷钾肥的净光合速率效应

通过肥料效应田间试验,检验中等土壤养分条件下‘温185’(Juglans regia‘Wen185’)核桃根施氮(N)、磷(P)、钾(K)肥的净光合速率效应,以期为新疆南疆盆地‘温185’核桃生产园的科学施肥管理提供参考。试验采用“3414”肥料效应田间试验与多元线性逐步回归分析相结合的方法。结果表明：‘温185’核桃净光合速率日均值(M)以10 为底的常用对数(log10M)同N肥的施用量（纯N量）和N肥施用量的自乘（N×N或N 2）存在极显著(P＜0.001)的线性相关关系,即：log10M? =0.724+0.231N-0.084N 2+0.153P 2。在土壤养分条件处于中等水平（有效P 14.0 mg/kg、速效K 77 mg/kg）的生产园,当N肥施用量（纯N量）小于2.75 kg/株时,对‘温185’核桃的净光合速率存在正效应,反之则存在负效应;施用P 肥有利于提高‘温185’核桃的净光合速率。