小肽营养素对奶牛泌乳性能的影响

试验选择泌乳期中国荷斯坦奶牛32头,随机分为4组,A组(对照组)为基础精料日粮组;B、C、D组分别为基础精料日粮 0.1%、0.3%、0.5%小肽营养素。正试期28d。结果表明,添加0.1%、0.3%、0.5%小肽营养素后,奶牛头日平均产奶量分别提高1.67kg(6.38%)(P<0.05)、1.75kg(6.69%)(P<0.05)和1.64kg(6.27%)(P<0.05)。添加小肽营养素后,乳蛋白和乳脂率均有所提高,其趋势随小肽营养素添加量的增加而提高。添加0.1%、0.3%、0.5%小肽营养素后,奶牛头日净增效益3.52元、3.40元、2.86元。综合生产性能和经济效益,以添加0.1%-0.3%小肽营养素为适宜。     

Use of comparative proteomics to identify the effects of creatine pyruvate on lipid and protein metabolism in broiler chickens

Four hundred male chickens were selected to study the effects of pyruvate (Pyr), creatine pyruvate (CrPyr) and creatine (Cr) on the expression of hepatic mitochondrial and cytoplasm proteins associated with lipid and protein metabolism. Mitochondrial purification was accomplished using the two-step differential centrifugation and density gradient method, and the activities of organelle-specific marker enzymes were determined to assess the purity of the mitochondria. Proteins were extracted and fractionated by two-dimensional electrophoresis and the differential protein spots were assessed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. CrPyr reduced fatty acid accumulation by down-regulating adipose differentiation-related protein, inhibited ATP synthase expression, and reduced cholesteryl ester transfer protein (CETP) expression, thus reducing the levels of high density lipoprotein and triglycerol (TG) levels (thereby lowering fat and cholesterol deposition). CrPyr increased the expression of eukaryotic translation initiation factor (eIF) 2B, calreticulin (CRT) and eIF3a, thus promoting protein synthesis. CrPyr up-regulated the expression of fatty acid-binding proteins, CETP and apolipoprotein A-IV in cytoplasmic extracts, and these proteins accelerated the decomposition of fatty acids and TG, thus reducing fat deposition. In conclusion, CrPyr plays an important role in lipolysis and protein synthesis, and this effect was more pronounced than was the effect of Pyr and Cr.     

Calcium homeostasis and its relationship to superoxide production in blood and milk neutrophils of lactating goats

Polymorphonuclear neutrophils (PMN), which comprise over 70% of the somatic cells in goat milk, are a major cellular component of innate immunity in the goat mammary gland. However, the function of milk PMNs is modified after diapedesis compared to PMNs in blood. As many aspects of PMN activity depend directly on intracellular Ca²⁺ concentration ((Ca²⁺)_i), the present study aimed to determine the changes in Ca²⁺ homeostasis of milk PMNs from lactating goats compared to autologous blood PMNs, and to examine the significance of these variations to the immuno-competency of milk PMNs. The intracellular Ca²⁺ store of freshly prepared milk cells was estimated from the elevation of (Ca²⁺)_i after ionomycin treatment, which was found to be significantly less than blood PMNs. Replenishment of the intracellular Ca²⁺ store in milk cells after intracellular Ca²⁺ depletion by Bapta-AM followed by spiking with 2.5 mM Ca²⁺ for 20 min was also compared to that of blood PMNs, showing that after depletion/spiking the intracellular Ca²⁺ store in milk cells was much less than blood PMNs. The production of superoxide anion (O₂^?) in vitro in response to (Ca²⁺)_i-dependent or (Ca²⁺)_i-independent modulators was used to evaluate the relevance of altered Ca²⁺ homeostasis on the immuno-competency of milk cells compared to blood PMNs. The results indicated that milk cells produced similarly low levels of O₂^? as blood PMNs when treated with ionomycin. However, the amount of O₂^? produced by milk cells in response to phorbol 12-myristate 13-acetate (PMA) stimulation, although greater than ionomycin treatment, was significantly less than that of blood PMNs. The capacity for O₂^? production by both cell types in response to PMA reverted to the resting state with use of the protein kinase C (PKC) inhibitor, staurosporine. In conclusion, the current study demonstrated an irreversible shortage of intracellular Ca²⁺ in the milk PMNs of lactating goats compared to blood PMNs. It also showed that preliminary O₂^–production, primed by ionomycin treatment, remained unchanged in milk PMNs, despite the shortage in intracellular Ca²⁺, but decreased O₂^? production capacity, mediated via the PKC pathway, in milk PMN. It is suggested that the defects in Ca²⁺ homeostasis in milk PMNs of lactating goats is partially attributable for the post-diapedesis functionality modifications.     

汕头市猪场猪瘟和猪禽流感血清学监测报告

为了了解和掌握我市猪场的猪瘟免疫情况及感染高致病性禽流感疫病的可能性，我所分别于2005年2月和4月两次对全市范围内各类型的养猪场免疫猪瘟的猪只采集血清941份，进行猪瘟血清抗体监测和猪高致病性禽流感疫情血清学监测。现将监测结果报告如下。     

杂交苜蓿(Medicago varia Martyn)根系特性的研究

杂交苜蓿是野苜蓿 (M .falcata)和紫苜蓿 (M .sativaL .)的杂交后代 ,兼具亲本的许多优良性状 ,适于广泛栽培。对其在根系特性上所表现出的优势进行研究发现 :根颈处的劈裂将植株分为母株与子株 ,实现营养繁殖 ;位于茎基部的当年芽数量明显大于亲本 ,是地上生物量增长的基础 ;明显的缩根现象有利于茎基部和根颈顶部芽的产生和越冬 ;明显优于亲本的侧根与不定根 ,为根劈裂分株繁殖的植株提高地上生物量奠定了基础     

A miniature lighted stylet for fast oral endotracheal intubation in rabbits

Efficient oral endotracheal intubation of laboratory animals is a challenging technique in veterinary research. This study introduces a miniaturized lighted stylet for rabbit intubation. An experiment with repeated measures on two factors was used to assess the feasibility and efficacy of this method. The first factor compared stylet intubation vs. laryngoscopic intubation. The second compared three practitioners, one with prior experience and two without. Success rates on the initial attempt were not statistically different (χ² = 2.46, P = 0.12). The time difference between methods was significant (F = 41.007, P < 0.001), although the effect of practitioners was not (F = 1.038, P = 0.365). The mean ± SD of the intubation time, combining results from the three practitioners, was 20.34 ± 17.15 s for the stylet method and 57.58 ± 64.21 s for the laryngoscopic method. The results of this study demonstrate that lighted stylet intubation is efficient, robust, and independent of practitioner experience.     

如何选择缉毒犬

实践已证明,在犬群中只有约二十分之一的犬适宜作为缉毒犬,因为本身的自然素质及心理素质存在着一定的差异,犬的潜能也是有区别的.好的受训犬能节省训犬员训练时间,提高训练成功率及训犬员的信心,更好地为人民服务.     

预防奶牛难产的几项基本措施

难产可使胎儿和母牛的死亡率升高,导致产后母牛繁殖力和生产性能降低,给养牛业造成很大的经济损失。奶牛难产可分为母源性和胎儿性难产,主要取决于产力、产道、胎儿三个因素以及他们的相互关系。其中,胎儿过大是影响难产发生率的最重要的原因,母牛初孕年龄、公母牛品种、胎次等     

广东省家禽生产现状与前景展望

文章介绍了广东省家禽业生产形势,详细分析了当前家禽市场低迷的原因,并对业界人士关心的今后广东省家禽业生产的趋势、市场形势和发展对策进行研究探析,指出广东省家禽业需要调整结构、凸显品牌、拓展市场、增长效益来提高生产效益。     

江苏联农畜禽有限公司王利明副总经理谈目前蛋鸡养殖行情

目前的金融危机对大部分行业都有或多或少的影响,国内整体经济放缓,大部分民工失去工作,企业开工不足,导致整体消费能力下降。危机对我们蛋鸡养殖行业的影响,肯定有,但还未真正到来,目前我们所能做的就是认真搞好自己的生产,树立信心,通过多种措施提前应对和化解危机对我们的影响。