结构创新的楼房猪场是防非保供的一种可行模式

传统的养猪模式难以应对诸如非洲猪瘟这样的疫病,普通平层猪场叠加而成的楼房没有从本质上得到改进,而结构创新之后的楼房猪场在养猪的可靠性上大大增强,并可能发展为城市养猪新模式,为防非保猪、稳产保供提供一种解决方案。在此基础上升级的"料、养、宰、商一体化"造肉工厂模式,更是一种能把运猪变为运肉的可行解决方案。当这些模式得到应用和推广时,困扰行业的"猪周期"问题也将得到妥善解决。     

Regulatory role of l-proline in fetal pig growth and intestinal epithelial cell proliferation

l-proline (Pro) is a precursor of ornithine, which is converted into polyamines via ornithine decarboxylase (ODC). Polyamines plays a key role in the proliferation of intestinal epithelial cells. The study investigated the effect of Pro on polyamine metabolism and cell proliferation on porcine enterocytes in vivo and in vitro. Twenty-four Huanjiang mini-pigs were randomly assigned into 1 of 3 groups and fed a basal diet that contained 0.77% alanine (Ala, iso-nitrogenous control), 1% Pro or 1% Pro + 0.0167% α-difluoromethylornithine (DFMO) from d 15 to 70 of gestation. The fetal body weight and number of fetuses per litter were determined, and the small and large intestines were obtained on d 70 ± 1.78 of gestation. The in vitro study was performed in intestinal porcine epithelial (IPEC-J2) cells cultured in Dulbecco''s modified Eagle medium-high glucose (DMEM-H) containing 0 μmol/L Pro, 400 μmol/L Pro, or 400 μmol/L Pro + 10 mmol/L DFMO for 4 d. The results showed that maternal dietary supplementation with 1% Pro increased fetal weight; the protein and DNA concentrations of the fetal small intestine; and mRNA levels for potassium voltage-gated channel, shaker-related subfamily, member 1 (Kv1.1) in the fetal small and large intestines (P < 0.05). Supplementing Pro to either gilts or IPEC-J2 cells increased ODC protein abundances and polyamine concentrations in the fetal intestines and IPEC-J2 cells (P < 0.05). In comparison with the Pro group, the combined administration of Pro and DFMO reduced the expression of ODC protein and spermine concentration in the fetal intestine, as well as the concentrations of putrescine, spermidine and spermine in IPEC-J2 cells (P < 0.05). Meanwhile, the percentage of cells in the S-phase and the mRNA levels of proto-oncogenes c-fos and c-myc were increased in response to Pro supplementation, whereas depletion of cellular polyamines with DFMO increased tumor protein p53 (p53) mRNA levels (P < 0.05). Taken together, dietary supplementation with Pro improved fetal pig growth and intestinal epithelial cell proliferation via enhancing polyamine synthesis.     

徐州某规模猪场防疫措施的建立与实施——“五流”生物安全防控

非洲猪瘟在我国流行已有两年多的时间,尽管很多科研团队都在致力于非洲猪瘟疫苗的研发,但尚未有治疗措施和有效的疫苗来控制该病。因此现阶段“生物安全”是控制非洲猪瘟最为有效,也是唯一的方法。文章总结出目前规模化猪场常见的感染风险有“人员流动、物品流动、车辆流动、水源流动、猪群流动”(即“五流”),并提出严格控制“五流”的生物安全防控措施(即“五流”生物安全防控),以减少外界病原与猪只的接触,稀释病原浓度,降低病原载量,最大程度地降低规模化养猪场感染疾病的风险。为当前规模化猪场建立有效的生物安全措施提供参考。     

饲料中呕吐毒素对不同阶段商品猪及种猪的影响

我国不仅是畜牧业生产和消费大国,同时饲料产量也居世界首位,作为饲料中最常添加的谷物原料,其质量安全对饲料生产和养殖业有着重要影响。小麦、玉米等谷物在其生长、收获及加工等阶段未及时按规定处理会产生大量的霉菌毒素,其中呕吐毒素最为常见。呕吐毒素(DON)主要由镰刀菌属(如禾谷镰刀菌、尖孢镰刀菌等)产生,会造成不同阶段商品猪及种猪呕吐、肌肉出血、生长性能和繁殖力的下降等。本文综述了饲料中DON的污染现状及其对养猪生产的危害,进而提出了综合防治措施,为畜牧业生产者更好地防治DON污染、提高养殖收益提供系统科学参考。     

Influence of soil phosphorus status,texture, pH and metal content on the efficacy of amendments to pig slurry in reducing phosphorus losses

Cost‐effective strategies for using chemically amended organic fertilizers need to be developed to minimize nutrient losses in surface and groundwater. Coupling specific soil physical and chemical characteristics with amendment type could increase their effectiveness. This study investigated how water‐extractable phosphorus (P) was affected by chemical amendments added to pig slurry and how this effect varied with soil properties. A 3‐month incubation study was conducted on 18 different mineral soils, stored at 10 °C and 75% humidity and treated with unamended and amended slurry which was incorporated at a rate equivalent to 19 kg total P (TP )/ha. The amendments examined were commercial‐grade liquid alum, applied at a rate of 0.88:1 [Al:TP ], and commercial‐grade liquid poly‐aluminium chloride (PAC ), applied at a rate of 0.72:1 [Al:TP ]. These amendments were previously identified by the authors as being effective in reducing incidental losses of P. The efficacy of the amendments varied with the soil test P, the degree of P saturation (DPS ) and the Mehlich aluminium, iron and calcium, but not soil texture. Chemical amendments were most effective in soils with DPS over approximately 20%. Due to their high cost, the incorporation of amendments into existing management practices can only be justified as part of a holistic management plan where soils have high DPS .     

政策认知、执行力度与资源化利用满意度——基于河北省380家生猪养殖主体调研数据(上)

参与主体对于政策的评价是衡量政策实施效果的重要指标，探明政策参与主体满意度影响因素有助于了解主体自身需求，从而提高政策实施水平。文章基于对河北省380家生猪养殖主体调研数据，运用多元有序Logistic回归方法，分析生猪养殖主体自身政策认知以及相关政策执行力度对畜禽养殖主体废弃物资源化利用满意度的影响。结果表明：养殖主体资源化利用政策了解程度能够显著提升其资源化利用政策满意度；仅考虑养殖主体政策参与力度，随着参与力度增加，满意度亦会显著提升。但综合考虑其他因素，参与力度对于满意度提升效果则不再显著；养殖主体感知政策执行力度增加不利于政策满意度提升。此外，生猪养殖主体废弃物资源化利用政策了解程度增加，可以显著提升其报告资源化利用政策“满意”可能性。而单纯提高资源化利用政策执行力度并不能显著提高养殖主体资源化利用政策满意度。因此，要提高养殖主体政策满意度，应多渠道提升宣传力度，鼓励养殖主体积极参与，提高其参与意识，不断改善现有政策执行方式。     

猪RUVBL2真核表达载体的构建及其在CHO细胞中的表达

RUVBL2(RuvB-like 2)蛋白是进化上高度保守AAA+(ATPases Associated With Diverse Cellular Activities,AAA)家族成员之一,CHO(Chinese Hamster Ovary)细胞被广泛地用于表达重组DNA蛋白。为探究猪睾丸组织的RUVBL2基因是否能够在CHO细胞中表达,本实验以猪睾丸组织的cDNA为模板,PCR扩增RUVBL2目的基因,并将其克隆至pIRES2-EGFP(Mammalian Expression Vectors pIRES2-EGFP)载体上,进一步转化到DH5α中,再进行PCR、酶切及测序鉴定;将重组质粒转染到CHO细胞中,再进行荧光、RT-PCR、Western blot检测。结果显示:PCR、酶切及测序都证实了RUVBL2基因正确地插入到了载体质粒pIRES2-EGFP的多克隆位点;荧光、RT-PCR、Western blot也证实了RUVBL2基因在CHO细胞中的成功表达。本实验成功构建了猪的pIRES2-EGFP-RUVBL2真核表达载体,并证实了猪睾丸组织中的RUVBL2基因能够在CHO细胞中表达。     

猪粪施用量对红壤旱地理化性质及酶活性的影响

为研究猪粪的合理施用及其对红壤旱地地力提升的效应,利用在第四纪红壤旱地中连续3年分别施用0、7.5、15、30、45 t·hm~(-2)猪粪的小区定位试验,比较不同处理下菠菜和玉米地上部生物量、土壤相关理化性质、碳氮磷循环相关酶活性的差异。结果表明:菠菜和玉米地上部生物量、土壤有机质、土壤全量和速效态氮磷钾含量均随猪粪施用量的增加呈线性增加。当猪粪施用量达45 t·hm~(-2)时菠菜、玉米平均地上部生物量分别达到11.48、20.84 t·hm~(-2),土壤有机质和全氮、全磷含量分别达14.6、1.07、0.73 g·kg~(-1),土壤碱解氮、有效磷、速效钾含量分别达85.47、106.9、411.7 mg·kg~(-1),但与猪粪施用量为15和30t·hm~(-2)时土壤养分含量的差异不显著,而土壤中与碳氮磷循环相关的6种酶活性则与猪粪施用量呈线性相关,且在施用量为30或45t·hm~(-2)时出现显著差异;6种酶活性与土壤有机质、养分含量间均具有显著或极显著正相关关系。研究结果显示,第四纪红壤旱地在本试验猪粪施用量范围内,土壤有机质和养分含量、酶活性等指标均随施用量的增加而相应提高,作物地上部生物量亦呈线性增加,但同时须注意土壤速效态养分含量过高可能带来的氮磷流失加剧等问题。     

长期施用沼肥对设施菜田土壤养分和盐分累积量的影响

为研究规模养猪场沼液沼渣在农田施用对土壤养分及盐分含量累积的影响,以安康市某养猪场农业园区施用沼液设施菜田土壤为研究对象,以当地常规施用化肥设施菜田为对照,定点采集施用沼肥区和对照区0 a、1 a、3 a、5 a和7 a的设施菜地土壤,分别测定土壤中碱解氮、有效磷、速效钾、有机质、全铜、全锌质量分数及电导率和pH。结果表明,随着沼液沼渣施用年限的增加,土壤中碱解氮、有效磷、速效钾、有机质、全铜、全锌质量分数和电导率均相应增加,7 a后分别达96.1 mg/kg、91.5 mg/kg、73.7 mg/kg、11.9 g/kg、118.5 mg/kg、263.4 mg/kg和0.366 mS/cm,分别是未施用沼液沼渣土壤中各成分含量的3.4倍、1.5倍、3.3倍、1.3倍、3.9倍、1.88倍和4.74倍,说明施用沼液沼渣能有效增加土壤养分含量,同时土壤养分和盐分快速累积,对土壤环境带来较大的污染风险。     

Vaccination with a genotype 1 modified live vaccine against porcine reproductive and respiratory syndrome virus significantly reduces viremia,viral shedding and transmission of the virus in a quasi-natural experimental model

The present study assessed the efficacy of vaccination against genotype 1 porcine reproductive and respiratory syndrome virus (PRRSV) in terms of reduction of the transmission. Ninety-eight 3-week-old piglets were divided in two groups: V (n = 40) and NV (n = 58) that were housed separately. V animals were vaccinated with a commercial genotype 1 PRRSV vaccine while NV were kept as controls. On day 35 post-vaccination, 14 NV pigs were separated and inoculated intranasally with 2 ml of a heterologous genotype 1 PRRSV isolate (“seeder” pigs, SP). The other V and NV animals were distributed in groups of 5 pigs each. Two days later, one SP was introduced into each pen to expose V and NV to PRRSV. Sentinel pigs were allocated in adjacent pens. Follow-up was of 21 days. All NV (30/30) became viremic after contact with SP while only 53% of V pigs were detected so (21/40, p < 0.05). Vaccination shortened viremia (12.2 ± 4 versus 3.7 ± 3.4 days in NV and V pigs, respectively, p < 0.01). The 50% survival time for becoming infected (Kaplan–Meier) for V was 21 days (CI_95% = 14.1–27.9) compared to 7 days (CI_95% = 5.2–8.7) for NV animals (p < 0.01). These differences were reflected in the R value as well: 2.78 (CI_95% = 2.13–3.43) for NV and 0.53 (CI_95% = 0.19–0.76) for V pigs (p < 0.05). All sentinel pigs (10/10) in pens adjacent to NV + SP pens got infected compared to 1/4 sentinel pigs allocated contiguous to a V + SP pen. These data show that vaccination of piglets significantly decrease parameters related to PRRSV transmission.