The effect of dietary high energy density and carbohydrate energy ratio on digestive enzymes activity,nutrient digestibility,amino acid utilization and intestinal morphology of weaned piglets

This study evaluated the effect of high or low digestible energy ratio of carbohydrate in a high or normal dietary energy density on performance, amino acid utilization and intestinal functions of weaned piglets. A total of 32 healthy weaners (9.60 ± 0.13 kg) were allocated to two dietary energy densities (3,400 and 3,800 kcal/kg) and two digestible energy ratio of carbohydrate to fat (9:1 and 3:1) in a 2 × 2 factorial arrangement. There were eight piglets per treatment. The feed intake of piglets was significantly increased by dietary high carbohydrate ratio (9:1) (p < 0.01); however, this did not result in improved body weight gain (p > 0.05). The piglets fed high carbohydrate energy ratio had a reduced villus height/crypt depth (VH/CD) ratio in the duodenum (p < 0.05), and dietary high energy density further decreased the VH/CD ratio in the ileum (p < 0.01). In the duodenum, the lymphocyte count was increased by dietary high energy density (p < 0.05), while dietary energy density and carbohydrate energy ratio interacted to increase lymphocyte count in the ileum (p < 0.05). The serum cholesterol, triglyceride and low‐density lipoprotein were not significantly affected (p > 0.05), but dietary energy density interacted with dietary energy ratio to increase high‐density lipoprotein concentration (p < 0.05) in piglets fed reduced carbohydrate energy ratio. Dietary high energy density reduced energy digestibility (p < 0.05), whereas high carbohydrate energy ratio increased crude protein digestibility in the piglets (p < 0.05). The intestinal sucrase, lactase activities and serum concentrations of histidine, leucine, lysine, methionine, phenylalanine, alanine, glycine, tyrosine and citrulline were higher in the piglets fed dietary increased carbohydrate energy ratio. Oxidative stress markers and volatile fatty acids concentrations were altered by the dietary treatments. It was concluded that dietary high energy density could be detrimental to piglets intestinal functions and that increased carbohydrate energy ratio could affect amino acid utilization and body weight gain in weaner pigs.     

番茄新品种东农712的选育

东农712是以01HN43为母本,以01HN37为父本配制而成的中晚熟番茄一代杂种,生育期117 d（天）左右,高抗番茄花叶病毒（ToMV）、叶霉病、枯萎病和黄萎病。果实高圆形,单果质量240~300 g,果实粉红色,果面光滑圆整,成熟果硬度0.49 kg·cm^-2,耐贮运;丰产性好,每667 m²产量6 500~8 500 kg,适合全国各地保护地和露地栽培。     

Skeletal unit construction of rat mandible based on the masticatory muscle anatomy and double microcomputed tomography

This study aimed to divide the mandible into skeletal units based on three‐dimensional (3D) muscular anatomy with microcomputed tomography (micro‐CT) of Sprague–Dawley rat. Five normal rats were micro‐CT scanned at 12 weeks of age before and after contrast enhancements for the masticatory muscles. Three‐dimensional reconstruction of the mandible was performed from the initial micro‐CT images, followed by segmentation of the masticatory muscles using the second enhanced micro‐CT data. Bone and muscle models were superimposed based on the teeth and bony structures to evaluate muscular orientation and attachment. The mandible was divided into skeletal units using the bony structures and muscle attachments. The mandibular foramen and mental foramen were adopted as the reference points based on their anatomical and developmental significance. The skeletal units consisted of the condylar, coronoid, angular, body and symphyseal units. Further evaluation of these units in relation to development, growth, and other biology and medicine will be helpful in elucidating their biological identities.     

苜蓿素对脂多糖诱导下奶牛乳腺上皮细胞炎症和乳蛋白合成相关基因表达的影响

为分析苜蓿素对脂多糖诱导下体外培养奶牛乳腺上皮细胞抗炎和乳蛋白合成相关基因表达的影响,本研究将体外培养的奶牛乳腺上皮细胞分成4组,即基础培养基(对照)和基础培养基中分别加入1μg·m L-1LPS(L)、1μg·m L-1LPS+10μg·m L-1苜蓿素(L+T)和10μg·m L-1苜蓿素(T)。结果显示,1)与对照组相比,L组奶牛乳腺上皮细胞的活性显著下降(P0.05),而T组则显著升高(P0.01)。2)L+T组细胞的超氧化物歧化酶(SOD)活性显著高于L组(P0.01),而一氧化氮(NO)、丙二醛(MDA)含量则显著低于L组(P0.01)。3)LPS能够显著升高细胞的白细胞介素1β(IL-1β)、IL-6、肿瘤坏死因子α(TNF-α)、Toll样受体2(TLR2)、TLR4和髓样分化因子88(My D88)表达水平(P0.01),而添加苜蓿素能够显著降低IL-1β、TNF-α、TLR2和TLR4的表达水平(P0.01)。4)与对照组相比,T组细胞的酪氨酸激酶2(JAK2)、信号转导子和转录激活子5(STAT5)、雷帕霉素靶蛋白(m TOR)、真核细胞始动因子4E结合蛋白1(4EBP1)和核糖体S6蛋白激酶1(S6K1)表达量显著升高(P0.01),而碱性氨基酸转运载体1(CAT1)表达量显著降低(P0.01)。LPS能够显著降低细胞的CAT1、L型氨基酸转运载体1(LAT1)、STAT5、m TOR和4EBP1表达水平(P0.01或P0.05),而添加苜蓿素能够显著升高STAT5表达水平(P0.01)。结果表明,乳腺细胞在LPS刺激下,导致细胞内炎症因子基因表达升高和抑制乳蛋白合成相关基因的表达,而添加苜蓿素能够抑制乳腺细胞内炎症因子基因表达,但对乳蛋白合成的相关基因表达作用不明显;无LPS刺激下,添加苜蓿素能够提高乳腺细胞活性和促进乳蛋白合成相关基因的表达。     

3株紫花苜蓿内生根瘤菌功能差异性分析

以3株紫花苜蓿(Medicago sativa)内生根瘤菌株(LP3、WLP2和WLG1)为材料,进行抗逆和促生能力研究,并采用试管砂培法对WL168HQ苜蓿(M.sativacv.WL168HQ)进行接种试验,以不含根瘤菌的培养液为对照,分析菌株的共生固氮能力。结果表明,菌株WLP2能耐受除红霉素和庆大霉素外的所有抗生素≥300μg·mL~(-1);能在6%NaCl、pH 5~11和温度8~40℃的环境下生长,对盐、pH和温度的适应范围广;能溶解有机磷和无机磷,分泌IAA能力强。菌株WLG1接种,单株结瘤数、地上干重和地下干重显著高于对照处理(P0.05),分别比对照增加了208.16%、72.35%和122.33%;单株有效根瘤重、根长和单株叶片数明显高于对照处理,分别比对照高了6.68%、9.57%和53.59%。综上所述,菌株WLP2对抗生素、盐、pH和温度的抗性以及促生能力较强,菌株WLG1对WL168HQ苜蓿接种效果最佳,共生固氮能力强。     

苜蓿黄酮对脂多糖诱导下奶牛乳腺上皮细胞凋亡的影响

研究苜蓿黄酮对脂多糖(LPS)诱导下奶牛乳腺上皮细胞凋亡的影响。将奶牛乳腺上皮细胞分成4个组,即基础培养基、基础培养基中加入1 μg·mL^-1的LPS、基础培养基中加入1 μg·mL^-1的LPS和75 μg·mL^-1苜蓿黄酮、基础培养基中加入75 μg·mL^-1苜蓿黄酮。细胞在37 ℃, 5% CO₂的培养箱中培养。结果表明:1)LPS刺激12 h后奶牛乳腺上皮细胞活性下降,而添加苜蓿黄酮能够极显著抑制LPS诱导下细胞活性的下降(P<0.01)。2)在LPS刺激下,细胞内的活性氧(ROS)浓度升高,而添加苜蓿黄酮能够显著降低其浓度(P<0.05)。3)LPS显著上调细胞的IL-1β、IL-6、TNF-α、TLR2、TLR4和MyD88表达(P<0.01),而苜蓿黄酮能够显著下调细胞的IL-1β、IL-6、TNF-α和TLR2表达(P<0.01或P<0.05)。4)在LPS刺激下,p53、Caspase3、p38和P-p38蛋白的表达显著升高(P<0.01或P<0.05),而添加苜蓿黄酮能够显著降低p53和p38蛋白的表达(P<0.05)。在LPS诱导下,苜蓿黄酮能够通过降低ROS浓度,抑制细胞凋亡,提高细胞活性;可能通过抑制TLR2/MyD88信号通路来降低细胞炎症因子的表达,从而保护细胞免受炎性损伤。     

我国6省市活禽销售商“知信行”相关性研究

为了解安徽、福建、广东、湖南、江苏、上海等6省市活禽批发商户和零售商户对"1110"制度的认知和态度,及其主要活禽销售行为,并探讨其相关性,以便有针对性地实施宣传干预,降低H7N9发病风险,采用自行设计的调查问卷,结合现场调查,对199户活禽销售商户进行了调查。结果显示:活禽销售商户的"1110"制度知晓率、接受率普遍偏低,其中批发商户和零售商户的知晓率分别为32.61%(30/92)和40.19%(43/107),接受率分别为20.65%(19/92)和28.04%(30/107),均无统计学差异(P0.05);多种活禽销售行为存在统计学差异(P0.05);零售商户的认知与态度呈正相关(P0.05);认知和态度与部分销售行为相关(P0.05)。因此,应对活禽销售商户加强"1110"制度宣传,促使其形成积极正向的态度,转变不良销售行为,从而提高活禽市场生物安全水平。     

非洲猪瘟的流行特征和传播路线

2018年8月3日辽宁省沈阳市某猪场首次暴发非洲猪瘟疫情。为了解全球非洲猪瘟流行形势,正确认识非洲猪瘟的病原学和流行病学特征,防止非洲猪瘟在我国进一步扩散和传播,本文简明阐述了非洲猪瘟特有的病原学特征、主要感染源、传播途径以及监测技术要点,分析了需特别关注的4种传染源,供相关人员参考,以便及早根除国内的非洲猪瘟疫情,保障我国养猪业健康发展。