苏打型盐碱化芦苇沼泽地“苇-蟹-鳜-鲴”模式研究

为探索苏打型盐碱化芦苇沼泽地优质高效的可持续利用模式,通过盐碱水环境下中华绒螯蟹、斑鳜与细鳞鲴的驯化养殖和农田工程、水质与水量管理及芦苇栽培的技术措施,建立了芦苇+中华绒螯蟹+斑鳜+细鳞鲴(苇蟹鳜鲴)模式23.6 hm2。据2006—2009年的试验结果,"苇蟹鳜鲴"模式的中华绒螯蟹、斑鳜和细鳞鲴的年产量分别为81.00 kg·hm-2、39.34 kg·hm-2和58.62 kg·hm-2;芦苇产量5 478 kg·hm-2,比原始沼泽地提高1.2倍,年平均增长22.0%;经济效益1.45×104元·hm-2,比原始沼泽地提高13倍;水环境盐度与碱度、土壤含盐量年平均分别下降19.1%、10.3%和20.3%,土壤有机质年平均增加8.9%。"苇蟹鳜鲴"模式的推广应用使人均纯收入年平均增长11.2%,对提高人均纯收入的贡献率为43%。"苇蟹鳜鲴"模式使芦苇沼泽地的生态功能与生产功能进一步提高,是经济效益、生态效益和社会效益协调发展,优质高效的湿地生态农业模式,可供苏打型盐碱化芦苇沼泽地的高效可持续利用借鉴。     

大蒜秸秆饲喂对肉羊增重及羊肉品质的影响

为研究大蒜秸秆饲喂对小尾寒羊增重及羊肉品质的影响,按照大蒜秸秆添加比例不同,把30只小尾寒羊随机分为试验组1、试验组2和对照组,每组10只,测定了不同饲料营养成分,不同组别小尾寒羊采食量、日增重、肠道疾病发生及羊肉品质等相关指标。与玉米饲料、玉米秸秆对比,大蒜新鲜秸秆的钙和粗纤维含量较高,蒜素含量为17.80 mg/100 g。不同大蒜秸秆饲料添加比例对肉羊增重影响显著,随着添加比例增加对肉羊增重具有显著的促进作用,试验组1和试验组2比对照组日增重增加35.29%和17.65%,大蒜秸秆作为粗饲料能够显著提高羊肉中不饱和脂肪酸和饱和脂肪酸的含量,粗料中添加大蒜秸秆比例较高（本试验70%）的条件下,羊肉中不饱和脂肪酸顺-9-油酸、亚油酸含量比对照增加370.58%和60.70%,限制性氨基酸、必需氨基酸和肉味氨基酸显著提高,分别比对照增加4.98%、3.82%和1.51%。肉羊养殖中,粗饲料中大蒜秸秆对比常规青贮玉米作为主要成分饲喂,对于小尾寒羊肉羊增重和羊肉品质都有显著的促进作用。     

Modulation of jejunal mucosa-associated microbiota in relation to intestinal health and nutrient digestibility in pigs by supplementation of β-glucanase to corn–soybean meal-based diets with xylanase

This study aimed to evaluate the effects of increasing levels of β-glucanase on the modulation of jejunal mucosa-associated microbiota in relation to nutrient digestibility and intestinal health of pigs fed diets with 30% corn distiller’s dried grains with solubles and xylanase. Forty pigs at 12.4 ± 0.5 kg body weight (BW) were allotted in a randomized complete block design with initial BW and sex as blocks. Dietary treatments consisted of a basal diet with xylanase (1,500 endo-pentosanase units [EPU]/kg) and increasing levels of β-glucanase (0, 200, 400, and 600 U/kg) meeting nutrient requirements and fed to pigs for 21 d. Blood samples were collected on day 19. On day 21, all pigs were euthanized to collect intestinal tissues and digesta. Tumor necrosis factor-alpha, interleukin (IL)-6, and malondialdehyde were measured in the plasma and mid-jejunal mucosa. Viscosity was determined using digesta from the distal jejunum. Ileal and rectal digesta were evaluated to determine apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients. Mucosa samples from the mid-jejunum were utilized for microbiota sequencing. Data were analyzed using the MIXED procedure on SAS 9.4. Overall, increasing dietary β-glucanase tended to increase (linear; P = 0.077) the average daily gain of pigs. Increasing dietary β-glucanase affected (quadratic; P < 0.05) the relative abundance of Bacteroidetes, reduced (linear; P < 0.05) Helicobacter rappini, and increased (linear, P < 0.05) Faecalibacterium prausnitzii. β-Glucanase supplementation (0 vs. others) tended to increase (P = 0.096) the AID of crude protein in the diet, whereas increasing dietary β-glucanase tended to increase (linear; P = 0.097) the ATTD of gross energy in the diet and increased (linear; P < 0.05) the concentration of IL-6 in the plasma of pigs. In conclusion, increasing β-glucanase up to 600 U/kg feed in a diet containing xylanase (1,500 EPU/kg) modulated mucosa-associated microbiota by increasing the relative abundance of beneficial bacteria and reducing potentially harmful bacteria. Furthermore, increasing β-glucanase up to 600 U/kg feed in a diet containing xylanase (1,500 EPU/kg feed) enhanced the status of the intestinal environment and nutrient utilization, as well as reduced systemic inflammation of pigs, collectively resulting in moderate improvement of growth performance. Supplementing β-glucanase at a range of 312 to 410 U/kg with xylanase at 1,500 EPU/kg feed showed the most benefit on jejunal mucosa-associated microbiota and reduced systemic inflammation of pigs.     

Gliadin and zein show similar and improved rheological behavior when mixed with high molecular weight glutenin

Small amplitude and lubricated squeezing flow tests were performed to investigate the effect of high molecular weight glutenin (HMWG) on the rheological properties of gliadin and zein dough composites. It was hypothesized that addition of small amounts of HMWG to zein cause changes in its viscoelastic properties in the same way as its addition to gliadin. Starch (87%, w/w) and protein/protein composites (13%, w/w), and water were mixed into dough. The water content of prepared dough was in the 41.7–45.3% range. Composites were gliadin-HMWG and zein-HMWG. Phase angle and complex modulus (G*) were obtained from frequency sweep tests at 0.5% strain amplitude over a 0.01–100 rad/s frequencies. Lubricated squeezing flow test were carried out at a range of strain rates to determine the sample extensional viscosities.     

大河乌猪磷酸酯转移蛋白基因内含子4的SNPs检测及其与生产性能的关联分析

本研究旨在阐明猪磷酸酯转移蛋白(phospholipid transfer protein,PLTP)基因第4内含子多态性及其与生长性状之间的关系。结果表明,该位点具有2种等位基因A/a,F4、F5、F6各群体中的基因频率分别为0.4172/0.5828、0.4155/0.5845、0.4309/0.5691。取不同基因型纯合子样品进行测序,共发现4个单核苷酸多态位点(SNPs),其有3个突变为转换,1个为颠换,多态位点分别为1085、1192、1286和1305 bp。应用最小二乘模型分析不同基因型对生长性状(初生重、45日龄体重、4月龄体重及6月龄体重、体高、体长、管围、背膘厚)的影响。结果显示,F4代各性状基因型间差异不显著(P>0.05);F5代Aa基因型个体初生重及背膘厚显著高于AA基因型(P<0.05),与aa基因型个体间差异不显著(P>0.05);F6代aa基因型个体4月龄体重及Aa基因型个体6月龄管围都极显著高于AA基因型(P<0.01),aa基因型个体6月龄体高显著高于AA基因型(P<0.05),Aa基因型个体初生重显著高于AA基因型(P<0.05)。另外,Aa基因型的雌性个体对初生重及膘厚性状的影响较AA基因型高(P<0.05);Aa基因型雄性个体对管围性状的影响较AA基因型高(P<0.01)。研究结果提示猪PLTP基因Aa基因型对生长性状有着重要的影响,该SNP可能是改良猪经济性状的重要分子标记位点。     

日粮蛋白质水平对海南猪生产性能和血液生化指标的影响

试验旨在研究日粮不同蛋白质(crude protein,CP)水平对海南猪生产性能和血液生化指标的影响。选初始体重为(15.88±1.82)kg健康海南猪36头,随机分为3组,即试验Ⅰ组(CP为16.5%)、试验Ⅱ组(CP为18.5%)和试验Ⅲ组(CP为20.5%),每组3个重复,每个重复4头,试验期为40 d。结果表明:①日粮中蛋白质的添加水平对海南猪生产性能的影响差异不显著(P>0.05),但以试验Ⅱ组(18.5%)生产性能最佳;②日粮中蛋白质的添加水平对血液总蛋白和球蛋白的含量有显著影响(P<0.05),且随着日粮中蛋白质水平的提高,海南猪血液总蛋白和球蛋白含量也升高。提示,在海南猪生长前期饲喂蛋白质水平以18.5%日粮较为适宜。     

2种日粮对不同生长阶段乌金猪脂肪组织脂类合成代谢相关基因表达的影响

为探讨不同日粮对乌金猪不同生长阶段脂类合成代谢相关基因表达的影响,试验选取体重约23 kg乌金猪36头,公、母各半,随机分为2个处理组,每个处理组3个重复,每个重复6头。处理1组饲喂乌金猪日粮,处理2组饲喂NRC日粮。分别于30、60和100 kg体重时屠宰,通过Real-time PCR比较研究3个脂肪合成代谢相关基因在脂肪组织中表达的差异。结果显示,体重30 kg时,处理1组脂肪酸合成酶(fatty acid synthase,FAS)的相对表达量显著低于处理2组(P<0.05),60和100 kg时,处理1组FAS基因的相对表达量高于处理2组,60 kg时达到显著水平(P<0.05);在各个体重时,处理1组固醇调节元件结合蛋白1c(sterol regulator element binding protein-1c,SREBP-1c)的相对表达量均高于处理2组,30和60 kg时达到显著水平(P<0.05);在各个体重时,处理1组二酰基甘油酰基转移酶1(diacylglycerol acyltransferase-1,DGAT-1)的相对表达量低于处理2组,100 kg时达到显著水平(P<0.05)。提示,不同日粮调控不同体重乌金猪脂类合成代谢相关基因表达存在着差异。     

长白山野猪与杜洛克猪杂交1代猪肌内脂肪代谢酶HSL和MDH活性的发育性变化规律及其对肌内脂肪沉积影响的研究

为了研究长白山野猪与杜洛克猪杂交1代猪肌内脂肪代谢酶激素敏感脂酶（hormone-sensitive lipase,HSL）和苹果酸脱氢酶（malate dehydrogenase,MDH）活性的发育性变化规律及其对肌内脂肪沉积的影响,试验以5个体重组（20、35、50、70和90 kg）的长白山野猪与杜洛克猪的杂交1代猪（简称野杜F1代猪,各40头,公、母各半）为研究对象,研究了肌肉组织中脂肪代谢酶活性的发育性变化规律与肌内脂肪含量和肌肉嫩度的关系。结果表明,在生长期随着体重的增加,肌肉组织中HSL和MDH的活性差异显著（P<0.05）,野杜F1代猪HSL活性均高于莱芜黑猪的活性（90 kg除外）,且在35 kg时,野杜F1代猪和莱芜黑猪差异极显著（P<0.01）;肌肉组织中的MDH活性变化,野杜F1代猪呈先升后降的趋势,活性最高点在70 kg;在90 kg时野杜F1代猪中MDH活性极显著低于莱芜黑猪（P<0.01）。不同体重阶段,肌肉嫩度差异显著（P<0.05）,且随着体重的增加而呈不断升高的趋势。相关分析结果表明,野杜F1代猪90 kg时肌肉组织中MDH活性与肌内脂肪含量呈极显著正相关（r=0.97,P<0.01）,HSL和MDH的活性与肌肉嫩度呈显著正相关（P<0.05）。研究结果提示,肌肉组织中的HSL和MDH对肌内脂肪的沉积量有一定的影响,可以通过控制其活性调节肌内脂肪的含量,且肌内脂肪的沉积量与肌肉嫩度有一定的联系。     

热应激对猪肉品质的影响及其机制的研究进展

在养殖过程中,热应激会影响猪的生理机能,改变猪肉的生化特性,使猪肉品质下降。因此,研究热应激影响猪肉品质变化的规律,对于指导实际生产具有十分重要的意义。作者综述了热应激对猪肉品质的影响,并从机体代谢改变的角度分析了肉质变化的机制,为进一步研究热应激与肉品质的关系提供新的思路。     

屎肠球菌T013复合制剂饲喂生长猪的效果研究

试验旨在研究日粮中添加屎肠球菌T013复合制剂对生长猪的生产性能、粪便微生物、环境指标及血清指标的影响。选用体重在(31.75±3.78)kg的杜×长×大三元杂交仔猪120头,随机分成对照组(基础日粮)、试验Ⅰ组(基础日粮中添加3%屎肠球菌T013复合制剂)和试验Ⅱ组(基础日粮中添加6%屎肠球菌T013复合制剂),每组4个重复,每个重复10头猪,试验期为28 d。结果表明,屎肠球菌T013复合制剂能增加生长猪日采食量和日增重,降低料重比,但差异不显著(P＞0.05),并且能显著减少腹泻率(P＜0.05);试验Ⅱ组能够极显著降低粪便pH和减少大肠杆菌数量,增加乳酸菌数量(P＜0.01);试验组均能够极显著的减少NH₃的排放(P＜0.01);试验Ⅱ组能够显著增加血清IgG含量和减少尿素氮含量(P＜0.05),对总蛋白、白蛋白、白蛋白/球蛋白和葡萄糖的含量无显著影响(P＞0.05)。因此,屎肠球菌T013复合制剂能够降低生长猪的腹泻率,改善肠道微生态环境,减少NH₃ 的排放,增强猪的免疫能力。