表达猪乳铁蛋白肽重组屎肠球菌对断奶仔猪生长性能的影响及其抗ETEC感染效果研究

本试验以表达猪乳铁蛋白肽的重组屎肠球菌（pNZ8112-PLFcin/Ef）饲喂断奶仔猪，研究其对仔猪生长性能的影响和抗产肠毒素大肠杆菌（enterotoxigenic Escherichia coli，ETEC）感染的效果。选取28日龄体重相近的健康断奶仔猪36头，随机分为3组（重组屎肠球菌组、空载体组和培养基组），每组3个重复，每个重复4头仔猪。重组屎肠球菌组和空载体组分别饲喂添加pNZ8112-PLFcin/Ef （6×10¹² CFU/kg）和pNZ8112/Ef （6×10¹² CFU/kg）的基础日粮，而培养基组饲喂含有相同体积的GM17液体培养基的基础日粮。试验期26 d。结果显示，与培养基组相比，重组屎肠球菌组断奶仔猪的平均日增重极显著提高（P<0.01）；料重比显著降低（P<0.05）；腹泻率明显降低，肠道菌群的均匀度和多样性指数均下降。为进一步探究表达猪乳铁蛋白肽的重组屎肠球菌对断奶仔猪抵抗ETEC感染的保护作用，在连续饲喂21 d后，每个重复中随机挑选1头体况相近的断奶仔猪灌服ETEC。结果发现，与培养基组相比，攻菌后重组屎肠球菌组断奶仔猪血清白细胞介素-2（IL-2）、免疫球蛋白G （IgG）含量、肠黏液中分泌型免疫球蛋白A （sIgA）水平均显著升高（P<0.05）；脾脏指数显著提高（P<0.05），但胸腺指数、肠段长度及重量则均无显著差异（P>0.05）。综上所述，表达猪乳铁蛋白肽的重组屎肠球菌能够起到促进断奶仔猪生长及抗ETEC感染的保护作用。     

亮氨酸对早期断奶湖羊瘤胃发育及细菌菌群的影响

本试验旨在研究日粮中添加亮氨酸对早期断奶湖羊瘤胃发育及瘤胃细菌菌群组成的影响。选用36只5日龄的湖羊羔羊,依据体重相近原则随机分成对照组(C,0 g/d)、亮氨酸低剂量添加组(L,0.66 g/d)和高剂量添加组(H,1.33 g/d),每组4个重复,每个重复3只羔羊。于30日龄断奶当天每组每个重复取1只羔羊屠宰以获得瘤胃组织及内容物样品(n=4)。结果表明:H组瘤胃乳头的长度较C组显著增加(线性,P<0.01);添加亮氨酸可使瘤胃挥发性脂肪酸水平显著提高(二次,P=0.05),但并未改变乙酸、丙酸和丁酸的摩尔比例(P>0.05);与C组相比,L与H组的瘤胃氨态氮浓度均显著降低(线性,P<0.05;二次,P>0.05);L组羔羊瘤胃内容物中微生物蛋白含量显著高于C组(二次,P=0.05);亮氨酸的添加并未改变瘤胃细菌物种丰富度和多样性指数,但对菌群组成有一定影响;L组瘤胃内最多的是厚壁菌门(49.5%);H组拟杆菌门(51.4%)显著高L和C组(二次,P=0.05);H组的普雷沃氏菌属最多(线性,P>0.05;二次,P>0.05),而L组的巨型球菌属最多(二次,P <0.01);与C组相比,L组的双歧杆菌属(二次,P<0.05)和光岗菌属显著增加(二次,P<0.05)。由此可见,添加亮氨酸可促进羔羊瘤胃发育,改变瘤胃细菌菌群组成。     

Effect of Dietary Lactobacillus fermentum from Pig on Growth Performance,Nutrient Apparent Digestibility,Faecal Microflora Number and Serum Immune Indices in Weaned Piglets

This experiment was conducted to study the effects of Lactobacillus fermentum on growth performance, nutrient apparent digestibility, faecal microflora number and serum immune indices of weaned piglets.A total of 160 weaned piglets with an average age of (30±2) days and averge body weight of (7.85±0.68) kg were randomly distributed into 4 groups with 4 replicates per group and 10 piglets per replicate feeding basal diet, 0.1%, 0.2%, and 0.3% Lactobacillus fermentum supplementation diets, respectively.The experiment lasted for 35 d.The results showed that, compared with the control group, the average daily gain, the feed conversion ratio, the apparent digestibility of crude protein, calcium and total phosphorusin of Lactobacillus fermentum groups were all increased in varying degrees.The optimum supplemental level of Lactobacillus fermentum should be 0.2%, and at this level, the average daily gain was significantly increased by 8.70% (P<0.05), the F/G was decreased by 4.62% (P<0.05), the apparent digestibility of crude protein, calcium and total phosphorus were significantly increased (P<0.05), the number of faecal E.coli was significantly decreased (P<0.05), and the serum IgG was significantly increased by 8.39% (P<0.05).The results indicated that Lactobacillus fermentum supplementation could improve the immune function, growth performance, the apparent digestibility of crude protein, calcium and total phosphorus and reduce the number of faecal E.coli of weaned piglets.     

复方中草药“强普素”对断乳仔猪血清补体4（C4）的影响

目的：研究复方中草药“强普素”对断乳仔猪血清C4的影响。方法：选择48头平均体重为（8.30±0.94）kg的（28±1）日龄杜×长×大断乳仔猪，按照随机区组设计分为4组，每组2个重复，每个重复6头仔猪（公母各半）。4个组分别为：（1）基础日粮（空白对照组）；（2）基础日粮+0.05%强普素（0.05%强普素组）；（3）基础日粮+0.1%强普素（0.1%强普素组）；（4）基础日粮+0.2%强普素（0.2%强普素组）。结果：添加0.1%和0.2%强普素的试验组仔猪血清C4水平显著高于空白对照组仔猪血清C4水平（P<0.05），添加0.05%强普素的试验组仔猪血清C4水平与空白对照组仔猪血清C4水平差异不显著（P>0.05）。结论：强普素能提高断乳仔猪血清中C4的含量。     

Effect of Dietary Supplementation with Hydrolyzed Wheat Gluten on Growth Performance,Cell Immunity and Serum Biochemical Indices of Weaned Piglets （Sus scrofa）

To investigate the effects of dietary supplementation with hydrolyzed wheat gluten (HWG) on growth performance, cell immunity and serum biochemical indices of weaned piglets, 160 crossed (Large White×Landrace) and weaned piglets were randomly divided into 4 treatments with 4 replicates of 10 piglets each. The piglets in each treatment were fed an experimental diet containing either 0 g kg-1 HWG (control group), 30 g kg-1 HWG (3% HWG group), 50 g kg-1 HWG (5% HWG group), or 2.5 g kg-1 glycyl-L-glutamine (0.25% Gly-Gln group). The results showed that the diarrhea rates in 3% HWG and 5% HWG groups were significantly lower than in control group from d 1 to 14 (P＜0.05), while the average daily gain (ADG) in each of two groups was increased (P＞0.05). When compared with control group, dietary supplementation with 3% HWG increased the ratio of CD4+:CD8+ and the ratio of serum albumin and globulin concentrations (A:G) on d 14 and 28, as well as the proliferation of T- and B-lymphocytes (P＞0.05) on d 28. In addition, on d 14 and 28, the A:G ratio in 5% HWG group was significantly higher than in control group (P＜0.05), while the ratio of CD4+:CD8+ increased slightly (P＞0.05). Interestingly, 0.25% Gly-Gln group had higher proportion of CD3+ (P＞0.05) and CD4+ (P＜0.05) on d 14 than control group, but growth performances of 0.25% Gly-Gln group were negatively affected at all experiment stages. These results suggested that HWG might improve the growth performance of piglets by strengthening cell immunity and decreasing the occurrence of diarrhea during the prophase after weaning.     

冬季暖床对断奶仔猪躺卧行为的影响

为了了解新型局部加热设施——暖床在断奶仔猪舍内的使用情况，本文通过测量挂帘与不挂帘暖床内外的温度和定时观察仔猪在暖床内外的躺卧情况，以分析暖床挂帘与否对仔猪躺卧行为的影响。试验结果表明，当舍内温度维持在13.0℃时，挂帘暖床和未挂帘暖床内部温度分别达到28.6℃和17.9℃；当舍内温度低于9.9℃，仔猪日龄小于48日龄时，超过98.9％仔猪选择挂帘暖床躺卧。随着仔猪日龄的增长，仔猪在挂帘暖床内躺卧比例由98.9％～83.3％下降到35.6％～54.1％，在未挂帘暖床内躺卧比例由15.3％上升到41.1％，表明冬季暖床可为仔猪提供良好的躺卧环境。     

Lysine restriction and realimentation affected growth,blood profiles and expression of genes related to protein and fat metabolism in weaned pigs

To investigate the effects of lysine restriction and subsequent realimentation on growth performance, blood profiles and gene expression of leptin and myostatin, 128 weaned pigs [initial body weight (BW) 6.96 ± 1.07 kg, 26 ± 2 days of age] were randomly allotted to four treatments. The starter diets during the first 2 weeks (P1) contained 100%, 80%, 70% or 60% of recommended lysine levels ( National Research Council, 1998 ). Then, common grower 1 and 2 diets were offered for 2 weeks (P2 and P3) each. During P1, average daily gain (ADG) was linearly reduced (p < 0.05) with the increasing levels of lysine restriction. Growth rate was greater in pigs previously fed lysine‐restricted diets than well‐fed pigs although it did not reach a significant level during realimentation. However, the final BW and overall ADG were the lowest (p < 0.05) and F/G was poor in pigs fed 60% lysine diet. Relative visceral organ weights and composition of skeletal muscle were similar (p > 0.05) among the treatment. Blood triglyceride and glucose levels were increased (p < 0.05) during P1, while blood urine nitrogen, total protein and albumin levels were decreased (p < 0.05) during P2 with the reduction in dietary lysine levels. The abundance of myostatin mRNA in skeletal muscle and leptin mRNA in subcutaneous adipose tissue were lower (p < 0.05) in lysine‐restricted pigs than in pigs fed non‐restricted diets. In conclusion, 80% and 70% lysine restriction of starter diets resulted in inferior growth and compensatory growth effect was noted during realimentation, while 60% lysine restriction had a negative influence on growth performance. Moreover, the changes in myostatin and leptin mRNA abundance caused by nutritional manipulations may be involved in the regulation of protein and fat deposition in young pigs.     

谷氨酰胺二肽的代谢及其在断奶仔猪中的应用

谷氨酰胺二肽是谷氨酰胺和其他氨基酸形成的二肽,因其特有的生物学功能,近年来逐渐受到动物营养学家的广泛关注,国内外许多研究者也开展了谷氨酰胺二肽在动物上的研究工作。笔者就谷氨酰胺二肽的代谢及其对早期断奶仔猪生长性能、能量利用、抗氧化机能等的影响进行了综述。     

复合中草药添加剂对断奶仔猪生长性能的影响

试验旨在研究不同剂量复合中草药添加剂对断奶仔猪生长性能的影响。选取84头(28±1)日龄、体重(8±0.5) kg的"杜×长×大"三元杂交断奶母仔猪,随机分成4组,每组3个重复,每个重复7头猪。试验1组饲喂基础日粮为对照组,试验2、3、4组分别添加2.0、2.5、3.0 g/kg的复合中草药添加剂。结果表明,试验3、4组仔猪平均日增重、平均日采食量显著高于试验1组(P<0.05);试验2、3、4组仔猪料重比、腹泻率显著低于试验1组(P<0.05)。试验3、4组仔猪的血清总蛋白、白蛋白含量显著高于试验1组(P<0.05);试验3、4仔猪血清尿素氮含量、谷丙转氨酶活性显著低于试验1组(P<0.05),试验4组仔猪血清碱性磷酸酶、过氧化氢酶活性显著高于试验1组(P<0.05)。试验4组仔猪血清免疫球蛋白G (IgG)、免疫球蛋白A (IgA)、补体C3、补体C4含量显著高于试验1组(P<0.05)。研究表明,日粮添加3.0 g/kg的复合中草药添加剂能有效提高断奶仔猪生长性能、调节代谢水平、增强免疫功能。     

发酵构树饲料对断奶仔猪生长性能、养分表观消化率和血清生化指标的影响

本试验旨在研究饲粮中不同比例发酵构树饲料对断奶仔猪生长性能、养分表观消化率和血清生化指标的影响。试验选取35日龄、体重为(7.4±1.1)kg的健康断奶仔猪216头,随机分为Ⅰ(对照)、Ⅱ、Ⅲ、Ⅳ组,每组3个重复,每个重复18头仔猪。其中,Ⅰ组饲喂基础饲粮;Ⅱ组饲喂3%发酵构树饲料+97%基础饲粮;Ⅲ组饲喂6%发酵构树饲料+94%基础饲粮;Ⅳ组饲喂9%发酵构树饲料+91%基础饲粮。预试期5 d,正试期25 d。结果表明:1)与Ⅰ组相比,Ⅱ、Ⅲ、Ⅳ组断奶仔猪的腹泻率显著降低(P<0.05),各组间平均日采食量(ADFI)、平均日增重(ADG)和料重比(F/G)无显著差异(P>0.05)。2)与Ⅰ组相比,Ⅱ、Ⅲ、Ⅳ组粗蛋白质(CP)、粗脂肪(EE)、钙(Ca)和磷(P)表观消化率均显著降低(P<0.05)。3)Ⅲ组血清总胆固醇(TC)含量较Ⅰ、Ⅱ、Ⅳ组显著降低(P<0.05);各组间其他血清生化指标无显著差异(P>0.05)。4)各组间血清超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量及总抗氧化能力(T-AOC)无显著差异(P>0.05)。综上所述,饲粮中不同比例发酵构树饲料可以显著降低断奶仔猪的腹泻率,未对生长性能、血清生化指标和抗氧化指标产生不利影响,其中6%的替代比例效果最佳。