饲粮中添加地衣芽孢杆菌和解淀粉芽孢杆菌对断奶仔猪生长性能及血液指标的影响

【目的】研究饲粮中添加地衣芽孢杆菌和解淀粉芽孢杆菌对断奶仔猪生长性能、血常规、血清生化及抗炎抗氧化指标的影响。【方法】选取108头28日龄杜长大断奶仔猪,按体重分为3组,每组6个重复,每个重复6头。对照组饲喂基础饲粮,其余两组分别在基础饲粮中添加1 g/kg地衣芽孢杆菌、1 g/kg解淀粉芽孢杆菌,试验期28 d。在试验第14和28天,空腹称重并计算采食量,每个重复选取2头仔猪,前腔静脉采血并用血细胞分析仪和试剂盒方法测定血常规及血清生化指标。【结果】各组断奶仔猪之间的平均日增重、平均日采食量、料重比均无显著性差异（P＞0.05）。与对照组相比,解淀粉芽孢杆菌组断奶仔猪的腹泻率显著降低（P＜0.05）;地衣芽孢杆菌组和解淀粉芽孢杆菌组断奶仔猪第14天血液淋巴细胞百分含量均显著升高,白细胞介素-2（IL-2）、丙二醛含量及乳酸脱氢酶、谷草转氨酶活性均显著降低（P＜0.05）;解淀粉芽孢杆菌组断奶仔猪第14天血液中碱性磷酸酶活性显著降低,血红蛋白含量显著升高,第28天血液中IL-2含量显著降低,总蛋白、球蛋白含量均显著升高（P＜0.05）。【结论】饲粮中添加地衣芽孢杆菌或解淀粉芽孢杆菌对断奶仔猪生长性能无显著影响,但能够改善仔猪血液指标,保护肝脏功能,且添加解淀粉芽孢杆菌还可以提高仔猪新陈代谢,降低仔猪腹泻率。     

猪瘟母源抗体衰减及保护水平分析

为分析仔猪体内猪瘟母源抗体的衰减规律及母源抗体保护水平,测定了断奶时母猪和仔猪抗体水平,并监测仔猪母源抗体水平至81日龄;分别对12头81日龄仔猪（来自5头母猪）和25头35日龄仔猪（来自5头母猪）进行了攻毒试验,并用RT—nPCR进行了跟踪检测,对7头攻毒耐过猪用兔体中和法测定了中和效价。结果表明,母猪抗体水平不均衡会导致仔猪群体母源抗体水平不均衡;仔猪群体抗体到60日龄时仍然有67％（12／18）的个体用ELISA检测阻断率在50％以上：81日龄攻毒组有3头（3／12）耐过,35日龄攻毒组能全部耐过（25／25）,但有2头（2／25）在攻毒27d后仍然呈PCR阳性,此时中和抗体水平从低于1：4到1：16不等,推测中和抗体水平1：8～1：16是母源抗体保护的临界线。     

纳米氧化锌对断奶仔猪生长性能和肠黏膜屏障的影响

本文旨在研究纳米氧化锌对断奶仔猪生长性能和肠黏膜屏障的影响及其机理。选用96头平均体重为(5.7±0.2)kg的21日龄"杜×长×大"断奶仔猪,随机分成3组:1)对照组,饲喂基础饲粮;2)氧化锌组,饲喂在基础饲粮中添加3 000 mg/kg锌(氧化锌)的试验饲粮;3)纳米氧化锌组,饲喂在基础饲粮中添加300 mg/kg锌(纳米氧化锌)的试验饲粮。每组4个重复,每个重复8头仔猪,试验期14 d。结果表明:1)与对照组相比,纳米氧化锌组断奶仔猪平均日增重提高了7.26%(P<0.05),腹泻率降低了70.82%(P<0.05),但与氧化锌组差异不显著(P>0.05)。2)与对照组相比,纳米氧化锌组仔猪28和35日龄绒毛高度分别提高了12.64%和10.80%(P<0.05);28日龄隐窝深度降低了15.42%(P<0.05);28和35日龄绒毛高度/隐窝深度分别提高了33.61%和17.11%(P<0.05);28和35日龄血浆D-乳酸含量分别降低了28.97%和20.23%(P<0.05),二胺氧化酶活性分别降低了28.61%和24.92%(P<0.05)。氧化锌组和纳米氧化锌组之间各指标差异不显著(P>0.05)。结果提示,断奶仔猪饲粮中添加300 mg/kg锌(纳米氧化锌)可提高平均日增重,降低腹泻率,改善肠黏膜形态,降低肠黏膜通透性,其效果与添加3 000 mg/kg锌(氧化锌)相当。     

Developmental changes in cholesterol 7alpha- and 27-hydroxylases in the piglet

Hepatic cholesterol 7alpha-hydroxylase (CYP7A) and sterol 27 hydroxylase activities were measured in fetal, newborn, suckling, and weaned piglets from 76 d into gestation to 49 d of age. Hepatic CYP7A activity was not detected in fetal microsomes, but it increased to 6.8 +/- 2.6 pmol/min x mg(-1) protein in suckling piglets at 21 d of age and to 18.2 +/- 2.5 in weaned piglets at 49 d of age. Hepatic CYP7A activity was not different between 49-d-old piglets weaned at 21 d and piglets suckled for 49 d (18.9 +/- 2.6 and 18.2 +/- 2.5 pmol/min x mg protein, respectively). Fasting for 14 h decreased CYP7A activity by 86% in both suckled and weaned piglets. Cholesterol 7alpha-hydroxylase activity remained decreased for at least 5 h after refeeding. Sterol 27-hydroxylase activity was also undetectable near birth, but was detectable by 21 d of age. Postnatally, sterol 27-hydroxylase activity was not influenced by age or suckling and weaning, as was CYP7A. Sterol 27-hydroxylase was decreased by 80% in piglets deprived of feed compared with piglets given free access. In contrast to CYP7A activity, 27-hydroxylase activity returned within 5 h after refeeding to levels observed in piglets given ad libitum access to feed. Similar to CYP7A enzyme activity, hepatic CYP7A mRNA was not detected in newborn piglets, but increased from 2.7 +/- 1.7 pg mRNA/microg RNA in suckling piglets at 21 d to 13.7 +/- 1.2 in 49-d-old piglets weaned at 21 d. As with enzyme activity, feed deprivation decreased CYP7A mRNA to barely detectable levels (< .5 pg/microg RNA), and which remained decreased for at least 5 h following refeeding (.6 +/- .3 and 2.67 +/- .4 pg mRNA/microg RNA for suckled and weaned piglets, respectively). In piglets allowed free access to feed, CYP7A mRNA concentrations were associated positively (P = .001) with enzyme activity. These results suggest that developmental regulation of CYP7A activity is the result of a pretranslational mechanism.     

Effects of epidermal growth factor on atrophic enteritis in piglets induced by experimental porcine epidemic diarrhoea virus

Epidermal growth factor (EGF) promotes gastrointestinal mucosal recovery by stimulating the mitogenic activity of intestinal crypt epithelial cells. The aim of this study was to determine the effects of EGF on atrophic enteritis induced in piglets by experimental infection with porcine epidemic diarrhoea virus (PEDV) strain Dr13. Two groups of 12 conventional, colostrum-deprived, 1-day-old, large White-Duroc cross breed piglets were inoculated orally with PEDV (3 x 10(5) 50% tissue culture infective doses), with or without EGF (10 microg/kg/day, intraperitoneally once daily for 4 days after infection) and compared to 12 uninfected, untreated control piglets. PEDV+EGF piglets had less severe clinical signs than PEDV only piglets at 48 and 60 h post-infection (hpi). Histologically, the ratio of villous height:crypt depth of PEDV+EGF piglets was significantly higher than PEDV only piglets at 36 and 48 hpi. Immunohistochemistry for Ki67 demonstrated increased proliferation in intestinal crypt epithelial cells of PEDV+EGF piglets compared to PEDV only piglets at 36, 48 and 60 hpi. EGF stimulates proliferation of intestinal crypt epithelial cells and promotes recovery from atrophic enteritis in PEDV-infected piglets.     

Effects of dietary lysozyme levels on growth performance,intestinal morphology,non‐specific immunity and mRNA expression in weanling piglets

The aim of the present study was to determine the effect of dietary lysozyme levels on growth performance, gut health and non‐specific immunity of weanling piglets. A total of 150 weanling piglets were allocated to six treatments. The piglets were fed the same basel diet supplemented with 0, 30, 60, 90 and 120 mg/kg lysozyme as well as antibiotics for 28 days. From day 14 to day 28 of dietary treatment, piglets fed 90 mg/kg lysozyme had greater average daily gain than piglets fed control diet. During the whole experimental period, piglets fed 120 mg/kg lysozyme tended to have greater average daily gain than piglets fed control diet. Compared with piglets fed control diet, piglets fed diets containing antibiotics and 90 mg/kg lysozyme had greater villus height to crypt depth ratio in duodenum and jejunum. Additionally, dietary supplementation of 60 and 90 mg/kg lysozyme as well as antibiotics enhanced the phagocytic activity of peritoneal macrophages in piglets. In conclusion, dietary lysozyme can accelerate the growth of weanling piglets by improving gut health and non‐specific immunity and supplementing 90 mg/kg lysozyme is as effective as antibiotics (20 mg/kg colistin sulphate + 50 mg/kg kitasamycin) in improving the growth performance of weanling piglets.     

壳聚糖铁对仔猪生长性能及免疫功能的影响

选24头体重相近、日龄相同的健康仔猪随机分为6组:1组为对照组,饲喂基础日粮;2组为壳聚糖组,在基础日粮中添加壳聚糖300 mg/kg;3组为硫酸亚铁组,以硫酸亚铁的形式在基础日粮中添加铁100 mg/kg;4~6组为壳聚糖铁组,以壳聚糖铁的形式分别在基础日粮中添加铁70 mg/kg、100 mg/kg和130 mg/kg,研究壳聚糖铁对仔猪生产性能及免疫功能的影响。结果显示:3~6组仔猪平均日增重显著高于第1组、第2组(P<0.05);第6组仔猪料重比显著低于第1组(P<0.05)。试验至15 d,第5、第6组仔猪外周淋巴细胞转化率显著高于第1~4组(P<0.05或P<0.01);第4组、第5组仔猪血清球蛋白含量显著高于第1组和第3组(P<0.05)。试验至30 d,第6组仔猪外周淋巴细胞转化率显著高于第1、第2组(P<0.05或P<0.01);第3~5组显著高于第1组(P<0.05)。试验至45 d和60 d,第5组、第6组仔猪外周淋巴细胞转化率显著高于第1~3组(P<0.05)。试验至45 d,第5组和第6组仔猪血清球蛋白含量显著高于第1组和第2组(P<0.05)。试验至60 d,第4~6组仔猪血清球蛋白含量显著高于第1组和第3组(P<0.05)。试验表明,壳聚糖铁能显著提高仔猪的生产性能,与硫酸亚铁基本一致;壳聚糖铁能增强仔猪免疫功能,效果要显著优于硫酸亚铁。     

猪瘟病毒持续感染对母猪繁殖性能及仔猪猪瘟疫苗免疫效力的影响

利用来源于同一猪场的2头猪瘟病毒(HCV)持续感染的带毒母猪及所产35头仔猪(包括13头死胎)和6头阴性对照猪,观察母猪的胎儿发育成活状况、仔猪HCV带毒率及HCV垂直传播对仔猪猪瘟兔化弱毒疫苗(HCLV)免疫效力的干扰作用,同时进行水平传播试验和观察HCV持续感染对母猪繁殖功能的影响。结果表明：HCV持续感染对其中1头母猪的胎儿发育和成活有明显影响,而对另1头母猪的胎儿发育没有明显影响;HCV持续感染母猪可经过胎盘垂直传播病毒给仔猪,传播率达45％～86％;吃初乳和接种HCLV不能阻止带毒仔猪的死亡,9头带毒仔猪在45d内死亡4头;免疫HCLV不能使带毒仔猪产生免疫保护力。5头猪在强毒攻击后死亡4头;HCV垂直传播的带毒猪可发生水平传播,并引起3／4感染猪死亡;HCV持续感染可引起母猪生殖系统病理变化。导致繁殖障碍。     

早期断奶转群对仔猪行为、生长性能和血液指标的影响

【目的】 试验旨在研究早期断奶转群对仔猪行为、生长性能和血液指标的影响，探寻适宜的断奶转群模式，为改善仔猪福利水平提供参考。【方法】 选择体况良好、体重相近（6.98 kg±0.63 kg）的21日龄杜×长×大三元杂交仔猪216头（公母各半），随机分为3组，每组6窝，每窝12头。Ⅰ组为对照组，仔猪不断奶不转群；Ⅱ组为断奶转群组，仔猪既断奶又转群；Ⅲ组为断奶非转群组，仔猪只断奶不转群。21日龄时实施早期断奶，试验期14 d。试验期间观察、统计仔猪行为表现、皮肤损伤、死亡率和腹泻率，采集仔猪血液，测定血清皮质醇和免疫指标。【结果】 与对照组相比，Ⅱ和Ⅲ组仔猪采食、休息、玩耍行为极显著下降（P<0.01），探究、独处、哀叫、抱团、攻击和恐人行为极显著上升（P<0.01）。试验处理后第3~5天，Ⅱ组仔猪的皮肤损伤程度极显著高于对照组（P<0.01）；Ⅱ组仔猪35日龄体重和平均日增重显著低于对照组（P<0.05），腹泻率极显著高于对照组和Ⅲ组（P<0.01）。各组仔猪死亡率由低到高的顺序为：Ⅰ组（0）<Ⅲ组（1.32%）<Ⅱ组（4%）。在试验处理当天，Ⅱ组仔猪的皮质醇浓度极显著高于对照组（P<0.01），Ⅲ组皮质醇浓度在等3、5天时极显著高于对照组（P<0.01）而极显著低于Ⅱ组（P<0.01）。Ⅱ和Ⅲ组仔猪在第7天免疫球蛋白A （IgA）和免疫球蛋白G （IgG）浓度极显著低于对照组（P<0.01），白介素-12（IL-12）和干扰素-γ（IFN-γ）浓度与对照组无显著差异（P>0.05）。【结论】 早期断奶转群不仅影响仔猪的行为表现、皮质醇浓度和免疫力水平，而且导致生长性能下降，皮肤损伤程度、死亡率和腹泻率上升，但早期仅断奶不转群仔猪的应激反应相对较低，可减少对仔猪的不利影响。     

表达乳铁蛋白肽的猪源罗伊氏乳酸杆菌对断乳仔猪抗霍乱沙门菌感染的效果分析

旨在分析表达牛乳铁蛋白肽的重组猪源罗伊氏乳酸杆菌pPG-LFCA-E/LR-CO21作为饲用微生态制剂对仔猪促生长与抵抗猪霍乱沙门菌感染的作用。将该重组菌连续饲喂28日龄断乳仔猪21 d,并设立空菌组、对照组以及抗生素组。第21天时对断乳仔猪连续口服感染猪霍乱沙门菌3 d,并设置7 d的观察期;仔猪感染后采集试验组与对照组血清、肠黏液及肠组织。检测结果显示重组菌组仔猪平均日增重与免疫器官指数均显著提高（P<0.05）,料重比极显著降低（P<0.01）。感染猪霍乱沙门菌后,相对于对照组,重组菌组仔猪日增重提高,腹泻率降低;重组菌组仔猪血液中IgG以及肠黏液中IL-4、sIgA的量极显著提高（P<0.01）,IL-2、IL-12、IL-6的量显著降低（P<0.05）;重组菌组仔猪肠道紧密连接蛋白ZO-1、Claudin-1的基因转录水平和TLR4、Myd88和MLCK的基因转录水平极显著提高（P<0.01）,仔猪肠道内猪霍乱沙门菌的数量极显著降低（P<0.01）;重组菌组与抗生素组无明显差异（P>0.05）。以上结果表明,表达牛乳铁蛋白肽的重组猪源罗伊氏乳酸杆菌pPG-LFCA-E/LR-CO21可以提高断乳仔猪的生长性能、促进肠道形态发育、增强肠道屏障功能,并且在一定程度上可以保护仔猪免受猪霍乱沙门菌的感染,表明重组菌作为微生态制剂替代断乳仔猪的饲用抗生素具有一定的应用前景。     

饲粮中添加卵黄抗体对断奶仔猪生长性能、血清生化指标、肠道形态及肠道微生物菌群的影响

本试验旨在研究饲粮中添加卵黄抗体对断奶仔猪生长性能、血清生化指标、肠道形态及肠道微生物菌群的影响。试验选取160头(25±1)日龄"杜×长×大"断奶仔猪,分为4个组,每个组4个重复,每个重复10头猪。各组分别饲喂以下4种饲粮:基础饲粮(对照组)、基础饲粮+0.4 kg/t硫酸黏杆菌素(抗生素组)、基础饲粮+1.0 kg/t卵黄抗体(卵黄抗体组)、基础饲粮+0.2 kg/t硫酸黏杆菌素+0.5 kg/t卵黄抗体(联用组)。试验期共计28 d。结果表明:1)与对照组相比,卵黄抗体组显著提高了断奶仔猪平均日增重(P0.05),显著降低了断奶仔猪料重比和腹泻率(P0.05),断奶仔猪平均日采食量无显著差异(P0.05)。与抗生素组相比,卵黄抗体组断奶仔猪生长性能无显著差异(P0.05),两者表现出相近的使用效果。2)与对照组相比,卵黄抗体组显著提高了断奶仔猪血清中总蛋白、白蛋白的含量(P0.05)。3)与对照组相比,卵黄抗体组显著增加了断奶仔猪回肠绒毛高度和绒隐比(P0.05),断奶仔猪十二指肠和空肠的绒毛高度、隐窝深度和绒隐比无显著差异(P0.05)。4)与对照组相比,卵黄抗体组显著降低了断奶仔猪回肠、盲肠中大肠杆菌数量(P0.05),显著增加了断奶仔猪回肠、盲肠中的乳酸杆菌数量(P0.05)。综上所述,饲粮中添加卵黄抗体能显著改善断奶仔猪生长性能,增强仔猪免疫力,提高肠道健康水平,促进有益菌生长,与抗生素有相近的使用效果,是很有发展潜力的抗生素替代品之一。     

大豆球蛋白和β-伴大豆球蛋白对断奶仔猪的免疫原性试验

选用56头7日龄"杜×长×大"三元杂交仔猪,按体重和性别随机分成7组,每组8头。仔猪经皮下注射进行免疫,其中对照组注射生理盐水0.5mg,试验组分别注射3个剂量(每千克体重100,500和1000μg)的大豆球蛋白(11S)和β-伴大豆球蛋白(7S),21日龄时进行二免。所有仔猪均于22日龄时断奶,在7、21、35日龄经前腔静脉采血,用于免疫指标的测定,同时进行仔猪的皮肤红斑直径试验。结果显示,仔猪对11S和7S的过敏反应呈++,并且7S的免疫原性显著高于11S的免疫原性(P<0.05)。与对照组相比,仔猪每千克体重注射100μg的11S和7S后皮肤红斑直径差异不显著,而每千克体重注射500、1000μg的11S和7S后红斑直径极显著降低(P<0.01),且每千克体重注射500μg和000μg的7S后的红斑直径分别极显著低于注射相应剂量的11S的红斑直径(P<0.01)。每千克体重注射500、1000μg的7S后能极显著提高仔猪的木糖吸收能力(P<0.01),并且能产生有效的抗体效价滴度,但两剂量之间差异不显著(P>0.05)。结果表明,对仔猪进行免疫11S和7S的最适剂量为每千克体重500μg。     

Effects of oral administration of tilmicosin on pulmonary inflammation in piglets experimentally infected with Actinobacillus pleuropneumoniae

OBJECTIVES: To determine the effects of oral administration of tilmicosin in piglets experimentally infected with Actinobacillus pleuropneumoniae. ANIMALS: Forty 3-week-old specific-pathogen free piglets. PROCEDURES: Piglets were assigned to 1 of 4 groups as follows: 1) uninfected sham-treated control piglets; 2) infected untreated piglets that were intratracheally inoculated with 10(7) CFUs of A pleuropneumoniae; 3) infected treated piglets that were intratracheally inoculated with A pleuropneumoniae and received tilmicosin in feed (400 ppm [microg/g]) for 7 days prior to inoculation; or 4) infected treated piglets that were intratracheally inoculated with A pleuropneumoniae and received chlortetracycline (CTC) in feed (1100 ppm [microg/gl) for 7 days prior to inoculation. Bronchoalveolar lavage (BAL) fluid and lung tissue specimens of piglets for each group were evaluated at 3 or 24 hours after inoculation. For each time point, 4 to 6 piglets/group were studied. RESULTS: Feeding of CTC and tilmicosin decreased bacterial load in lungs of infected piglets. Tilmicosin delivered in feed, but not CTC, enhanced apoptosis in porcine BAL fluid leukocytes. This was associated with a decrease in LTB4 concentrations in BAL fluid of tilmicosin-treated piglets, compared with untreated and CTC-treated piglets, and also with a significant decrease in the number of pulmonary lesions. Tilmicosin inhibited infection-induced increases in rectal temperatures, as measured in untreated and CTC-treated piglets. Pulmonary neutrophil infiltration and prostaglandin E2 concentrations in the BAL fluid were not significantly different among groups at any time. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of tilmicosin to infected piglets induces apoptosis in BAL fluid leukocytes and decreases BAL fluid LTB4 concentrations and inflammatory lung lesions.     

Antioxidant capacity and concentration of redox-active trace mineral in fully weaned intra-uterine growth retardation piglets

Background: The redox status of intra-uterine growth retardation(IUGR) piglets post-weaning has been poorly studied.Methods: Newborns from twenty-four sows were weighted, weaned at 21 d and fed a starter diet until sampling.Sampling was done at 14 d post-weaning. A piglet was defined as IUGR when its birth weight was 2 SD below the mean birth weight of the total population. At weaning, eighteen piglets with nearly equal body weight from each category(i.e. IUGR or normal birth weight(NBW) piglets) were selected and then allocated to two treatments,consisted of six replicates with each pen having three piglets.Results: Compared with NBW group, IUGR significantly decreased average daily gain(P 0.001), average daily feed intake(P = 0.003), and feed efficiency(P 0.001) of piglets during the first two weeks post-weaning. IUGR decreased the activities of total antioxidant capacity(P = 0.019), total superoxide dismutase(T-SOD, P = 0.023),and ceruloplasmin(P = 0.044) but increased the levels of malondialdehyde(P = 0.040) and protein carbonyl(P = 0.010) in plasma. Similarly, the decreased activities of T-SOD(P = 0.005), copper- and zinc-containing superoxide dismutase(Cu/Zn-SOD, P = 0.002), and catalase(P = 0.049) was observed in the liver of IUGR piglets than these of NBW piglets. IUGR decreased hepatic Cu/Zn-SOD activity(P = 0.023) per unit of Cu/Zn-SOD protein in piglets when compared with NBW piglets. In addition, IUGR piglets exhibited the decreases in accumulation of copper in both plasma(P = 0.001) and liver(P = 0.014), as well as the concentrations of iron(P = 0.002) and zinc(P = 0.048) in liver. Compared with NBW, IUGR down-regulated m RNA expression of Cu/Zn-SOD(P = 0.021) in the liver of piglets.Conclusions: The results indicated that IUGR impaired antioxidant capacity and resulted in oxidative damage in fully weaned piglets, which might be associated with the decreased levels of redox-active trace minerals. This study highlights the importance of redox status in IUGR offspring and provides a rationale for alleviating oxidative damage by dietary interventions aiming to supplement trace minerals and to restore redox balance in the future.     

饲粮添加银耳多糖对断奶仔猪生长性能和腹泻的影响

试验旨在研究银耳多糖对断奶仔猪生长性能和腹泻的影响。试验选取健康、体重接近的断奶仔猪72头,采用单因素完全随机化设计分为3个处理,即对照组(饲喂基础饲粮)、无抗组(在对照组饲粮基础上饲喂完全不含抗生素的饲粮)和TP组(在无抗组饲粮的基础上补充0.2%的银耳多糖)。每个处理3个重复,每个重复8头猪。试验期24 d。结果表明:与对照组相比,仔猪饲喂无抗饲粮日采食量增加0.95%、日增重增加1.75%、料重比下降了0.98%、腹泻率增加12.54%,但是对断奶仔猪的日采食量、日增重、料重比和腹泻率均无显著影响,表明不添加抗生素未对断奶仔猪生长性能造成负面影响;与无抗组相比,饲粮添加0.2%银耳多糖,仔猪日采食量提高9.76%、日增重提高12.98%、料重比下降2.46%、腹泻率下降17.80%,表明饲粮添加0.2%银耳多糖能够显著提高断奶仔猪的生长性能;与对照组相比,饲粮添加0.2%银耳多糖,仔猪日采食量提高10.80%、日增重提高14.95%、料重比下降3.41%、腹泻率下降7.49%,表明添加0.2%银耳多糖能够显著提高仔猪的生长性能。研究表明,饲粮中不添加抗生素会增加仔猪腹泻率,但未对其他生长性能造成负面影响;添加0.2%银耳多糖能够降低腹泻率、显著提高仔猪生长性能,并且能够替代抗生素发挥作用。     

茶多酚对氧化应激仔猪生长性能和免疫功能的影响

采用Diquat诱导仔猪氧化应激,考察茶多酚(TP)对应激仔猪生长性能和免疫功能的影响。将36头28日龄仔猪按体重相近原则分为3组,每组12头,分别用TP含量为0、500、1 000 mg/kg的日粮预试14 d后,再将每组分成应激组(注射10 mg/kg.BW的Diquat)与非应激组(注射等量生理盐水),饲喂7 d。结果表明:注射Diquat可极显著降低仔猪ADG和ADFI(P<0.01)、升高F/G(P<0.01),提高血液CD8+细胞比例(P<0.01)、降低CD4+细胞及CD4+/CD8+(P<0.01),降低血清IgA(P<0.05)和IgG、IgM(P>0.05),升高血清INF-γ、IL-2(P>0.05)、降低IL-4(P>0.05);而添加TP使应激仔猪的ADG和ADFI升高(P<0.01)、F/G降低(P<0.05),CD4+细胞比例及CD4+/CD8+升高(P<0.01),血清IgG、IgA和IgM升高(P>0.05),IL-2和IL-4提高(P>0.05)、INF-γ下降(P<0.05)。上述结果表明,氧化应激降低仔猪生长性能和免疫功能,添加TP能缓解应激对仔猪生长性能和免疫功能的抑制。     

Effect of introducing piglets from farrow-to-finish breeding farms into all-in all-out fattening batches in Spain on productive parameters and economic profit

A prospective study was conducted to assess the effect of introduction of piglets from farrow-to-finish farms on the global performance of all-in all-out fattening batches in Galicia (NW Spain). Two hundred and thirty-nine fattening batches from 48 fattening farms integrated in a cooperative were used in the study. All-in all-out fattening batches were classified according to the category of farm that supplied the piglets. Origin F was a fattening batch where all feeder piglets came from one or more farrow to feeder units versus origin FF, in case a group of piglets or all piglets of the batch came from farrow-to-finish farms. Productive parameters of fattening batches included in the study were recorded. Crude comparisons of performance of 37 fattening batches from origin F and 202 from origin FF were made. Mixed multiple linear regression models were used to assess the association between type of origin of feeder piglets and the following parameters: feed consumed per market hog, percentage of deaths (mortality) and time to slaughter. In all models, variables with presumable relationships with the outcomes were offered to the models as well as the biologically plausible interaction terms.

Mortality was higher in fattening batches with piglets coming from farrow-to-finish farms (0.67% higher than origin F; P < 0.05). Time to slaughter was longer when feeder piglets were from origin FF (3.1 days longer; P < 0.05).

We found a significant effect of type of origin on feed consumed per marketed hog. Additionally, a significant interaction was found: feed consumed per marketed hog was higher for fattening batches with all piglets from farrow-to-finish farms if slaughtered before 109 days and vice versa. A Monte Carlo simulation model was used to assess the economic impact of using origin F or FF as source of piglets. Results of the model indicated that the difference in expected profit per marketed hog between the types of sources of piglets was small (€11.50, S.D. 1.79 for origin F versus €10.44, S.D. 2.72, for origin FF).     

黄芪多糖对断奶仔猪生产性能的影响

为了分析黄芪多糖对断奶仔猪生产性能的影响,选择28日龄的杜大长三元杂交断奶仔猪108头,公母各半,体重接近。随机分为4组,每组27头,每组3圈,每圈9头。对照组饲喂基础日粮,Ⅰ、Ⅱ、Ⅲ组为试验组,分别在基础饲粮中加入黄芪多糖200、500 mg/kg和1000 mg/kg,试验期28 d。结果表明:含黄芪多糖日粮对仔猪的日增重、营养物质消化率、料肉比及腹泻率均有所改善,添加组与对照组在腹泻率方面差异显著(P<0.05),其中以添加500mg/kg为宜。     

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。     

转基因猪中抗生素标记基因neo漂移风险评估

本试验旨在研究转基因猪中抗生素标记基因neo漂移的可能性。利用Southern blotting鉴定F1代仔猪的显隐性,结果发现6头仔猪中有3头为转基因仔猪,3头为阴性仔猪。通过PCR技术对试验仔猪血液和消化道组织中neo基因进行检测,结果发现neo基因没有在血液水平和消化道组织中发生漂移。通过PCR技术对试验仔猪肠道细菌中neo基因进行检测,在肠道细菌基因组中没有检测到neo基因的存在。检测结果表明,仔猪血液、肠道细菌和消化道组织等都没有发生neo基因的漂移。