液态复合添加剂对断奶1周内仔猪生长性能、养分消化率及血液指标的影响

本试验旨在研究仔猪断奶1周内补饲液态复合饲料添加剂对其生长性能、养分消化率、消化道p H及血液指标的影响。挑选20日龄仔猪105头,断奶前屠宰5头,其他100头在21日龄断奶后分为对照组和试验组,每组5个重复,每个重复10头猪。对照组仔猪饲喂教槽料,试验组仔猪在每次饲喂教槽料后补喂液态复合饲料添加剂(主要成分为酸化剂、中药提取物、壳寡糖、复合离子调节剂)。试验从断奶当天至断奶后第8天,共计7 d。结果表明:试验组的平均日增重高于对照组(P0.05),腹泻率显著低于对照组(P0.05);试验组粗蛋白和钙的表观消化率较对照组显著增加(P0.05);试验组仔猪断奶后第2天和第8天胃部p H、断奶后第8天十二指肠p H、断奶后第4天回肠p H均显著低于对照组(P0.05),断奶后第4天氯离子含量、断奶后第2天和第8天球蛋白、断奶后第4天和第8天血清Ig G和Ig A含量均显著高于对照组(P0.05),而断奶后第2天血清尿素氮显著低于对照组(P0.05)。由此表明,断奶1周内给仔猪补饲液态复合饲料添加剂,可降低消化道p H,提高养分消化率,并改善机体免疫功能,从而提高仔猪断奶1周内的生长性能,降低仔猪腹泻率。     

复合植物精油对脂多糖刺激仔猪肝脏的保护作用

试验旨在研究复合植物精油(OCT)对脂多糖(LPS)刺激仔猪肝脏的保护作用。选取18头仔猪,随机分为对照组、LPS组和OCT+LPS组,每组6个重复。对照组与LPS组饲喂基础日粮,OCT+LPS组在基础日粮中添加50 mg/kg OCT。试验期21 d。于试验第21天,LPS组与OCT+LPS组仔猪腹腔注射LPS,对照组注射等量的生理盐水,3 h后采血,6 h后屠宰。结果表明:与对照组相比,LPS刺激提高了血浆谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(ALP)、谷酰转肽酶(GGT)、肝脏诱导型一氧化氮合酶(i-NOS)的活力(P0.05),肝脏热休克蛋白70(HSP70)基因的相对表达量显著提高(P0.05);仔猪肝脏表皮生长因子(EGF)、白细胞介素10(IL-10)、胰岛素样因子(IGF-1)、丝氨酸蛋白激酶(mTOR)基因的相对表达量显著降低(P0.05)。在日粮中添加50 mg/kg的OCT,可缓解LPS导致的仔猪血浆ALT、AST、GGT活力的升高以及肝脏i-NOS活力的升高(P0.05),且有缓解LPS导致的仔猪肝脏MPO活力升高的趋势(P0.1),另外可缓解LPS导致的仔猪肝脏HSP70基因相对表达量的升高以及EGF、IL-10、IGF-1、mTOR等基因相对表达量的降低(P0.05)。综上可知,日粮中添加50 mg/kg的OCT可缓解LPS刺激引起的肝脏炎症反应,提高仔猪肝脏细胞的生长和增殖,进而缓解LPS刺激导致的仔猪肝脏氧化应激损伤。     

仔猪黄白痢发病原因及综合防治

仔猪黄白痢是一种由致病性大肠埃希氏菌引起的肠道传染病，长期困扰着养猪业的健康发展。本文就仔猪黄白痢的流行病学、发病原因、症状及综合防治措施进行了综述。     

Factors affecting porcine sperm mediated gene transfer

“Sperm mediated gene transfer” (SMGT) is based on the ability of sperm cells to bind exogenous DNA. The main objective of this study was to improve the production of transgenic pigs by SMGT. Taking into account that there is a lack of repeatability in studies of SMGT and that the mechanism of binding and internalization of exogenous DNA is a question that has not been solved, different factors involved in the production of transgenic animals by SMGT method were evaluated. Here we set out to: (1) evaluate the sperm capacity to bind exogenous DNA after DMSO treatment; (2) determine the location of the transgene–spermatozoa interaction; and (3) evaluate the efficiency of production of transgenic piglets by deep intrauterine artificial insemination (AI) with sperm incubated with DNA. The percentage of DNA binding was higher than 30% after 2 h of co-culture, but it was not affected by sperm treatment with DMSO (0.3% or 3%). The integrity of the sperm plasma membrane plays a critical role in DNA interaction, and altered plasma membranes facilitate interactions with exogenous DNA. DNA bound mainly to spermatozoa with reduced viability. DNA molecules were found to be mainly associated to the post-acrosomal region (61.9%). After deep intrauterine AI a total of 29 piglets were obtained, but none of them integrated the transgene. In conclusion, although it has been confirmed that DNA can associate with boar spermatozoa, the efficiency of producing transgenic pigs by AI was not confirmed by the present experiments, mainly due to a reduced DNA binding to functional spermatozoa.     

酶制剂对仔猪早期断奶后腹泻的影响

选用４４头２８±２日龄断奶的仔猪分为对照组和试验组。对照组饲喂基础日粮,试验组饲喂基础日粮＋０．ｌ%酶制剂。结果表明,试验组与对照组相比,平均日增重提高了５．８８%,平均日采食量降低了４．８４%,料肉比降低了１０．３８%;试验组的腹泻发生率、腹泻频率和死亡率分别降低了４．５５%(Ｐ＞０．０５)、２８．０６%(Ｐ＜０．０５)和６６．６４%(Ｐ＞０．０５);干物质、粗蛋白和粗纤维的消化率分别提高了３．１４%、１６．７７%和４５．１４%。提示日粮中添加酶制剂可弥补仔猪早期断奶后内源酶的降低,提高饲料转化率,促进仔猪生长,降低仔猪腹泻发生率和死亡率。     

Effect of prebiotic or probiotic supplementation and ileo rectal anastomosis on intestinal morphology of weaned piglets

Forty eight 21 days old piglets were used to compare the effect of prebiotic or probiotic supplementation and ileo rectal anastomosis on the morphology of the small intestine. Half of the piglets were maintained intact and the other half was subjected to an ileo rectal anastomosis (IRA). Each group of piglets received one of the following diets: 1) basal diet (C), 2) basal diet supplemented with a Xylo-oligosaccharide (XOS), 3) basal diet supplemented with a Saccharomyces cerevisiae (SC) and 4) basal diet supplemented with XOS and SC. Villus height was greatest with XOS and with XOS + SC, only in the ileum, as compared to controls. In the duodenum, crypt width was highest in the control group, but no significant differences were found in the jejunum and ileum. The IRA piglets had longer villi in the jejunum and shorter villi in the ileum. The crypt depth was greater in the duodenum and in the ileum of IRA piglets. Villus height/crypt depth was lower in the duodenum and in the ileum, in the IRA piglets. In conclusion, the XOS, but not the SC, moderately modified the intestinal morphology. The IRA modified the intestinal villus and crypt architecture but its consequence on the absorption of nutrients needs to be investigated.     

Effects of additional zinc and phytase on zinc availability in piglets and chicks fed diets containing different amounts of phytates

Two maize based diets containing 2.3 g phytic P and 38 mg Zn/kg (P+) or 1.3 g phytic P and 25 mg Zn/kg (P−) were formulated. A third diet (P+/Phytase) was P+ supplemented with 3-phytase (500 FTU/kg). Each of these three basal diets, supplemented or not with 15 mg Zn/kg, was given during 20 days to weaned piglets and to 1-day-old chicks. Chicks fed the P− diets were removed from the data set because of an abnormally low feed intake.

In piglets, added Zn increased bone (P < 0.05) and plasma Zn (P < 0.01) irrespective of the basal diet (basal diet × Zn, P > 0.05). Supplementing P+ with phytase was more efficient in improving these indicators of Zn status than replacing P+ by P−. In chicks, supplemental Zn improved Zn status in a higher extent when added to P+ than to P+/Phytase (basal diet × Zn, P < 0.05). Phytase increased Zn status in a lesser extent than 15 ppm supplemental Zn. More Zn was soluble in gizzard than in stomach which corresponded to the differences in pH (4.2 vs 5.0). Phytase increased soluble Zn in stomach (P < 0.05) but not in gizzard. These results suggest a higher availability of Zn in chicks than in piglets in the absence of phytase. This may explain the higher efficacy of phytase for improved Zn availability in piglets than in chicks.     

Effects of dietary changes on the antibacterial activity of pancreatic juice in weaned piglets

At weaning, low feed intake level is a major factor responsible for gut disorders. However, less is known on adaptation of the antibacterial activity of pancreatic juice in response to variations in feed intake level. Moreover bovine colostrum has been demonstrated to decrease coliform counts in duodenal digesta and to improve health status of weaned piglets. Aims of the present study were to evaluate effects of feed intake level and of a bovine colostrum-supplemented diet on the pancreatic secretion of antibacterial activity in piglets at weaning. At 33 days of age, twenty-eight piglets fitted with two permanent catheters (for pancreatic juice collection and reintroduction) were weaned and allocated to one of the following three dietary treatments for 5 days: low feed allocation with a starter diet (L), gradually increased feed allocation with a starter diet (Ctrl), or gradually increased feed allocation with a starter diet supplemented with bovine colostrum (Col). In Ctrl piglets, the post-weaning secretion of antibacterial activity did not significantly differed from pre-weaning values. The pancreatic secretion of antibacterial activity in L piglets was higher than that in Ctrl piglets at day 5 (+ 300%; P < 0.05). Moreover in Col piglets the secretion of the antibacterial activity tended to increase by 55% (P = 0.08) compared to Ctrl piglets. Variations in the pancreatic secretion of antibacterial activity could constitute an adaptive phenomenon to maintain bacterial homeostasis in the upper small intestine during the early post-weaning period.     

胎儿宫内发育迟缓对新生仔猪小肠组织发育的影响

为研究胎儿宫内发育迟缓(IUGR)对新生仔猪肠道生长发育的影响,比较了初生组(D0)、母乳饲喂3 d组(D3)和母乳饲喂7 d组(D7)3组中正常仔猪和宫内发育迟缓仔猪的小肠长度和重量、组织形态学结构及黏膜DNA、RNA和蛋白质含量。结果显示,初生时,新生正常仔猪小肠总重和黏膜重、RNA和蛋白质含量显著高于IUGR仔猪(P<0.05)。新生IUGR仔猪小肠的肠壁厚度、绒毛高度显著低于正常仔猪(P<0.05);而IUGR仔猪相对于体重的小肠长度极显著高于正常仔猪(P<0.01)。生长至3日龄时,正常猪小肠长度、小肠黏膜重显著高于IUGR猪(P<0.05),小肠总重、肌肉重极显著高于IUGR猪(P<0.01);IUGR仔猪小肠的肠壁厚度、绒毛高度显著低于正常仔猪(P<0.05),而IUGR仔猪相对于体重的小肠长度显著高于正常仔猪(P<0.05)。7日龄时,正常猪的小肠黏膜RNA含量显著高于IUGR猪(P<0.05),其余指标没有显著差别。整个试验结果表明宫内发育迟缓对仔猪小肠组织发育造成不利影响,导致新生仔猪小肠黏膜重量、蛋白质含量、肠壁厚度和绒毛高度的降低;IUGR仔猪的小肠组织生长在出生后1周内能部分实现补偿,而且补偿生长的实现是随着日龄增加逐步完全的。     

仔猪感染猪等孢球虫后T细胞亚群的动态变化

为了研究仔猪感染猪等孢球虫后T细胞亚群的变化规律,应用纯种猪等孢球虫孢子化卵囊人工感染9头6日龄仔猪,分别检测了感染前1d和感染后1、3、6、9、11d(DPI)外周血中CD3 、CD4 、CD8 T细胞。结果显示,DPI3,CD3 、CD4 T细胞增加,之后下降,但差异均不显著(p>0.05);CD8 T细胞在DPI6增加,DPI 9达峰值(P<0.05)。CD4 /CD8 值在DPI 6下降,DPI 11达到最低点。表明DPI 3感染仔猪的免疫功能有所增强,而DPI 8后仔猪免疫功能受到抑制。