不同加工处理大豆产品对早期断奶仔猪的过敏反应、腹泻和粪中大肠杆菌影响的研究

选用72头35日龄断奶仔猪随机分为4组，每组18头，分别喂给4个处理的断奶日粮(脱脂奶粉日粮、膨化全脂大豆日粮、豆粕日粮和膨化豆粕日粮)，每个处理3个重复，检测仔猪皮褶厚度、血清抗glycinin IgG和β-conglycin IgG效价、腹泻、粪中大肠杆菌数及其4个致病性血清型的分类数字。结果表明，与采食其余两个大豆产品日粮的仔猪相比，采食膨化豆粕日粮的仔猪表现了最小的皮褶厚度、最低的血清抗glycinin IgG和β-conglycini IgG效价、最小的粪水含量及最轻程度的腹泻;各处理仔猪采食断奶日粮前后粪中大肠杆菌数无显著变化，但除脱脂奶粉处理组外，其余各处理仔猪采食断奶日粮后粪中致病性大肠杆菌发生了增殖(P<0.01)，增殖程度以膨化豆粕处理为轻(P<0.05);采食断奶日粮后，带致病性大肠杆菌仔猪数比采食断奶日粮前多(P<005);对于大多表现腹泻和某些健康仔猪，其粪中常见的致病性大肠杆菌血清型为O_(149);K_(91)和O(141);K_(85)。     

不同大豆蛋白饲料对仔猪断奶早期的营养效应研究

将20头3周龄断奶的DLY仔猪随机分成4组,断奶后第1周分别饲喂以膨化全脂大豆、膨化豆粕、膨化去皮豆粕和大豆浓缩蛋白为主要蛋白源的全价日粮,第2周开始,所有仔猪均饲喂同一日粮10d,以考察不同大豆蛋白饲料的营养效应。结果表明:4种大豆蛋白饲料对仔猪断奶后第1周生产性能无明显影响,但膨化豆粕能显著改善试验后期及全期仔猪生产性能。第1周膨化豆粕日粮蛋白质利用率显著高于膨化全脂大豆日粮和膨化去皮豆粕日粮(P<0.05)。膨化豆粕较其他大豆蛋白饲料更有利于仔猪断奶早期的氮代谢和提高机体的的免疫机能。综合本试验结果表明,膨化豆粕是3周龄断奶仔猪断奶早期饲粮的适宜大豆蛋白源。     

我国猪营养研究新进展(续)

4 营养、免疫与断奶后腹泻近年来,围绕仔猪断奶后腹泻原因及控制方法的探索,国内学者开始了对营养与免疫关系的研究.李德发等(1993)测定了5个不同脲酶活性的大豆饼粕日粮对35日龄断奶仔猪肠内膜形态、木糖吸收能力和免疫反应的影响.结果表明,脲酶活性与肠绒毛形态及吸收能力密切相关,脲酶活性越低,免疫反应越弱.谯仕彦、李德发(1995,1996)以脱脂奶粉为对照,研究了炒大豆、膨化全脂大豆、膨化豆粕和豆粕等4种不同加工处理的大豆蛋白日粮对35日     

不同温度湿法挤压膨化全脂大豆在仔猪饲料中的应用效果

本试验采用 4个膨化温度处理全脂大豆饲喂断奶前后的仔猪 ,研究不同膨化温度生产的全脂大豆对仔猪生产性能以及腹泻的影响。结果表明 ,断奶前仔猪采食量低 ,其生产性能受母猪泌乳能力影响远远大于日粮因素影响 ;4种膨化全脂大豆日粮可提高断奶后仔猪的生产性能 ,其中以采食 135℃膨化大豆日粮仔猪的生产性能最好 ;与其它 3种膨化大豆日粮相比 ,15 0℃膨化大豆日粮可减轻仔猪过敏反应 ,降低仔猪腹泻 ,与豆粕 +油日粮相比 ,膨化大豆日粮可明显缓减断奶仔猪腹泻     

膨化豆粕与全脂膨化大豆对仔猪生长性能、表观消化率和血清生化指标的影响

试验旨在研究普通豆粕、膨化豆粕和全脂膨化大豆粗蛋白质体外消化率的差异,以及以膨化豆粕和全脂膨化大豆替代玉米-豆粕型基础日粮中部分豆粕对仔猪生长性能、养分表观消化率、血清生化指标的影响。以胃蛋白酶-胰蛋白酶两步消化法测定体外消化率。动物试验选用108头初始体重为（10.10±0.57）kg的42日龄健康杜×长×大仔猪（公母各半）,按区组随机分为3组,每组6个重复,每个重复6头猪。对照组饲喂玉米-豆粕型基础日粮,膨化豆粕组以9.66%膨化豆粕替代对照组日粮中9.66%的豆粕,全脂膨化大豆组以12%全脂膨化大豆替代对照组日粮中9.66%豆粕和2.34%豆油。试验期为28 d。结果表明：膨化豆粕与全脂膨化大豆的体外粗蛋白质消化率均高于普通豆粕（P<0.05）,且膨化豆粕高于全脂膨化大豆（P<0.05）;与对照组相比,膨化豆粕组降低了仔猪耗料增重比（P<0.05）,其他生长性能指标无显著差异;与对照组相比,膨化豆粕组与全脂膨化大豆组均提高了干物质、总能、粗蛋白质、粗脂肪以及有机物的表观消化率（P<0.05）;膨化豆粕组血清中白蛋白含量高于对照组和全脂膨化大豆组（P<...     

不同大豆蛋白质饲料对仔猪断奶早期生长性能的影响

选择18日龄杜长大仔猪(未去势)16窝,按窝平均体重分为4组,每组4个重复,每个重复1窝。参试猪均于21日龄断奶。试验1、2、3、4组仔猪全价饲粮的大豆蛋白源分别为膨化全脂大豆、膨化豆粕、膨化去皮豆粕和大豆浓缩蛋白,各试验组饲粮营养水平一致,重点考察不同大豆蛋白饲料对仔猪断奶后第1周生长性能的影响。试验期为1周。结果表明,试验2组平均日增重为73.36g,与试验3、1、4组相比分别提高27.29%、17.38%和6.50%;料重比为2.05,分别降低45.48%、12.39%和18.33%;腹泻指数为1.33,分别降低60.06%、55.67%和64.53%。虽然统计分析均差异不显著,但可见膨化豆粕在提高仔猪断奶早期生长性能方面优于其它大豆蛋白饲料。     

不同大豆蛋白饲料对仔猪断奶早期的营养效应研究

田刚等（2008）为研究不同大豆蛋白饲料对仔猪断奶早期的营养效应,将20头3周龄断奶的健康杜长大仔猪按体重相近原则随机分为4个处理,每个处理5个重复,每个重复1头猪,在代谢笼内单笼饲养。试验第1阶段,即仔猪22～28日龄时,分别饲喂以膨化全脂大豆、膨化豆粕、膨化去皮豆粕和大豆浓缩蛋白为主要蛋白源的全价饲粮;第2阶段,即仔猪29～38日龄时,     

不同温度膨化全脂大豆对仔猪氮平衡和氨基酸消化率的影响

本试验目的在于检测不同温度下蒸汽膨化的全脂大豆对仔猪氮平衡和氨基酸消化率的影响。2个氮平衡试验共用24头杂交去势公猪,平均体重5.1公斤,21日龄断奶时,在小肠末端手术安装T—形瘘管。所用基础日粮含1.25％赖氨酸,10％豆油。10％葡萄糖和浸提豆粕,利用经110℃、130℃和150℃蒸汽膨化处理的三种全脂大豆,以等氮和等赖氨酸来替代基础日粮中的豆粕,用玉米淀粉补足日粮的百分比。代谢试验室内安有自动控温和通风设备。每个氮平衡试验收集粪尿和食糜样本2期。结果表明,仔猪采食含有在130℃下膨化的全脂大豆日粮后,氮消化率高于(p<0.05)在110℃下膨化的全脂大豆。而经150℃膨化处理的大豆,氮存留量,氮消化率,氮存留量没有进一步的改善,经130℃膨化的全脂大豆其赖氨酸、蛋氨酸和异亮氨酸的回肠表观消化率,高于(p<0.05)经110℃和150℃处理的大豆。但是,苏氨酸、缬氨酸和亮氨酸的回肠末端表观消化率随膨化温度的升高而增加。本试验表明,全脂大豆经130℃蒸汽膨化处理有利于改善仔猪对大豆中赖氨酸、蛋氨酸和异亮氨酸的回肠表观消化率,可以改善氮沉积量和氮存留率,但与优质豆粕相比,效率不显著。     

无鱼粉高效仔猪饲料配方研究

研究用发酵豆粕和膨化大豆提供蛋白营养源,建立无鱼粉仔猪高效饲粮配方。试验选择30日龄断奶三元杂交仔猪240头,按血缘、性别、体重相近的原则分为8组,每组3个重复。在含有等量膨化大豆的日粮中将发酵豆粕设4个梯度,即A1组5%、A2组10%、A3组15%、A4组20%;按等氮替代原则在含有等量发酵豆粕的日粮中,膨化大豆相应设4个梯度,即B1组6.94%、B2组13.88%、B3组20.83%、B4组27.77%,配制成8种仔猪日粮进行饲养试验。仔猪30日龄断奶后即开始试验,试验分前期和后期各2周,至58日龄时结束。结果表明:试验前期,随着发酵豆粕用量的增加,日增重和日采食量有显著提高(P<0.05),料肉比得到改善(P>0.05),腹泻减少;随着膨化大豆用量的增加,日增重和日采食量有下降的趋势(P>0.05),并且膨化大豆用量过高时腹泻加重。试验后期,随着膨化大豆用量的增加,日增重显著提高(P<0.05),料肉比得到改善(P>0.05);随着发酵豆粕用量的增加,日增重呈上升趋势,但差异不显著(P>0.05)。前期筛选出的无鱼粉饲料配方使仔猪日增重为326.03g,料肉比1.34;后期筛选的配方使仔猪日增重为558.77g,料肉比1.40,有生产实用价值。     

日粮中添加乳清粉和膨化豆粕对断奶仔猪生产性能影响

选择30日龄断奶三元杂交仔猪(杜×长×大)64头。随机分成对照组、Ⅰ、Ⅱ、Ⅲ组,对照组饲以基础日粮,试验Ⅰ组日粮以膨化豆粕替代普通豆粕,试验Ⅱ组由3%的乳清粉替代3%的豆粕。试验Ⅲ组中膨化豆粕替代普通豆粕同时由3%的乳清粉替代3%的膨化豆粕。试验结果:对照组培育仔猪需46d,试验Ⅰ组(膨化豆粕组)培育仔猪需40d,试验Ⅱ组(乳清粉组)培育仔猪需43d,试验Ⅲ组(膨化豆粕+乳清粉组)培育仔猪需39d;平均日增重试验Ⅱ组显著高于对照组(P<0.05),试验Ⅰ、Ⅲ组极显著高于对照组(P<0.01),试验Ⅲ组极显著高于Ⅱ组(P<0.01)、显著高于试验Ⅰ组(P<0.05);饲料利用率试验Ⅲ组最高,对照组饲料利用率最差;腹泻率试验Ⅰ组下降了38.13%,试验Ⅱ组下降了34.63%,试验Ⅲ组下降了47.08%。结果表明利用膨化大豆或乳清粉等优质蛋白。调整日粮结构,可显著降低TI等抗营养因子和抗原物质的含量,减少腹泻率,提高生长性能。     

补料及开食料中不同种类蛋白质对仔猪过敏反应及腹泻程度的影响

用３周龄断奶仔猪研究了补料和开食料中不同蛋白料对断奶后的过敏反应和腹泻程度的影响、补饲和开食料中分别以玉米－豆饼、豆饼、醇处理豆饼或乳蛋白为唯一蛋白来源的补料。仔猪７日龄开始补饲，试验至３５日龄结束。结果表明，断奶后保持蛋白来源不变时仔猪的过敏和腹泻程度比改用复合开食料时低，木糖吸收和养分消化率高（Ｐ＜０．０１），但补豆饼组例外；乳蛋白引起的过敏反应最弱，腹泻程度最低，木糖吸收率和养分消化率最高，豆饼引起的腹泻最严重，腹泻开始最早，持续时间最长，木糖吸收率和养分消化率最低，玉米－豆饼和醇处理豆饼引起的腹泻程度居中（Ｐ＜０．０５）；断奶各组３５日龄木糖吸收率极显著高于２８ｍ日龄吸收率（Ｐ＜０．０１），但低于不断奶的对照组相应值（Ｐ＜０．０１）。粪中大肠杆菌计数表明，腹泻程度与微生物增殖无关。由此认为，肠道对日粮抗原过敏是仔猪断奶后腹泻的主要原因；过敏和耐受程度及补饲约影响取决于日粮蛋白质种类。     

Effect of dietary soybean meal on the microscopic anatomy of the small intestine in the early-weaned pig

Two experiments were conducted to determine the effect of soybean meal in postweaning diets on villus height (VH), villus shape and lamina propria depth (LPD) in the small intestine. Intestinal samples were taken at 25, 50 and 75% of the small intestine's length. The first experiment determined the normal effects of age on these structures in nursing pigs from 9 to 36 d of age. Villus height decreased (P less than .01 at the 50 and 75% locations) and LPD increased (P less than .01 at the 25% location) in a quadratic fashion with increasing age. In the second experiment, pigs were weaned at 21 d of age and fed one of three 20% protein diets: 1) protein from hydrolyzed casein (CAS), 2) soybean meal (SBM) or 3) a conventional corn-soybean meal diet (CSBM). Intestinal samples were taken 0, 3, 6, 9, 12 and 15 d post-weaning. Villus height decreased dramatically the first 3 d postweaning, with a continuing decline until 12 d post-weaning. Averaged over the d 3 to 15 interval, VH were generally greater for pigs fed CAS than for pigs fed CSBM or SBM. Pigs fed SBM or CSBM had deformed villi, and pigs fed SBM had greater (P less than .05) LPD at all intestinal locations, suggesting less mature enterocytes on the villi. These data suggest that feeding high concentrations of soybean meal to the pig post-weaning has a detrimental effect on the small intestine, but this effect was minimized when soybean meal was fed as part of a corn-based diet.     

Interrelationship between hypersensitivity to soybean proteins and growth performance in early-weaned pigs.

The objective of this growth trial was to determine the interrelationship between immunological criteria, gut morphology, and performance of starter pigs fed soybean proteins processed by different methods. One hundred twenty-five pigs were orally infused with 6 g/d of either dried skim milk, soybean meal (48% CP), soy protein concentrate, extruded soy protein concentrate, or experimental soy protein concentrate from 7 to 11 d of age and then fed a diet containing the same protein sources from weaning (d 21) to 35 d of age. All pigs were fed a corn-soybean meal diet containing 10% dried whey, 1.25% lysine, and 3% soybean oil for the remaining 21 d of the experiment. Xylose absorption and anti-soy immunoglobulin G (IgG) titers were measured on d 6 postweaning, and skin-fold thickness after intradermal injection of protein extracts was measured on d 7 postweaning. A total of 25 pigs (five pigs/treatment) was euthanatized on d 7 postweaning. Villus height and crypt depth from duodenum samples were measured. These measurements were obtained to elucidate a relationship between the hypersensitivity responses to soybean products and growth performance of baby pigs. Pigs fed diets containing soybean meal had a lower (P less than .05) rate of gain (d 0 to 14) and villus height, higher (P less than .01) serum anti-soy IgG titers, and increased skin-fold thickness (d 6 and 7 postweaning) after intradermal injection compared with those fed dried skim milk. Pigs fed other soy proteins also had lower ADG from d 0 to 14 postweaning; however, pigs fed moist extruded soy protein concentrate tended (P less than .09) to have higher ADG and improved feed utilization when compared with pigs fed soybean meal (d 0 to 14).(ABSTRACT TRUNCATED AT 250 WORDS)     

Apparent ileal digestibility of amino acids and the digestible and metabolizable energy content of dry extruded-expelled soybean meal and its effects on growth performance of pigs

We conducted three experiments to determine the apparent ileal digestibility of amino acids (Exp. 1), metabolizable and digestible energy (Exp. 2), and feeding value (Exp. 3) of dry extruded-expelled soybean meal with (DEH) or without (DENH) hulls compared with solvent-extracted soybean meal with hulls removed (SBMNH). Soybeans used to produce DEH were unadulterated prior to extrusion, but those used for DENH were dehulled prior to extrusion. In Exp. 1, six nonlittermate barrows (initially 39 kg) were fitted with ileal T-cannulas and used in a replicated 3 x 3 Latin square design digestion trial. Experimental diets (0.80% total lysine) were cornstarch-based and contained soybean meal from one of the three different sources as the sole source of lysine. Apparent ileal digestibilies of nutrients were similar (P > 0.10) for DEH and DENH. Apparent ileal digestibilies of CP, Lys, Ile, Leu, Arg, Phe, and Val were greater (P < 0.05) for DEH and DENH than for SBMNH. In Exp. 2, six barrows (initially 41 kg) were fed three corn-based diets containing 25% of one of the three soybean meal sources. A fourth diet was fed at the end of the trial containing all ingredients except soybean meal, so that energy values of the soybean meal could be determined by difference. Digestible energy and ME contents were similar (P > 0.10) for DEH and DENH and both had greater (P < 0.05) DE and ME contents than SBMNH. In Exp. 3, pigs (n = 216, initially 10.6 +/- 1.3 kg and 35 +/- 3 d of age) were blocked by weight and allotted to six dietary treatments. Corn-soybean meal-based diets (0.95% digestible lysine and 3.44 kcal/g ME) containing DEH or DENH were compared with similar diets containing SBMNH or solvent-extracted soybean meal with hulls (SBMH). In addition, a diet containing a second expelled soybean meal with hulls (ESBM) was compared with a diet containing SBMH and soy oil. Growth performance of pigs fed diets containing DEH or DENH was not different (P > 0.10) than that of pigs fed corresponding diets containing SMBH or SBMNH. Pigs fed ESBM had lower (P < 0.05) ADG and G/F compared with its corresponding SBMH and soy oil diet. In conclusion, DEH and DENH are more digestible than conventional soybean meal and can be successfully used in swine diets.     

Effect of Maillard reaction products on ruminal and fecal acid-resistant E. coli, total coliforms, VFA profiles, and pH in steers

Six ruminally cannulated Angus-cross steers (362 kg) were used in a replicated 3 x 3 Latin square design to determine effects of supplementing Maillard reaction products (MRP) on acid-resistant E. coli and coliform populations. Steers were fed roughage-based diets supplemented (DM basis) with either 10% soybean meal (SBM), 10% nonenzymatically browned SBM (NESBM), or 10% SBM top-dressed with 45 g of a lysine-dextrose Maillard reaction product (LD-MRP). Equal weights of dextrose, lysine hydrochloride, and deionized water were refluxed to produce the LD-MRP. The NESBM was manufactured by treating SBM with invertase enzyme, followed by heating to induce nonenzymatic browning. Steers were allowed slightly less than ad libitum access to diets fed twice daily and were adapted to their respective treatments within 10 d. On d 11, ruminal and fecal samples were collected at 0, 2, 4, 6, 8, and 12 h after feeding from each of the steers and transported to the laboratory for microbial analysis. Ruminal samples and feces were analyzed for pH and VFA, and both ruminal fluid and feces were tested for acid-resistant E. coli and total coliforms by incubating samples in tryptic soy broth adjusted to pH 2, 4, and 7. Ruminal pH and total VFA concentrations did not differ among treatments. The molar proportion of ruminal acetate was higher (P < 0.05) for steers receiving NESBM than for steers receiving SBM and LD-MRP. At pH 4, steers that received NESBM had lower (P < 0.05) ruminal populations of E. coli and total coliforms than steers that received SBM. No differences were observed for ruminal E. coli and total coliforms at pH 2 and 7. Fecal pH was lower (P < 0.05) for steers fed NESBM than for steers fed SBM or LD-MRP. Molar proportions of fecal acetate were lower (P < 0.05) and proportions of butyrate and isovalerate were higher (P < 0.05) for steers fed NESBM compared with steers fed SBM. Fecal E. coli at pH 4 was lower (P < 0.05) for steers fed NESBM than for steers fed LD-MRP. Fecal E. coli and total coliforms at pH 2 and 7 did not differ among treatments. Dietary MRP had limited effectiveness at decreasing acid-resistant coliforms in the rumen and feces of cattle. Acid resistance in coliforms may depend on protein availability.     

Measuring suitability of soybean products for early-weaned pigs with immunological criteria

Two trials were conducted to determine the suitability of soybean products for baby pigs. Weanling pigs (n = 40 and 48 in Trials 1 and 2, respectively) were infused orally (6 g/d) with dried skim milk, soybean meal (SBM, 48% CP); soy protein concentrate, moist extruded soy protein concentrate, or soy protein isolate from d 7 to 12 of age. Pigs were then fed a diet containing the same protein source for 1 (Trial 1) or 2 (Trial 2) wk after weaning (d 21 of age). To avoid exposure of pigs to soybean proteins, the dams of pigs were fed a corn-corn gluten meal-based diet supplemented with lysine and tryptophan from d 109 of gestation. All pigs in Trial 1 were killed at 28 d of age, and samples of ileal digesta and small intestine were obtained. In Trial 2, the soy protein isolate was not included, and all pigs were fed a diet containing 4% soybean oil and 1.25% lysine for the last 3 wk of the trial. Growth performance, skin-fold thickness, after intradermal injection of extracts of the corresponding proteins, and anti-soy immunoglobulin G (IgG) titers were measured. Results indicated that pigs fed diets containing SBM had lower (P less than .05) villus height and xylose absorption but higher (P less than .05) serum anti-soy IgG titers and increased skin-fold thickness compared with the mean of pigs given milk and all other soy treatments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of weaning on diarrhea caused by enterotoxigenic Escherichia coli in three-week-old pigs

We attempted to determine whether weaning is required for induction of diarrhea in pigs with postweaning enterotoxigenic Escherichia coli infection. Three-week-old newly weaned pigs and their suckling littermates were inoculated with the K88+ enterotoxigenic E coli strain M1823B. Fourteen of 21 weaned and 12 of 20 suckling pigs were genetically resistant to intestinal adhesion by the K88+ strain of E coli; they remained healthy, and gained weight at similar rates. Both groups of K88-resistant pigs gained weight faster, and shed fewer bacteria of strain M1823B in their feces, than did their K88-susceptible counterparts. Diarrhea developed in K88-susceptible pigs in the weaned (6 of 7 pigs) and suckling (4 of 8 pigs) groups, and 1 of the 4 affected suckling pigs died from complications resulting from diarrhea. The incidences of diarrhea, weight gain rates, and the numbers of strain M1823B shed in feces of susceptible weaned and suckling pigs were not significantly (P greater than 0.05) different. Diarrhea scores of susceptible weaned pigs were significantly (P less than 0.02) higher than those of susceptible suckling pigs on the second day after inoculation. In this experimental model, it was concluded that weaning is not required for induction of diarrhea, but may modestly increase its severity.     

Nutrient digestibility of extruded canola meal in ileal-cannulated growing pigs and effects of its feeding on diet nutrient digestibility and growth performance in weaned pigs

Canola meal (CM) contains less crude protein (CP) and more fiber and anti-nutritional factors such as glucosinolates than soybean meal (SBM) and consequently has a lower nutrient digestibility. Therefore, processing strategies that may increase the feeding value of CM warrant study. In two experiments, the effects of extrusion of Brassica napus CM on apparent (AID) and standardized ileal digestibility (SID) of amino acids (AA), apparent total tract digestibility (ATTD) of gross energy (GE) in growing pigs, and growth performance and diet digestibility in weaned pigs were assessed. Solvent-extracted CM was extruded using a single-screw extruder at three screw speeds: 250 (CM-250), 350 (CM-350), or 450 (CM-450) rpm. In exp. 1, in a double 4 × 4 Latin square, eight ileal-cannulated barrows (initial body weight [BW], 68.1 kg) were fed corn starch-based diets containing 50% CM or extruded CM. The CM sample contained 43.2% CP, 33.2% total dietary fiber (TDF), and 8.9 µmol of total glucosinolates/g on a dry matter (DM) basis. Extrusion increased (P < 0.05) the AID of CP, reduced (P < 0.05) apparent hindgut fermentation of CP, and decreased (P < 0.05) predicted net energy (NE) value of diets. Extrusion increased diet AID and CM SID of most indispensable AA by 3.1 to 5.3%-units. In exp. 2, 200 weaned pigs (initial BW, 8.3 kg) were fed diets containing 20% SBM, CM, or extruded CM starting 2 wk postweaning for 3 wk. The CM sample contained 42.7% CP, 28.3% TDF, and 5.3 µmol total glucosinolates/g DM. Wheat-based diets provided 2.3 Mcal NE/kg and 5.1 g SID Lys/Mcal NE. Dietary inclusion of extruded CM replacing SBM decreased (P < 0.05) diet ATTD of DM, GE and CP, and DE value. Average daily feed intake, average daily gain (ADG), and gain:feed (G:F) of pigs did not differ between extruded CM and SBM diets and were not affected by extrusion, but increasing extruder screw speed linearly increased (P < 0.05) ADG for day 1 to 7 and G:F for the entire trial. In conclusion, extrusion increased diet AID and CM SID of AA but not DE and predicted NE values of CM. However, increasing extruder speed did not further increase the SID of most of the AA of CM in growing pigs. Dietary inclusion of 20% CM or extruded CM did not affect the growth performance in weaned pigs.     

不同粉碎粒度的豆粕对断奶仔猪生长性能和养分消化率的影响

本试验研究不同粉碎粒度的豆粕对断奶仔猪生长性能和养分消化率的影响,选用26～28日龄断奶(7.9±0.7)kg杜×长×大健康仔猪80头,按体重、性别相同原则随机分为4个处理,每处理设5个重复,每个重复4头猪。各个处理组采用相同的日粮组成,对照组饲喂含常规粉碎豆粕(目标粒径为750μm)的日粮,处理1、2、3分别饲喂含目标粒径为150、30、6μm豆粕的日粮。结果表明:使用粉碎粒度低于30μm豆粕的日粮提高了断奶仔猪日增重(P<0.05),明显提高采食量(P>0.05),降低饲料增重比(P<0.05),显著降低断奶仔猪的腹泻频率;使用粉碎粒度低于30μm豆粕的日粮提高断奶仔猪日粮氮、磷表观消化率(P<0.05),改善能量消化率(P=0.063)和有机物表观消化率(P=0.082),显著提高必需氨基酸的表观消化率(P<0.05)。粉碎粒度低于30μm的超微粉碎豆粕可显著提高断奶仔猪日粮蛋白质的消化效率,提高断奶仔猪的生长性能,改善了豆粕作为蛋白质营养源的生物适应性。     

Transient hypersensitivity to soybean meal in the early-weaned pig

An experiment was conducted to determine whether baby pigs develop hypersensitivity to dietary soybean proteins. Thirty-two pigs were orally infused with either dried skim milk (5 g/d; control) or soybean meal (48% CP; 5 g/d) from d 7 to 14 after birth. Sows were fed a corn-corn gluten meal-based diet supplemented with lysine and tryptophan to avoid exposure of pigs to soybean proteins. Pigs were weaned at 21 d of age and fed diets containing either soybean meal or milk proteins until d 56. One half of the pigs were killed at 28 d of age and the rest at 56 d of age. Segments of small intestine were collected, and intraepithelial lymphocytes were isolated. At 28 d of age, pigs fed diets containing soybean meal had lower (P less than .05) villus height (221 vs 298 microns) and rate of gain (86 vs 204 g/d) than control pigs did. Pigs fed a diet containing soybean meal had higher (P less than .05) immunoglobulin G (IgG) titers to soybean protein than did pigs fed a milk protein-based diet. Blood and intestinal lymphocytes collected on d 28 and 56 did not exhibit any proliferative response when cultured with purified soy proteins (2.5 or 5 microns/ml). Phytohemagglutinin- and pokeweed mitogen-induced lymphocyte proliferations were higher (P less than .05) at d 56 than at d 28, but there were no differences attributable to protein source. There were no differences (P greater than .05) in skin-fold thickness measurements following intradermal injection with soy or milk proteins. Decreased villus height and increased serum IgG titers to soybean proteins coinciding with inferior performance of early weaned pigs fed diets containing soybean meal indicate that conventionally processed, commercial soybean meal may retain some antigens that can cause transient hypersensitivity in piglets.