饲粮蛋白质水平与早期断奶仔猪组织病理变化的关系

选择３０头２８±２日龄断奶仔猪（平均体重４．５ｋｇ），研究饲粮粗蛋白质（ＣＰ）水平对早期断奶仔猪组织病理变化的影响。试验结果显示：（１）饲粮ＣＰ水平分别与仔猪的ＣＰ摄入量、ＣＰ表观消化率、可消化ＣＰ摄入量、未消化ＣＰ摄入量存在显著（Ｐ＜０．０５）或极显著（Ｐ＜０．０１）的正相关。（２）ＣＰ真消化率则不受饲粮ＣＰ水平的影响，两者的相关关系不显著（Ｐ＞０．０５）。（３）饲粮ＣＰ水平分别与结肠内容物中挥发性盐基氮（ＶＢＮ）和氨氮（ＡＮ）含量存在显著（Ｐ＜０．０５）的正相关。（４）饲粮ＣＰ水平与血浆ＶＢＮ含量存在显著（Ｐ＜０．０５）的正相关；但血浆ＡＮ含量则不受饲粮ＣＰ水平的影响，两者的相关关系不显著（Ｐ＞０．０５）。（５）随着饲粮ＣＰ水平升高，仔猪结肠、肝、肺和肾组织的病变指数增加。试验结果表明，随着饲粮ＣＰ水平升高，仔猪结肠内蛋白质腐败作用增强，腐败产物产量增加，吸收进入体内的腐败产物亦增加；腐败产物的增加使仔猪器官组织的损伤加重     

乳清粉对刚断奶仔猪消化机能的影响研究

本试验研究了不同水平的乳清粉对刚断奶仔猪消化性能的影响。试验根据乳清粉含量（5，10，20％），设3个处理。结果表明：营养物质消化率均随乳清粉水平的提高而提高，其中干物质和粗脂肪均达到显著水平（P＜0．05）；粗蛋白和无氮浸出物消化率均随乳清粉水平提高而呈上升趋势，但差异不显著（P＞0．05）；乳清粉含量由5％升至20％，腹泻率依次降低，但差异不显著（P＞0．05）；粪便大肠杆菌数随乳清粉水平的提高呈下降趋势，差异显著（P＜0．05），各组间乳酸直菌数差异显著（P＜0．05），以含20％乳清粉的处理组最高，与其他两个组比较，差异均达显著水平（P＜0．05）。     

饲粮蛋白质水平对早期断奶仔猪大肠蛋白质腐败作用和腹泻的影响

选５７头２８日龄断奶仔猪（平均体重约４．５ｋｇ），研究饲粮粗蛋白质（ＣＰ）水平对早期断奶仔猪大肠蛋白质腐败作用和腹泻的影响。结果显示：（１）饲粮ＣＰ水平分别与仔猪的ＣＰ、未消化ＣＰ日摄入量，结肠内容物中大肠杆菌、挥发性盐基氮（ＶＢＮ）和氨氮（ＡＮ）含量，以及腹泻指数之间存在显著（Ｐ＜０．０５）或极显著（Ｐ＜０．０１）的正相关。（２）结肠内容物中ＶＢＮ和ＡＮ含量分别与仔猪腹泻指数呈显著（Ｐ＜０．０５）的正相关。（３）饲粮ＣＰ水平分别与盲肠内容物中ＶＢＮ和ＡＮ含量之间的相关关系不显著（Ｐ＞０．０５）。（４）随着饲粮ＣＰ水平的升高，仔猪结肠组织病理变化亦增加。（５）与ＣＰ２０．４％的全植物蛋白型饲粮和ＣＰ１９．２％的复合蛋白型饲粮比较，低蛋白质氨基酸平衡饲粮（ＣＰ１６．５％）可有效地降低仔猪结肠内容物中ＶＢＮ和ＡＮ含量及腹泻指数。试验表明，饲粮ＣＰ水平对结肠蛋白质腐败作用可产生显著的影响。随着饲粮ＣＰ水平的升高，结肠内蛋白质腐败、结肠组织病理变化和仔猪腹泻指数均有增加。平衡饲粮氨基酸使ＣＰ水平降低可减少结肠内蛋白质的腐败和仔猪断奶后腹泻。     

糙米与玉米型饲粮对肉猪饲用价值比较研究

研究了以糙米与玉米分别为主要能量饲料时,2种饲粮对生长育肥猪生产性能、消化代谢、胴体性状及肉品质的影响。结果表明,糙米与玉米型饲粮组生长育肥全期（29kg～90kg）平均日增重分别为715g、703g（P＞0．05）;料重比分别为3．17：1,3．19：1;糙米型饲粮的干物质、有机物质、无氮浸出物、总能的消化率比玉米型饲粮高,其差异达显著水平（P＜0．05）,粗蛋白质、粗脂肪消化率极显著高于玉米型饲粮组（P＜0．01）。糙米型饲粮氮沉积率较玉米型饲粮高22．7％、（P＜0．05）,能量代谢率显著高于玉米饲粮组（P＜0．05）。糙米型饲粮喂猪达上市体重时,其胴体性状及肉品质指标与玉米型饲粮差异不显著（P＞0．05）。     

泌乳母猪饲粮适宜赖氨酸水平的初步研究

将30头大长北经产母猪随机分为3组，产后饲喂0．60％（I组），0．80％（II组），1．00％（III组）3种赖氨酸水平的泌乳期饲粮，研究饲粮赖氨酸水平对泌乳母猪生产性能及血液，奶生化指标的影响，结果表明，增加饲粮赖氨酸浓度对哺乳21天的母猪体重，采食量，断奶至再发情天数（P＞0．10）和21日龄的平均窝仔数，仔猪腹泻率无显著影响（P＜0．05），21日龄仔猪窝重随着饲粮赖氨酸浓度的增加而显著增加（P＜0．06），初生至7日龄（P＜0．06），14日龄（P＜0．03）和21日龄（P＜0．01），的窝增重均随饲粮赖氨酸浓度增加而增加，产后14天猪乳蛋白II组，III组极显著（P＜0．01）高于I组；固形物含量II组显著（P＜0．05）高于I组，产后21天猪乳固形物含量II组显著（P＜0．05）高于I组，泌乳期母猪血清尿素氮[浓度I组显著（P＜0．05，泌乳14天），极显著（P＜0．01，泌乳21天）高于II组，III组；白蛋白浓度II组显著（P＜0．05），高于I组，从本次试验的结果看出，在生产条件下，大长北母猪泌乳期饲粮赖，氨酸水平以0．80－1．00％为宜。     

饲料蛋白质水平和组成对早期断奶仔猪腹泻和生产性能的影响

选用18头早期断奶杂交仔猪研究了饲粮蛋白质水平和组成对早期断奶仔猪腹泻和生产性能的影响。经30 d的饲养试验结果表明两个低蛋白氨基酸平衡饲粮(CP17％)组仔猪平均日增重显著高于高蛋白饲粮(CP 20％)组(P＜0.01)，断奶10 d内的腹泻频率显著降低(P＜0.01)，而且腹泻的发生主要集中在断奶10 d内；在粗蛋白均为17％且氨基酸平衡的条件下，饲粮蛋白质组成不同(植物蛋白分别占总饲粮蛋白90.5％和84.0％)对仔猪腹泻和平均日增重没有显著影响(P＞0.05)。结果证明通过平衡饲粮氨基酸降低蛋白质水平，可以有效地降低仔猪断奶后腹泻和提高生产性能。     

豆油和油脂粉对断奶仔猪生产性能的影响

试验豆油及HTL316脂肪粉对早期断奶仔猪的添加效果。选择28日龄体质量为（6．6±0．51）kg的断奶仔猪150头，分为3组，分别饲喂3种饲粮：对照日粮（组1）、对照日粮＋豆油（组2）、对照日粮＋HTL316（组3）。试验分3期。试验结果表明，在断奶后0～10、11～22、23～38、0～38d，组3的平均日增质量比组2分别提高12．9％（P〈0．05）、5．4％（P〉0．05）、10．6％（P〈0．05）、6．6％（P〉0．05），料肉比分别降低9．7％（P〉0．05）、8．0％（P〉0．05）、10．1％（P〈0．05）、7．0％（P〉0．05）。在断奶后0～10d，组3的有机物消化率、粗脂肪消化率及总能消化率分别比组2提高11．08％、10．89％和11．31％，差异均显著。在断奶后23～38d，组3的有机物消化率和粗脂肪消化率显著高于组2。在断奶后0～10、11～38和0～38d，组3的增质量饲料成本比组2分别低0．46、0．35和0．37元／kg。结论是断奶仔猪日粮中添加HTL316可提高生产性能，降低饲养成本。     

断奶仔猪赖氨酸需求参数的研究

试验选取体重约８千克的杜×大×长三元杂交断奶仔猪（公母各半）７２头，随机分为６组，每组２个重复，每个重复６头猪，分别喂以含赖氨酸（Ｌｙｓ）水平为０．８５，０．９５，１．０５，１．１０，１．１５，１．２０％的饲粮。通过测定饲粮Ｌｙｓ水平对断奶仔猪生产性能和血清氮浓度的影响，探讨断奶仔猪Ｌｙｓ的需求参数。结果表明，随着饲粮中Ｌｙｓ水平的提高，仔猪的平均日增重增加，饲料转化率显著改善（Ｐ＜０．０５），并且在１．１５％的Ｌｙｓ组生产性能达到最佳，进一步提高Ｌｙｓ水平，生产性能反而下降。各组采食量差异不显著（Ｐ＞０．０５）。当饲粮Ｌｙｓ水平由０．８５％升至１．１５％，血清氮浓度无显著差异（Ｐ＞０．０５），但１．２％组极显著地高于其他各组（Ｐ＜０．０１），反映该组猪对蛋白质利用较差，这与该组猪生产性能差相符。以上结论提示，８～１９千克断奶仔猪Ｌｙｓ需求参数为饲粮的１．１５％，按ＡＥＣ（１９８９）有关饲料Ｌｙｓ可消化率数据，折算其相应真可消化和表观可消化Ｌｙｓ为１．０３２％和０．９６７％。     

日粮中添加不同水平的乳糖及海藻提取物对断奶仔猪生产性能的影响

试验采用3×4设计来考察日粮中添加乳糖和海藻提取物（来源于海带属．主要成分为昆布多糖和岩藻依聚糖）对断奶仔猪生产性能和养分消化率的影响。乳糖添加量分别为60、150和250g／kg，海藻提取物添加量分别为0、1、2和4g／kg。试验选择24日龄、7．5±1kg断奶仔猪384头，按体重随机分为12个处理组（每个处理组8个重复）。结果表明，试验全期（0～21d）．乳糖X海藻提取物互作对断奶仔猪日增重（ADG）影响显著．当低和中等乳糖添加组13粮中海藻提取物的添加量增加到2g/kg时．断奶仔猪日增重显著增加（P〈0．05）。然而．当高乳糖组日粮中海藻提取物的添加量增加到lg／kg以上水平时．断奶仔猪日增重没有进一步提高。在试验期间．乳糖×海藻提取物互作对断奶仔猪饲料转化率（FCR）影响显著（P〈0．05）。当低乳糖添加组日粮中海藻提取物的添加量增加到4g／kg时．断奶仔猪饲料转化率极显著增加（P〈0．01）。当中等乳糖添加组日粮中海藻提取物的添加量增加到2g／kg时．断奶仔猪饲料转化率显著增加。但是．在高乳糖添加组13粮中增加海藻提取物的添加量对断奶仔猪饲料转化率没有影响（P〉0．05）。在整个试验期间．随着日粮中海藻提取物添加量的增加．断奶仔猪平均日采食量（ADFI）呈线性增加（P〈0．05）。随着日粮中乳糖添加量的增加．断奶仔猪对灰分的消化率呈线性增加（P〈0．01），氮（N）和中性洗涤纤维的消化率呈二次曲线规律下降（P〈0．01）。总之，在每个不同乳糖水平日粮中添加海藻提取物水平不同对断奶仔猪的影响效果不同。在饲粮中添加高浓度乳糖（60g/kg）或海藻提取物可通过提高养分消化率来提高断奶仔猪的日增重和饲料转化效率．也可以减轻仔猪断奶后发生的一些常见问题．     

赖氨酸螯合铁在母猪日粮中的应用

分别进行了用赖氨酸螯合铁和硫酸亚铁饲喂妊娠、哺乳期母猪、用葡萄糖铁给初生仔猪补铁的试验。结果表明，饲喂赖氨酸螯合铁组母猪所生仔猪比对照组母猪所生仔猪断奶成活率高9．2个百分点（P＜0．05），平均断奶重高18．8％（P＜0．01）；比饲喂硫酸亚铁组母猪所生仔猪断奶成活率高3．1个百分点（P＞0．05），平均断奶重高9．9％（P＜0．05）；与给3日龄仔猪注射葡聚糖铁相比，成活率和断奶重分别提高0．2个百分点和2．3％（P＞0．05）。     

Effects of Different Dietary Crude Protein Levels on the Nutrient Absorbability in the Small Intestine of Lambs

This experiment was conducted to study the effects of different dietary crude protein levels on the nutrient absorbability in the small intestine of lambs.Three Kazakh lambs (30 kg body weight) fitted with permanent ruminal,duodenal and ileal fistula were selected.3×3 Latin square design was adopted.A dual-phase marker system with LiCr-EDTA and Yb-Ac as the liquid-phase or particulate-phase digesta flows maker was adopted to measure the true digesta flows at duodenal and ileal fistula,respectively.The results showed that nitrogen intake,total tract apparent digestibility,N deposition,the apparent digestibility of dry matter and organic matter were significantly increased with increasing levels of dietary crude protein (P<0.05),but had no significant effects on intestinal digesta flows (P>0.05).Increasing dietary crude protein levels had significant effects on most part of nutrients of duodenal digesta except fat and purine (P<0.05),while it only significantly effected CP,Ash,dry matter,neutral detergent fibre and acid detergent fiber of ileal digesta flows (P<0.05).In addition,intestinal absorbability of nutrients except for CP,Ash,dry matter,neutral detergent fibre and acid detergent fiber were significantly affected with increasing levels of dietary crude protein(P<0.05).The test provided basis for further study of the effects of dietary CP level on the digestibility and utilization of lamb.     

不同粗蛋白质水平日粮对育肥羊小肠养分吸收率的影响

本研究旨在比较不同粗蛋白质（CP）水平日粮对育肥羔羊小肠养分吸收率的影响。选用体重30 kg左右,安装有瘤胃、十二指肠近端和回肠末端瘘管的3只哈萨克育肥羊为试验动物,采用3×3拉丁方试验设计,采用醋酸镱（Yb-Ac）、锂铬乙二胺四乙酸（LiCr-EDTA）分别作为消化道固相和液相食糜标记物测定小肠食糜流量。结果显示,增加全混合日粮中CP水平可显著提高育肥羊N的进食量、全消化道表观消化率和N沉积（P<0.05）,显著提高干物质（DM）和有机物（OM）的表观消化率（P<0.05）,但对小肠食糜流量无显著影响（P>0.05）;提高日粮CP水平对十二指肠食糜除EE和嘌呤外的营养成分流量均产生显著的影响（P<0.05）,仅对回肠食糜中CP、粗灰分（Ash）、DM、中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）流量的影响显著（P<0.05）,且对CP、Ash、DM、NDF和ADF的小肠吸收率影响显著（P<0.05）。本试验为进一步深入分析增加日粮CP水平对其在育肥羊体内的消化利用奠定基础。     

饲粮不同粗蛋白质水平对育肥羔羊小肠氨基酸流量及吸收率的影响

本研究旨在比较饲粮不同粗蛋白质(CP)水平对育肥羔羊小肠氨基酸(AA)流量及吸收率的影响。选用体重(30.0±3.7)kg,安装有瘤胃、十二指肠近端和回肠末端瘘管的3只哈萨克羊公羔为试验动物,采用3×3拉丁方试验设计,各处理饲粮CP水平分别为11.00%、12.00%和13.00%;预试期10 d,正试期10 d。采用镱锕(Yb-Ac)、锂铬乙二胺四乙酸(Li Cr-EDTA)分别作为消化道固相和液相食糜标记物测定小肠食糜流量。结果表明:提高饲粮CP水平可增加羔羊氮进食量、表观消化率和氮沉积,13.00%CP处理显著高于11.00%CP处理(P0.05),并有增加饲粮干物质(DM)、有机物(OM)和中性洗涤纤维(NDF)表观消化率的趋势(0.05≤P0.10),但不影响酸性洗涤纤维(ADF)的表观消化率(P0.05)。提高饲粮CP水平虽然对小肠真食糜流量及氨基酸吸收率无显著性影响(P0.05),但十二指肠氮、总氨基酸(TAA)流量以及必需氨基酸(EAA)中精氨酸(Arg)、组氨酸(His)和赖氨酸(Lys)的吸收率在数值上有所增加。结果显示,提高饲粮CP水平有提高消化率、小肠食糜流量及氨基酸吸收率的潜在趋势。     

Determination of true ileal amino acid digestibility and the endogenous amino acid outputs associated with barley samples for growing-finishing pigs by the regression analysis technique

This study was conducted to determine true ileal AA digestibility coefficients and the endogenous AA outputs associated with barley samples for growing-finishing pigs using the regression analysis technique with dual digestibility markers. Six barrows, with 30.5 and 58.6 kg average initial and final BW, were fitted with a simple T-cannula at the distal ileum and fed six barley-based diets at close to ad libitum feed intake according to a 6 x 6 Latin square design. The six diets contained 97% of six barley samples varying from low to high in CP and AA contents (8.5, 9.2, 9.8, 11.5, 12.6, and 15.6% CP, respectively, on DM basis). The dietary NDF content ranged from 16.8 to 23.8% on DM basis. Chromic oxide (Cr2O3) and acid-insoluble ash (AIA) were used as digestibility markers. Each experimental period lasted 7 d. Ileal digesta were collected, at 2-h intervals, for a total of 24 h during d 6 and 7. There were linear relationships (P < 0.01) between dietary contents of apparent ileally digestible and total CP and AA as determined by using either Cr2O3 or AIA as a digestibility marker. The use of Cr2O3 vs AIA affected (P < 0.01) the determination of true ileal AA digestibility coefficients and the endogenous CP and AA outputs. However, there were no differences (P > 0.01) in the true ileal AA digestibility coefficients in barley samples between this study and the average values reported in the literature. The endogenous CP and AA outputs determined in this study were higher (P < 0.01) than reported values (35.1+/-3.0 vs 14.7+/-1.1 g CP/kg DMI). It is concluded that dual digestibility markers should be used to measure true ileal AA digestibility coefficients and endogenous AA outputs when dietary fiber content is high and the ileal digesta is collected through a simple T-cannula in the pig. True rather than apparent ileal AA digestibility coefficients determined in barley samples should be used in diet formulation for swine. The gastrointestinal endogenous AA secretion, recycling, and output losses are important in whole-body AA utilization and homeostasis, especially when fiber-enriched diets are fed to growing-finishing pigs.     

水貂不同赖氨酸、蛋氨酸水平颗粒饲料对营养物质消化代谢的影响

为确定水貂适宜氨基酸组成、降低饲料成本,试验选取成年健康公母水貂各60只,随机分成6组,采用2×3因子试验设计,即赖氨酸2个水平,分别为1.85%和1.7%,蛋氨酸3个水平分别为0.81%、0.99%和1.24%,对采食正常试验组水貂进行了消化代谢试验。结果表明:①日粮赖氨酸水平的变化对公母貂干物质摄入、排出及消化率影响不显著(P>0.05);蛋氨酸水平的变化对母貂干物质摄入、排出及消化率影响不显著(P>0.05),公貂粪干物质排出量蛋氨酸水平为0.99%组显著低于蛋氨酸水平为1.24%组(P<0.05),公貂干物质消化率蛋氨酸水平为0.99%组极显著地高于蛋氨酸水平为0.81%组和1.24%组(P<0.01)。②日粮赖氨酸水平的变化对公母貂有机物摄入、排出及消化率影响不显著(P>0.05);蛋氨酸水平的变化对公母貂有机物摄入、排出及母貂消化率影响不显著(P>0.05),公貂蛋氨酸水平为0.99%组有机物消化率显著高于蛋氨酸水平为0.81%组(P<0.05),与蛋氨酸水平为1.24%组差异不显著(P>0.05)。③公母貂蛋白质消化代谢受赖氨酸水平变化的影响不显著(P>0.05);公母貂蛋白质摄入及粪蛋白的排出受蛋氨酸水平变化影响不显著(P>0.05),蛋氨酸为1.24%时公貂尿蛋白排出显著高于0.99%水平组(P<0.05),与0.81%水平组尿蛋白排出差异不显著(P>0.05);公貂蛋白存留0.99%水平组极显著高于1.24%水平组(P<0.01);公貂蛋白质消化率0.99%水平组显著高于1.24%水平组(P<0.05),与0.81%水平组差异不显著(P>0.05);母貂蛋氨酸水平变化对各消化代谢率指标影响不显著(P>0.05)。④1.85%赖氨酸水平组公貂赖氨酸摄入、尿排出及消化代谢率均显著高于1.7%赖氨酸水平组(P<0.05),母貂间差异不显著(P>0.05),赖氨酸水平对公母貂蛋氨酸摄入、粪尿排出及消化代谢率无显著影响(P>0.05);蛋氨酸水平对公母貂赖氨酸摄入、粪尿排出无显著影响(P>0.05),蛋氨酸0.99%水平公貂赖氨酸消化代谢率均极显著高于蛋氨酸1.24%水平和0.81%水平公貂(P<0.01),蛋氨酸水平对母貂间赖氨酸消化代谢率无显著影响(P>0.05);蛋氨酸水平对公母貂蛋氨酸摄入、粪尿排出及消化代谢率均有显著影响(P<0.05),随着蛋氨酸水平的降低,蛋氨酸的摄入逐渐降低,而尿排出蛋氨酸1.24%组显著高于0.99%和0.81%水平组(P<0.05);蛋氨酸0.99%和1.24%水平组公母貂蛋氨酸的消化代谢率均极显著高于0.81%水平组(P<0.01),蛋氨酸0.99%和1.24%水平组公母貂蛋氨酸的消化代谢率无显著差异(P>0.05)。     

Effects of increasing crude protein level on nitrogen retention and intestinal supply of amino acids in lambs fed diets based on alkaline hydrogen peroxide-treated wheat straw.

The effects of increasing dietary CP level on N retention (Exp. 1) and intestinal supply of amino acids (AA; Exp. 2) were studied in lambs fed diets based on alkaline hydrogen peroxide-treated wheat straw (AHPWS). Soybean meal (SBM) was substituted for corn to increase CP level in both experiments. In Exp. 1, an incomplete design for the two-way elimination of error was used to allot 24 ram lambs (mean BW = 25 kg) within breed to six CP levels (6, 8, 10, 12, 14, and 16% of DM). Neutral detergent fiber digestibility and N retention increased quadratically (P = .06 and P less than .01, respectively) with increasing CP level. Nitrogen retention, expressed as a percentage of N intake, was greatest for lambs fed 12% CP (20.7%) but was greatest for lambs fed 14% CP when expressed as grams per day (4.0 g/d). In Exp. 2, five multicannulated St. Croix lambs (34 kg) were used in a 5 x 5 Latin square design. Treatments were 8.5, 11, 13.5, 16, and 18.5% dietary CP. Chromic oxide was used as a digesta flow marker and purines were used as a bacterial marker. Protein level had no effect on extent of dietary CP degradation in the rumen (69 +/- 3.2%). True ruminal OM digestibility increased (P less than .01) linearly and ruminal fluid NH3 N concentration increased (P less than .01) quadratically with increasing CP level. Total, bacterial, and nonbacterial N and AA flows to the duodenum increased (P less than .05) linearly with increasing CP level. Duodenal AA profile (g/100 g total AA) was altered slightly. The essential AA valine, isoleucine, phenylalanine, lysine, and arginine increased (P less than .05) and methionine decreased (P less than .05) in proportion to other AA with increasing CP level. Flows of all essential AA increased with increasing CP level. Apparent small intestinal N and AA disappearance increased linearly (P less than .05) and apparent total tract N digestibility increased (P less than .01) quadratically with increasing CP level. These data are interpreted to indicate that maximal N retention and fiber digestibility in diets based on AHPWS are obtained at 12% CP, even though the intestinal supply of AA continues to increase with increasing CP level. Supplementation of diets based on AHPWS with an extensively degraded protein source (SBM) does not substantially alter the profile of AA entering the duodenum compared to the AA profile of bacterial protein.     

The influence of soy oligosaccharides on apparent and true ileal amino acid digestibilities and fecal consistency in growing pigs

Fourteen ileally cannulated pigs (BW = 35 +/- 2 kg) were randomly allotted to a replicated 7 x 7 Latin square design experiment to evaluate the influence of the soybean oligosaccharides (OS), raffinose and stachyose, on ileal nutrient digestibility and fecal consistency. Semipurified diets containing soy protein concentrate (SPC) or soybean meal (SBM) as the sole protein sources were fed. Soy solubles (SS), a by-product of SBM processing containing 3.5% raffinose and 11.5% stachyose, were used to increase dietary raffinose and stachyose concentrations. The seven dietary treatments were SPC, SPC + 9% SS, SBM, SBM + 9% SS, SBM + 18% SS, SBM + 24,000 U alpha-galactosidase enzyme preparation/kg diet, and a low-protein casein (LPC) diet used to calculate true digestibility. Diets, with the exception of the LPC diet, were formulated to contain 17% CP. All diets contained 0.5% chromic oxide as a marker for ileal digestibility determination. The experimental periods were divided into a 5-d diet adaptation followed by 2-d of ileal digesta collection. Diets and digesta were analyzed for DM, N, Cr, amino acids (AA), raffinose, and stachyose. Fecal consistency was determined on d 6 and 7 of each experimental period. The apparent and true ileal AA digestibilities were not different (P < 0.05) for the SPC and SBM control diets. When SS was added to the SPC diet, apparent and true N and AA digestibilities were depressed (P < 0.05) with the exception of Trp and Pro. The apparent and true ileal N and AA digestibilities were not different (P > 0.05) between the SBM control and SBM + 9% SS diets with the exception of Glu. There was a linear decrease (P < 0.05) in apparent and true DM, Val, Gly, and Tyr digestibilities when increasing levels of SS were added to the SBM diet. The addition of alpha-galactosidase did not improve apparent or true ileal N or AA digestibilities except for apparent and true Val and Tyr. Ileal raffinose digestibility was improved (P < 0.05) by addition of a-galactosidase, but was not affected by any other dietary treatment. Ileal stachyose digestibility was not affected (P > 0.58) by treatment. Fecal consistency likewise was not affected (P > 0.36) by dietary treatment. In conclusion, soy OS reduced nutrient digestibilities, but the reductions were small, ranging from approximately 1.1 to 7.4 percentage units. This suggests that other factors may be negatively impacting SBM digestibility.     

饲粮蛋氨酸添加水平对断奶至3月龄獭兔生长性能、免疫功能及血清生化指标的影响

本文旨在探讨饲粮蛋氨酸添加水平对断奶至3月龄獭兔生长性能、免疫功能及血清生化指标的影响。选用30日龄断奶生长獭兔200只,随机分成5组,每组40个重复,每个重复1只兔。各组分别饲喂在基础饲粮中添加不同水平(0、0.15%、0.30%、0.45%、0.60%)蛋氨酸的试验饲粮。预试期7 d,正试期53 d。结果表明:1)饲粮蛋氨酸添加水平对平均日采食量影响不显著(P>0.05);对平均日增重影响显著(P<0.05),在0.45%添加组时达到最大值16.76 g/d;对料重比影响极显著(P<0.01),在0.45%添加组时达到最小值3.55。2)饲粮蛋氨酸添加水平对摄入氮、粪氮、尿氮、可消化氮、沉积氮、氮表观消化率、氮利用率和氮生物利用率均无显著影响(P>0.05)。3)饲粮蛋氨酸添加水平对血清免疫球蛋白A、免疫球蛋白G和免疫球蛋白M含量均无显著影响(P>0.05)。4)饲粮蛋氨酸添加水平对血清总蛋白、白蛋白、甘油三酯含量及碱性磷酸酶活性均无显著影响(P>0.05),但极显著影响血清尿素氮含量(P<0.01),其中0.30%和0.45%添加组极显著低于0和0.15%添加组(P<0.01),在0.45%添加组时达到最小值5.70 mmol/L。综合考虑本试验所测指标,断奶至3月龄獭兔的蛋氨酸适宜添加水平为0.45%(饲粮总蛋氨酸水平为0.68%)。     

Practice on improving fattening local cattle production in Vietnam by increasing crude protein level in concentrate and concentrate level

Two experiments were conducted to determine the effects of crude protein (CP) level in concentrate (experiment 1) and concentrate level (experiment 2) on feed intake, nutrient digestibility, nitrogen (N) retention, ruminal pH and NH₃-N concentration and average daily gain (ADG) of Vietnamese local fattening cattle. Animals (24 cattle, initial live weight (LW) 150.3?±?11.8 kg in experiment 1 and 145.1?±?9.8 kg in experiment 2) were allotted based on LW to one of four treatments in a randomised complete block design. In experiment 1, concentrate with four levels of CP (10, 13, 16 and 19 %) was fed at 1.5 % of LW. In experiment 2, concentrate was fed at 1.0, 1.4, 1.8 and 2.2 % of LW. In both experiments, roughage was 5 kg/day native grass and ad libitum rice straw (fresh basis). Results showed that the CP level in concentrate significantly affected dry matter (DM) intake (P?<?0.05), N retention, ADG and ruminal NH₃-N concentration (P?<?0.01), but it had no significant effect on DM, organic matter (OM) and neutral detergent fibre (NDF) digestibility (P?>?0.05), whereas CP digestibility increased (P?<?0.001) along with the CP level. DM intake, N retention and ADG increased (P?<?0.001) linearly with concentrate intake. DM and CP digestibility were not significantly affected by concentrate intake (P?>?0.05). OM digestibility and NH₃-N concentration increased linearly (P?<?0.05), whereas NDF digestibility and ruminal pH declined linearly with increased concentrate consumption (P?<?0.01). These results indicate that 16 % CP in concentrate and feeding concentrate at the rate of 2.2 % of LW are recommendable for fattening local cattle in Vietnam.