辣木在生长猪上的营养价值评定

本试验通过在生长猪上测定辣木叶和辣木枝的消化能、代谢能和氨基酸标准回肠消化率,旨在评定辣木在生长猪上的营养价值。选择24头回肠末端安装T型瘘管的“杜×长×大”去势公猪,平均体重为(39.80±1.06)kg,随机分为4个组,分别饲喂无氮饲粮、玉米-豆粕型基础饲粮、辣木叶饲粮和辣木枝饲粮,每组6个重复。预饲7 d后,进行4 d消化代谢试验,收集全部粪尿,用于测定消化能和代谢能。消化代谢试验结束后,继续2 d收集回肠食糜用于测定氨基酸表观回肠消化率和标准回肠消化率。结果表明:与辣木枝相比,辣木叶含有较高含量的营养成分,尤其是粗蛋白质、粗脂肪和钙,含量分别为26.29%、6.25%和2.70%。辣木叶的消化能、代谢能和总能表观消化率分别为9.35、8.24 MJ/kg和49.26%,辣木枝的消化能、代谢能和总能表观消化率分别为7.51、6.03 MJ/kg和40.81%,辣木叶的有效能值和总能表观消化率显著高于辣木枝(P<0.05)。辣木叶总必需氨基酸、总非必需氨基酸和粗蛋白质标准回肠消化率分别为42.05%、42.59%和49.03%,而辣木枝总必需氨基酸、总非必需氨基酸和粗蛋白质标准回肠消化率分别为35.13%、37.31%和40.15%,辣木叶的总必需氨基酸、总非必需氨基酸和粗蛋白质标准回肠消化率显著高于辣木枝(P<0.05)。综上所述,辣木叶的消化能、代谢能和总必需氨基酸标准回肠消化率分别为9.35、8.24 MJ/kg和42.05%,而辣木枝的消化能、代谢能和总必需氨基酸标准回肠消化率分别为辣木叶的80.3%、73.3%和83.5%。因此,辣木叶具有更高的营养价值,更适合作为生长猪的蛋白质饲料原料。     

生长猪对国产双低菜籽粕与进口普通菜籽粕营养价值的比较

本研究旨在比较国产双低菜籽粕与进口普通菜籽粕营养价值的不同,共分为2个试验。试验1:选取18头初始体重[(48.3±2.4)kg]相近的健康去势公猪,采用全收粪法进行消化代谢试验,随机分为3组(每组6个重复,每个重复1头猪),分别饲喂基础饲粮和2种试验饲粮。分别以国产双低菜籽粕和进口普通菜籽粕替代基础饲粮中能量饲料的20%配制2种试验饲粮。试验期14 d(前9天为适应期,后5天为收集期)。试验2:选取18头初始体重[(35.3±3.8)kg]相近的装有简单T型瘘管的健康去势公猪,采用指示剂法进行氨基酸回肠末端消化率试验,随机分为3组(每组6个重复,每个重复1头猪),分别饲喂无氮饲粮和2种试验饲粮。分别以国产双低菜籽粕和进口普通菜籽粕作为唯一蛋白质和氨基酸来源配制2种试验饲粮。试验期7 d(前5天为适应期,后2天为收集期)。结果表明:国产双低菜籽粕的表观消化能和能量的表观消化率极显著低于进口普通菜籽粕(P<0.01),国产双低菜籽粕的表观代谢能显著低于进口普通菜籽粕(P<0.05);国产双低菜籽粕的氨基酸标准回肠末端消化率较低。由此可见,国产双低菜籽粕的营养价值较进口普通菜籽粕低。     

喷雾干燥鸡血浆蛋白粉在仔猪上的营养价值评定

本试验旨在对喷雾干燥鸡血浆蛋白粉在仔猪上的营养价值进行评定。试验采用单因子设计,将24头健康的"杜×长×大"三元杂交去势公猪(初始体重(24.96±1.05)kg)随机分配到3个处理,每个处理8个重复。分别饲喂无氮饲粮、玉米-豆粕型基础饲粮、鸡血浆蛋白粉饲粮(等氮替代基础饲粮中40%的氮)。所有仔猪预饲6d后,进行4d的消化代谢试验,收集全部粪尿,用于测定养分消化率和利用率。试验结束后所有仔猪麻醉屠宰,采集回肠末端食糜,用于测定氨基酸表观回肠消化率和标准回肠消化率。结果表明:喷雾干燥鸡血浆蛋白粉的粗蛋白质高达69.36%,赖氨酸含量为4.53%,蛋氨酸含量为1.65%,赖氨酸∶蛋氨酸∶色氨酸∶苏氨酸=100∶36∶30∶91,与猪的理想蛋白质氨基酸模式较接近;鸡血浆蛋白粉的表观消化能为16.02 MJ·kg-1,表观代谢能为15.39MJ·kg-1;粗蛋白质的表观消化率和真消化率分别为87.58%和91.11%;除了甘氨酸外,所有氨基酸的标准回肠消化率都高于80%。综上表明,喷雾干燥鸡血浆蛋白粉是一种优质的动物性蛋白质原料。     

储存时间对玉米猪有效能值和营养物质消化率的影响

本试验旨在研究储存时间对玉米猪消化能、代谢能和营养物质消化率的影响。试验采集储存时间分别为1、2、3、4、5年的普通黄色马齿型玉米样品。试验一:选用30头初始体重为(35.3±3.3) kg的杜×长×大三元杂交去势公猪,采用直接法测定5个玉米样品的消化能、代谢能和营养物质的表观全肠道消化率。试验二:选用6头初始体重为(35.3±2.0) kg装有简单T型瘘管的杜×长×大三元杂交去势公猪,采用6×6拉丁方试验设计,采用直接法测定5个玉米样品中粗蛋白质和氨基酸的表观和标准回肠末端消化率。结果显示:随着储存时间的延长,玉米中干物质和淀粉含量线性降低(P0.05)。除了精氨酸,储存时间对玉米中粗蛋白质和各氨基酸含量均未产生显著影响(P0.05)。随着储存时间的延长,玉米的消化能和代谢能以及总能、淀粉、中性洗涤纤维和酸性洗涤纤维的表观全肠道消化率呈线性降低(P0.05)。另外,随着储存时间的延长,玉米的粗蛋白质以及各氨基酸的表观和标准回肠末端消化率均线性降低(P0.05)。总而言之,随着储存时间的延长,玉米的猪消化能和代谢能以及纤维物质和氨基酸的消化率均线性降低,从而导致其饲用价值逐渐降低。     

棉籽浓缩蛋白营养价值评定及其对断奶仔猪生长性能的影响

本研究旨在评价棉籽浓缩蛋白的营养价值及其替代大豆浓缩蛋白对断奶仔猪生长性能、营养物质消化率和血清生化指标的影响。试验1：将12头生长猪随机分成2组（每组6个重复，每个重复1头猪），分别饲喂玉米基础饲粮和棉籽浓缩蛋白饲粮。采用全收粪尿法和套算法测定棉籽浓缩蛋白的消化能和代谢能。试验2：将12头生长猪随机分成2组（每组6个重复，每个重复1头猪），分别饲喂无氮饲粮和棉籽浓缩蛋白饲粮。采用指示剂法和直接法测定棉籽浓缩蛋白的粗蛋白质和氨基酸标准回肠消化率。试验3：将192头断奶仔猪随机分成4组（每组6个重复，每个重复8头猪），分别饲喂棉籽浓缩蛋白水平为0、2%、4%和6%（等量替代大豆浓缩蛋白）的试验饲粮，试验期28 d。结果表明：1）风干基础下棉籽浓缩蛋白消化能、代谢能和总能消化率分别为16.51 MJ/kg、15.38 MJ/kg和89.78%。2）棉籽浓缩蛋白的粗蛋白质和氨基酸标准回肠消化率89%和75%～94%。3）不同添加水平的棉籽浓缩蛋白替代大豆浓缩蛋白对断奶仔猪生长性能、营养物质消化率及血清生化指标均没有显著影响（P>0.05）。由此可见，棉籽浓缩蛋白在断奶仔猪饲粮中可以完全...     

白酒糟发酵粉对生长猪消化能、代谢能和氨基酸标准回肠消化率的评定

研究旨在分析白酒糟发酵粉的化学组成并测定生长猪的消化能、代谢能及氨基酸标准回肠消化率,同时以豆粕为对比,评价白酒糟发酵粉作为猪蛋白质饲料原料应用的可行性。试验一选用6头杜×长×大三元杂交去势公猪[体重为(35.3±3.5)kg],采用3×3双拉丁方设计,应用套算法,全收粪技术,测定白酒糟发酵粉和豆粕的消化能和代谢能;每个试验期10 d,前5 d为适应期,后5 d为粪尿收集期。试验二选用6头安装简单T型瘘管的杜×长×大三元杂交去势公猪[体重为(32.3±2.8)kg],采用3×3双拉丁方设计,测定白酒糟发酵粉和豆粕的氨基酸标准回肠消化率;每个试验期7 d,前5 d为适应期,后2 d为食糜收集期。结果表明,白酒糟发酵粉和豆粕的消化能分别为9.42 MJ/kg和14.77 MJ/kg;代谢能分别为8.91 MJ/kg和14.39 MJ/kg。白酒糟发酵粉消化能和代谢能均显著低于豆粕(P<0.05),分别为豆粕的64%和62%。白酒糟发酵粉和豆粕必需氨基酸标准回肠消化率分别为59.26%和79.85%;非必需氨基酸标准回肠消化率分别为44.77%和74.72%;总氨基酸标准回肠消化率分别为52.82%和77.57%。除色氨酸和胱氨酸外,均显著低于豆粕(P<0.05)。白酒糟发酵粉的必需氨基酸、非必需氨基酸和总氨基酸的标准回肠消化率分别为豆粕的74%、60%和68%。综上所述,白酒糟发酵粉的消化能、代谢能和氨基酸标准回肠消化率低于豆粕,但仍具有较高的饲用价值。白酒糟发酵粉可作为蛋白质饲料原料应用于养猪生产。     

水解羽毛粉作为生长猪蛋白质原料饲喂效果的研究

研究旨在测定水解羽毛粉的消化能、代谢能及其日粮回肠末端氨基酸消化率。试验1采用全收粪法测定水解羽毛粉消化能及代谢能;试验2采用指示剂法测定水解羽毛粉日粮粗蛋白和氨基酸的表观回肠末端消化率和标准回肠末端消化率。结果表明:干物质基础状态下水解羽毛粉的消化能和代谢能分别为15.04和12.80 MJ/kg,生长猪日粮中添加14.50%水解羽毛粉时,除蛋氨酸外,日粮中粗蛋白质和氨基酸的表观回肠末端消化率和标准回肠末端消化率较低,氮的有效利用率低。     

复合酵母的营养价值评定

本研究旨在评定复合酵母对仔猪的营养价值,重点评定复合酵母在仔猪上表观消化能、表观代谢能、粗蛋白质的真消化率、粗蛋白质的真利用率和氨基酸的回肠消化率。通过化学分析和仔猪消化代谢试验测定复合酵母的营养成分和主要养分的生物利用率。饲养试验采用单因子设计,选用体重(19.9±1.2)kg的"杜×长×大"三元杂交仔猪12头进行消化代谢试验,随机分为2组,每组6个重复,每个重复1头猪。各组分别饲喂无氮饲粮和以复合酵母作为唯一蛋白质源的半纯合饲粮。试验期7 d,预试期3 d,正试期4 d。结果表明:复合酵母粗蛋白质含量高达47.35%,赖氨酸含量为3.43%,蛋氨酸含量为0.72%,赖氨酸∶蛋氨酸∶色氨酸∶苏氨酸=100∶21∶19∶64,与猪的理想蛋白质氨基酸模式接近;复合酵母的表观消化能为14.98 MJ/kg,表观代谢能为14.05 MJ/kg;粗蛋白质的真消化率、真利用率分别为89.71%和69.53%;除了苏氨酸,其他必需氨基酸的回肠真消化率都高于80%。由此可见,复合酵母属于优质蛋白质饲料,蛋白质含量高,氨基酸平衡性好,有效能值高,仔猪对复合酵母的蛋白质、氨基酸的消化利用效果理想。     

发酵玉米浆的营养价值评定及其对育肥猪生长性能和血清生化指标的影响

本试验旨在评定发酵玉米浆的营养价值并探究其对育肥猪生长性能和血清生化指标的影响。试验1采用全收粪法测定发酵玉米浆对猪的有效能值和营养物质表观消化率。选取12头初始体重为（27.60±2.50）kg的“杜×长×大”三元杂交去势公猪，随机分为2组，每组6个重复，每个重复1头猪。对照组饲喂玉米-豆粕型基础饲粮，试验组饲粮以发酵玉米浆替代基础饲粮中24.25%的供能组分。试验期12 d，包括7 d饲粮适应期和5 d粪尿收集期。试验2采用无氮饲粮和半纯合饲粮法测定发酵玉米浆氨基酸回肠末端消化率。选取6头初始体重为（37.17±1.17）kg装有简单T型瘘管的“杜×长×大”三元杂交去势公猪，随机分为2组，每组3头猪。采用2×2拉丁方设计，包括2个试验期和2个饲粮处理。每个试验期7 d，包括5 d饲粮适应期和2 d食糜收集期。试验饲粮包括1个以玉米淀粉-蔗糖为基础的无氮饲粮和1个含有40%发酵玉米浆的待测饲粮。试验3选取192头初始体重为（82.30±5.85）kg的“杜×长×大”三元杂交猪，随机分为4组，每组6个重复，每个重复8头猪（公母各占1/2）。对照组（CON组）饲喂玉米-豆粕-麦麸型基础饲...     

不同储存时间小麦在生长猪上的营养价值评定

本试验旨在研究不同储存时间小麦在猪上的消化能和营养物质消化率。试验于2016年在河北省国家粮仓分别采集2012、2013、2014、2015和2016年收获的小麦样品。试验1:选取30头初始体重为(45.2±1.5) kg杜×长×大三元杂交健康去势公猪,采用全收粪法测定5个小麦样品的消化能和营养物质表观全肠道消化率。试验2:选用6头初始体重为(32.6±1.2) kg装有简单T型瘘管的杜×长×大三元杂交健康去势公猪,采用6×6拉丁方试验设计,测定5个小麦样品中氨基酸的表观和标准回肠消化率以及淀粉的表观回肠消化率。结果表明:储存时间显著影响小麦的消化能以及总能、粗蛋白质和中性洗涤纤维表观全肠道消化率(P0.05)。2012—2016年小麦对生长猪的消化能分别为14.16、14.11、14.06、14.43和14.06 MJ/kg。2015年小麦的消化能以及总能和中性洗涤纤维表观全肠道消化率显著高于其他年份小麦(P0.05),2015年小麦的粗蛋白质表观全肠道消化率显著高于2014和2016年小麦(P0.05)。从氨基酸表观和标准回肠消化率来看,2015年小麦多种氨基酸的表观和标准回肠消化率均处在较高水平。综上可知,以河北省国家粮仓储存的小麦为研究对象,储存1年后对于生长猪的营养价值最佳,其后随储存时间延长,小麦的营养价值降低。     

浓缩脱酚棉籽蛋白生长猪消化能评定及其对仔猪生长性能、血清生化指标和养分表观消化率的影响

本研究旨在通过猪消化代谢试验测定浓缩脱酚棉籽蛋白(CDCP)生长猪消化能,同时研究其对仔猪生长性能、血清生化指标和养分表观消化率的影响。试验选取65日龄、体重(38.80±2.60)kg的“杜×(长×大)”健康阉公猪8头,随机分成2组(每组4个重复,每个重复1头猪),分别饲喂基础饲粮和试验饲粮(80%基础饲粮+20%CDCP),单笼饲养,采用交叉法进行消化代谢试验测定消化能。然后选取(31±2)日龄、体重(10.00±0.60)kg的“杜×(长×大)”健康仔猪132头,按随机区组设计分成2组(对照组和CDCP组),每组6个重复,每个重复11头猪。对照组饲喂基础饲粮(鱼粉用量为4%),CDCP组饲喂试验饲粮(利用CDCP完全替代基础饲粮中的鱼粉),2种饲粮消化能和回肠标准可消化赖氨酸、蛋氨酸、苏氨酸、色氨酸水平均满足或超过NRC(2012)仔猪营养需要。试验期28 d。结果显示:生长猪对CDCP的能量表观消化率为86.64%,消化能为15.61 MJ/kg。2组仔猪的平均日增重、平均日采食量、料重比、腹泻率和血清生化指标差异均不显著(P>0.05);CDCP组的能量和粗脂肪表观消化率显著低于对照组(P<0.05),而2组干物质、粗蛋白质和粗灰分表观消化率差异不显著(P>0.05)。综上所述,CDCP生长猪消化能为15.61 MJ/kg。在消化能和回肠标准可消化赖氨酸、蛋氨酸、苏氨酸、色氨酸水平满足或超过NRC(2012)条件下,CDCP替代饲粮中鱼粉不影响仔猪的生长性能。     

2种指示剂测定玉米干酒糟及其可溶物生长猪标准回肠氨基酸消化率的比较研究

本试验旨在研究三氧化二铬和氧化钛2种指示剂对测定玉米干酒糟及其可溶物(D D G S)生长猪标准回肠氨基酸消化率的影响。试验选用6头安装简单T型瘘管的三元杂交(杜洛克×大白×长白)去势公猪,初始体重为(35.1±2.1)kg,应用6×6拉丁方试验设计,分为6期,6种日粮,分别以三氧化二铬和氧化钛配制4种含D D G S日粮,2种无氮日粮。结果表明:玉米D D G S的赖氨酸和色氨酸标准回肠消化率最低;除组氨酸和苯丙氨酸外,2种指示剂对测定其他必需氨基酸和非必需氨基酸标准回肠消化率均无显著影响(P>0.05)。结果提示,三氧化二铬和氧化钛均可用于测定玉米D D G S氨基酸消化率。     

Determination of the ileal amino acid and energy digestibilities of corn distillers dried grains with solubles using grower-finisher pigs

An experiment evaluated the ileal apparent and standardized AA and apparent energy digestibilities in grower-finisher pigs of 5 sources of distillers dried grains with solubles (DDGS) from corn. The 5 DDGS sources were analyzed for AA, GE, NDF, ADF, and color score. Diets were formulated to contain 15% CP from the test DDGS sources (approximately 60% of the diet). A low-protein (5% casein) diet was used to estimate basal endogenous AA losses. The experiment was conducted in 2 replicates of a 6 x 6 Latin Square design, with 6 treatments and six 1-wk periods. The experiment used 12 crossbred barrows [(Yorkshire x Landrace) x Duroc], averaging 28 kg of BW and 60 d of age, and surgically fitted with a T-cannula in the distal ileum. After a 10-d recovery period, treatment diets were fed in meal form, initially at 0.09 kg . BW(0.75). Feed intake was equalized between pigs within each period and increased for each subsequent period. Periods included 5 d of diet acclimation followed by two 12-h ileal digesta collections, one on d 6 and one on d 7. Apparent and standardized digestibility of AA was calculated using chromic oxide (0.4%) as an indigestible marker. The results demonstrated that apparent and standardized lysine digestibilities ranged from 24.6 to 52.3% and 38.2 to 61.5%, respectively. Average apparent essential AA digestibility was lower (P < 0.05) in sources 1 and 5, the 2 sources that were darkest in color. Apparent and standardized digestibility of the averaged nonessential AA were lower (P < 0.05) in source 5 than in all other sources. Source 5, the darkest colored DDGS, had a 10% lower (P < 0.05) average apparent and standardized essential AA digestibility and was more than 15% lower (P < 0.05) in lysine digestibility than the 3 lightest colored sources. Apparent ileal energy digestibility did not differ among the 5 sources. Lysine content and digestibility seemed to be reduced to a greater extent by the darker colored DDGS than the other essential AA, suggesting that the Maillard reaction reduced total lysine content and lowered its digestibility. These results, therefore, imply that darker colored DDGS sources may have lower (P < 0.05) analyzed lysine contents, as well as lower (P < 0.05) lysine and essential AA digestibilities, than lighter colored DDGS sources.     

Effects of Dietary Starch Source on Nutrient and Energy Absorption via the Portal Vein of Growing Pigs

Four crossbred(Duroc×Landrace×Yorkshire)boars,weighing an average of 22.40 ± 1.08 kg and fitted with permanent catheters in their portal and mesenteric veins as well as their carotid artery,were utilized in a 4 × 4 latin square design experiment in order to investigate the effects of different starch sources(maize,brown rice,sticky rice,and resistant starch)on the absorption of energy sources through the portal vein.Portal blood flow averaged 30.68,28.40,29.99,and 30.12 mL/min per kg BW for pigs fed the maize,brown rice,sticky rice,and resistant starch diets,respectively,and did not differ(P0.05)between treatments.The absorptions of glucose,plasma ammonia,and total amino acids were significantly lower(P0.05)in pigs fed the resistant starch diet than pigs fed the other starch sources.In contrast,significantly(P0.05)higher amounts of propionate and total volatile fatty acids were absorbed from the portal vein of pigs fed resistant starch than pigs fed diets based on maize,brown rice,or sticky rice.In addition,significantly(P0.05)more lactic acid was absorbed from the portal vein by pigs fed the sticky rice diet than pigs fed the other three diets.The energy absorbed from the portal vein in the form of glucose and amino-N as well as the total energy absorbed was significantly(P0.05)lower in pigs fed the resistant starch diet than pigs fed the other three starch sources.In contrast,the amount of energy absorbed in the form of volatile fatty acids was significantly(P0.05)higher in pigs fed resistance starch than pigs fed the other three starch sources.The total energy absorbed through the portal vein as a percentage of the gross energy and digestible energy consumed in pigs fed maize were 50.8% and 54.6%,respectively,which were significantly(P0.05)higher than the values in pigs fed resistant starch(41.5% and 46.6% respectively).The results indicate that energy is absorbed in different forms and with different utilization efficiencies in the digestive tract of pigs as a result of feeding different starch sources.Starch sources supplying most of their energy in the form of glucose had higher energy utilization efficiencies,while starch sources supplying most of their energy in the form of volatile fatty acids or lactic acid had lower energy utilization efficiencies.     

Effect of soybean meal particle size on amino acid and energy digestibility in grower-finisher swine

A study was conducted using the ileal digestibility technique with grower-finisher pigs to evaluate the effects of particle size reduction of soybean meal (SBM) on amino acid and energy digestibility. Soybean meal was processed through a hammer mill to achieve average particle sizes of 900, 600, 300, and 150 microm. The treatments included the use of two soybean meal sources and soy protein concentrate. One source of SBM was ground to four different particle sizes (i.e., 949, 600, 389, 185); a second source was a common SBM source used in other trials (i.e., 800 microm). The soy protein concentrate had an average particle size of 385 microm. A low-protein (5% casein) diet was fed to determine endogenous amino acid losses. This experiment was conducted in a 7 x 7 Latin Square design in two replicates using 14 crossbred barrows ([Landrace x Yorkshire] x Duroc) that averaged 28 kg BW and 60 d of age. Animals were surgically fitted with a T-cannula at the distal ileum. Treatment diets were fed in meal form, initially at 0.09 kg BW(0.75) and at graded increases at each subsequent period. Pigs within replicate were fed a constant quantity of their treatment diet for a 5-d adjustment period followed by a 2-d collection of ileal digesta samples. Apparent and true digestibility of amino acids was calculated by use of chromic oxide (0.5%) as an indigestible marker. Apparent digestibility of isoleucine, methionine, phenylalanine, and valine increased linearly (P < 0.05) as particle size decreased. True digestibility of isoleucine, methionine, phenylalanine, and valine increased linearly (P < 0.05) as particle size decreased. When the essential amino acids were averaged, apparent digestibility increased (P < 0.10) from 83.5% to 84.9% as particle size decreased, whereas, nonessential amino acid digestibility increased only slightly (P > 0.15). Essential amino acid true digestibility increased numerically from 91.0% to 92.4% as particle size decreased. Energy digestibility was not affected by particle size (P > 0.15). These results suggest that a reduction in particle size of soybean meal resulted in a small increase in the digestibility of its amino acids with the essential amino acids being affected more than the nonessential amino acids. The largest improvement in digestibility, however, was obtained when the particle size was reduced to 600 microm.     

Effects of the Standardized Heal Digestible Lysine to Metabolizable Energy Ratio On Performance,Nutrient Digestibility,and Plasma Parameters of 10 to 28 kg Pigs

A total of 480 nursery pigs(Duroc×Landrace×Large White) were utilized in two experiments conducted to determine the effects of different ratios of standardized ileal digestible lysine(SIDLys)to metabolizable energy(ME)ratio on the performance,nutrient digestibility,plasma urea nitrogen (PUN),and plasma free anlino acids of 10 to 28 kg pigs.In Exp.1,192 pigs(10.58 kg)were assigned to one of four treatments.,The treaunents consisted of diets with a ME content of 3.2,3.25,3.3,or 3.35 McaL/kg with a constant SID-Lys:ME ratio of 3.7 g/Meal.The experiment lasted 28 days.Pigs which were fed the diets containing 3.3 and 3.35 Mcal/kg ME had lower feed intakes(P<0.05)than those fed 3.2 Mcal/kg.Feed efficiency was linearly improved with increasing dietary ME(P<0.05).Increasing the dietary ME level also increased (P<0.05)dry matter and energy digestibility.Therefore.3.3 Mcal/kg ME Was selected for Exp.2in which 288 pigs(10.60 kg)were assigned to one of six treatments.Treatments consisted of SID-Lys:ME ratios of 3.1,3.3,3.5,3.7,3.9,or 4.1 g/Meal witIl all diets providing 3.3 Meal of ME/kg.Weight gain and feed efficiency were increased(P<0.05)as the SID-Lys:ME ratio in diet increased.Based on a straight broken-line model,the estimated SID-Lys:ME ratio to maximize weight gain was 3.74.     

牛至油对生长猪生产性能和养分表观消化率的影响

选用健康、体重25kg左右的荣×大×杜杂交猪60头,随机分到2个组,每组6个重复,每个重复5头猪,每圈为1个重复,研究添加牛至油对生长猪生产性能和养分消化率的影响。试验组在对照组的基础上添加100g/t的牛至油,测定猪的生产性能和养分表观消化率。试验结果表明,在生长猪日粮中添加100g/t的牛至油具有改善猪只生产性能、提高养分表观消化率的趋势,可降低单位增重饲料成本。     

小麦基础饲粮中添加木聚糖酶对生长猪生长性能、血清生化指标及肠道微生物菌群的影响

本试验旨在研究在小麦基础饲粮中添加木聚糖酶对生长猪生长性能、营养物质表观消化率、血清生化指标及肠道微生物菌群的影响,探讨适宜的木聚糖酶添加水平。选择80头健康、平均体重40 kg的"杜×长×大"生长猪,随机分为5个处理,每个处理4个重复,每个重复4头猪。正对照组饲喂玉米-豆粕型基础饲粮,负对照组饲喂小麦-豆粕型基础饲粮,木聚糖酶组分别饲喂在负对照基础饲粮上添加500、1 000和2 000 U/kg木聚糖酶的试验饲粮。试验期28 d。结果表明:1)小麦基础饲粮中添加木聚糖酶可极显著提高生长猪平均日增重(P<0.01),显著或极显著提高平均日采食量和营养物质表观消化率(P<0.05或P<0.01),其中2 000 U/kg木聚糖酶组效果最好,平均日增重和平均日采食量分别提高了26.0%和16.5%(P<0.01);2)小麦基础饲粮中添加木聚糖酶显著或极显著提高了生长猪血清葡萄糖、三碘甲腺原氨酸、四碘甲腺原氨酸和D-木糖含量(P<0.05或P<0.01),极显著降低血清尿素氮含量(P<0.01);3)饲粮组成和木聚糖酶可显著影响猪肠道微生物菌群,添加木聚糖酶可维持动物肠道微生物菌群的平衡,2 000 U/kg木聚糖酶组肠道菌群结构和玉米-豆粕饲粮饲喂条件下接近。由此可见,添加2 000 U/kg的木聚糖酶可显著改善饲喂小麦基础饲粮生长猪的生长性能和营养物质表观消化率,维持肠道微生物菌群的平衡。在木聚糖含量为11.2%的生长猪小麦基础饲粮中,木聚糖酶的适宜添加水平为2 000 U/kg。     

发酵床养猪模式与传统养猪模式饲养效果比较

为了比较发酵床与传统模式的饲养效果,选择日龄相近、生长发育良好的杜×长×大三元配套系商品猪分为小猪组和大猪组。小猪组36头,试验组和对照组各18头;大猪组32头,分为试验组和对照组各16头,分别在发酵床和传统模式两种环境中生长。结果表明：发酵床模式与传统模式相比,小猪和大猪的试验组日增重比对照组分别提高4．52%、16．73%;料重比分别降低3．16％、7．43%;传统模式舍内环境与发酵床模式差异不显著。总体分析采用发酵床技术饲养育肥猪,每头可多获利126．24元。发酵床养猪模式的饲养效果优于传统养猪模式的饲养效果。