【作者】 王杰；

【导师】 陈玉林；

【作者基本信息】 西北农林科技大学 ， 动物营养与饲料科学， 2004， 硕士

【摘要】 本研究以柠檬酸、延胡索酸、磷酸、乳酸、苹果酸和酒石酸为组分，自行设计并配制了6种复合酸化剂，经筛选试验，选择出4种对断奶仔猪使用效果较好的复合酸化剂。在此基础上，采用五处理单因子试验设计，选用28±3日龄断奶三元杂交仔猪90头，随机分成5组，每组3个重复，每个重复6头仔猪。各处理组基础日粮相同，对照组为空白对照，试验组分别添加AⅠ、AⅡ、AⅢ、和AⅣ4种复合酸化剂，添加水平均为0.2%，系统开展复合酸化剂的优化研究，试验分为四部分：第一部分为饲养试验，记录各组断奶仔猪的采食量、（日）增重、饲料转化率、腹泻率和成活率等生长指标；第二部分为消化生理试验，于试验末随机从各试验组内随机选3头仔猪屠宰，以测定其消化道的pH值、消化道酶活性，培养盲肠和结肠内的大肠杆菌和乳酸杆菌；第三部分为血液生化指标试验，测定仔猪血液的总蛋白含量、血糖和尿素氮浓度。第四部分为消化试验，采用全收粪法。于试验的第二周对每组6头仔猪进行3天的全收粪，以测定粗蛋白（CP）、能量（GE）和干物质（DM）的表观消化率，获得以下结果：⑴ 4种复合酸化剂均具有良好的作用，通过比较认为复合酸化剂AⅢ最好，AⅠ次之。⑵ 仔猪日粮中添加0.2%复合酸化剂能明显地提高仔猪的采食量、增重、日增重和饲料报酬；极显著的降低仔猪的腹泻率（P<0.01）。通过比较认为在4种供试复合酸化剂中，以AⅠ和AⅢ的作用效果较佳。⑶ 仔猪日粮中添加0.2%复合酸化剂可明显降低仔猪胃和小肠内容物的pH值，极显著提高胃蛋白酶、空肠和回肠胰蛋白酶的活性（P<0.01），以AⅢ的作用效果较佳；极显著的降低空肠和回肠胰淀粉酶的活性（P<0.01）；显著的降低盲肠和结肠的大肠杆菌数（P<0.05），AⅢ和AⅣ的作用效果较佳；显著的增加乳酸杆菌数（P<0.05），AⅢ的作用效果较佳。⑷ 仔猪日粮中按0.2%比例添加4种复合酸化剂，均可降低仔猪血糖浓度和血液尿素氮水平，提高仔猪血液总蛋白含量。通过比较认为AⅠ的作用效果较明显。⑸ 仔猪日粮中添加0.2%复合酸化剂后，提高了仔猪的总采食量和排粪量同时也提高了粗蛋白、能量和干物质的表观消化率。以AⅠ和AⅢ的作用效果较明显。更多还原

【Abstract】 Two experiments was conducted to single out the better acidifiers and study the effects and mechanism of acidifiers in diets for weaning pigs. The acidifiers’ components are the same (Citric Acid, fumaric Acid, Phosphorus Acid, Lactic Acid, Cider Acid, Tartaric Acid). In exp.1, Four acidifiers, AⅠ、AⅡ、AⅢ、and AⅣ, were single out. And based on these, In exp.2, 90 4-wk-old weaning pigs were used to study the effects of acidifiers. Five treatments and single facter were utilized. And one group (a negative control) was offered feed free of acidifier ad libitum, four groups were offered the same diet ad libitum supplemented with 0.2% AⅠ、AⅡ、AⅢ and AⅣ respectively. Exp.2 included four sections. Basic diets of the five treatments were same during three weeks. Part One for feeding. Feed intake, weight gain, average daily gain( ADG ), feed efficiency, rate of diarrhoea and livability of each group were measured. Part Two for Digestive physiology. Three selected piglets randomly from every treatment at the third weekend for slaughter test.to determine the pH of digestive tract, didestive enzyme; E.coli counts and lactobacillus counts in cecum and colon. Part Three for blood biochemical test. Totol serum protein, blood sugar and urea nitrogen were measured. Part Four for digestion trial. The whole-feces -collected method was used in digestion trial to measure apparent digestibility of crude protein, dry matter and general energy. The results shows:⑴Four acidifiers are well to pigs and AⅢ is the best and AⅠ is better.⑵0.2% Acidifiers added in the diets significantly rised the feed intake, gain weight and daily gain weight (P<0.01); remarkably improved feed efficiency and decreased the diarrheoa rate. The effect of AⅠ and AⅢ is better.⑶0.2% Acidifiers added in the diets obviously lowed the pH in stomach and small intestine; significantly promoted the activity of pepsin, trypsin in the jejunum and ileum(P<0.01), The effect of AⅢ is better; and decreased the <WP=7>activity of amylase in the jejunum and ileum(P<0.01)；decreased E.coli counts and increased the lactobacillus counts obviously (P<0.05), The effect of AⅢ is better.⑷0.2% Acidifiers added in the diets decreased the blood sugar and urea nitrogen on piglets respectively and increased the total serum protein.The effect of AⅠ is better⑸0.2% Acidifiers added in the diets obviously promoted the total counts of intake and the feces; increased the apparent digestibility of CP, DM and GE. The effect of AⅠ and AⅢ is better更多还原