【作者】 李玉；

【导师】 龚月生；

【作者基本信息】 西北农林科技大学 ， 动物营养与饲料科学， 2009， 硕士

【摘要】 本试验以奶公犊为动物模型,采用国产的全脂奶粉、挤压全脂大豆,大豆浓缩蛋白以及玉米蛋白粉作为蛋白来源,研究植物蛋白分别代替总蛋白的60%、70%和80%的代乳粉对早期断奶犊牛营养物质表观消化率及胃肠组织形态等方面的影响,为犊牛代乳粉产品开发提供技术参考。该试验选择新生荷斯坦奶公犊牛20头,分4组,编号为A、B、C和D。其中A、B、C为试验组,分别饲喂植物蛋白含量占总蛋白的60%、70%和80%的代乳粉,D为对照组,饲喂鲜奶,每组5头。营养物质表观消化率试验结果显示:对照组犊牛略高于试验组犊牛,但差异不显著(P > 0.05),仅干物质和蛋白质的消化率方面对照组D显著高于B、C两组(P < 0.05)。结果显示60%植物蛋白的代乳粉对犊牛营养物质表观消化率影响不大。胃容积、重量测定结果显示:仅C组的网胃容积显著小于D组(P < 0.05)。胃组织形态学指标比较结果显示:仅A组网胃底乳头高度显著低于其他各组(P < 0.05)。小肠重量、长度测定结果显示:十二指肠与回肠的重量各组间差异均不显著(P > 0.05),空肠重量B组显著大于其他各组(P < 0.05),A组大于C组,且差异显著(P < 0.05),但与D组差异不显著(P > 0.05)。十二指肠长度仅B组显著小于其它三组(P < 0.05),空肠长度仅C组显著小于其它三组(P < 0.05)。小肠组织形态学指标比较结果显示:十二指肠绒毛长度和绒毛宽度,A组显著大于其他各组(P < 0.05);隐窝深度:A组仅深于D组,且差异显著(P < 0.05)。空肠前段绒毛长度,D组仅显著长于C组(P < 0.05);绒毛宽度,A组显著宽于C、D两组(P < 0.05)。空肠后段绒毛长度:A组显著长于C组与D组(P < 0.05);绒毛宽度,仅B组大于D组(P < 0.05);隐窝深度,C组显著深于B、D两组(P < 0.05)。十二指肠、空肠的粘膜厚度和肌层厚度各组差异不显著(P < 0.05)。回肠,仅A组粘膜厚度显著厚于C、D两组(P < 0.05)。通过比较各组肠段绒毛长度与隐窝深度的比值(V/C值),发现十二指肠的V/C值,B、C两组显著低于A、D两组(P < 0.05);空肠后段的V/C值,C组显著低于D组;回肠各组V/ C值差异不显著。比较结果显示,植物蛋白含量在70%以下的代乳粉使犊牛十二指肠和空肠的绒毛长度、宽度增加,促进了犊牛小肠的发育,但过高植物蛋白配制的代乳粉会使犊牛的V/C值升高,从而降低消化率。通过扫描电镜观察胃肠表面形态,发现过高比例植物蛋白配制的代乳粉会造成犊牛小肠表面的损伤,特别是十二指肠表面,但粗蛋白中植物蛋白含量为60%的试验组与对照组相比较无明显差异。更多还原

【Abstract】 The experiment was conducted with calves to study the milk replacers which were fed containing 60,70,and 80% vegetable protein. The vegetable proteins come from Soy protein concentrate, expanded soybean and corn gluten meal. Objectives of this experiment were to text production and process of milk replacer, performance, digestibility and stomach and intestine morphology of calves and economy benefit in calf rearing.Holstein bull calves(n=20) were purchased,housed individually within an environmentally uncontrolled facility,were randomly allotted in batches to receive 1 of 4 experimental treatments. Treatments divided in 3 groups(A 60%,B 70%,and C 80%), the animal of control group(D) fed whole milk.The trial results showed that compared on apparent nutrient digestibility of calves the control group was more superiority than other three experimental treatments. But dry matter digestibility and protein digestibility were no significant differences(P > 0.05) between control D and test group A. The weight and volume of stomach were not different among treatment groups(P > 0.05),except reticulum volume of A and D were significant differences(P < 0.05). In piece of intestine, the weight of jejunum B compared to A, C, D were significant difference(sP < 0.05), the same between A and C. The length of duodenum and jejunum C and other test groups were significant differences(P < 0.05).The results of histological section reacted that the treat group of feeding 60% vegetable protein was no significant differences with feeding the whole milk group(P > 0.05). Other groups were affected by milk protein content. The indexes of stomach were no significant differences(P > 0.05). Intestine indexes were value. Among villous height of duodenum and posterior of jejunum, villous width of forepart of jejunum, mucosa width of ileum, A and other groups were significant differences(P < 0.05).And the scanning election microscopy picture indicated that the milk replacers of higher proportion vegetable protein were made injury in calves’stomach and intestine, especially in the surface of duodenum. But the threatment group of contenting 60% vegetable protein was no significant differences with control group.更多还原