【作者】 王艳红；

【导师】 姚军虎；

【作者基本信息】 西北农林科技大学 ， 动物营养与饲料科学， 2007， 硕士

【摘要】 本试验采用单因素完全随机设计,研究不同日粮淀粉水平对山羊消化道淀粉酶活性、消化道形态及生产性能的影响。1.日粮淀粉水平对山羊消化道淀粉消失率及α-淀粉酶活性的影响试验一旨在研究日粮淀粉水平对山羊胃肠道淀粉消失率及淀粉酶活性的影响。18只青年关中山羊随机分为三组,每组6只。依据NRC(2001)标准,设低(27.62%)、中(35.20%)、高(45.61%)三种淀粉水平日粮,三种日粮粗蛋白含量相等,以全混日粮形式投喂,日喂两次,试验期35d。饲养试验结束后将试验羊全部屠宰,取胃肠道食糜测定瘤胃、小肠淀粉消失量及消化率,取胰腺组织及小肠不同部位食糜测定α-淀粉酶活性。结果表明,随日粮淀粉水平的提高,过瘤胃淀粉数量线性提高(P<0.05)。淀粉在瘤胃和小肠中的消失量随日粮淀粉水平的提高而提高(P<0.05﹚。中淀粉日粮显著提高胰腺重(P<0.05)和单位体重胰腺重(P<0.05)。胰腺α-淀粉酶比活性随日粮淀粉水平的提高而提高(P<0.05),低淀粉组胰腺α-淀粉酶总活性(P<0.05)和单位体重活性(P<0.05)显著低于中淀粉组和高淀粉组。低淀粉水平组小肠60部位淀粉酶活性显著低于其他两组(P<0.05),80(P<0.05)和100(P<0.005)部位淀粉酶活性随淀粉水平的提高而提高。2.日粮淀粉水平对山羊消化道形态及食糜pH的影响试验二旨在研究日粮淀粉水平对山羊消化道形态及不同部位食糜pH的影响。本试验与试验一同时进行。饲养试验结束后,试验羊全部屠宰,立即取瘤胃腹囊、背囊,十二指肠、空肠、回肠组织,待做组织切片,并于屠宰后立即测定瘤胃、皱胃和小肠不同部位食糜pH值。结果表明,日粮淀粉水平不影响消化道粘膜总重、瘤胃粘膜重及小肠粘膜重(P>0.05﹚。瘤胃腹囊处,中淀粉组瘤胃乳头高度、乳头表面积和肌层厚度显著高于低淀粉组和高淀粉组(P<0.05);瘤胃背囊处,中淀粉组和低淀粉组瘤胃乳头高度显著高于高淀粉组(P<0.05),中淀粉组瘤胃乳头表面积(P<0.05)和肌层厚度(P=0.05)显著高于其它两组。高淀粉日粮显著降低瘤胃pH(P=0.05)。中淀粉组极显著提高空肠绒毛高度(P<0.05),低淀粉组趋于提高回肠绒毛宽(P=0.06)、腺窝深(P=0.10)及绒毛与腺窝比值(P=0.10)。3.日粮淀粉水平对山羊生产性能及屠宰性能的影响试验三旨在研究日粮淀粉水平对山羊生产性能及消化器官发育的影响。本试验与试验一同时进行。分别于试验前三天和最后三天早饲前测羊只体重,将前三天平均值作为初重,最后三天体重平均值作为末重。试验期结束后,将试验羊全部屠宰,测胴体重、复胃粘膜总重、瘤胃粘膜重、小肠粘膜重以及皱胃重,计算日增重、饲料转化率及屠宰率。结果表明,山羊日增重随淀粉水平的增加而提高(P<0.05﹚,高淀粉水平显著提高饲料效率(P<0.05﹚。日粮淀粉水平不影响屠宰率和胴体重(P>0.05﹚。结论:淀粉在瘤胃和小肠中的消失量随日粮淀粉水平的提高而提高。高淀粉水平日粮可提高日增重改善饲料效率。胰腺和小肠食糜α-淀粉酶总活性随日粮淀粉水平的提高而降低。高淀粉水平日粮降低瘤胃乳头高度、乳头表面积以及瘤胃pH。淀粉水平不影响小肠形态及小肠食糜pH。本研究表明,高日粮淀粉水平可能已影响动物健康,可推测,其生产性能的提高只是短期的暂时性的提高,长期饲喂45%淀粉日粮是否影响山羊生产性能还需进一步研究。更多还原

【Abstract】 1. Effect of dietary starch level on starch digestibility and activity ofα-amylase in goatsThe objective of this experiment was to determine the effects of dietary starch level on starch digestibility and activity ofα-amylase in the pancreas and the digesta of small intestine in goats. Eighteen Guanzhong male goats aged 9 months (initial body weight 28.4±1.6kg) were assigned randomly to three dietary treatments (6goats/treatment) in a completely random design. Experimental diets were: (1) low starch level (LS); (2) medium starch level (MS) and (3) high starch level (HS), and contained 27.62%, 35.20%, 45.61% starch level respectively, the major starch source is corn grain ,which is cracked to pass through a 3-mm screen. Diets were formulated to contain similar crude protein and were fed twice daily for 35d. Dry matter intake was restricted to be similar (1.0 kg/d) among the treatments. After a 35d feeding period, goats were slaughtered, the digesta were collected from the rumen and small intestine to determin the starch digestibility andα-amylase activity, the pancreas were also collected to measure the weight andα-amylase activity. The results showed that disappearance amount of starch in rumen and small intestine were increased with increasing dietary starch level(P<0.05﹚. The weight of pancreas in goats fed MS diets significantly great when compared to goats fed LS and HS diets(P<0.05﹚. Increasing starch level can increase rumen escape starch and pancreasα-amylase activity.2. Effect of dietary starch level on gastroenteric morphology and digesta pH in goatsThe objective of this study was to determine the effects of dietary starch level on rumen and small intestinal morphology and pH in goats. Eighteen Guanzhong male goats aged 9 months (initial body weight 28.4±1.6kg) were assigned randomly to three dietary treatments (6goats/treatment) in a completely random design. Experimental diets were: (1) low starch level (LS); (2) medium starch level (MS) and (3) high starch level (HS), and contained 27.62%, 35.20%, 45.61% starch level respectively. After a 35d feeding period, goats were slaughtered to obtain rumen and small intestinal sample, and the pH of rumen liquid and small intestinal digesta were determined at the time of the goats were slaughtered. The ruminal pH in goats fed HS diets was significantly lower than goats fed LS and HS diets (P=0.05). In ventral ruminal sac, the papillae height for goats fed the MS diet was greater (P<0.05) compared with goats fed the LS and HS diets. Papillae surface for goats fed the MS diets was larger than goats fed LS diets, and the latter was greater than goats fed HS diets (P<0.05). In dorsal ruminal sac, goats fed the HS diets had lowest papillae height(P<0.05) compared with goats fed the LS and MS diets, papillae surface (P<0.05) for goats fed MS diets was larger than goats fed LS and HS diets. Villus height of jejunum in goats fed MS diets were significantly larger than goats fed LS and HS diets (P<0.05). This study indicated that dietary starch intake affect ruminal morphology and pH, high starch diet impaired the ruminal morphology development and reduced the ruminal pH, but dietary starch level did not affect the morphology and digesta pH of the small intestine.3. Effect of dietary starch level on performance and slaughtering characteristic in goatsThe objective of this experiment was to determine the effect of dietary starch level on performance and slaughtering characteristic in goats. Eighteen Guanzhong male goats aged 9 months (initial body weight 28.4±1.6kg) were assigned randomly to three dietary treatments (6goats/treatment) in a completely random design. Experimental diets were: (1) low starch level (LS); (2) medium starch level (MS) and (3) high starch level (HS), and contained 27.62%, 35.20%, 45.61% starch level respectively. The results indicated that the average daily gain (ADG)was increased as dietary starch level increased(P<0.05﹚. The weight of abomasum was significantly increased(P<0.05﹚in goats fed MS diets, the other visceral organ were not affected by dietary treatment(P>0.05﹚. Feed efficiency of HS group was significantly improved compare with the other two groups(P<0.05﹚.更多还原