【作者】 刘洁；

【导师】 高艳霞； 孙凤莉；

【作者基本信息】 河北农业大学 ， 农业硕士（专业学位）， 2023， 硕士

【摘要】 犊牛生长早期生长发育和健康状况对成年后生产性能具有重要影响,本试验旨在研究开食料中单宁酸水平对犊牛生长性能、血液指标、瘤胃发酵参数以及细菌群落的影响。试验选取健康的且初生重（39.9±1.92 kg）相近的60头健康荷斯坦母犊牛,随机分为4组,每组15头。对照组（CON）饲喂开食料,试验组在开食料中添加天然栗木和白坚木的单宁提取物（Quebracho-chestnut tannin extracts,QTE,单宁酸≥73%）,添加量分别为0.30%DM（QTE1）、0.45%DM（QTE2）、0.60%DM（QTE3）。试验期70 d,所有试验牛只在犊牛岛养殖,饲养管理保持一致,在犊牛第64日龄进行断奶,随后7 d监测犊牛的生长和发育情况。研究结果表明:1对犊牛生理指标的影响。添加QTE对试验期第0天和第70天呼吸频率无显著影响（P>0.05）,在第35天时,呼吸频率线性显著降低（P<0.05）,在第63天时,呼吸频率有降低趋势（P=0.09,二次）;对第0天和第70天直肠温度无显著影响（P>0.05）,在第35天时,直肠温度显著线性降低（P<0.05）,在第63天时直肠温度显著降低（P<0.05,二次）。2对犊牛生长性能的影响。在第35天时,体重差异不显著（P>0.05）,在第63天和第70天时,体重显著增加（P<0.05,二次）;在第36～63天时,平均日增重（ADG）线性升高（P<0.05）,第0～63天时,ADG显著升高（P<0.05,二次）,在第64～70天时,ADG有线性升高的趋势（P=0.09）;在第64～70天时,平均日开食料干物质采食量（ADFI）显著增加（P<0.05,二次）;料重比（F/G）在第36～63天和第0～63天时,线性降低（P<0.05）。添加QTE对体高、体斜长、胸围、腹围、管围均无显著影响（P>0.05）。3对犊牛粪便评分和腹泻率的影响。在第36～63天时,粪便评分线性降低（P<0.05）,在第0～63天和第64～70天时,粪便评分显著线性降低（P<0.05）;在第0～35天和第0～63天时,腹泻率显著降低（P<0.05,二次）,在第36～63天时腹泻率显著线性降低（P<0.05）,在第64～70天时腹泻率线性降低（P<0.05）。4对犊牛营养物质消化率的影响。在第63天时,干物质（DM）和有机物（OM）显著线性增加（P<0.05）,粗蛋白（CP）线性增加（P<0.05）,中性洗涤纤维（NDF）有线性升高趋势（P=0.10）,对第63天时酸性洗涤纤维（ADF）和粗脂肪（EE）无显著影响（P>0.05）;添加QTE对第35天和第70天时DM、CP、OM、NDF、ADF和EE无显著影响（P>0.05）。5对犊牛血液指标的影响。添加QTE对血液中谷草转氨酶（AST）、谷丙转氨酶（ALT）、碱性磷酸酶（ALP）、葡萄糖（Glu）、总蛋白（TP）、白蛋白（ALB）、总胆固醇（TC）和甘油三脂（TG）均无显著影响（P>0.05）。在第35天时,β-羟基丁酸（BHBA）显著升高,且QTE2组BHBA水平高于QTE1、QTE3和CON组（P<0.05,二次）,尿素氮（BUN）有线性降低趋势（P=0.06）;在第63天和第70天时,BHBA显著升高,且QTE2组BHBA水平显著高于其他三组（P<0.05,二次）,BUN显著降低（P<0.05,二次）。在第35天时,总抗氧化能力（T-AOC）、丙二醛（MDA）、超氧化物歧化酶（SOD）和过氧化物酶（CAT）均无显著影响（P>0.05）;在第63天时,T-AOC线性升高（P<0.05）,MDA有线性降低趋势（P=0.10）,SOD显著升高（P<0.05,二次）,CAT浓度升高（P<0.05,二次）;第70天时,T-AOC显著线性升高（P<0.05）,MDA有线性降低趋势（P=0.08）,SOD显著升高（P<0.05,二次）,CAT线性升高（P<0.05）。在第35天时,白细胞介素-1β（IL-1β）和白细胞介素-6（IL-6）均无显著影响（P>0.05）,肿瘤坏死因子-α（TNF-α）线性降低（P<0.05）,脂多糖（LPS）显著降低（P<0.05,二次）;在第63天时,IL-1β和IL-6均无显著影响（P>0.05）,TNF-α有线性降低趋势（P=0.06）,LPS线性降低（P<0.05）;第70天时,IL-1β无显著影响（P>0.05）,IL-6有降低趋势（P=0.08,二次）,TNF-α有线性降低趋势（P=0.06）,LPS显著降低（P<0.05,二次）。在第35天时,D-乳酸（D-LA）和二胺氧化酶（DAO）均无显著影响（P>0.05）;在第63天时,D-LA显著降低（P<0.05,二次）,DAO有降低趋势（P=0.10,二次）;第70天时,D-LA和DAO显著降低（P<0.05,二次）。在第35天时,皮质醇（Cortisol）线性降低（P<0.05）,热休克蛋白（HSP）有线性降低趋势（P=0.06）;在第63天时,皮质醇有降低趋势（P=0.10,二次）,HSP降低（P<0.05,二次）;第70天时,皮质醇显著降低（P<0.05,二次）,HSP无显著影响（P>0.05）。6对犊牛瘤胃发酵参数的影响。开食料中添加QTE对瘤胃pH、微生物蛋白（MCP）、总挥发性脂肪酸浓度（TVFA）、乙酸和戊酸摩尔比例以及乙丙比无显著影响（P>0.05）,氨态氮（NH₃-N）浓度降低（P=0.05,二次）,丙酸摩尔比例有线性升高的趋势（P=0.10）,丁酸摩尔比例升高（P<0.05,二次）,异丁酸摩尔比例有线性降低趋势（P=0.08）,异戊酸摩尔比例线性降低（P=0.05）。7对犊牛瘤胃微生物的影响。随着开食料中QTE添加比例的增加,Shannon指数显著升高（P<0.05,二次）。在门水平上,厚壁菌门（Firmicutes）的相对丰度线性降低（P<0.05）;拟杆菌门（Bacteroidetes）的相对丰度有线性增高的趋势（P=0.09）;放线菌门（Actinobacteria）的相对丰度线性升高（P<0.05）;疣微菌门（Verrucomicrobia）的相对丰度有升高的趋势（P=0.10,二次）;厚壁菌门/拟杆菌门比值降低（P<0.05,二次）。在属水平上,普雷沃氏菌属（Prevotella）相对丰度线性升高（P<0.05）;丁酸弧菌属（Butyrivibrio）相对丰度有线性降低趋势（P=0.06）;欧陆森氏菌属（Olsenella）相对丰度线性升高（P<0.05）;梭菌科（Clostridiaceae）的相对丰度有降低趋势（P=0.06,二次）。8对犊牛粪便微生物的影响。添加QTE对Faith＿pd、Goods＿coverage、Pielou＿e和Simpson指数均无显著影响（P>0.05）。在第35天时,Shannon指数升高（P<0.05,二次）。在第63天时,Chao1指数和Shannon指数显著升高（P<0.05,二次）,Observed＿species指数显著线性升高（P<0.05）;在第70天时,Shannon指数显著升高（P<0.05,二次）。在门水平上,第35天时,随着QTE水平的增加,未分类菌门（TM7）相对丰度升高（P<0.05,二次）;第63天时厚壁菌门（Firmicutes）的相对丰度显著升高（P<0.05,二次）,拟杆菌门（Bacteroidetes）的相对丰度显著降低（P<0.05,二次）,厚壁菌门/拟杆菌门比值显著升高（P<0.05,二次）;第70天时厚壁菌门（Firmicutes）的相对丰度显著升高（P<0.05,二次）,拟杆菌门（Bacteroidetes）的相对丰度显著降低（P<0.05,二次）,蓝细菌门（Cyanobacteria）线性升高（P<0.05）,变形菌门（Proteobacteria）有线性降低趋势（P=0.08）,厚壁菌门/拟杆菌门比值显著升高（P<0.05,二次）。第35天时,随着QTE水平的增加,对属水平下微生物并无显著影响;第63天时,随着QTE水平的增加,丁酸梭菌（Clostridium）的相对丰度线性升高（P<0.05）,栖粪杆菌属（Faecalibacterium）和乳杆菌属（Lactobacillus）相对丰度显著升高（P<0.05,二次）,链球菌属（Streptococcus）、志贺氏菌属（Shigella）和不动杆菌属（Acinetobacter）相对丰度显著降低（P<0.05,二次）;第70天时,瘤胃球菌属（Ruminococcus）相对丰度显著线性升高（P<0.05）,普雷沃氏菌属（Prevotella）的相对丰度显著降低（P<0.05,二次）,丁酸梭菌（Clostridium）的相对丰度升高（P<0.05,二次）。综上所述,犊牛饲喂QTE在不影响平均日开食料干物质采食量的情况下,通过优化瘤胃菌群结构,改善瘤胃发酵,促进瘤胃发育,提高机体的抗氧化能力、降低炎性因子、优化肠道菌群结构、缓解肠道氧化应激、改善肠道屏障功能提高了犊牛的生长性能。本试验条件下的QTE最佳添加水平为0.45%。更多还原

【Abstract】 The growth development and health status of calves at the early stage of growth have important effects on adult performance.This study aimed to explore the effects of adding different levels of tannic acid on growth performance,blood indicators,rumen fermentation parameters and bacterial communities in calves.In this experiment,60 healthy Holstein female calves with similar birth weight(39.9 ± 1.92 kg)were randomly divided into 4 groups of 15 calves.The control group(CON)was fed calf starter and the experimental group were added Quebracho-chestnut tannin extracts(QTE,tannin ≥73%),0.30% DM(QTE1),0.45% DM(QTE2)and 0.60% DM(QTE3),respectively.During the trial period of 70 days,the experiment lasted for 70 days,and all the experimental cattle were raised on the calf Island with the same feeding management.The calves were weaned at the 64 th day of age,and the growth and development of the calves were monitored at the following 7 days.The results show that:1 Effects on physiological indicators of calves.The respiratory rate at d 0 and d 70 were not affected by QTE supplementation(P > 0.05).At d 35,the respiratory rate significantly decreased linearly(P < 0.05).At d 63,the respiratory rate tended to decrease(P = 0.09,quadratic).The rectal temperature at d 0 and d 70 were not affected by QTE supplementation(P > 0.05).At d 35,the rectal temperature significantly decreased linearly(P < 0.05).At d 63,the rectal temperature significantly decreased(P < 0.05,quadratic).2 Effects on growth performance of calves.At d 35,the body weight was not affected by QTE supplementation(P > 0.05).At d 63 and d 70,the body weight was significantly increased(P < 0.05,quadratic).At d 36-63,the average daily gain(ADG)increased linearly(P < 0.05),and significantly increased at d 0-63(P < 0.05,quadratic).At d 64-70,ADG tended to increase linearly(P = 0.09).At d 64-70,the average daily calf starter dry matter intake(ADFI)significantly increased(P < 0.05,quadratic).At d 36-63 and d 0-63,F/G decreased linearly(P < 0.05).Body height,body length,hearth girth,abdominal circumference and cannon circumference were not affected by QTE supplementation(P > 0.05).3 Effects on fecal score and diarrhea rate of calves.At d 36-63,the fecal score decreased linearly with increasing QTE doses(P < 0.05).At d 0-63 and d 64-70,the fecal score significantly decreased linearly(P < 0.05).At d 0-35 and d 0-63,the diarrhea rate significantly decreased(P < 0.05,quadratic).At d 36-63,the diarrhea rate significantly decreased linearly(P < 0.05).At d 64-70,the diarrhea rate decreased linearly with increasing QTE doses(P < 0.05).4 Effects on nutrient digestibility of calves.At d 63,dry matter(DM)and organic matter(OM)significantly increased linearly with increasing QTE doses(P < 0.05),and crude protein(CP)increased linearly(P < 0.05),and neutral detergent fiber(NDF)tended to increase linearly(P = 0.10).Supplementation of QTE did not affect acid detergent fiber(ADF)and ether extract(EE)at d 63(P > 0.05).DM,CP,OM,NDF,ADF and EE at d 35 and d 70 were not affected by QTE supplementation(P > 0.05).5 Effects on blood indicators of calves.Supplementation of QTE did not affect blood concentration of glutamate aminotransferase(AST),alanine aminotransferase(ATL),alkaline phosphatase(ALP),glucose(Glu),total protein(TP),albumin(ALB),Total cholesterol(TC),triglyceride(TG),(P > 0.05).At d 35,β-hydroxybutyric acid(BHBA)significantly increased,and the BHBA concentration in the QTE2 treatment was higher than the CON treatment,QTE1 treatment and QTE3 treatment(P < 0.05,quadratic).Blood concentration of urea nitrogen(BUN)tended to decrease linearly at d 35(P = 0.06).At d63 and d 70,BHBA significantly increased,and the BHBA concentration in the QTE2 treatment was higher than the CON treatment,QTE1 treatment and QTE3 treatment(P <0.05,quadratic),and BUN significantly decreased(P < 0.05,quadratic).At d 35,supplementation of QTE did not affect blood concentration of total antioxidant capacity(TAOC),malondialdehyde(MDA),activity of super oxide dismutase(SOD)and peroxidase(CAT)(P > 0.05).At d 63,T-AOC increased linearly with increasing QTE supplementation(P < 0.05),and MDA tended to decrease linearly(P = 0.10),and SOD significantly increased(P < 0.05,quadratic),and CAT increased(P < 0.05,quadratic).At d 70,T-AOC significantly increased linearly(P < 0.05),and MDA tended to decrease linearly(P = 0.08),and SOD significantly increased(P < 0.05,quadratic),and CAT increased linearly(P <0.05).At d 35,supplementation of QTE did not affect blood concentration of interleukin-1β(IL-1β)and interleukin-6(IL-6)(P>0.05),tumor necrosis factor-α(TNF-α)decreased linearly(P < 0.05),and lipopolysaccharide(LPS)significantly decreased(P < 0.05,quadratic).At d 63,supplementation of QTE did not affect blood concentration of IL-1βand IL-6(P > 0.05),TNF-α tended to decrease linearly(P = 0.06),and LPS decreased linearly(P < 0.05).At d 70,supplementation of QTE did not affect blood concentration of IL-1β(P >0.05).IL-6 tended to decrease(P = 0.08,quadratic),TNF-α tended to decrease linearly(P = 0.06),and LPS significantly decreased(P < 0.05,quadratic).At d 35,D-lactic acid(D-LA)and diamine oxidase(DAO)were not affected by QTE supplementation(P >0.05).At d 63,D-LA significantly decreased(P < 0.05,quadratic),and DAO tended to decrease(P = 0.10,quadratic).At d 70,D-LA and DAO significantly decreased(P < 0.05,quadratic).At d 35,cortisol decreased linearly(P < 0.05),heat shock protein(HSP)tended to decrease linearly(P = 0.06).At d 63,cortisol tended to decrease(P = 0.10,quadratic),HSP decreased(P < 0.05,quadratic),At d 70,cortisol significantly decreased(P < 0.05,quadratic),HSP was not affected by QTE supplementation(P > 0.05).6 Effects on rumen fermentation parameters of calves.QTE supplementation in the calf starter did not affect rumen pH,microbial protein,rumen total volatile fatty acid concentration,the molar ratio of acetic acid and valeric acid,and acetic/propionic(P >0.05).However,with increasing QTE supplementation in the calf starter,the concentration of ammonia-nitrogen decreased(P = 0.05,quadratic),the molar proportion of propionate tended to increase linearly(P = 0.10),the molar proportion of butyrate increased(P < 0.05,quadratic),the molar proportion of isobutyric acid followed a trend to decrease linearly(P= 0.08),and the molar proportion of isovalerate decreased linearly(P = 0.05).7 Effects on rumen microorganisms of calves.With increasing QTE addition,the Shannon index significantly increased(P < 0.05,quadratic).At the phylum level,with the increase of the proportion of QTE in the calf starter,the relative abundance of Firmicutes decreased linearly(P < 0.05),the relative abundance of Bacteroides tended to increase linearly(P = 0.09),the relative abundance of Actinomycetes increased linearly(P < 0.05),the relative abundance of Verrucomicrobia tended to increase(P = 0.10,quadratic),and the ratio of Firmicutes/Bacteroides decreased(P < 0.05,quadratic).At the genus level,the relative abundance of Prevotella increased linearly(P < 0.05),the relative abundance of Butyrivibrio tended to decrease linearly(P = 0.06),the relative abundance of Olsenella increased linearly(P < 0.05),and the relative abundance of Clostridiaceae tended to decrease(P = 0.06,quadratic).8 Effects on fecal microorganisms of calves.Supplementation of QTE did not affect fecal microorganisms of Faith＿pd,Goods＿coverage,Pielou＿e and Simpson(P > 0.05).At d 35,Shannon increased(P < 0.05,quadratic).At d 63,Chao1 and Shannon significantly increased(P < 0.05,quadratic),Observed＿species significantly increased linearly(P <0.05).At d 70,Shannon significantly increased(P < 0.05,quadratic).At the phylum level,with the increase of the proportion of QTE in the calf starter,the relative abundance of TM7 increased at d 35(P < 0.05,quadratic).At d 63,the relative abundance of Firmicutes significantly increase(P < 0.05,quadratic),the relative abundance of Bacteroidetes significantly decrease(P < 0.05,quadratic),and the ratio of Firmicutes/Bacteroides significantly increased(P < 0.05,quadratic).At d 70,the relative abundance of Firmicutes significantly increased(P < 0.05,quadratic),the relative abundance of Bacteroidetes significantly decreased(P < 0.05,quadratic),the relative abundance of Proteobacteria tended to decrease linearly(P = 0.08),and the ratio of Firmicutes/Bacteroides significantly increased(P < 0.05,quadratic).QTE supplementation in the calf starter did not affect fecal microorganisms of the genus level at d 35(P > 0.05).At d 63,with the increase of the proportion of QTE in the calf starter,the relative abundance of Clostridium increased linearly(P < 0.05),the relative abundance of Faecalibacterium and Lactobacillus significantly increased(P < 0.05,quadratic),the relative abundance of Streptococcus,Shigella and Acinetobacter significantly decreased(P < 0.05,quadratic).At d 70,the relative abundance of Ruminococcus significantly increased linearly(P < 0.05),the relative abundance of Prevotella significantly decreased(P < 0.05,quadratic),the relative abundance of Clostridium significantly increased(P < 0.05,quadratic).In conclusion,feeding QTE to calves improved growth performance by optimizing the structure of rumen flora,improving rumen fermentation,promoting rumen development,improving the antioxidant capacity,reducing inflammatory factors,optimizing the structure of intestinal flora,alleviating intestinal oxidative stress,and improving intestinal barrier function,without affect the average daily dry matter intake of starter.The optimal addition level of QTE under the condition of this study was 0.45%.更多还原