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1.
犊牛断奶应激是指因饲料、生长环境等发生变化引起的一系列应激反应,会影响犊牛的食欲、采食量,削弱犊牛的身体免疫力,导致犊牛出现身体炎症以及腹泻等疾病,增加犊牛的死亡率。针对犊牛的断奶应激预防,可以选择在犊牛饲料中加入益生菌、植物提取物丁酸、谷氨酰胺等物质,这对缓解犊牛断奶应激,增强犊牛的身体免疫力,降低犊牛腹泻疾病的发生概率有着积极影响。 相似文献
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<正>早期断奶的仔猪,因诸多方面应激因素和机体内环境的不适应往往会导致断奶后的1～2d内仔猪出现腹泻或水肿,少数为内毒素休克,常被称为早期断奶仔猪应激综合症。早期断奶仔猪应激导致仔猪发病死亡或生长停 相似文献
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我国目前集约化生产的养猪场一般在3～4周龄断奶.断奶是仔猪生活中的一次大转折.断奶时将仔猪和母猪分开,仔猪的饲料由全乳日粮变为干饲料.此时断奶仔猪处于强烈生长发育时期,但消化机能和抗病能力又不够强,日粮剧烈的变化,加上环境的变化,对仔猪产生强烈的应激.仔猪常表现为食欲差、消化功能紊乱、腹泻、生长迟滞等,这就是所谓的“仔猪早期断奶综合症”.部分仔猪因此变成僵猪.配制适合早期断奶仔猪消化生理的饲粮是克服早期断奶综合症的有效方法.但环境因素对仔猪断奶应激的程度也有较大的影响.创造一个条件适合的小环境可以缓和仔猪的断奶应激. 相似文献
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现代养猪生产中,规模化猪场已逐步采用仔猪超早期断奶(SEW)或早期断奶,国外有的提前到5～10日龄,而我国较多是4周龄断奶[1].早期断奶可以提高母猪年生产力,降低饲养成本,提高养猪生产效益.然而仔猪阶段是生长发育最强、饲料转化率最高,同时也是死亡最高、饲养管理最复杂的阶段[2].主要是由于仔猪消化系统和免疫器官发育不完善,消化酶系统和胃酸分泌量不足,正常的消化道微生态系统还未完全建立,断奶应激往往导致仔猪食欲减退,消化能力差,饲料利用率低,抗病力差,出现腹泻等"仔猪早期断奶综合症"[3].仔猪早期断奶应激主要有心理、营养和环境三方面,本文就其中营养因素中的日粮酸化调控进行探讨. 相似文献
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从初生到20kg阶段的仔猪,是一生中相对生长最快的时期。在仔猪从哺乳期过渡到保育期断奶时,由于仔猪生长发育快、消化生理功能及免疫系统尚未发育成熟等方面的特点,同时遭遇心理、营养、环境等因素的应激,临床表现为采食量和饲料利用率低、腹泻和死亡、生长差甚至体重下降等仔猪断奶综合症,其中断奶营养应激是最主要的。近年来,国内外集约化猪场逐渐采用隔离式早期断奶(Segregated early-weaning,简称SEW)仔猪饲养管理技术措施,以防止疫病传染、提高仔猪生产性能和母猪繁殖效率、降低生产成本,仔猪早期断奶应激综合症显得更为突出。为了解… 相似文献
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R Kirsch 《Tier?rztliche Praxis》1986,14(2):211-216
Considerable economic loss can arise from virus-caused enteritis in calves, in the form of so-called infectious factor diseases, which often develop more seriously when bacterial organisms, such as E. coli become involved. Rota-, corona- and parvoviruses are of particular interest. These pathogens have a marked predilection for intestinal epithelium. Rotavirus destroys the epithelial cells of the upper parts of the villi. Coronavirus penetrates to the base of the small intestinal villi and the superficial and crypt colonic epithelium is frequently affected. Infection of the small intestinal crypt epithelium is characteristic of parvovirus; loss of epithelium at the villus tip is also observed. Damage of the mucosa results in a reduction in digestive and absorbing capacity. It is not possible to treat these virus strains specifically. Great importance is therefore attached to the vaccination of dams as immune prophylaxis. Consumption of sufficient colostrum and milk from vaccinated dams affords the calves good protection. The mechanism is based on the presence of milk antibodies in the calf's intestine which neutralise orally ingested pathogens. 相似文献
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The amino acid (AA) absorption along the intestinal tract of the Pacific bluefin tuna (Thunnus orientalis) was evaluated using two hydrolysed protein sources (fresh sardine muscle and soybean meal) with the everted intestine technique. Pork pepsin and pancreatic enzyme extract from the bluefin tuna were used to hydrolyse the protein from fresh sardine (FSH) and soybean meal (SMH) under optimal bluefin tuna fish physiological conditions. Both of the hydrolysate solutions were tested within three intestinal sections from the bluefin tuna. The everted intestinal fractions immersed in the hydrolysate solutions were sampled at different times to analyse for AA and absorption rate calculations. Fresh sardine and SMH contained greater amounts of essential amino acids (EAA) than those of non‐essential amino acids (NEAA); however, the profiles of AA absorbed showed higher absorption of NEAA in both cases. Using a similar concentration solution, the absorption rates within the intestinal fractions showed a preferential absorption in the proximal and distal regions for Arg and His when FSH was used. However, the absorption rates for Lys resulted in a decreasing proximal‐to‐distal gradient between the different intestinal regions for FSH and SMH. The possibility of a catabolic role of certain AAs in the enterocytes being able to explain the differences in absorption is discussed. 相似文献
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Magali Zacarias-Soto Benjamín Barón-Sevilla Juan P. Lazo 《Fish physiology and biochemistry》2013,39(5):1331-1339
Studies aimed to assess the digestive physiology of marine fish larvae under culture conditions are important to further understand the functional characteristics and digestive capacities of the developing larvae. Most studies to date concentrate on intestinal lumen digestion and little attention to the absorption process. Thus, the objectives of this study were to histochemically detect and quantify some of the enzymes responsible for absorption and intracellular digestion of nutrients in the anterior and posterior intestine of California halibut larvae. Alkaline and acid phosphatases were detected from the first days post-hatch (dph). Alkaline phosphatase maintained a high level of activity during the first 20 dph in both intestinal regions. Thereafter, a clear intestinal regionalization of the activity was observed with the highest levels occurring in the anterior intestine. Acid phosphatase activity gradually increased in both intestinal regions during development, and a regionalization of the activity was not observed until late in development, once the ocular migration began. Highest levels were observed in the anterior intestine at the end of metamorphosis concomitant with the stomach development. The results from this study show some morphological and physiological changes are occurring during larval development and a clear regionalization of the absorption process as the larvae develops. These ontological changes must be considered in the elaboration of diets according to the digestive capacity of the larvae. 相似文献
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Natriuretic peptide inhibition of intestinal salt absorption in the Japanese eel: physiological significance 总被引：2，自引：0，他引：2
Electrophysiological studies in vitro demonstrated the significant inhibition by natriuretic peptides (NP) of short-circuit current across the eel intestine, an important osmoregulatory organ. Inhibitory potencies of several members of the NP family were assessed by voltage-clamp determination of net transepithelial salt absorption measured as the short-circuit current Isc across the intestine of the freshwater-adapted (FW) and seawater-adapted (SW) Japanese eel (Anguilla japonica); the order of potency of synthetic eel peptides was: amidated atrial natriuretic peptide (ANP-NH2) > ventricular natriuretic peptide (VNP) > atrial natriuretic peptide (ANP) >> C-type natriuretic peptide (CNP). Neither the order of potency nor the absolute potencies were effected by salinity adaptation. The observed potency sequence suggests that inhibition of intestinal absorption is mediated by A-type guanylyl cyclase-coupled NP receptors. The relatively low sensitivity of the intestinal response to NP compared with circulating NP concentrations suggests a role for intestinal regulation by NP which is independent of systemic delivery from cardiac sources. A novel model, incorporating the known immunohistochemical localization of NP-ergic cells and processes in the epithelial layer of the intestine and the dissipation of the Na+ electrochemical gradient along the alimentary tract, is developed in which local secretion of NP (in response to a bolus of food) inhibits salt absorption across the intestine regionally in favor of increased nutrient absorption. 相似文献
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In 46 newborn calves with and without respiratory distress syndrome which had been delivered prematurely by caesarean section a blood coagulation profile was established. These animals were compared with 26 healthy, 5- to 8-day-old calves. Prematurely delivered calves showed a lower average plasma fibrinogen concentration than animals delivered in due time. Calves which developed a respiratory distress syndrome had a slightly prolonged prothrombin time and partial thromboplastin time as well as a lower antithrombin III activity already immediately postnatum compared with healthy prematures and some-day-old calves. It has to be assumed that in calves with respiratory distress syndrome--in analogy to pulmonary immaturity--the blood clotting mechanism is not yet fully developed. In healthy prematures and surviving asphyctic calves hemostasis remains largely stable during the first day of life, whereas plasma fibrinogen concentration increases. In the calves not surviving the examination period prothrombin time and partial thromboplastin time postnatum became significantly longer. Only in these severely asphyctic calves the presence of a consumption coagulopathy seems likely. A secondary reactive fibrinolysis was not observed. 相似文献
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本研究对斑点叉尾鮰(Ictalurus punctatus)的发酵饲料进行了合理饲喂,并确定了其对斑点叉尾鮰生长、肠道菌群和代谢组学的影响。实验设置3组：持续投喂组(A)(即在膨化饲料中持续添加发酵饲料),间隔投喂组即向膨化饲料中按周间隔添加发酵饲料(B),对照组仅投喂膨化饲料(C)。实验共持续6个月。实验结束后,对斑点叉尾鮰进行称重,并用16S rRNA扩增子测序技术和基于液相色谱的代谢组学技术分别检测斑点叉尾鮰肠道菌群组成以及代谢组学。结果显示,间隔投喂组斑点叉尾鮰终末体重(FBW)显著高于对照组和持续投喂组(P<0.05)。间隔投喂组的群落丰富度和多样性最高,持续投喂组群落丰富度最低(P>0.05)。厚壁杆菌门(Firmicutes)、放线菌门(Actinobacteriota)、蓝藻门(Cyanobacteria)、变形菌门(Proteobacteria)、梭杆菌门(Fusobacteriota)、绿弯菌门(Chloroflexi)和异常球菌门(Deinococcota)是优势细菌门。优势肠道菌属包括未命名的叶绿体科中的一个属(norank_f_norank_o_Chloroplast)、分枝杆菌属(Mycobacterium)、鲸杆菌属(Cetobacterium)、罗姆布茨菌属(Romboutsia)、微小杆菌属(Exiguobacterium)和狭义梭菌属(Clostridium_sensu_stricto_1)。代谢组学分析表明,持续投喂组主要通过N-乙酰-D-半乳糖胺显著上调影响肠道菌群半乳糖和磷酸转移酶系统代谢通路(P<0.05),进而影响鱼体对碳水化合物的消化吸收。而间隔投喂组差异代谢产物L-丝氨酸和L-苯丙氨酸显著上调(P<0.05),影响斑点叉尾鮰肠道菌群硫代谢、氨基酸代谢等,继而影响斑点叉尾鮰能量吸收、抗炎症和免疫等能力。本研究为斑点叉尾鮰发酵饲料投喂方式的探索和健康绿色养殖提供了理论依据。 相似文献
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M Langanke M Steinhardt U Bünger U Fiebig J Kutschke I Gollnast 《Tier?rztliche Praxis》1992,20(5):462-468
Post-mortem examinations were carried out on 65 calves which were stillborn or died within 24 hours of birth. All calves came from a large dairy unit with about one thousand cattle of the Schwarzbuntes Milchrind breed. To evaluate the perinatal losses, the farm records of parturitions from 1985-1990 were used. The calves had gross damage of the CNS, the musculature, subcutaneous tissue and internal organs such as lung and intestines. It may be assumed that a lesser degree of similar damage would also be present in the surviving calves. The level of perinatal losses is determined particularly by deaths following prolonged parturition due to foetal oversize in heifers and young cows, but also by the birth of immature calves of low weight after pregnancy of normal or decreased duration and by twin pregnancies with high total calf mass and relative immaturity of the calves. 相似文献
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以霍氏肠杆菌(E3)和乳酸菌(R3)2株益生菌对凡纳滨对虾进行为期4周的养殖饲喂实验,饲喂后期利用Biolog-ECO方法对实验组及空白组的凡纳滨对虾肠道微生物菌群多样性的差异进行比较分析,以评价益生菌对凡纳滨对虾肠道微生物菌群代谢功能的影响。结果显示,添加霍氏肠杆菌(E3)或乳酸菌(R3)的实验组,与空白组相比较,平均每孔颜色变化率显著上升,表明益生菌增强了肠道微生物活性;凡纳滨对虾肠道微生物利用各类碳源的整体能力显著增强,表明益生菌可以促进水产动物的代谢功能;肠道微生物多样性指数(包括Shannon、Simpson和McIntosh指数)有明显差异,表明饲喂2株益生菌可以提高凡纳滨对虾肠道菌群的丰富度。其中,停喂霍氏肠杆菌后第1天和第5天取样结果表明,Shannon指数显著降低,Simpson和McIntosh指数显著升高;停喂乳酸菌后的第1天和第5天取样结果表明,Shannon指数无显著差异,Simpson和McIntosh指数显著升高;二者在第10天取样的结果中均无显著差异,表明饲料中添加益生菌可以改变凡纳滨对虾肠道内原有菌群的数量和结构,促进对虾肠道内微生物群落间复杂的相互作用,进而在维持或者促进对虾健康方面发挥着重要的作用,同时也表明此两株益生菌在凡纳滨对虾肠道中停留时间最少为5 d。 相似文献
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The digestion and selective absorption of dietary fatty acids in Arctic charr, Salvelinus alpinus 总被引：1，自引：0，他引：1
To compare the rates of digestion and absorption of individual fatty acids, Arctic charr, Salvelinus alpinus (L.), were fed isoenergetic diets containing 40 g kg?1 coconut oil, and various combinations of 10 g kg?1 of polyunsaturated fatty acids (PUFA) (18:2n-6 or 18:3n-3) and monounsaturated fatty acids (MONO) (20:1n-9 or 22:1n-9) in the form of free fatty acids (FFA) or triacylglycerol (TAG). The average lipid digestibility for all diets measured by use of the chromic oxide method in the pyloric caeca area, midgut and hindgut were 72%, 83% and 88%, respectively, showing that lipid digestion and absorption occur mainly in the pyloric caeca area, but also extend throughout the intestinal tract. Analyses of digesta present in the intestinal segments suggest the predominance of non-specific lipolytic activity producing primarily FFA and glycerol from dietary TAG. Comparisons of the fatty acid composition of the lipid classes in the digesta showed that the utilization of dietary TAG was dependent both on the rate of release of the individual fatty acids from TAG, and their subsequent rate of absorption. When supplied as either FFA or TAG, the levels of PUFA (18:2n-6 or 18:3n-3) in the digesta were very low, indicating almost complete utilization. Both MONO used (20:1n-9 or 22:1n-9) were absorbed less efficiently than PUFA, but the rate of release from TAG seemed to be rate limiting only for 22:1n-9, which accumulated in the digesta. The rates of absorption of 20:1n-9 and 22:1n-9 when fed as FFA were the same. Comparisons of the levels of fatty acids in the dietary coconut oil TAG with those of the digesta lipids showed that 12:0 was a good substrate for intestinal lipase and was quickly absorbed. The lipolysis of 14:0 and 16:0 was intermediate while the longer-chain 18:0 appeared very resistant to digestion and was a major component of TAG, diacylglycerols and monoacylglycerols present in particularly the hindgut digesta. The absorption of 18:0 also appeared to be very low. The results suggest that PUFA are released very rapidly from dietary TAG by intestinal lipases in Arctic charr, and are specifically absorbed compared with long-chain saturated and monounsaturated fatty acids. The rate of lipolysis may be the rate-limiting step in the digestion of very long chain monounsaturated fatty acids such as 22:1n-9, while both the rate of lipolysis and absorption may be rate limiting for long-chain saturated fatty acids such as 18:0. 相似文献