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1.
《饲料工业》2019,(16):1-10
反刍动物消化系统在结构上与单胃动物不同,对营养物质的消化存在差异。营养物质在瘤胃内被微生物降解利用,产生的挥发性脂肪酸被瘤胃壁吸收供能;菌体蛋白与未降解的饲料流入小肠,由胰腺分泌的消化酶消化成小分子物质,如葡萄糖、氨基酸等被小肠上皮直接吸收利用。理论上小肠内淀粉类营养物质化学性消化利用效率远高于瘤胃,但淀粉小肠内的消化受到胰腺淀粉酶分泌不足的限制,因此调控营养物质在小肠内的化学性消化对于高产奶牛更加迫切。本课题组从胰腺外分泌功能的调控入手,研究反刍动物小肠营养物质的化学性消化的调控,尤其是日粮碳水化合物结构及功能性氨基酸的调控作用。基于此,本文综述反刍动物胰腺的生理结构、对碳水化合物的消化、外分泌的影响因素及其调控机理,旨在为提高反刍动物营养物质的消化利用效率、减少饲料资源的浪费提供理论依据。  相似文献   

2.
Because of the unique features of the ruminant digestive system, variations in diet composition and intake produce dramatic changes in ruminal fermentation. Optimizing nutritional management requires an understanding of how these variations and changes influence digestion and metabolism. Although the pancreas plays a central role in digestion and subsequent nutrient metabolism, relatively little is known about pancreatic adaptation to nutritional changes in the ruminant. Increasing starch intake has been suggested to increase pancreatic alpha-amylase; however, recent work suggests that dietary energy per se may drive these changes, and interactions with other nutrients, such as protein, may exist. Studies describing the influence of altered protein and lipid intakes on pancreatic adaptation in ruminants are lacking. Pancreatic secretion of both insulin and glucagon respond to the intravenous infusion of VFA in a dramatic fashion; however, feeding studies suggest that the influence of VFA on insulin and glucagon may be more subtle. Interactions exist between stimulatory signals and physiological state, such as lactation. Assessment of pancreatic endocrine secretion is further complicated by a variable removal of insulin and glucagon by hepatic tissues. These studies point out that pancreatic hormone secretion is controlled by integrated and complex mechanisms. Studies of these controlling mechanisms should consider the entire array to more fully understand hormone secretion.  相似文献   

3.
BACKGROUND: Response to therapy in canine exocrine pancreatic insufficiency (EPI) varies considerably, making it difficult to determine prognosis for individual patients. HYPOTHESIS: Response to initial treatment (RIT) and survival are affected by signalment, clinical variables, and therapeutic regimen employed. ANIMALS: Client-owned dogs diagnosed with EPI between 1990 and 2002 were included in this study. METHODS: The study comprised a retrospective, questionnaire-based review. RESULTS: One hundred seventy-eight completed questionnaires were returned. RIT was good in 60% of treated dogs, partial in 17%, and poor in 23%. On univariate analysis, dogs that received antibiotics (P = .037) or had high serum folate concentration (P = .037) had a poorer RIT. On multivariate analysis, there were no strong predictors of good RIT. Nineteen percent of treated dogs were euthanized within 1 year, but overall median survival time for treated dogs was 1919 days. No clear benefit of changing to a fat-restricted diet could be demonstrated, but marked hypocobalaminemia (< 100 ng/L) was associated with shorter survival (P = .012). Use of uncoated pancreatic enzyme supplements, antibacterials, or H2 antagonists was not associated with longer survival. Breed, sex, age at diagnosis ( < or = 4 years or > 4 years), and clinical signs at diagnosis also made no difference. CONCLUSIONS AND CLINICAL IMPORTANCE: Long-term prognosis in canine EPI is favorable for dogs that survive the initial treatment period. Although there are few predictors of good RIT or long-term survival, severe cobalamin deficiency is associated with shorter survival. Therefore, parenteral cobalamin supplementation should be considered when hypocobalaminemia is documented.  相似文献   

4.
Seaweeds are macroalgae, which can be of many different morphologies, sizes, colors, and chemical profiles. They include brown, red, and green seaweeds. Brown seaweeds have been more investigated and exploited in comparison to other seaweed types for their use in animal feeding studies due to their large sizes and ease of harvesting. Recent in vitro and in vivo studies suggest that plant secondary compound-containing seaweeds (e.g., halogenated compounds, phlorotannins, etc.) have the potential to mitigate enteric methane (CH4) emissions from ruminants when added to the diets of beef and dairy cattle. Red seaweeds including Asparagopsis spp. are rich in crude protein and halogenated compounds compared to brown and green seaweeds. When halogenated-containing red seaweeds are used as the active ingredient in ruminant diets, bromoform concentration can be used as an indicator of anti-methanogenic properties. Phlorotannin-containing brown seaweed has also the potential to decrease CH4 production. However, numerous studies examined the possible anti-methanogenic effects of marine seaweeds with inconsistent results. This work reviews existing data associated with seaweeds and in vitro and in vivo rumen fermentation, animal performance, and enteric CH4 emissions in ruminants. Increased understanding of the seaweed supplementation related to rumen fermentation and its effect on animal performance and CH4 emissions in ruminants may lead to novel strategies aimed at reducing greenhouse gas emissions while improving animal productivity.  相似文献   

5.
The goal of the study was to determine whether hyperglycaemia or hyperlipidaemia causes pancreatitis in cats and to assess the effect of excess serum glucose and lipids on amylase and lipase activity. Ten-day hyperglycaemic and hyperlipidaemic clamps were carried out in five and six healthy cats, respectively. Ten healthy cats received saline and served as controls. The activity of amylase was below the normal range in 4 of 5 hyperglycaemic cats by day 10. The activity of lipase did not vary in any of the cats. Samples of exocrine pancreas were normal on histological examination, but the number of tissue neutrophils was increased in hyperglycaemic cats (P < 0.05). In a retrospective study 14 of 40 (35%) cats with naturally occurring diabetes mellitus had amylase activities below the reference range at the time of admission. Amylase activities normalised within 1 week of insulin therapy and subsequent glycaemic control. Lipase activity was increased in 26 of 40 (65%) diabetic cats and remained elevated despite glycaemic control. In conclusion, hyperglycaemia, but not hyperlipidaemia, increases pancreatic neutrophils in cats. However, because the histological morphology of the exocrine pancreas was normal, hyperglycaemia may play only a minor role in the pathogenesis of pancreatitis. Low amylase activities in diabetic cats may reflect an imbalance in glucose metabolism rather than pancreatitis.  相似文献   

6.
Few studies of the prevalence of histologic lesions of the exocrine pancreas in dogs have been reported, and none of them systematically evaluate the localization of these lesions. The purpose of this study was to describe the anatomic localization of pancreatic inflammation, necrosis, and fibrosis in dogs presented for postmortem examination. Seventy-three pancreata from dogs presented for postmortem examination were evaluated and investigated for the presence of suppurative inflammation (SI), pancreatic necrosis (PN), and lymphocytic inflammation (LI). Sections that showed evidence of SI, PN, or LI also were evaluated for pancreatic fibrosis (F). The tendency for a preferred localization for SI, PN, and LI was evaluated by chi-square analysis. A total of 47 pancreata with histologic evidence of pancreatitis (SI, PN, or LI; F alone was not considered evidence of pancreatitis) were identified. Twenty-four (51.1%) had SI, 23 (48.9%) had PN, and 34 (72.3%) had LI. Of the 47 dogs with SI, PN, or LI, 28 (59.6%) had F. The distribution of SI, PN, and LI between the right and the left limb of the pancreas and among the 5 anatomic regions was random, based on a goodness-of-fit test. We conclude that pancreatic inflammation tends to occur in discrete areas within the pancreas rather than diffusely throughout the whole organ. These findings suggest that a single biopsy is insufficient to exclude subclinical pancreatitis and that there is no preferred site for pancreatic biopsy collection unless gross lesions are apparent.  相似文献   

7.
铜是反刍动物必需微量元素之一,铜在反刍动物机体内具有很广泛的分布及多种生物学功能,而反刍动物对铜元素的利用率很低。文中论述了铜在反刍动物体内的分布及消化代谢特点、作用机制、影响铜利用的因素和铜对反刍动物所产生的生物学效应以及今后铜制剂的研制方向。  相似文献   

8.
Four yearling goats (31.2 ± 2.5 kg), surgically fitted with common bile duct reentrant and duodenal catheter, were used in two 4 × 4 Latin square design experiments to investigate the effects of duodenal infusion of phenylalanine for different times on pancreatic exocrine secretion (PES). In experiment 1 (the long‐term experiment), goats were duodenally infused with 0, 2, 4 or 8 g/day phenylalanine for 14 day. Pancreatic juice and jugular blood samples were collected over 1‐h intervals for 6 h daily from day 11 to day 14 to encompass a 24‐h day. In experiment 2 (the short‐term experiment), goats were infused with phenylalanine for 10 h continuously at the same infusion rate as experiment 1 after feed deprivation for 24 h repeated every 10 day. Pancreatic juice and blood samples were collected at 0, 1, 2, 4, 6, 8 and 10 h of infusion. The volume and pH of pancreatic juice were measured, and a 5% subsample was composited and frozen until analysis of enzyme activities. Plasma was frozen until analysis of insulin and cholecystokinin (CCK). In experiment 1, pancreatic juice, α‐amylase secretion and plasma CCK concentration responded quadratically (p < 0.05), with the top value observed at the 2 g/day phenylalanine. Trypsin secretion had a quadratic response (p < 0.05), with secretion increasing up to 4 g/day phenylalanine and decreasing thereafter. Phenylalanine linearly decreased pancreatic protein and lipase secretion (p < 0.05). The results of correlation analysis showed significant correlations (p < 0.05) between plasma CCK concentration and secretion of α‐amylase and trypsin. However, the short‐term phenylalanine infusion did not influence (p > 0.05) pancreatic juice, protein, α‐amylase, lipase, trypsin secretion and plasma CCK concentration. These results indicate PES of ruminants is stimulated by phenylalanine and is potentially mediated by CCK in the long‐term duodenal infusion treatment, but is not influenced by phenylalanine in the short‐term duodenal infusion treatment.  相似文献   

9.
蒸汽压片玉米调控瘤胃发酵与营养物质消化的研究进展   总被引:1,自引:0,他引:1  
玉米作为反刍动物重要能量饲料,在饲养实践中通常需要进行一定加工处理之后进行饲喂,以提高其养分利用率.蒸汽压片技术是目前一种重要的玉米加工方式,可以显著提高玉米淀粉全消化道消化率,并在维持瘤胃微生物正常发酵方面具有重要作用.本文综述了蒸汽压片玉米调控瘤胃中营养物质消化和微生物发酵的作用功效与机理,以期为蒸汽压片玉米的进一...  相似文献   

10.
本文简述了中草药饲料添加剂在畜禽生产中应用的意义,重点论述了中草药饲料添加剂在反刍家畜生产研究中的应用现状及当前存在的主要问题和发展前景。  相似文献   

11.
12.
This study describes the ultrasonographic and cytopathological characteristics of malignant neoplasms of the exocrine pancreas and their value in making an antemortem diagnosis. The medical records of eight dogs and five cats were reviewed. The clinical presentations were variable and at times mimicked pancreatitis. Overall, cytopathology of ultrasound or fluoroscopic-guided biopsies or fine-needle aspirates, or impressions from surgical biopsies were helpful in establishing the diagnosis in 10 of 12 animals where it was performed. Histopathology of ultrasound or fluoroscopic-guided biopsies provided a diagnosis in five of six cases where it was performed.  相似文献   

13.
The purpose of this study was to determine the prevalence of pancreatic nodular hyperplasia (NH) and its relation to age in the dog. A total of 101 dogs were enrolled. The pancreas was evaluated by histology and hyperplastic lesions were detected and scored. Age was recorded from the medical records. Correlation of age with inflammation and presence of hyperplastic lesions was evaluated. Of the 101 dogs, 81 (80.2%) had evidence of NH. Twenty-five of the 101 dogs did not have evidence of pancreatic inflammation, necrosis, and/or fibrosis, 17 (68.0%) of which had evidence of NH. Mean +/- SD age in dogs with NH was significantly higher compared with dogs without NH (9.5 +/- 3.4 years versus 3.4 +/- 3.3; P-value < 0.0001). We conclude that NH is a common pathologic lesion in dogs and shows a positive correlation with age regardless of the presence or absence of pancreatic inflammation, necrosis, or fibrosis.  相似文献   

14.
牧草的营养价值研究及其在反刍家畜中的应用   总被引:3,自引:0,他引:3  
根据牧草的基本营养价值特性,综合了近年来人们对反刍家畜利用牧草及提高牧草营养价值的生物学研究成果。  相似文献   

15.
Background: An assay for the measurement of pancreatic elastase in dog feces has been introduced. Hypothesis/Objectives: The goal of this study was to evaluate the rate of false‐positive fecal‐elastase test results in dogs with suspected exocrine pancreatic insufficiency (EPI) and to assess serum cholecystokinin (CCK) concentrations in dogs with a false positive fecal elastase test result. Animals: Twenty‐six fecal and serum samples from dogs suspected of EPI, for which samples had been submitted to a commercial laboratory (Vet Med Labor) for analysis. Methods: Prospective study. Serum trypsin‐like immunoreactivity (TLI) was measured in 26 dogs with a decreased fecal elastase concentration of <10 μg/g feces. Serum CCK concentrations were measured in 21 of these dogs. Results: Of 26 dogs with a decreased fecal elastase concentration, 6 (23%) had serum TLI concentrations within or above the reference range. Serum CCK concentrations were significantly higher in dogs with a true positive fecal elastase test result (median: 1.1 pmol/L; range: 0.1–3.3 pmol/L) than in those with a false positive fecal elastase test result (median: 0.1 pmol/L; range: 0.1–0.9 pmol/L; P value = .0163). Conclusions and Clinical Importance: The rate of false positive fecal elastase test results was high in this group of dogs, suggesting that diagnosis of EPI must be confirmed by other means. The decreased CCK concentration in dogs with a false positive fecal elastase test result could suggest that false positive results are because of decreased stimulation of exocrine pancreatic function caused by other conditions.  相似文献   

16.
Ghrelin-28 was found to inhibit the pancreatic enzyme output in rats, although the effect of pentaghrelin has not been studied. The effect of ghrelin on pig exocrine pancreas remains largely unknown. The aim of the present study was: (1) to establish a model of porcine dispersed pancreatic acinar cells in vitro and compare it with an existing rat model, and (2) to investigate the effect of pentaghrelin on amylase release from the rat and pig pancreatic acini. The rat and porcine acinar cell preparations released amylase in response to cholecystokinin octapeptide (CCK-8) stimulation in a dose-related manner. Pentaghrelin hardly inhibited the amylase release in rat preparations (maximum inhibition with 10− 9 M pentaghrelin). It stimulated amylase release in porcine preparations, however, no dose response was found in a range of doses between 10− 10 and 10− 7 M. Concluding, pentaghrelin may stimulate amylase release from porcine acinar cells through as yet unknown mechanisms.  相似文献   

17.
Small doses of caerulein (10, 20, 40, 100 ng/kg/h) were given to conscious dogs with chronic duodenal and gastric fistulas, and the exocrine pancreatic response was compared with that obtained by a testmeal. Maximal protein and bicarbonate secretion varied between 20 and more than 100 ng/kg/h, depending on the individual animal. Testmeal-stimulated pancreatic secretion was approximately equivalent to that achieved with 10 ng caerulein/kg/h. Plasma secretin levels did not change significantly during testmeal stimulation.  相似文献   

18.
钙依赖蛋白激酶(CDPKs)是生长发育信号和逆境信号诱发的钙信号的重要信号传递体,在调控植物信号转导途径中下游基因的表达、生化代谢、离子和水分跨膜运输等生物学过程中具有重要作用。本研究对植物种属CDPK的结构特点、CDPK在植株体内的分布特征、CDPK生理生化特性及生化反应调控特性、CDPK 在信号转导中的作用,以及CDPK在植株体内的生物学功能进行了概述。旨在为今后牧草作物CDPK的鉴定及其介导的信号转导机制的研究提供参考依据。  相似文献   

19.
蛋白质是反刍动物的必需营养素,不同蛋白质水平日粮使瘤胃发酵参数发生改变。本文就不同蛋白水平日粮对瘤胃pH、NH3-N、VFA的浓度和瘤胃微生物区系组成的影响研究进展情况进行综述,为进一步开展相关研究奠定基础。  相似文献   

20.
本文论述了反刍动物消化生理特点、秸秆饲料的营养特性、营养作用和调制技术,以及旱区秸秆畜牧业发展的战略意义。  相似文献   

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