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1.
Anderson CD 《Journal of fish diseases》2006,29(8):445-453
A mechanism for the development of bloat in salmonids is proposed and explained in terms of the physiology of digestion and osmoregulation in fish. Understanding the causal factors for bloat enables control measures to be identified. In farmed salmonids, the chyme produced during the digestion of nutrient-rich pelleted foods that rapidly disintegrate in the stomach will be a potent activator of a negative feedback mechanism (enterogastric control), which slows stomach emptying to protect the small intestine from nutrient overload. In saline environments salmonids continuously drink sea water to replace fluid lost across the gills. Fluid loss is increased during periods of stress caused by factors such as low oxygen levels, elevated temperature or high salinity. When ingestion of nutrient-rich food results in prolonged activation of enterogastric control, slowed stomach emptying leads to decreased absorption of water, thirst and increased drinking. This further exacerbates stomach distention. The proposed mechanism for the development of bloat is supported by on-farm experience where measures to control bloat include reducing food intake, altering the composition of the diet and using appropriate strategies to reduce stress. 相似文献
2.
胃扩张-肠扭转(Gastric Dilatation-Volvulus--GDV)又称为"臌"、"胃扭转"。GDV是一个极其严重,并应视为严重威胁犬生命的紧急事件,是仅次于癌症导致犬死亡的第二大杀手。24%的犬臌是由胃膨胀引起的。但是大多数的情况(75%)是由于胃扭转,弯曲和切断胃内容物的流入和流出。由于胃部膨胀,可旋转90°至360°,固定附着在食道和十二指肠之间缠绕。膨胀的胃妨碍腹部静脉、减少血液返回到心脏,丧失血液供应,导致低血压、胃缺血、休克、脏器损害,要在育种,饲养和管理上加强监管,有效的降低形成和促发GDV风险因子的条件,加强对GDV风险因子的预警和识别,以及发生后的及时发现和立即处理治疗。 相似文献
3.
The efficacy of selenium dioxide (SeO2) was similar to sodium selenate (Na2SeO4.10H2O), in terms of increasing and maintaining blood Se concentrations. when administered orally twice daily to give 0.64 rng of Se/dav to grazing dairy cows for 56 days. 相似文献
4.
A. Jonker M. Y. Gruber Y. Wang B. Coulman J. J. McKinnon D. A. Christensen P. Yu 《Grass and Forage Science》2012,67(3):369-381
Foam stability related to pasture bloat from alfalfa pastures might be reduced by introducing a gene that stimulates the accumulation of mono‐/polymeric‐anthocyanidin. The objective of this study was to determine the foam formation (at 0 min) and stability (at 150 min) from aqueous leaf extracts of three transgenic Lc‐alfalfa progeny (BeavLc1, RambLc3 and RangLc4), parental non‐transgenic (NT) alfalfa and AC Grazeland (bloat‐reduced cultivar) harvested at 07:00 or 18:00 h. Initial and final foam volumes at 07:00 h were lower for AC Grazeland compared with all other treatments and lower for RangLc4 compared with the other two Lc‐progeny at 0 min and NT‐alfalfa at 150 min. At 18:00 h, initial foam volume was larger for NT‐alfalfa and final foam volume was larger for RambLc3 compared with AC Grazeland, BeavLc1 and RangLc4. Spectroscopic vibration associated with carbohydrates increased initial foam volume and stability. More amide I relative to amide II, fewer α‐helices relative to β‐sheets and leaf extract ethanol‐film and protein content increased initial foam volume but did not stabilize it. Spectroscopic vibration associated with all carbohydrates other than structural carbohydrates was more important than vibration from protein structures for foam formation and stabilization. In conclusion, Lc‐alfalfa accumulated anthocyanidin and had reduced foaming properties compared with parental NT alfalfa but AC Grazeland and RangLc4 had the lowest foaming properties. 相似文献
5.
E.J. Batham 《New Zealand veterinary journal》2013,61(3):74-76
dAim: To evaluate the effectiveness of a liquid formulation of monensin in reducing bloat score in milking cows grazing pasture. dMethods: AFriesian x Jersey crossbred herd which had been genetically selected for high bloat susceptibility since 1973 was used in this study. Two trials were conducted, each involving two groups of 15 cows, randomly allocated toTreated or Control groups.Trial 1 involved twice-daily administration of a novel liquid formulation of monensin given toTreated cows at morning and afternoon milkings. Trial 2 involved once-daily administration of the same product toTreated cows at the morning milking only. Control cows received no preven tative treatment. The total daily dose of monensin in each trial was 300 mgper cow, given in a total volume of 100 ml of liquid. Animals were scored for bloat twice-daily whilst grazing on white-clover/ryegrass or red-clover pastures. The scoring system used a scale of 0, 1, 1.5, 2, 2.5, or 3, representing scores of increasing bloat severity as assessed by palpation of abdominal pressure on the left and right sides of the cow. dResults: In Trial 1, severe bloat was recorded at 9 out of 23 scoring sessions.Twelve Control cows required therapeutic treatment for bloat on at least one day, compared to 3 cows in theTreated group (p=0.003). In Trial 2, severe bloat in 3 of 9 scoring sessions led to 8/15 Control animals requiring therapeutic treatment compared to 1/14 cows in theTreated group (p=0.02). dConclusions: Oral drenching with the liquid formulation of monensin tested was effective in reducing bloat score in milking cows grazed on pasture. 相似文献
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7.
Junichiro ISHII Hiroshi OMURA Tadao MITSUI Norichika EGUCHI Takashi UENO Hisaya GOTO Hiroshi ITO 《Animal Science Journal》2012,83(1):36-42
This study evaluated the effects of hinokitiol (a natural antibacterial compound extracted from Thujopsis dolabrata var. hondai) and an organic acid mixture (citrate content 50%) on ruminal fermentation. Antibacterial properties were examined by measuring minimal inhibitory concentration. Hinokitiol at 1.56 µg/mL or an organic acid mixture at 1600 µg/mL inhibited Streptococcus bovis growth. The combination of 0.78 µg/mL hinokitiol and 200 µg/mL of an organic acid mixture also inhibited S. bovis growth. Both hinokitiol and the hinokitiol and an organic acid mixture combination showed strong antibacterial properties on Gram‐positive bacteria such as S. bovis, but relatively weak antibacterial activities on Gram‐negative bacteria such as Megasphaera elsdenii. Three ruminally cannulated heifers were fed a bloat‐producing diet containing barley, pelleted alfalfa meal, soybean meal and salt without long‐cut roughage to investigate the ruminal characteristics in vivo. Feeding to heifers a bloat‐producing diet containing 7.8 mg/kg hinokitiol and 0.2% of an organic acid mixture significantly decreased the increase in stable ingesta volume. Hinokitiol or an organic acid mixture did not affect ruminal volatile fatty acids, protozoa and bacteria. These results suggest that a combination of hinokitiol and an organic acid mixture might reduce frothy bloat in cattle fed high‐grain diets. 相似文献
8.
Summary Populations of 59 Trifolium taxa were screened for condensed tannin content using the vanillin-HC1 test. Eight species (T. arvense, T. aureum, T. badium, T. campestre, T. dubium, T. micranthum, T. patens and T. spadiceum) were shown to contain tannins. These species are all found in Section Chronosemium or Section Trifolium Subsection Arvensia of the genus, and thus presence of tannins appears to have a taxonomic significance. Screening populations within species showed differences in tannin content, but no plants in these species were free of tannins. 相似文献
9.
Objective
To estimate the relative frequency of various disease signs in dairy cattle fed brassicas in south-eastern Australia, to estimate the incidence of disease signs within affected groups and to identify risk factors for commonly reported signs in brassica-fed dairy cows.
Design
A case series study and a case-control study.
Procedures
Case data was collected using an incident reporting system. Herd managers and veterinarians recorded details about disease incidents in brassica-fed dairy cattle in summer and autumn 1995 using a standard questionnaire. Potential risk factors for photosensitisation were assessed using a case-control study.
Results
Disease signs were reported in 66 groups of brassica-fed dairy cattle. Photosensitisation and bloat were the more frequently reported signs. While high incidences were reported in some groups, the incidence of disease signs was low within most affected groups. Photosensitisation occurred more frequently among groups of cows fed brassica crops treated with nitrogenous fertilisers or which were low yielding. Risks of other disease signs were greatest while the first one quarter of the crop was grazed.
Conclusions
In the study population, most disease outbreaks occurring in brassica-fed cattle were of low incidence. However, some high incidence outbreaks occurred. Results from this study suggest that important risk factors exist for disease signs in brassica-fed dairy cattle. Further studies are required if these risk factors are to be fully identified. This would allow the development of preventative strategies for high incidence disease outbreaks while feeding brassicas to dairy cattle. 相似文献
To estimate the relative frequency of various disease signs in dairy cattle fed brassicas in south-eastern Australia, to estimate the incidence of disease signs within affected groups and to identify risk factors for commonly reported signs in brassica-fed dairy cows.
Design
A case series study and a case-control study.
Procedures
Case data was collected using an incident reporting system. Herd managers and veterinarians recorded details about disease incidents in brassica-fed dairy cattle in summer and autumn 1995 using a standard questionnaire. Potential risk factors for photosensitisation were assessed using a case-control study.
Results
Disease signs were reported in 66 groups of brassica-fed dairy cattle. Photosensitisation and bloat were the more frequently reported signs. While high incidences were reported in some groups, the incidence of disease signs was low within most affected groups. Photosensitisation occurred more frequently among groups of cows fed brassica crops treated with nitrogenous fertilisers or which were low yielding. Risks of other disease signs were greatest while the first one quarter of the crop was grazed.
Conclusions
In the study population, most disease outbreaks occurring in brassica-fed cattle were of low incidence. However, some high incidence outbreaks occurred. Results from this study suggest that important risk factors exist for disease signs in brassica-fed dairy cattle. Further studies are required if these risk factors are to be fully identified. This would allow the development of preventative strategies for high incidence disease outbreaks while feeding brassicas to dairy cattle. 相似文献
10.
MB Allworth M McQuillan SR McGrath CS Wilson M Hernandez-Jover 《Australian veterinary journal》2023,101(3):121-126
Frothy bloat, associated predominantly with grazing legume-based pastures, is considered the second most costly disease in beef cattle in southern Australia, costing $84.4 M annually. It frequently results in the sudden death of cattle. In response to concerns from cattle producers, an online survey was conducted in southern Australia in late 2020 to determine the impact of bloat, identify risk factors and determine the efficacy of current preventive measures. For 217 responses, over two-thirds (70%) of producers reported bloat occurring in the previous 12 months, with estimated morbidity and mortality rates of 3.7% and 5.0% respectively. Bloat was associated with clover or clover-dominant paddocks (79%) and was not associated with grass or grass-dominant pastures or low clover pastures (92%) nor grazing crops (27%). For bloat that occurred in the past 12 months, cattle were very commonly grazing on clover or clover-dominant paddocks (90%) and occasionally lucerne-dominated paddocks (7%). Two-thirds of producers reported having preventive measures in place when losses occurred. Bayesian Network analysis confirmed that grazing clover-based pastures for more than 7 days, yearling cattle and the months of July–September were the main risk factors for bloat occurrence, with pasture type (clover) being the most important. Conversely, no clear relationship between weather conditions and bloat occurrence was evident. This survey highlights the known risk of clover-based pastures for causing bloat in cattle, and that losses occur in many cases despite preventive measures being used. This suggests that current methods for preventing bloat in cattle are suboptimal. 相似文献