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81.
FJ Golder SA Robertson A Valverde DC Bolser 《Veterinary anaesthesia and analgesia》2003,30(2):115-115
Urethane is widely used as a rodent anesthetic in the laboratory setting, and is characterized as producing long‐lasting anesthesia. The purpose of this study was to evaluate the quality of anesthesia provided by a single dose of urethane based on the response to a noxious stimulus. If the quality of anesthesia was insufficient to prevent gross purposeful movement (GPM), isoflurane was also administered until no response to noxious stimulation occurred. Five adult Harlan Sprague Dawley rats (6 months of age, 250–300 g) were given urethane (1.4 g kg?1 IP) and evaluated for 120 minutes post‐injection. If the rats became laterally recumbent by 20 minutes post‐injection, a large hemostat was positioned around the tail and the response to tail clamping was assessed. If no GPM occurred, an additional 20 minutes was allowed to elapse. If the rats were not laterally recumbent or GPM was present, they were placed in a chamber and isoflurane in oxygen was administered. Inspired isoflurane concentrations (ISO) were measured using a S/5 anesthetic gas analyzer (Datex‐Ohmeda Division, Helsinki, Finland) calibrated before each experiment with a standardized calibration gas mixture (DOT‐34 NRC 300/375 m 1014, Datex‐Ohmeda Division, Helsinki, Finland). A period of 20 minutes was allowed for equilibration to inspired ISO. The tail‐clamp stimulus was then re‐applied and the animal's response recorded. If GPM was absent, ISO was lowered by 10–20% and an additional 20 minute interval elapsed. In contrast, if GPM was present, ISO was increased by 10–20%. This procedure was repeated until the ISO required to prevent GPM was determined in duplicate. The position within the estrus cycle influenced pain thresholds in the rats. As such, a vaginal smear was prepared from each rat and the position in the estrus cycle was determined based on vaginal cytology. Rats were euthanatized at the end of the study period. All values were mean ± SD. Four rats became recumbent after urethane injection (time to recumbency: 45 ± 17 seconds). Of these, two rats (one estrus, one metestrus) did not require isoflurane supplementation for the duration of the study. The three remaining rats (two metestrus, one estrus) required isoflurane supplementation. The mean ISO required to prevent GPM was 0.26 ± 0.16%. Position within the estrus cycle did not appear to affect the animal's response to urethane. These results indicate that urethane anesthesia is not long lasting in all rats and provides variable quality of anesthesia. This is of particular concern in the laboratory setting where muscle relaxants are often administered to rats shortly after urethane injection. 相似文献
82.
Deborah C. Mandell VMD DACVECC Prue Neath BVSc Kenneth J. Drobatz DVM DACVECC 《Journal of Veterinary Emergency and Critical Care》2000,10(3):173-175
A four-year old female Rottweiler presented with a 34-hour history of dystocia. Physical examination revealed a purple-black, fluid-filled sac protruding from vulva and suspended by a similar colored stalk. Digital vaginal examination indicated that the stalk of tissue extended up into the cervix and beyond. Due to the grossly necrotic appearance, the stalk of tissue was ligated, and the sac was removed. Three puppies were delivered vaginally, but a subsequent caesarian section was required due to uterine inertia likely secondary to exhaustion. Three more live puppies were delivered via the c-section. Further abdominal exploration revealed a tear in the left vaginal wall, one ligated ureter, and the second ureter free at its distal end and leaking urine into the abdomen. The surgical findings indicated that the bladder, ureters, and urethra had herniated through the vaginal tear and prolapsed through the vulva. 相似文献
83.
In randomized experiments, analysis of covariance is used to increase precision of treatment comparisons. However, for factors that are observational (e.g., breed) or for covariates measured after treatments are applied, it may not be biologically meaningful to calculate treatment means adjusted to a common value of the covariate. For example, in beef cattle trials, it may not be meaningful to compare hot carcass weights of medium- and large-framed breeds adjusted to a common weaning weight because the breeds have naturally different mean weights at weaning. If done, this would typically result in an undesirable downward adjustment of mean carcass weight for the large-framed breed and upward adjustment of the mean carcass weight for the small-framed breed. However, it is desirable to evaluate the mean carcass weight for two diets, adjusted to a common weaning weight. Because of randomization, the expected weaning weights of animals on the two diets are equal and hence the only effect of covariance adjustment is to increase precision of the diet comparison. This paper presents the statistical methodology for estimating covariance adjusted means (termed partially adjusted means) when the levels of some of the factors are compared at a common value of the covariate but the levels of other factors are compared at differing values of the covariate. The methodology is extended to include several covariates, several factors, and arbitrary interactions among covariates, among factors, and between factors and covariates. These methods can be implemented using existing statistical software for linear models. Data are presented from an experiment in which hot carcass weight was recorded for beef cattle. Analyses of these data illustrate that adjusted means, partially adjusted means, and unadjusted means may differ substantially in magnitude, significance, and in the ranking of treatments. 相似文献
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86.
Close-in giant planets (e.g., "hot Jupiters") are thought to form far from their host stars and migrate inward, through the terrestrial planet zone, via torques with a massive gaseous disk. Here we simulate terrestrial planet growth during and after giant planet migration. Several-Earth-mass planets also form interior to the migrating jovian planet, analogous to recently discovered "hot Earths." Very-water-rich, Earth-mass planets form from surviving material outside the giant planet's orbit, often in the habitable zone and with low orbital eccentricities. More than a third of the known systems of giant planets may harbor Earth-like planets. 相似文献
87.
Effects of supplemental dietary vitamin C on quality of semen from Nile tilapia (Oreochromis niloticus) breeders
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NLAF Sarmento EFF Martins DC Costa WS Silva CC Mattioli MR Luz RK Luz 《Reproduction in domestic animals》2017,52(1):144-152
The objective of this study was to evaluate the effects of vitamin C on growth and quality of semen from Oreochromis niloticus breeders. One hundred and sixty males were fed with different levels of vitamin C (0, 261, 599 and 942 mg/kg diet). The higher weight values were recorded for 599 (166 g) and 942 (175 g) mg of vitamin C/kg diet. Sperm motility, vigour and concentration were higher with 599 and 942 mg of vitamin C/kg diet. The semen volume, gonadosomatic index and plasma protein data from the last week showed a direct relationship with increasing levels of vitamin C. No changes were observed in the hepatosomatic index and blood glucose. The haematocrit and erythrocyte showed higher values estimated by equations derived at 850 and 638 mg vitamin C/kg diet, respectively. The leucocytes were inversely proportional to the increasing levels of vitamin C. After 100 days of feeding, animals fed the diet containing 942 mg vitamin C/kg diet had higher sperm motility, linearity, curvilinear velocity, straight line velocity and average path velocity (p < .05). Higher values of beat cross‐frequency were observed in broodfish fed diets containing 942 and 599 mg vitamin C/kg. The different vitamin C levels did not cause differences in straightness, lateral head displacement and sperm morphology. For Nile tilapia males on intensive rearing and handling conditions, vitamin C levels between 599 and 942 mg/kg may be used for a better performance and quality of semen. 相似文献
88.
M Piagentini DC Silva CPF Dell'Aqua CF Moya‐Araujo VM Codognoto AA Ramos E Oba 《Reproduction in domestic animals》2017,52(3):355-358
The aim of this study was to investigate the effects of different concentrations of oral supplementation with selenium (Se) upon ram sperm parameters. Thirty rams managed in stall under intensive system were used and divided into five groups (six animals per group) as follows: control group (G1) mineral mixture supplementation without Se, group 2 (G2) mineral mixture supplemented with 5 mg/kg Se, group 3 (G3) supplemented with 10 mg/kg Se, group 4 (G4) supplemented with 15 mg/kg Se and group 5 (G5) supplemented with 20 mg/kg Se. For each group, there was an adjustment period of 14 days. The experimental period was 350 days. Every 56 days, the animals were weighed and semen samples were collected by electroejaculation. Semen analysis included volume, mass moviment, total motility, vigour, concentration and morphology. For plasmatic and acrosomal membrane integrity evaluation and mitochondrial membrane potential were used a combination of fluorescent probes. Differences between means values obtained by analysis of variance were verified by Tukey test with 5% probability. There was no statistical difference between treatment groups in relation to volume, mass moviment, total motility, vigour, concentration, plasma and acrosomal membrane integrity (p > .05). Sperm morphology was different between treatment groups, the G1 (0 mg of selenium) had the highest percentage of major defects (11.11 ± 1.11a; p < .05). It was concluded that selenium decrease the percentage of sperm defects and did not directly influence on ram sperm volume, mass moviment, total motility, vigour, concentration and membrane integrity. 相似文献
89.
Faucitano L Chouinard PY Fortin J Mandell IB Lafrenière C Girard CL Berthiaume R 《Journal of animal science》2008,86(7):1678-1689
Five beef cattle management regimens were evaluated for their effect on meat quality, fatty acid composition, and overall palatability of the longis-simus dorsi (LD) muscle in Angus cross steers. A 98-d growing phase was conducted using grass silage with or without supplementation of growth promotants (Revalor G and Rumensin) or soybean meal. Dietary treatments in the finishing phase were developed with or without supplementation of growth promotants based on exclusive feeding of forages with no grain supplementation, or the feeding of grain:forage (70:30) diets. Growth promotants increased (P < 0.01) shear force and tended (P = 0.06) to increase toughness of the LD muscle due to limited postmortem proteolytic activity (lower myofibrillar fragmentation index value; P = 0.02). Grain feeding increased DM and intramuscular fat content (P = 0.03 and P = 0.05, respectively) in the LD but decreased the sensory panel tenderness score (P = 0.01). Growth promotants increased (P = 0.05) the proportion of C18:0, C20:0, trans isomers of C18:1, and cis-9, trans-11 C18:2. Exclusive feeding of forages increased the proportion of cis-9, cis-12, cis-15 C18:3 as well as several other isomers of the n-3 family and decreased in the ratio of n-6 to n-3 fatty acids in the LD muscle as compared with supplementing grain (P < 0.05). In addition, the forage-based diet increased (P < 0.01) the concentration in the intramuscular fat of several intermediates (cis-9, trans-11, cis-15 C18:3; trans-11, cis-15 C18:2; trans-11 C18:1) of ruminal biohydrogenation. Forage feeding also increased the proportion of cis-9, trans-11 C18:2 (P < 0.01) and decreased the concentration of trans-10 C18:1 in the LD muscle (P = 0.03). It is concluded that quality demands of health-conscious consumers can be met through a forage-finishing and growth promotants-free beef production system. 相似文献
90.
Rene S Hendriksen Dik J Mevius Andreas Schroeter Christopher Teale Eric Jouy Patrick Butaye Alessia Franco Andra Utinane Alice Amado Miguel Moreno Christina Greko Katharina DC St?rk Christian Berghold Anna-Liisa Myllyniemi Andrzej Hoszowski Marianne Sunde Frank M Aarestrup 《Acta veterinaria Scandinavica》2008,50(1):19