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1.
This study describes the age-related variation in boar taint compounds, skatole and androstenone, and testosterone, oestradiol-17 beta (E17 beta), oestrone sulphate (ES), dehydroepiandrosterone sulphate (DHEAS), triiodothyronine (T(3)) and insulin-like growth factor-1 (IGF-1) in six boars. Three pairs of littermates of crossbred entire male pigs (from three Yorkshire x Duroc dams and one Hampshire sire) were included. Blood samples were taken at the age of 9-15 weeks and thereafter at weekly intervals from the age of 20-32 weeks. Plasma concentrations of skatole, androstenone, testosterone, E17 beta, ES, DHEAS, T(3) and IGF-1 were measured. We found that skatole levels in boars increased at the age around puberty after an increase in the levels of testicular steroids. Levels of skatole were not associated with the levels of sex steroids, T(3) and IGF-1. However, the increased level of testicular steroids is probably the underlying factor needed for high skatole levels to occur although the specific mechanism leading to increased skatole levels remains unknown.  相似文献   
2.
The objectives of this study were to evaluate the effects of pre- and postpartum undegraded intake protein (UIP) supplementation on body condition score (BCS), BW, calf weight, milk production, serum IGF-I concentrations, and postpartum interval in primiparous beef heifers (n = 44). Heifers were maintained on endophyte-free stockpiled tall fescue (11.7% CP, 38% ADF) and individually fed supplement daily beginning 60 d prepartum. Pre- and postpartum supplements provided 19.3% CP, 83.4% TDN (UIP); 14.1% CP, 84.1% TDN (Control); 21.5% CP, 81.5% TDN (UIP); and 14.6% CP, 81.4% TDN (Control); respectively. Blood meal (146 g/d) was the source of UIP. Six heifers were removed from the study due to calf loss unrelated to treatment; therefore, postpartum measurements are based on 19 animals per treatment. Statistical analyses using ANOVA and a split-plot design revealed no effects of treatment (P > 0.2) on BCS, BW, calf weight, milk production, or postpartum interval. There tended to be a treatment x time interaction on BCS (P < 0.09) with UIP heifers having higher BCS than Control at wk 5, 7, and 9 postpartum. There was a treatment x time interaction on serum IGF-I (P < 0.06) during the first 35 d postpartum. In UIP heifers, serum IGF-I was greater at calving compared with Control heifers (117.5 vs 92.4 ng/mL, respectively); however, these differences were not related to changes in BCS or BW. Although serum IGF-I concentrations were increased at calving in heifers receiving UIP, there were no treatment effects on postpartum interval (P > 0.7). During the first 30 d postpartum, IGF-I differed (P < 0.01) among heifers with postpartum intervals defined as short, < 50 d (128.9 ng/mL); medium, 51 to 65 d (115.2 ng/mL); and long, 66 to 130 d (52.9 ng/mL). When analyzed as a regression, a 1 ng/mL increase in IGF-I (UIP and Control heifers) at calving (P < 0.05) and throughout the postpartum period (P < 0.01) corresponded to a decrease in postpartum interval of 0.13 d. Based on the results of this study, the inclusion of UIP in diets for primiparous heifers and its effects on postpartum interval warrant further evaluation.  相似文献   
3.
The expression of growth factors was evaluated immunohistochemically in normal and cystic ovaries of sows. The immunohistochemically stained area (IHCSA) was quantified by image analysis to analyse the expression of these proteins in the follicular wall of secondary, tertiary and cystic follicles. IGF‐I immunoreactivity was strong in the granulosa cell layer (GC), moderate in the theca interna (TI) and mild in the theca externa (TE) of the normal follicles. There was severe reduction of the labelling to IGF‐I in the GC of the follicular and luteinized cysts. In the normal follicles, the reactivity for IGF‐II was very similar to pattern noted in IGF‐I. There was reduction of the IHCSAs in the GC of the follicular and luteinized cysts, but the decrease was not significant. The staining of the IGF‐II in the TI and TE of the cysts was increased, in comparison with normal follicles. The IHCSAs for VEGF were higher in the GC and TE of the normal follicles in contrast to TI, but this difference was noted only in the tertiary follicle. The VEGF reactivity increased in the GC of the cysts, in relation to normal follicles. The results of the current study show that the formation of ovarian cysts in sows is associated with alterations in the immunohistochemical expression of some growth factors.  相似文献   
4.
Our objective was to determine duodenal and ileal flows of total and esterified fatty acids and to determine ruminal fermentation characteristics and site and extent of nutrient digestion in sheep fed an 80% concentrate diet supplemented with high-linoleate (77%) safflower oil at 0, 3, 6, and 9% of DM. Oil was infused intraruminally along with an isonitrogenous basal diet (fed at 2% of BW) that contained bromegrass hay, cracked corn, corn gluten meal, urea, and limestone. Four crossbred wethers (BW = 44.3 +/- 15.7 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a 4 x 4 Latin square experiment, in which 14 d of dietary adaptation were followed by 4 d of duodenal, ileal, and ruminal sampling. Fatty acid intake increased (linear, P = 0.004 to 0.001) with increased dietary safflower oil. Digestibilities of OM, NDF, and N were not affected (P = 0.09 to 0.65) by increased dietary safflower oil. For total fatty acids (free plus esterified) and esterified fatty acids, duodenal flow of most fatty acids, including 18:2c-9,c-12, increased (P = 0.006 to 0.05) with increased dietary oil. Within each treatment, duodenal flow of total and esterified 18:2c-9,c-12 was similar (P = 0.32), indicating that duodenal flow of this fatty acid occurred because most of it remained esterified. Duodenal flow of esterified 18:1t-11 increased (P = 0.08) with increased dietary safflower oil, indicating that reesterification of ruminal fatty acids occurred. Apparent small intestinal disappearance of most fatty acids was not affected (P = 0.19 to 0.98) by increased dietary safflower oil, but increased (P = 0.05) for 18:2c-9,c-12, which ranged from 87.0 to 97.4%, and for 18:2c-9,t-11 (P = 0.03), which ranged from 37.9% with no added oil to 99.2% with supplemental oil. For esterified fatty acids, apparent small intestinal disappearance was from 80% for 18:3c-9,c-12,c-15 at the greatest level of dietary oil up to 100% for 18:1t-11 and 18:1c-12 with 0% oil. We concluded that duodenal flow of 18:2c-9,c-12 was predominately associated with the esterified fraction, suggesting that the extent of ruminal lipolysis was decreased with increased dietary high-linoleate safflower oil. Furthermore, biohydrogenation intermediates observed in the esterified fatty acids indicated that some reesterification occurred, and the high level of apparent absorption of esterified fatty acids indicated that intestinal lipolysis did not limit overall digestion of the fatty acids fed to the sheep.  相似文献   
5.
AIMS: To determine the frequency with which porcine reproductive and respiratory syndrome (PRRS) virus (PRRSv) would become established in a non-commercial pig herd in New Zealand due to illegal feeding of uncooked food waste containing virus-contaminated pigmeat. To determine the likelihood of a single incursion resulting in a multi-farm outbreak of the disease, and describe the spatio-temporal characteristics of such an outbreak.

METHODS: A Monte Carlo simulation model was constructed to determine the expected annual frequency of PRRSv infection being initiated in a non-commercial pig herd as a result of inadvertent feeding of pigmeat imported from countries endemically infected with the disease. Once the likelihood of PRRSv becoming established in a single pig herd was determined, stochastic spatially explicit infectious disease modelling software was utilised to model the temporal and spatial characteristics of the resulting epidemic.

RESULTS: Assuming the proportion of imported pigmeat remained at current levels, consumption patterns of pigmeat in households in New Zealand remained steady, and limited compliance with recently reintroduced regulations to prevent feeding of uncooked food waste, at least 4.3 pig herds per year were predicted to become infected with PRRSv. Simulation modelling of PRRSv epidemics related to initial infection of a non-commercial farm produced an estimate that 36% of these incursions would spread from the initial herd, and that these outbreaks would involve 93 herds on average in the first year. By increasing the estimated persistence of PRRSv infection in small herds, an average of 205 herds became infected in the first year.

CONCLUSIONS: Given a mean of 4.3 infected premises per year and a 36% probability of infection spreading beyond the initial infected herd, there was a 95% likelihood of a multi-farm PRRS outbreak occurring within 3 years.

CLINICAL RELEVANCE: Introduction of PRRSv through importation of virus-contaminated pigmeat presents a high risk for establishment of the disease in the pig industry in New Zealand.  相似文献   
6.
Abstract

AIM: To describe the patterns of use of antimicrobial drugs by veterinary surgeons treating commonly presented bacterial infections in companion animals in New Zealand.

METHODS: A postal survey of 800 randomly selected companion animal veterinarians practicing in New Zealand was conducted between August and December 2008. Data were collected regarding the antimicrobials prescribed for recent cases of skin, ear and urinary tract infections; the use of culture and susceptibility testing; and veterinarian characteristics such as proportion of time spent treating companion animals and recent attendance at continuing professional development (CPD) events. Potential associations within the data were explored using extended mosaic plots and multivariable regression models.

RESULTS:Completed surveys from 393 respondents were available for analysis, providing data on systemic antimicrobial drug use for 1,799 cases of presumptive bacterial infections. The most frequently prescribed drugs were amoxicillin-clavulanic acid (864 cases, 48%), cephalexin (558, 31%), and fluoroquinolones (198, 11%). Of 359 cases of canine superficial pyoderma, 157 (44%) were treated with amoxicillin-clavulanic acid and 155 (43%) were treated with cephalexin with median reported treatment durations of 7 and 10 days, for these two drugs respectively. Culture and susceptibility tests had been used in 376 of 1,984 (19%) of all reported cases and 160 (43%) of these were suspected urinary tract infections. Practitioners that spent 100% of their time treating companion animals and who had attended a CPD course related to companion animals within the 12 months prior to completing the survey were more likely to submit a sample for culture and susceptibility testing and to prescribe longer courses of antimicrobials for the treatment of canine pyoderma than practitioners who spent less than 100% of their time treating companion animals and had not attended a CPD course in the last 12 months.

CONCLUSIONS: Broad-spectrum drugs considered by the World Health Organisation to be critically important for human health, such as fluoroquinolones and amoxicillin-clavulanic acid, are amongst the most frequently prescribed antimicrobials in companion animal medicine, and these drugs are often prescribed without submitting a sample for culture and susceptibility testing.

CLINICAL RELEVANCE: Many cases of superficial pyoderma were treated for less than the recommended duration of 21 days, which may contribute to a higher rate of recurrent pyoderma and the development of drug resistance within the causal bacteria. Veterinarians should be aware that the use of fluoroquinolones, in particular, should be based upon the results of a culture and susceptibility test.  相似文献   
7.
The control of foot-and-mouth disease virus (FMDV) outbreaks in non-endemic countries relies on the rapid detection and removal of infected animals. In this paper we use the observed relationship between the onset of clinical signs and direct contact transmission of FMDV to identify predictors for the onset of clinical signs and identify possible approaches to preclinical screening in the field. Threshold levels for various virological and immunological variables were determined using Receiver Operating Characteristic (ROC) curve analysis and then tested using generalized linear mixed models to determine their ability to predict the onset of clinical signs. In addition, concordance statistics between qualitative real time PCR test results and virus isolation results were evaluated. For the majority of animals (71%), the onset of clinical signs occurred 3–4 days post infection. The onset of clinical signs was associated with high levels of virus in the blood, oropharyngeal fluid and nasal fluid. Virus is first detectable in the oropharyngeal fluid, but detection of virus in the blood and nasal fluid may also be good candidates for preclinical indicators. Detection of virus in the air was also significantly associated with transmission. This study is the first to identify statistically significant indicators of infectiousness for FMDV at defined time periods during disease progression in a natural host species. Identifying factors associated with infectiousness will advance our understanding of transmission mechanisms and refine intra-herd and inter-herd disease transmission models.  相似文献   
8.
Fast recession of a west antarctic glacier   总被引:2,自引:0,他引:2  
Satellite radar interferometry observations of Pine Island Glacier, West Antarctica, reveal that the glacier hinge-line position retreated 1.2 +/- 0.3 kilometers per year between 1992 and 1996, which in turn implies that the ice thinned by 3.5 +/- 0.9 meters per year. The fast recession of Pine Island Glacier, predicted to be a possible trigger for the disintegration of the West Antarctic Ice Sheet, is attributed to enhanced basal melting of the glacier floating tongue by warm ocean waters.  相似文献   
9.
The purpose of this study was to estimate the expression and relative amounts of estrogen (ER) and progesterone receptors (PR) and their isoforms as well as heat shock protein 70 (HSP70) in ovaries of rats with induced cystic ovarian disease (COD). Primary, secondary, tertiary, atretic and cystic follicles were evaluated by immunohistochemistry and total ovarian proteins were analyzed by Western blot. In the granulosa layer, growing and cystic follicles in the treated group have a higher expression of ERα than growing follicles of control individuals. In the theca interna layer, tertiary follicles presented a significantly higher expression of ERα in the treated group. An increase in total ERα protein was detected in the treated group. Granulosa cells of all growing, atretic and cystic follicles show a lower expression of ERβ in animals with COD, and the total protein expression of ERβ was lower in this group. The expression of PR was lower in the granulosa cell layer of tertiary and cystic follicles in treated animals, and theca interna layer had less intense immunostaining in this group. Although there were no differences in the expression of PR-B by Western blotting, the expression of PR-A was higher and the expression of PR-C was smaller in the treated group. An intense HSP70 immunostaining was observed in the cells of cystic follicles. By Western blotting, higher protein expression of HSP70 was detected in the ovarian samples of the control group than those of the treated ones. Ovaries of animals with COD exhibited an altered steroid receptor expression and subtype balance as compared with control animals, and an increase in HSP70 immunoexpression.  相似文献   
10.
The objective of this trial was to determine if daily supplementation of flaxseed for 85 d to steers finished on grasslands of the northern Great Plains would influence growth and carcass characteristics or the fatty acid profile, tenderness, and sensory characteristics of beef steaks. Eighteen Angus yearling steers (initial BW 399 ± 21 kg) were randomly divided into 3 groups. Steers in treatment 1 (FLX; n = 6) received a daily supplement of ground flaxseed (0.20% of BW), whereas steers in treatment 2 (CSBM; n = 6) received a daily supplement of ground corn and soybean meal (0.28% of BW), with contents of CP and TDN being similar to the supplement for FLX. Control steers (CONT; n = 6) were not supplemented. Treatments were given to each individual steer in side-by-side stalls and were fed from mid-August to November 7, 2007, the day before slaughter. All steers grazed growing forage from early May through the first week of November. Growth rate of steers fed FLX was 25% greater (P < 0.01) than that of steers fed CONT, but was similar (P = 0.45) to that of steers fed CSBM. No differences were observed for carcass characteristics (P ≥ 0.14), tenderness (Warner-Bratzler shear force; P ≥ 0.24), or sensory attributes (P ≥ 0.40) except for a slight off-flavor detected in steaks from steers fed FLX compared with CONT (7.4 vs. 7.8, respectively, with 8 indicating no off-flavor and 1 indicating extreme off-flavor; P = 0.07) and CSBM (7.9; P = 0.01). The n-3 fatty acids α-linolenic acid and eicosapentaenoic acid were 62 and 22% greater, respectively, in beef from steers fed FLX compared with those fed CONT (P < 0.001). The ratio of n-6 to n-3 fatty acids was smaller (P < 0.001) in beef from steers fed FLX compared with the ratios in beef from steers fed CONT and CSBM. Daily supplementation of flaxseed to steers grazing growing vegetation on the northern Great Plains may improve growth rate and enhance the n-3 fatty acid profile of the steaks.  相似文献   
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