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1.
1. The disposition kinetics and the plasma availability of moxifloxacin were investigated in Japanese quails (Coturnix japonica) following different routes of administration at 5 mg/kg body weight.

2. Tissue residue profiles (liver, kidney, lung and muscle) and plasma were also studied after multiple intramuscular and oral administrations of 5 mg/kg body weight, once daily for 5 consecutive days.

3. Following intravenous injection, plasma concentration–time curves were best described by a two-compartment open model.

4. After intramuscular and oral administration of moxifloxacin, the peak plasma concentrations (Cmax) were 2.14 and 1.94 μg/ml and were obtained at 1.40 and 1.87 h (Tmax), post administration, respectively.

5. The systemic bioavailabilities following intramuscular and oral administration, respectively, of moxifloxacin were 92.48 and 87.94%.

6. Tissue concentrations following i.m. and p.o. administration were highest in liver and kidney, respectively, and decreased in the following order: plasma, lung and muscle. No moxifloxacin residues were detected in tissues and plasma after 120 h after i.m. or oral administration.  相似文献   


2.
1. Male chickens of an egg‐laying strain were used in an investigation of the effects of pinealectomy at 1 d after hatching.

2. Pinealectomised birds killed at 28 d of age were significantly heavier than sham‐operated chickens; intraperitoneal treatment of intact birds during the same period with 10 mg melatonin/kg d depressed weight gain, while 200 μg triiodothyronine (T3)/kg d given intramuscularly had no effect.

3. Pinealectomized birds aged 11 weeks ate some food during the night, in contrast to intact birds, and ate significantly more food per 24 h; their short‐term food intake responded to melatonin and T3 in a manner similar to that of intact birds.

4. The electroencephalogram (EEG) of pinealectomised birds was affected to a slight degree by darkness, while in intact chickens there is a rapid and marked change in the EEG.  相似文献   


3.
1. A study was conducted to estimate the prevalence and quantification by species of Campylobacter infection in broiler flocks at the end of the rearing period and to identify associated risk factors.

2. A questionnaire about the rearing period was completed and caecal samples were collected from 121 broiler flocks in Brittany, France, during 2008.

3. Campylobacter was isolated in 87 out of 121 flocks – a prevalence of 71.9% (95% CI, 63.7–80.1%), including 40.5% of Campylobacter jejuni and 29.8% of Campylobacter coli.

4. The average concentration, in positive flocks, was 7.96 log10 cfu/g and ranged from 3.15 to 10.32 log10 cfu/g.

5. The average concentration by species was: 7.57 log10 cfu/g for C. jejuni and 8.44 log10 cfu/g for C. coli.

6. There was a seasonal effect, with increased risk of Campylobacter colonisation in June, July and August (odds ratio (OR) = 9.59, 95% CI 1.15–79.75).

7. The other factors, associated with lower risk of Campylobacter colonisation, were the acidification of drinking water (OR = 0.33, 95% CI 0.13–0.86), antibiotic treatment at the beginning of the rearing period (OR = 0.20, 95% CI 0.07–0.55) and rodent control around the house (OR = 0.18, 95% CI 0.03–0.95).

8. The results show that hygiene practices and biosecurity measures could lead to a reduction in Campylobacter colonisation.  相似文献   


4.
5.
1. Two groups of 12‐week‐old female chicks were selected for their ability to oxidise 14C‐trimethylamine (TMA) after being fed on a diet containing 100 g high‐glucosinolate rapeseed meal (RSM)/kg for 14 d. A third group (control) was fed on a rapeseed‐free diet. Measurements of thyroid activity and hepatic TMA oxidase activity were made after a further week on the diets.

2. After feeding RSM, hepatic TMA oxidase was very low (P < 0–001) in one group (sensitive) but was unaffected in the other group (resistant). Thyroid size was increased in both groups receiving RSM but was larger (P<0–001) in sensitive birds.

3. Plasma half life of thyroxine (T4) and its metabolic clearance rate were not affected by feeding RSM; thyroidal secretion was reduced (P < 0–05) to the same extent in both groups.

4. Plasma concentration of triiodothyronine was decreased in both groups after feeding RSM (P<0–05); plasma T4 concentration was increased (P<0–05) only in sensitive birds.

5. The results indicate that the short‐term depression of TMA oxidation in birds sensitive to RSM is not mediated by the thyroid.  相似文献   


6.
1. Xanthine oxidase (XO) has many physiological functions associated with the synthesis of both antioxidant (uric acid: UA) and numerous oxidants (e.g. H2O2), which makes it an important regulator of the cellular redox potential involving organogenesis. The ontogenetic study of hepatic and renal XO makes a better understanding of the putative role of this enzyme in the development of these tissues.

2. Developmental changes of gene expression of xanthine oxidoreductase (XOR), XO activity and UA content of liver and kidney tissues in both broiler and layer chicken embryos were examined during incubation d 14–21.

3. In both strains, hepatic XOR gene expression peaked on d 21 while renal XOR gene expression did not change.

4. The XO activity was higher in kidney than liver in both strains. Hepatic XO activity of both strains peaked on d 18 and thereafter was decreased on d 21. Renal XO activity peaked on d 18 and from then on did not show any significant changes until d 21 in both strains.

5. The UA content was higher in kidney vs. liver in both strains. The hepatic and renal UA values of the both strains increased significantly from d 14 to d 21.

6. The present results showed dissimilar behaviour of XOR gene expression, XO activity and UA content of liver and kidney tissues in both broiler and layer chicken embryos.  相似文献   


7.
1. Two experiments were designed to investigate the effects of mixing eggs of different genotype and incubating with different CO2 concentrations on embryonic parameters. Half of the eggs were incubated in a CO2 controlled incubator (VCO2) during the first 10 d of incubation and the other half was incubated at standard incubation ventilation rate (SV).

2. From 10 to 18 d of incubation, thick albumen and embryos were weighed. Blood samples were collected at d 18 of incubation, at internal pipping and at hatch for determination of triiodothyronine (T3), thyroxine (T4) and corticosterone concentration. During the last 2 d of incubation, hatching events of individual eggs were monitored every 2 h.

3. From 4 to 5 d of incubation in the SV group of Experiment 1, pH values of Ross strain chickens were lower than those of Isa Brown. From d 12 of incubation onwards, Ross embryos grew faster than those of Isa Brown. At 14 and 16 d of incubation, Ross eggs in the CO2 controlled incubator had lower albumen weights compared to all other treatments.

4. T3 concentrations in Ross embryos were higher than those of Isa Brown embryos. Chicken weight at hatch was in the following order: Isa Brown SV < Isa Brown VCO2 = Ross SV < Ross VCO2.

5. In Experiment 2, incubation time of VCO2 eggs until internal pipping, external pipping and hatch was significantly shorter than that of SV eggs.

6. It was concluded that mixing of hatching eggs of differential embryo developmental trajectory affects their hatching process.  相似文献   


8.
1. Metabolic rate was determined once a week in broilers from a commercial source, from 1 to 63 d of age.

2. The equations relating minimal resting metabolic rate (oxygen consumption, ml/bird h,y) and body weight (W) were: males 45 to 497 g, y = 3.2 W0.882 597 to 3000 g, y = 40.5 W0.483; females 45 to 514 g, y = 2.52 W0.881; 514 to 2500 g,y = 12.3 W0.627.

3. The relationship between lower critical temperature (Tcl , °C,y) and age (d, x) may be described by the following equations: chicks 1 to 21 d, y = 34.2 ‐ 0.32 x; 14 to 63 d,y = 49.4 × ?0194.

4. The relationship between Tcl and W may be described by one equation for both sexes between 100 and 3000 g, y = 62.15 W?0.135..

5. The equations for Tcl and data for upper critical temperature (Tcu ) could be used to obtain maximal performance from broilers, with reduced costs, by providing a suitable environment related to age or body weight.  相似文献   


9.
1. Metabolic rate was determined once a week in pullets from commercial flocks of the local White Leghorn strain from the age of 1 d to 13 weeks.

2. The equations relating minimal resting metabolic rate and body weight were: for body weights of 40 to 163 g Y ‐ 1–83 W 0.986, and for 163 to 1 200 g Y = 11.64 W 0.623, where Y = O2 consumption (ml/bird h) and W = body weight (g).

3. The relationship between lower critical temperature (Td) and age may be described by two equations: for pullets of 1 to 21 d of age Y = 35 ‐ 0.286 X, and for 21 to 70 d of age Y = 63.3 X 0.254, where Y = T d(°C) and X = age (d).

4. Td related to body weight is also described by two equations: for body weights of 40 to 163 g Y = ’42 ‐ 1.18 W0.480 , and for 163 to 800 g r = 42 ‐ 3.60 W0.260

5. These equations could be used to calculate the Td on a day‐to‐day basis related to age or body weight.  相似文献   


10.
1. The ovulatory cycle of the domestic hen (Gallus domesticus) was postulated to be the result of the interaction of two independent systems.

2. A circadian system was postulated to control the restriction of ovulation to an 8‐h period of the day under conventional 14 h light: 10 h dark regimes.

3. The final phase of follicular maturation was postulated to commence after ovulation of the preceding ovum in the hierarchy.

4. Ovulation was postulated to occur when a mature follicle was present in the ovary during the appropriate phase of the circadian‐linked system.

5. The predicted times of oviposition were within the standard error of the observed times of oviposition under 21‐, 24‐ and 28‐h photoschedules.

6. It was concluded that this hypothesis for the control of the ovulatory cycle of the hen is consistent with current knowledge.  相似文献   


11.
1. The effect of reducing food intake to 75% of the ad libitum intake was determined from hatching to 8 weeks in young Light Sussex chickens.

2. Restricted birds were lighter throughout the experiment.

3. Relative adrenal weight tended to be greater in restricted birds but the difference decreased with time.

4. There was no depletion of adrenal cholesterol: from week 5 there was a significantly greater amount in the adrenals of restricted birds.

5. After 1 week of restriction plasma corticosterone concentration was 73% greater than in controls. It decreased progressively, falling within the normal range at 5 weeks.

6. Restricted birds were hypoglycaemic from weeks 2 to 7 and hyper‐lipacidaemic throughout. A negative correlation between plasma glucose and free fatty acids was found.  相似文献   


12.
1. The present study investigated the effects of encapsulated benzoic acid (BA) supplementation in broiler feed on performance and gastrointestinal microbiota.

2. Eighty broilers were randomly divided into two groups. Birds in the control group were fed on maize–soybean-based diets. Birds in the treatment group were provided the same diet supplemented with 2 g/kg BA encapsulated in a vegetable oil matrix.

3. At the end of the trial (d 35), pH, bacterial composition and metabolites were determined in the crop, jejunum, ileum and caecum.

4. Growth performance variables and pH were not significantly different.

5. BA concentration decreased rapidly in the proximal gut. However, the treatment diet showed higher BA in the crop, jejunum, ileum and caecum.

6. Total lactate in the crop and D-lactate in the jejunum was higher in the BA treated group. Caecal total and branched chain fatty acids were decreased due to the treatment.

7. Lactobacilli populations were significantly altered by BA supplementation. A trend for increased lactobacilli was observed in the crop, while it became significant in the jejunum and ileum. Lactobacillus species responded differently to the treatment. Four of 5 measured Lactobacillus species, particularly in the ileum, followed the course observed for total lactobacilli; only Lactobacillus salivarius was not modified.

8. Correlation analysis showed that BA modified the intestinal microbiota. Lactobacilli correlated negatively to all studied clostridial clusters and enterobacteria. Clostridial clusters IV and XIVa were significantly increased in the jejunum, whereas only clostridial cluster XIVa was increased in the caecum.

9. Encapsulated BA modified the intestinal microbiota which can lead to the conclusion, that the main beneficial mode of action of BA in the gut appears to be the enhancement of lactic acid bacteria, which in turn may act as a vanguard against pathogens.  相似文献   


13.
1. The occurrence of low respiratory quotients (RQ) in fowls and the reliability of oxygen consumption, carbon dioxide output and heat production data in indirect calorimetry were studied.

2. The RQ, data from the gravimetric and the combined gravimetric‐volumetric systems were essentially the same, while differences in O2 and CO2 between the systems were primarily due to variations in environmental temperature.

3. Fasting RQ, was never less than 0.70 in these systems.

4. In the volumetric system the O2, CO2 and RQ, data from the diaferometer were significantly different from the infra‐red and paramagnetic analyses.

5. The CO2 values from the diaferometer were correct, but the O2 values were too low. In the specific analysers the reverse was seen, the paramagnetically‐determined O2 values being correct and the CO2 values from infra‐red analysis being too low.

6. Thus the fasting RQ values from the diaferometer were too high (0.762) and from the specific analysers too low (0.683).  相似文献   


14.
1. The expression of insulin-like growth factor-1 (IGF1) and myostatin (MSTN) mRNA in breast and leg muscle was quantified in 70-d-old Taihu and Wanxi geese by using a Multiplex Competitive Fluorescent–PCR method and the correlations between mRNA levels and carcass traits were analysed.

2. IGF1 mRNA expression in breast muscle in Taihu geese was significantly higher than that in Wanxi geese and the MSTN mRNA level in leg muscle in Taihu geese was significantly higher than that in Wanxi geese.

3. There was no significant difference in breast muscle MSTN or leg muscle IGF1 mRNA expression between the two breeds.

4. Within the same breed, the IGF1 mRNA expression in leg muscle of male geese was significantly higher than that in female geese, and MSTN mRNA expression in leg muscle was significantly higher than that in breast muscle.

5. There was no difference in the IGF1 mRNA expression between tissues.

6. There was a positive correlation between IGF1 mRNA and MSTN mRNA and a negative correlation between IGF1 mRNA expression of breast muscle and leg muscle ratio.

7. In Wanxi geese, MSTN mRNA expression in leg muscle was negatively associated with body weight and leg muscle weight.  相似文献   


15.
1. The present study investigated the effects of dietary supplementation with Gynura procumbens on egg yolk and serum cholesterol and triglycerides, excreta microflora, laying performance and egg quality.

2. A total of 160 Hy-Line Brown layers (45 weeks old) were randomly assigned into 4 treatments on the basis of laying performance. Each treatment had 4 replicates with 10 birds each.

3. Dietary treatments were basal diet supplemented with 0 (control), 2.5, 5.0 and 7.5 g/kg diet G. procumbens during 56-d feeding period.

4. Serum (d 21, 42 and 56) and egg yolk (d 28, 42 and 56) cholesterol and triglycerides concentrations were linearly reduced with increasing dietary concentrations of G. procumbens.

5. Increasing dietary concentrations of G. procumbens linearly reduced the excreta total anaerobic bacteria (d 28), Clostridium sp. and Escherichia coli (d 28 and 56) populations.

6. Overall egg production and egg mass were linearly increased, and overall feed efficiency was linearly improved with increase in dietary G. procumbens.

7. Dietary increasing concentrations of G. procumbens linearly improved egg yolk colour (d 28 and 56) and breaking strength of eggs (d 56).

8. The results obtained in the present experiment indicate that dietary supplementation with G. procumbens could reduce the egg yolk cholesterol, suppresses harmful excreta microflora and improves layers performance.  相似文献   


16.
1. Two experiments were designed to determine the effect of dietary boron (B) in broiler chickens. In Experiment 1, a 2 × 4 factorial arrangement of treatments was used to investigate the effect of dietary calcium (Ca) and available phosphorus (aP) (adequate or deficient) and supplemental B (0, 20, 40, and 60 mg/kg diet). In Experiment 2, B, at 20 mg/kg, and phytase (PHY) (500 FTU/kg diet) were incorporated into a basal diet deficient in Ca and aP, either alone or in combination.

2. The parameters that were measured were growth performance indices, serum biochemical activity as well as ash and mineral (i.e. Ca, P, Mg, Fe, Cu and Zn) content of tibia, breast muscle and liver.

3. Results indicated that both supplemental B and dietary Ca and aP had marginal effects on performance indices of chickens grown for 42 d.

4. There were positive correlations (linear effect) between B concentrations of serum, bone, breast muscle and liver and the amount of B consumed.

5. Serum T3 and T4 activities increased linearly with higher B supplementation.

6. Increasing supplemental B had significant implications on breast muscle and liver mineral composition. Lowering dietary Ca and aP level increased Cu content in liver and both Fe and Zn retention in breast muscle. Tibia ash content and mineral composition did not respond to dietary modifications with either Ca–aP or B.

7. The results also suggested that dietary contents of Ca and aP do not affect the response to B regarding tissue mineral profile. Dietary combination with B and PHY did not create a synergism with regard to growth performance and bioavailability of the minerals.  相似文献   


17.
1. The occurrence of Giant Fibres (GF) in three muscles (Pectoralis major (PM), Iliotibialis lateralis and Semimembranosus) with different types of energy metabolism was studied in slow- and fast-growing chicken strains.

2. A total of 20 one-day-old Leghorn chicks (slow-growing) and 20 broiler (Ross 508) chicks (fast-growing) were reared to 100 and 45 d, respectively.

3. A small percentage of GF was seen in pre rigor muscle samples even at 3 min post mortem in both genotypes and in all muscle types studied.

4. From 3 min to 24 h post mortem GF increased both in Leghorn and broiler chickens but to a different extent according to muscle type and genotype.

5. The highest GF 24 h post mortem value was found in the PM muscles belonging to the fast-growing broiler line.

6. It was concluded that every type of muscle can develop GF, but this phenomenon is more evident in the PM especially in animals selected for increased growth rate.  相似文献   


18.
1. A 31P topical magnetic resonance study of whole chicken's eggs in vivo is described.

2. Resonances from adenosine triphosphate, phosphocreatine, inorganic phosphate and phosphorous storage protein were observed. These changed in relative intensity as the embryo developed.

3. No ill effects due to exposure to radiofrequency radiation or magnetic fields were observed.

4. It is concluded that topical magnetic resonance can make a useful contribution to the study of embryonic development in avian eggs.  相似文献   


19.
1. The relative sensitivities of broiler chicks, White Leghorn chicks, quail chicks, goslings and turkey poults to increasing dietary contents of aflatoxin from 1 to 21 d of age were determined. Aflatoxin was included in the diets at three concentrations (0.7, 1.4 and 2.1 mg aflatoxin Ba equivalents /kg).

2. Data were analysed for species differences in food consumption, body weight, food utilisation, mortality and liver pathology.

3. There were no significant effects of aflatoxin in broiler and Leghorn chicks. Aflatoxin at 0.7 mg/kg decreased the body weight of turkey poults but tended to increase the growth rate of goslings. At 1 ‐4 mg aflatoxin/kg food consumption, body weight and weight gain of goslings were adversely affected.

4. Liver damage occurred in goslings and quail chicks at all inclusions of aflatoxin and was extensive at 2.1 mg/kg.

5. Poults and goslings appeared to be the most sensitive, quail were intermediate and domestic chicks were most resistant.  相似文献   


20.
1. The results of 47 experiments with broilers over the period 1974 to 1983 were selected for regression analysis. Included were those dealing with the relationship of growth and food utilisation to content of dietary protein (DP), metabolisable energy (DME) and added fat (DAF) in conventional feedingstuffs.

2. Significant correlations were found between DP and DME (0#lb50; P < 0#lb01), DP and DAF (0#lb61; P < 0#lb01), and DME and DAF (0#lb65; P < 0#lb01) contents.

3. Using multiple regression models, growth and food utilisation efficiency (FUE) were found to be dependent on the linear and quadratic effects of DME (r2 values = 0#lb67 and 0–64 respectively). Growth and FUE were also dependent on the linear and quadratic effects of DP (r2 values = 0#lb70 and 0#lb49 respectively).

4. By including the effects of DME, DP and DAF in the gain and FUE models it was shown that growth and FUE were dependent on DME, DP and DAF (r2 values = 0#lb76 and 0#lb79 respectively).

5. It was concluded that hypotheses concerning the broiler's response to DME and DAF were both correct but incomplete. DME, DP and DAF contents must all be known to predict accurately growth and FUE.  相似文献   


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