2. Sexual development was essentially the same in all groups. Egg numbers were decreased slightly by the short light‐dark cycles but daily egg mass output was the same in all groups. Food utilisation was best in group 1 and worst in the control group.
3. In general egg weight and shell quality were improved by the short light‐dark cycles; the effect appearing with the first eggs and being especially marked for group 3.
4. On intermittent regimes ovipositions were equally distributed between the four daily light‐dark periods when the light :dark ratio was near unity but were more numerous during the first half of the solar day when the ratio was 1.5 L:4.5 D. 相似文献
2. The automatic method gave as good a record as manual weighing for the purpose of controlling food intake.
3. The results suggest that care has to be taken regarding the time period over which the weighing equipment is used.
4. It is important that as many records as possible are obtained during a period of the day when body weight is not varying substantially. 相似文献
2. Birds which received diets containing the exogenous enzymes grew faster for the first 3 weeks but after that there was no apparent difference in rate of growth.
3. β‐Glucanase activities in the crop and small intestine of birds given exogenous enzymes were generally higher than those of birds given only the basal diet.
4. Viscosity of intestinal fluid in birds given only the basal diet decreased with age but there was no corresponding increase in β‐glucanase activity. This discounts bacterial β‐glucanase as a contributory factor in the adaptation to β‐glucanase apparent in older birds. 相似文献
2. Growth rate of LL chickens was reduced by the lower sulphur‐containing amino acid (SAA) concentrations whereas that of FL was not modified.
3. LL chickens exhibited a larger feather protein gain than FL, which was stimulated by SAA intake.
4. SAA retention, when plotted against SAA consumption, was always greater in LL than in FL.
5. Large differences were observed between genotypes for plasma‐free amino acids. Lysine, glutamic acid, histidine and serine were found at significantly higher concentrations in LL birds. Branched amino acids, aromatic amino acids, SAA and arginine were found at higher concentrations in FL. No differences were observed for aspartic acid, glycine, alanine and total amino acids. Methionine supplementation decreased free amino acid concentrations, with the exceptions of arginine and leucine.
6. It is concluded that lean chickens require a higher dietary concentration of SAA than FL. This is mainly caused by their lower food consumption and their greater feather synthesis. However, LL use SAA more efficiently than FL. 相似文献
2. In experiment 1 egg production was 84% using a conventional control diet, 61% with a basal low‐protein diet, and 79% with the basal diet supplemented with 10 essential amino acids + L‐glutamic acid (GA).
3. In experiment 2 supplementation with lysine and methionine (L + M) alone increased egg production significantly from 54 to 72%, compared with 83% with the conventional diet.
4. In experiment 3 egg production was 55% with the basal diet, 71% with the basal diet + L + M, 75% with a diet containing 141 g protein/kg + L + M, and 73% with the conventional diet.
5. In all three experiments supplementation with GA alone either gave no significant response or a depression in production.
6. Daily intakes of 1.24 g nitrogen as non‐essential amino acids and 13 to 14 g total crude protein per bird resulted in good egg production. Supplementation of the basal diet with L + M resulted in a daily intake of 413 mg methionine/bird day which was considered adequate, and a daily intake of 710 mg lysine which was considered slightly inadequate. 相似文献
2. The laying rate of albinos was higher than that of nonalbinos before the forced moult but not afterwards. Hierarchical follicles in albino hens were smaller than those of nonalbinos before but not after the moult.
3. Growth intensity of hierarchical follicles was greater in albino hens before the moult, suggesting that follicular maturation was more rapid, possibly explaining the higher egg production observed.
4. All differences between genotypes disappeared after the moult, suggesting that the state of the ovary before a moult is independent of that afterwards. 相似文献
2. The growth of treated birds was significantly better than that of controls fed on a basal diet, but no combination of additives was significantly superior to the additives given singly.
3. Performance up to 56 d of birds fed continuously on a diet supplemented with zinc bacitracin (25 mg/kg) from 1 d old was better than that obtained when the supplement was either introduced or withdrawn at different ages. 相似文献
2. In experiment 1, enzyme treatment of rye (1–0 g Tv cellulase/kg rye) improved weight gains by 15% (P<0–05) and food:gain ratios by 14% (P<0–05) but did not affect food consumption (P>0–05). Corresponding improvements produced by water‐soaking were 7 (P>0–05), 16 (P<0–05) and 10% (F<0–05). In the second experiment, similar trends occurred but improvements were less pronounced.
3. The second experiment also demonstrated that both enzyme supplementation and water‐soaking reduced the viscosity of both the diet and excreta, and increased the retention of fat.
4. Water‐soaking and fungal enzyme treatment caused an increase in extractable water‐soluble pentosans which were of sufficient molecular mass (not monomers or oligomers) to be almost entirely precipitated by 80% ethanol. Sufficient hydrolysis of these polysaccharides had occurred by both enzyme and soaking treatments, but not by normal digestion by chickens, to lower viscosity. The results suggest that the viscosity of rye can be reduced slowly by endogenous enzymes present in rye (water‐soaking), rapidly by a fungal enzyme preparation and in the lower sections of the gastrointestinal tract by microbial enzymes.
5. Both water‐soaking and enzyme treatment greatly improved the nutritive value of rye by bringing about a reduction in the viscosities of the water‐soluble and highly viscous pentosans. The results also suggest that the production of monomers or oligomers was not necessary for the lowering of viscosity observed with the two treatments. 相似文献
2. Follicles of diameter greater than 1.4 mm were classified into size groups, and the numbers in these groups in the anterior and posterior halves of the ovary were compared for the effects of line and feeding régimen.
3. There were more yellow follicles ( > 8 mm diameter) in the anterior half of the ovary, and this difference was greater for ad libitum birds. Ad libitum feeding did not influence the number of yellow follicles in the posterior segment of the ovary.
4. The increase in numbers of yellow follicles in the anterior segment of the ovary differed according to line at point of lay, but not at 47 weeks of age.
5. Birds of 47 weeks of age showed higher numbers of follicles 1.4–6 mm in diameter in the posterior segment of the ovary, and smaller numbers of follicles 6–8 mm in diameter. Thus, although large numbers of white follicles were in the earlier stages of growth, there were fewer ovulable yellow follicles because of higher levels of atresia. 相似文献
Background
E‐point‐to‐septal‐separation (EPSS) and the sphericity index (SI) are echocardiographic parameters that are recommended in the ESVC‐DCM guidelines. However, SI cutoff values to diagnose dilated cardiomyopathy (DCM) have never been evaluated.Objectives
To establish reference ranges, calculate cutoff values, and assess the clinical value of SI and EPSS to diagnose DCM in Doberman Pinschers.Animals
One hundred seventy‐nine client‐owned Doberman Pinschers.Methods
Three groups were formed in this prospective longitudinal study according to established Holter and echocardiographic criteria using the Simpson method of disk (SMOD): control group (97 dogs), DCM with echocardiographic changes (75 dogs) and “last normal” group (n = 7), which included dogs that developed DCM within 1.5 years, but were still normal at this time point. In a substudy, dogs with early DCM based upon SMOD values above the reference range but still normal M‐Mode measurements were selected, to evaluate if EPSS or SI were abnormal using the established cutoff values.Results
ROC‐curve analysis determined <1.65 for the SI (sensitivity 86.8%; specificity 87.6%) and >6.5 mm for EPSS (sensitivity 100%; specificity 99.0%) as optimal cutoff values to diagnose DCM. Both parameters were significantly different between the control group and the DCM group (P < 0.001), but were not abnormal in the “last normal” group. In the substudy, EPSS was abnormal in 13/13 dogs and SI in 2/13 dogs.Conclusions and Clinical Importance
E‐point‐to‐septal‐separation is a valuable additional parameter for the diagnosis of DCM, which can enhance diagnostic capabilities of M‐Mode and which performs similar as well as SMOD. 相似文献Background
GastroGard, an omeprazole powder paste formulation, is considered the standard treatment for gastric ulcers in horses and is highly effective. Gastrozol, an enteric‐coated omeprazole formulation for horses, has recently become available, but efficacy data are controversial and sparse.Objectives
To investigate the efficacy of GastroGard and Gastrozol at labeled doses (4 and 1 mg of omeprazole per kg bwt, respectively, PO q24h) in healing of gastric ulcers.Animals
40 horses; 9.5 ± 4.6 years; 491 ± 135 kg.Methods
Prospective, randomized, blinded study. Horses with an ulcer score ≥1 (Equine Gastric Ulcer Council) were randomly divided into 2 groups and treated for 2 weeks each with GastroGard followed by Gastrozol (A) or vice versa (B). After 2 and 4 weeks, scoring was repeated and compared with baseline. Plasma omeprazole concentrations were measured on the first day of treatment after administration of GastroGard (n = 5) or Gastrozol (n = 5).Results
Compared with baseline (squamous score (A) 1.65 ± 0.11, (B) 1.98 ± 0.11), ulcer scores at 2 weeks ((A) 0.89 ± 0.11, (B) 1.01 ± 0.11) and 4 weeks ((A) 1.10 ± 0.12, (B) 0.80 ± 0.12) had significantly decreased in both groups (P < .001), independent of treatment (P = .7). Plasma omeprazole concentrations were significantly higher after GastroGard compared with Gastrozol administration (AUCGG = 2856 (1405‐4576) ng/mL × h, AUCGZ = 604 (430‐1609) ng/mL × h; P = .03). The bioavailability for Gastrozol was 1.26 (95% CI 0.56–2.81) times higher than for GastroGard.Conclusions and Clinical Importance
Both Gastrozol and GastroGard, combined with appropriate environmental changes, promote healing of gastric ulcers in horses. However, despite enteric coating of Gastrozol, plasma omeprazole concentrations after single labeled doses were significantly higher with GastroGard. 相似文献Background
Long‐term microscopic agglutination test (MAT) results after vaccination with 4‐serovar Leptospira vaccines are not available for all vaccines used in client‐owned dogs.Hypothesis/Objectives
To determine antibody responses of client‐owned dogs given 1 of 4 commercially available Leptospira vaccines.Animals
Healthy client‐owned dogs (n = 32) with no history of Leptospira vaccination for at least the previous year.Methods
Dogs were given 1 of 4 Leptospira vaccines on week 0 and then approximately on week 3 and week 52. Sera were collected before vaccine administration on week 0 and then within 3 days of week 3, within 2 days of week 4, and approximately on weeks 7, 15, 29, 52, and 56. Antibody titers against Leptospira serovars bratislava, canicola, grippotyphosa, hardjo, icterohemorrhagiae, and pomona and were determined by MAT.Results
When compared among vaccines, MAT results varied in maximal titers, the serovars inducing maximal titers, and the time required to reach maximal titers. Each vaccine induced at least some MAT titers ≥1 : 800. Most dogs were negative for antibodies against all serovars 1 year after vaccination, and anamnestic responses were variable.Conclusions and Clinical Importance
Dogs vaccinated with Leptospira vaccines have variable MAT titers over time, and antibodies should not be used to predict resistance to Leptospira infection. MAT titers ≥1 : 800 can develop after Leptospira spp. vaccination, which can complicate the clinical diagnosis of leptospirosis. 相似文献Background
Serum N‐terminal pro‐C‐natriuretic peptide (NT‐proCNP) concentration at hospital admission has sufficient sensitivity and specificity to differentiate naturally occurring sepsis from nonseptic systemic inflammatory response syndrome (SIRS). However, little is known about serum NT‐proCNP concentrations in dogs during the course of sepsis.Objective
To determine serum NT‐proCNP and cytokine kinetics in dogs with endotoxemia, a model of canine sepsis.Samples
Eighty canine serum samples.Methods
Eight healthy adult Beagles were randomized to receive Escherichia coli lipopolysaccharide (LPS, 5 μg/kg) or placebo (0.9% NaCl) as a single IV dose in a randomized crossover study. Serum collected at 0, 1, 2, 4, and 24 hours was stored at −80°C for batch analysis. Serum NT‐proCNP was measured by ELISA and 13 cytokines and chemokines by multiplex magnetic bead‐based assay.Results
Serum NT‐proCNP concentrations did not differ significantly between LPS‐ and placebo‐treated dogs at any time. When comparing serum cytokine concentrations, LPS‐treated dogs had higher interleukin‐6 (IL‐6), IL‐10, TNF‐α and KC‐like at 1, 2, and 4 hours; higher CCL2 at 1, 2, 4, and 24 hours; and higher IL‐8 and CXCL10 at 4 hours compared to placebo‐treated dogs. There were no differences in serum GM‐CSF, IFN‐γ, IL‐2, IL‐7, IL‐15 or IL‐18 between LPS‐ and placebo‐treated dogs.Conclusions and Clinical Importance
Serum NT‐proCNP concentration does not change significantly in response to LPS administration in healthy dogs. Certain serum cytokine and chemokine concentrations are significantly increased within 1–4 hours after LPS administration and warrant further investigation as tools for the detection and management of sepsis in dogs. 相似文献2. Growth was poorer with the basal diet than with a practical diet and it was not improved by an increase in the concentration of vitamins or supplementation with isolated soy protein, water or liver.
3. An increase in the amount of mineral mixture or of magnesium alone gave a significant improvement in growth, so that it approximated that obtained with the practical diet. Food conversion efficiency was significantly better with the mineral‐supplemented than with the practical diet.
4. The basal purified diet supplemented with magnesium to provide 684 mg Mg per kilogram was satisfactory for the early growth; chicks fed on this diet did not respond to sources of “unidentified factors” such as fresh or freeze‐dried liver and soy‐protein. 相似文献
2. The proportions of ingredients eaten by the chickens given a free choice varied widely during the first 56 h of the trial. Thereafter, the proportions did not vary widely and birds given the free choice ate approximately ½ of their intake as whole wheat, ? of their intake as concentrate (high protein meals plus vitamin and mineral premixes), and 1/7 of their intake as whole sorghum each week for the three‐week trial period.
3. The nutrient composition of the free‐choice diet selected by the birds over the trial period averaged 12.09 MJ ME/kg feed, 210 g/kg crude protein, 14 g/kg calcium and 7 g/kg phosphorus.
4. At the end of the trial the average live body weights of the birds differed significantly according to method of feeding, in the descending order of pellets > mash > free choice.
5. The empty gizzard weight of birds differed significantly according to the method of feeding, in the descending order of free choice > mash > pellets.
6. The plucked empty bodies of birds given the free choice had a significantly lower concentration of crude protein than the plucked empty bodies of birds fed on mash or pellets. There were no significant differences between the treatments in the plucked empty body concentrations of fat, calcium or phosphorus.
7. Financial analysis indicated that free‐choice feeding was more profitable than feeding mash or pelleted diets to broiler chickens by 3.6% and 33.4% respectively. 相似文献
2. Both cephalosporins and all the nine penicillins tested were active.
3. Of six aminoglycosides, streptomycin and gentamicin had the greatest activity and neomycin had none.
4. Growth rate was significantly improved by clindamycin, lincomycin, vancomycin, spectinomycin, rifampicin, oxytetracycline, chlortetracycline, erythromycin, tylosin, flavomycin, virginiamycin and zinc bacitracin. Chloramphenicol and nalidixic acid were inactive. Polymixin B, novo‐biocin, cycloserine, phosphonomycin, and sodium fusidate had little activity. Fusidic acid promoted growth at 250 mg/kg diet.
5. Trimethoprim was inactive alone and in combination with sulpha‐diazine. Of seven 5‐nitroimidazoles, only dimetridazole and metronidazole showed slight activity. Of the six 5‐nitrofurans, only nitrovin, the standard reference substance used, promoted growth.
6. Caprylohydroxamic acid, a urease inhibitor, had no beneficial effect on growth rate or on the efficiency of food conversion.
7. The growth‐promoting properties of the various substances could not be related with their known antimicrobial and absorption characteristics in mammals. 相似文献
2. A total of 2160 seven‐day‐old male broiler chicks were used. The feeding programme consisted of a starter diet from 7 to 21 d, and a finisher diet till the end of the experiment. The starter basal diet contained 6.1 g/kg total sulphur‐containing amino acids (TSAA), and an estimated metabolisable energy (ME) content of 13.2 MJ/kg. The finisher diet contained 5.8 g/kg TSAA and an estimated ME content of 13.6 MJ/kg. Four concentrations of DL‐methionine and DL‐MHA‐FA were added at 0.5g/kg increments on an equimolar basis. Therefore, there were 9 experimental treatments which were each applied to 6 replicates of 40 chicks. Weight gain and food efficiency were determined at 35 d of age. Breast yield and carcase fat were measured at 41 d.
3. Significant responses to graded amounts of both methionine sources were observed in weight gain, food efficiency, breast meat percentage, and food cost per kg of breast meat. The responses fitted exponential regression curves. Based on the regression coefficients, equimolar bioefficacy of DL‐MHA‐FA relative to DL‐methionine was 80% for daily gain, 83% for food efficiency, 51% for breast meat yield, and 66% for food cost per kg of breast meat. Differences between the 2 sources were significant (P< 0.05) for breast meat yield and food cost per kg of meat and (P< 0.10) for food efficiency. 相似文献
2. Deposition of 14C label into breast and heart muscles responded positively to dietary lysine concentration. There was no apparent relationship between dietary lysine intake and deposition of label into carbon dioxide or excreta.
3. Efficiency of lysine retention, above maintenance, was estimated to be 0.523 ± 0.034.
4. Turkeys exhibited variable metabolic efficiency in the use of lysine as indicated by loss of U‐14C‐lysine label to expired carbon dioxide and to excreta by individual turkeys. 相似文献