2. Both IGF‐I and IGF‐II administration resulted in a rapid, significant decrease in plasma GH concentrations, but the concentrations of both triiodothyronine and thyroxine remained unchanged.
3. Immunisation against both IGF‐I and IGF‐II produced a significant elevation in plasma GH.
4. These data show that both IGFs can regulate GH concentrations in birds. Furthermore, the immunoneu‐tralisation data suggest that these hormones have a physiological role in the regulation of GH secretion. 相似文献
2. The egg‐shells were colonised by yeasts also, but the growth of these organisms appeared to be dependent upon the pseudomonads for the release of nutrients from the cuticle.
3. The pseudomonads would not grow on cuticle in situ unless the relative humidity was about 100%. 相似文献
2. GH concentrations were higher in restricted compared with ad libitum‐fed birds at 17 to 21 weeks of age and were similar thereafter. Plasma IGF‐I concentrations were higher in restricted compared with ad libitum‐fed birds throughout the sampling period of the experiment.
3. The age at first egg was delayed by about two weeks in restricted birds. At 54 weeks of age they had laid 114 compared with 67 eggs in birds fed ad libitum throughout and had produced less than half the number of eggs with defective shells.
4. It was suggested that differences in egg production between ad libitum and restricted broiler breeder females could be related to changes in the pattern of GH and/or IGF‐I secretion. 相似文献
2. Compared with the normal diet the low‐protein diet caused a decrease in growth rate which at 38 d was 37% and 25% for male and female chickens, respectively.
3. A genotype‐level of protein interaction was demonstrated for weight at 38 d. Expressed as a genetic correlation for the same trait and measured in the two feeding environments the values were about 0.33.
4. In estimating the genetic correlation the interaction as well as the covariance method were used. The two methods did not give the same estimates.
5. Heritabilities for weight at 38 d tend to be larger in the low‐protein environment. 相似文献
2. Growth virtually ceased after feeding ethionine for 2 d.
3. Ethionine induced an accumulation of lipid, decreased the activities of malic enzyme and isocitrate dehydrogenase and increased the activity of lactate dehydrogenase.
4. The concentration of glycogen in the liver of ethionine‐fed chickens increased for 3 d in spite of a decrease in food intake, but then decreased. 相似文献
2. The broilers ate more and grew twice as fast as the layers. They also converted their food more efficiently, partly because they digested their food slightly better than the layers did, but also because their total energy expenditure was probably considerably less than that of the layers. They were very inactive and spent less time feeding, so presumably they could devote proportionately more food energy to growth than the layers could.
3. In the same experiment broiler and layer chicks were reared together in mixed groups, and it was found that each strain affected the other's growth and behaviour slightly. The broilers grew slightly faster in the mixed groups than in the single‐strain groups, whereas the layers grew slightly slower. 相似文献
2. Chicks receiving a zinc sulphate solution directly into the crop ate an amount of zinc‐deficient diet similar to that of the zinc‐sufficient diet eaten by the control chicks; palatability was thus ruled out as the cause of the anorexia.
3. Only chicks receiving the zinc‐deficient diet displayed signs of zinc deficiency. 相似文献
2. The increase in hypothalamic GnRH‐I content which occurs during sexual development was advanced in TAM‐treated birds, in association with precocious testicular development, an early rise of plasma testosterone content and enhanced comb growth.
3. Plasma LH concentrations behaved similarly and were higher in the TAM‐treated than in control birds, during most of the experimental period. Plasma PRL concentration, which is high at hatching, decreased more quickly in TAM‐treated than in control birds; plasma GH values were not consistently affected by TAM treatment.
4. Both the growth and the involution of the bursa of Fabricius in the TAM‐treated cockerels preceded that in the control chicks.
5. It is concluded that TAM treatment induces precocious puberty in the cockerel by blocking the negative feedback action of aromatised testicular androgens on the hypothalamus. 相似文献
2. Food consumption up to 20 weeks of age was significantly reduced by all three treatments; mortality was increased and sexual maturity was delayed.
3. Greatest uniformity was observed amongst pullets fed on the low protein and the low lysine diets
4. By 70 weeks there were no significant differences in food conversion based on food consumed between 20 and 70 weeks of age, but based on consumption between 8 and 70 weeks the quantitatively restricted birds converted food most efficiently.
5. The most favourable method of restriction appeared to be the feeding of a low lysine or low protein diet, since rearing costs were low, and the performance of the pullets on these treatments was high. 相似文献
2. Duodenal infusions of hyperosmotic solutions of sorbitol and KC1 at 3 osm significantly decreased food intake within an hour of infusion. Glucose infusions decreased intake only in birds starved for 3 h before the experiment.
3. The results are discussed in relation to the site of infusion and nutritive visceral mechanisms of food intake control. It is likely that there is a major osmotic control in the duodenum which may affect a secondary control system in the upper gastro‐intestinal tract. 相似文献
2. Brain serotonin, 5‐hydroxyindoleacetic acid and norepinephrine concentrations were increased dose‐dependently with 1.0, 2.0 and 3.0 g/kg supplemental dietary tryptophan.
3. Supplemental dietary tryptophan had no effect on body weight gain, food intake, food efficiency or mortality.
4. Carcase and individual thigh weights were significantly heavier in those birds fed l.0 g/kg supplemental tryptophan. 相似文献
2. Extrusion cooking of rice bran resulted, in improved chick weight gain and food efficiency for the first two weeks of feeding, but this advantage was lost by the end of the feeding period.
3. Addition of 10 g calcium/kg to the stabilised rice bran diet prevented the decline in performance after two weeks of age, and birds fed on this diet continued to gain at an increasing rate until the end of the experiment.
4. Calcium supplementation of stabilised rice bran diets produced significantly greater gains and superior food utilisation compared to stabilised rice bran diets without added calcium.
5. Calcium supplementation did not affect weight gain of chicks fed on diets containing raw rice bran.
6. Taste panel evaluation of meat from birds fed on diets containing raw rice bran, stabilised rice bran, or no rice bran indicated a significant preference in only one combination tested. Any ‘off flavour could not be related to dietary treatment. 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2. No differences in body weight, food conversion efficiency or arterial pressure index were observed although haematological data indicated that early‐life food restriction may enhance the incidence of ascites.
3. Allometric growth equations fitted to the data suggested that ascites is associated with the slower development of the heart, lungs and liver of the broiler, relative to whole body growth and development. 相似文献