2. Thirty-six male Bi?goraj geese were fed control diets with low phytoestrogen content (containing grass meal) and diets with high phytoestrogens (containing alfalfa meal and soy).
3. Testes were obtained from both groups of ganders at three different times of the breeding season: peak of reproductive activity (March), second half of reproductive activity (May) and beginning of photorefractoriness (July).
4. Isolated Leydig cells were incubated with LH as well as genistein, daidzein, equol and coumestrol and the concentration of testosterone in the medium was determined by radioimmunoassay.
5. The mean weight of testes from ganders in May and July decreased relative to their weights in March, but no significant differences among experimental groups were noted.
6. No differences were observed in basal and LH-stimulated testosterone secretion by Leydig cells of ganders fed the control diets and the diets with higher phytoestrogen content. In July, LH did not stimulate testosterone secretion in either group. In vitro treatment with genistein, daidzein and equol (5 and 50?µM) inhibited basal and LH-stimulated testosterone production by Leydig cells from both groups. Coumestrol (5 and 50?µM) inhibited basal testosterone secretion only in March in the control group.
7. Dietary exposure to phytoestrogens had a slight effect on in vitro testicular secretion in ganders. In vitro treatment with phytoestrogen inhibited testosterone production by Leydig cells. Genistein showed the strongest effect and coumestrol had the weakest influence on testicular secretion. 相似文献
2. No difference was found in the qualitative electrophoretic patterns of the anterior pituitary homogenates at different ages and between the sexes.
3. Pituitary PRL concentrations in males were generally higher than in females.
4. Pituitary PRL concentrations in castrated immature cockerels were higher than in intact birds, while PRL concentration was depressed by the injection of testosterone propionate or oestradiol benzoate.
5. Prolactin concentration in intact immature cockerels was decreased by daily injection of testosterone or oestradiol for 3 weeks but not by injection of the hormones for 1 week. 相似文献
2. The troop consisted of 11 emus (5 females and 6 males) aged 12 years, kept in a free-range system. Observations were carried out during a period of 3 weeks in each season, during which 60-min observation sessions took place on 3 randomly chosen days.
3. A significant effect was found of each season on the behaviour patterns related to feeding, sand intake, plumage care, resting and agonistic behaviour.
4. Time of day affected the behaviour associated with the collection of food and water, foraging, pecking and ingesting sand and plumage preening.
5. Most of the time, regardless of season and time of day, the emus were standing still, walking aimlessly or observing the surrounding area. 相似文献
2. Although the protein content of all tissues varied with age, the only statistically significant effect was on the level of protein in the gizzard.
3. The moisture content of the gizzard was significantly affected by age and blood by age and sex.
4. The fat content of the gizzard was significantly affected by age, as was the effect of sex on the fat content of blood.
5. The ash contents of heart and gizzard were significantly affected by age.
6. The phosphorus contents of the gizzard, heart and liver were significantly affected by age, as were the chloride content of heart and the calcium content of the liver. Blood potassium was significantly affected by sex. Fluctuations in the contents of other elements are discussed.
7. The variability in organ composition is discussed with respect to the degree of trimming and preparation of the samples. 相似文献
2. Protein and energy metabolism were studied in males from these selected lines fed on a diet of intermediate protein content.
3. All selected birds retained more nitrogen than those studied 10 years previously.
4. There was no difference in nitrogen retention between groups, although relative growth rate of group B birds was higher.
5. Heat productions relative to gross energy intake were 0.38 (group B) and 045 (group A). Energy retentions relative to gross energy intake were 0.39 (group B) and 0.35 (group A); the difference being primarily due to higher fat retention in group B.
6. Using a common maintenance requirement for metabolisable energy, group B utilised metabolisable energy for growth (0.78) better than did group A (0.71).
7. At 53 d of age plasma glucose (10%) and insulin (50%) were higher in group B than in group A. 相似文献
2. Dry plucking increased weight loss due to plucking and eviscerating, and reduced chilled carcass yield.
3. Dry eviscerating increased carcass water uptake during chilling.
4. Pre‐chilling with running water increased carcass water uptake compared with chilling in ice and water alone.
5. Water uptake during chilling appeared to be increased by longer eviscerating time. 相似文献
2. From 28 to 55 d of age, birds were given apilarnil orally. The effects of low (2.5 g/bird) and high (7.5 g/bird) doses of apilarnil on growth performance, testicular weight, secondary sexual characteristics, blood lipids, testosterone and fearful behaviour were evaluated.
3. Apilarnil administration did not cause a positive effect on growth performance of male and female broilers suggesting that apilarnil did not have an anabolic effect.
4. Apilarnil administration suppressed blood glucose and cholesterol.
5. Birds receiving apilarnil remained immobile for a shorter period in a tonic imobiliy test and showed less home-cage avoidance responses suggesting a lower level of fearfulness.
6. Increases in testicular weight, testosterone concentration and comb growth in males receiving apilarnil implied that it stimulates the sexual maturation at an early age. However, a similar stimulation of secondary sexual characteristics was not observed in females. 相似文献
2. The data contain information about the laying performance of 1831 individuals in the first year of laying. To describe the trajectory of the laying performance, 10 mathematical models were tested. For the genetic parameter estimation of egg production, data from 1038 birds were used with a production higher than 20 eggs during the first season of laying.
3. The analysis of egg production was based on single and multi-trait models. Heritability, genetic and phenotypic correlations between phases of the laying performance as well as breeding values were estimated.
4. The best adaptation to the goose egg laying curve was the Ali and Schaeffer model. The estimates of heritability were 0.20 (0.06 SE) using the single-trait model and ranged from 0.12 to 0.24 using the multi-trait model.
5. The results suggest that the BLUP method can support the conservation programme. 相似文献
2. In 4 consecutive trials, 4752 hens were recorded for keel bone status. Evaluation of plumage condition was made for 1440 hens and bone breaking strength was recorded for 1200 hens. A total of 4962 eggs were analysed for internal and external egg quality traits. Analyses involved 30 small group compartments per trial.
3. The layer line had a much more pronounced influence on humerus breaking strength than on tibia breaking strength.
4. Plumage condition, particularly on the neck, was positively correlated with humerus breaking strength in both layer lines.
5. An average of 34% of LB and 23% of LSL hens showed keel bone deformities, with higher proportions of slight deformities.
6. Slight keel bone deformities, rather than moderate to severe, increased significantly during the laying period.
7. Stocking density had no influence on bone breaking strength, keel bone status and egg quality traits.
8. LB layers had a 1.4-fold higher humerus, but only a 1.06-fold higher tibia breaking strength compared to LSL layers.
9. Tibia breaking strength was significantly affected by the interaction of group size and layer line. LSL layers in small groups had lower tibia breaking strengths than those of the large groups. 相似文献
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
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
2. Half the hens had undergone beak trimming at 18 weeks, but in many cases regrowth had occurred.
3. Plumage damage and loss was significantly reduced in beak‐trimmed birds compared with birds with normal beaks. Tier and cage design had no effect.
4. This finding supports the idea that feather pecking is the important factor in causing plumage damage, rather than abrasion.
5. A comparison between 64 birds in which beak regrowth had occurred, and 64 in which it remained truncated, showed that both groups had similar plumage scores.
6. It appears to be the beak‐trimming procedure which is important; subsequent regrowth being irrelevant. 相似文献
2. A randombred control population of known pedigree was used to measure the environmental trends.
3. Selection in pure lines resulted in concomitant improvement in the crosses for the selected as well as the correlated traits.
4. Cross performance was comparatively more than expected on the basis of mid‐parent values, indicating involvement of non‐additive gene action in the expression of cross performance.
5. Crosses responded better to independent culling level selection for egg weight than their parents.
6. Heterosis appeared to increase in later generations as compared with initial generations of selection. 相似文献
2. The Na and water contents of skeletal muscles were increased by TA treatment while K was unaltered.
3. The extracellular space expressed as a proportion of starved body weight was unaffected by TA implantation.
4. Plasma or serum concentrations of P, Ca, Mg, Na and K and activities of the enzymes aspartate aminotransferase [EC 2.6.1.1], creatine kinase [EG 2.7.3.2] and γ‐glutamyl transferase [EC 2.3.2.2] were not changed by TA treatment.
5. Packed cell volume was significantly increased by TA implantation after a delay of some 2 to 3 weeks while plasma protein concentrations were immediately decreased for a period of two weeks before nearly normal concentrations were obtained again.
6. Erythrocyte sedimentation rate was decreased by TA treatment, but serum protein electrophoretic pattern was unchanged. 相似文献
2. Protein content generally increased with age in all muscles and decreased in skin. Protein content in skin of males was always higher than that in females.
3. Moisture content in all muscles decreased with age. In the skin, moisture decreased with age considerably more in females than in males.
4. Fat content increased with age in all tissues, while ash content of breast, thigh and skin decreased with age.
5. Phosphorus, chloride, magnesium and potassium all decreased with age in all the tissues. Thigh and skin calcium content were affected by age, as was the sodium content of drumstick and skin.
6. The sex effect on the inorganic constituents was variable. 相似文献
2. Increased mortality, perosis and other pathological changes involving a number of tissues were observed in birds fed on a low‐choline diet.
3. Methionine replaced part of the dietary requirement for choline at low dietary choline concentrations.
4. High dietary concentrations of choline (> 1 750 mg/kg) increased the requirement for dietary TSAA.
5. Increasing the dietary choline while maintaining the TSAA at an inadequate level may decrease performance. 相似文献
2. The different varieties of wheat investigated contained different proportions of water‐soluble to water‐insoluble hemicelluloses.
3. By comparison of the arabinose to xylose ratios it was concluded that water‐soluble and insoluble arabinoxylans of wheat were branched to the same degree.
4. Starch from six wheat varieties grown in the U.K. was very well digested by adult cockerels and true metabolisable energy values of the wheats were high.
5. Small amounts of cell wall carbohydrates were digested by adult cockerels. 相似文献
2. Growth rate, food intake, food utilisation and proportion of dietary nitrogen retained were much poorer in chicks receiving salseed meal.
3. The chicks receiving salseed meal developed pathological lesions in liver and kidney.
4. The red blood cell count, white blood cell count, haemoglobin concentration and packed cell volume of the chicks receiving salseed meal were lower than those of chicks receiving maize.
5. The apparent metabolisable energy value of salseed meal was determined as 6.83 MJ/kg. 相似文献
2. Some plants and their respective volatile oils and extracts have the potential to alleviate coccidiosis and reduce its severity.
3. Most plant bioactives improve some, but not all, aspects of coccidiosis with variable effectiveness against different species of Eimeria.
4. Difficulties in comparing research findings have arisen from the use of different experimental models, different active components and infectious dose of Eimeria.
5. Current knowledge of their potential anti-coccidial effects may provide guidance for the use of botanical extracts in the control of the coccidiosis. 相似文献