共查询到20条相似文献，搜索用时 62 毫秒
1.
The variation in shell membrane thickness (μ), membrane weight (mg./cm.2), membrane nitrogen (μg. N/cm.2) and packing index (μg./cm.2/μ) from the broad pole, excluding the air space, to the narrow pole of the same egg has been studied. The pattern of variation for a given characteristic was the same in different eggs from the same bird. Two thickness patterns were found. In Group I thickness decreased from the B collar to the equator, increased again to the G collar and then decreased sharply at the H cap. In Group II the increase from the equator to the G collar was replaced by a continued, but less‐marked, decrease. There was a high, positive correlation between weight and nitrogen, but the relationship between weight and thickness varied within and between eggs. All eggs showed a very similar pattern of packing index variation, decreasing from the B to about the C collar and then increasing to the H cap, the pattern being the same whether measurements were made on wet or dry membranes. 相似文献
2.
It is expected that when birds consume a diet with a fixed calcium content variation in the rate of egg production, in body weight or in egg weight will lead to variation in calcium consumption. This analysis investigated whether, in a particular experiment, this also led to variation in egg shell thickness. Data from 67 birds over ten consecutive 28‐d periods were considered. Within birds and within periods it was found that the relationships between shell thickness and these production characters varied at different dietary calcium levels and in some cases the partial regression coefficients calculated were different in sign from those expected. However, only comparatively small amounts of variation in shell thickness could be ascribed to yariation in egg numbers, body weight or egg weight and, after regression, significant (P<0.001) differences still existed in shell thickness between birds. In this investigation there was little tendency for the egg shells to become thinner as the birds aged and hence the correlation coefficients between shell thickness and each of the three production characters due to common seasonal or ageing effects were small. The correlation between the angular transformation of the percentage cracked egg shells produced by each bird and its'mean shell thickness was — 0.357. 相似文献
3.
The reproductive tracts of turkey breeder hens from five flocks were examined grossly and histologically. Hens from one flock had a normal reproductive history, but hens from the four other flocks had poor records in both egg production and hatchability. Nodular growths occurred in the oviducts of birds in all five flocks. The incidence of lesions varied from flock to flock and from bird to bird. In four flocks, lesions were small and consisted of areas of dysplasia with adenomatous change. Histologically, the lesions in some birds in the fifth flock were adenocarcinomas. No metastases were observed. 相似文献
4.
A B Gilbert G G Mitchell M F Davidson K F Laughlin B O Hughes 《Research in veterinary science》1982,33(2):216-220
The injection of 50 mg/kg bodyweight of a prostaglandin synthetase inhibitor (indomethacin) brought about a delayed oviposition time in birds of three breeds of layers, whereas the injection of 5 mg indomethacin had no effect. The daily ingestion of up to 400 mg aspirin or up to 10 mg indomethacin for three weeks, or 750 mg aspirin or 200 mg indomethacin for two weeks had no effect on egg production, oviposition time, egg-shell water conductance, oviducal prostaglandin synthetase activity or bird behaviour. Prostaglandin synthetase activity was demonstrable in both control and treated birds only in the tubular glands of the shell gland. These observations suggest that prostaglandins play a minor role in normal reproductive activity in the female domestic fowl. 相似文献
5.
6.
Ning LI Zheng WANG Shuai ZHANG Chuan YAN Xinhai LI Changhu LU 《Integrative zoology》2019,14(5):470-478
Habitat fragmentation is globally one of the most important drivers of change in biodiversity. Seed dispersal by birds is crucial for tree regeneration in remnant patchy forests, yet how bird traits affect seed dispersal pattern is still poorly understood. We studied the extent to which bird traits affect seed‐removal networks and whether these traits affect seed deposition and seedling recruitment for 3 co‐fruiting tree species (Taxus chinensis, Cinnamomum bodinieri and Machilus thunbergii) in a patchy forest. A total of 17, 18 and 10 bird species were recorded foraging for seeds of T. chinensis, M. thunbergii and C. bodinieri, respectively. Frequency of bird visitation increased with tail length, wing length and body length. Furthermore, bird body length, bill length, body weight and wing length were important in the strength of the seed removal network. During foraging, 6 bird species exhibited different patterns of microhabitat utilization and their perching frequency increased with bird weight and tarsus length. As a consequence, frequency of habitat use, bird length and tarsus length were important in determining the number of deposited seeds. For seedling recruitment, seedling number increased with bird tarsus length and weight, but decreased with wing length. Overall, our results showed that various bird traits not only affected seed removal, but also influenced the subsequent processes of seed deposition and seedling distribution in a patchy forest. These results thus highlight the importance of large‐bodied birds for plant recruitment and point out the need to prioritize the protection and conservation of these birds in remnant patchy forests. 相似文献
7.
8.
9.
Phenotypic and genotypic characterization of Salmonella arizonae from an integrated turkey operation
Fifty cases submitted between 2000 and 2002 were selected for retrospective analysis to evaluate possible relationships between Salmonella arizonae isolated from breeder flocks, hatching eggs, and meat bird flocks belonging to a single turkey integrator. In all the meat bird cases selected for this study, arizonosis was the primary diagnosis. In birds under 1 month of age, clinical signs and pathologic changes were observed in older birds. The Salmonella arizonae isolates were analyzed by antibiotic resistance pattern and serotype and genotyped by pulsed-field gel electrophoresis (PFGE). Serotyping and PFGE yielded similar results, but the antibiotic resistance patterns did not correspond to either serotyping or PFGE typing. The presence of common pulsed-field patterns in breeder flocks, eggs, and meat bird flocks suggested that S. arizonae was being transmitted vertically from the breeder flock. 相似文献
10.
C. J. Savory 《British poultry science》1978,19(5):631-641
1. In 10 laying Brown Leghorn hens, hourly patterns of food and water intake followed each other closely, both throughout the day and in relation to oviposition time.
2. Only half the birds showed significant (P < 0.05) positive correlations between food and water intake on a daily basis, but all of them showed highly significant correlations on an hourly basis. However, on average, about 20% of both the daily and the hourly variation in water intake could be accounted for by variation in food intake, and vice versa.
3. Restricting the daily water supply of each bird to 90% of its ad libitum intake, for a period of 6 weeks, caused a predicted reduction in daily food intake with only 3 out of 10 birds, but a very precise reduction to the level predicted with the overall mean food intake of all the birds. This suggests that water restriction may be a good way of controlling the food consumption of groups of birds but not of individuals.
4. Although egg production did not differ significantly between the ad libitum and water restriction periods, it did decline in the second half of the restriction period, at a time when the birds were gaining weight. This appears to confirm the widely‐held view that water restriction cannot be used to control the body weight of laying birds without it first affecting egg production. It is concluded that water restriction has little or no practical application for layers, but may be of value for reducing the growth rate of young birds in order to delay sexual maturity. 相似文献
11.
T G Taylor 《British poultry science》1965,6(1):79-87
The influence of two diets, differing only in their phosphorus content, on egg shell thickness was compared in 24 pullets in a change‐over experiment lasting 8 weeks. The mean shell thickness of the eggs laid on the low‐phosphorus diet (0.46 per cent total phosphorus) was 2 per cent greater than the mean thickness expressed interms of mg./cm.2 on the high‐phosphorus diet (1 per cent total phosphorus), and this difference was statistically significant. It is suggested that the increase in shell thickness on the low‐phosphorus diet was due to increased absorption and retention of dietary calcium, but this suggestion could not be confirmed experimentally in two balance periods of 6 days each owing to the great variations in calcium retention observed both between and within birds. The skeletal weights of birds killed after laying for approximately 11 months on one or other of the two rations showed no correlation between dietary treatment and skeletal weight, percentage egg production or mean shell thickness. 相似文献
12.
1. Dwarf broiler breeders were either fed ad libitum or restricted to allow growth to mean body weights of 1.4 or 1.8 kg at 20 weeks of age. During the breeding period these birds were fed ad libitum, or food was restricted to different degrees and the birds subjected to two different incremental lighting patterns. 2. Egg production of birds fed ad libitum during the breeding period increased with the degree of food restriction during rearing. 3. Food restriction during the breeding period increased the egg production of birds weighing 1.8 kg at 20 weeks but decreased that of birds weighing only 1.4 kg. 4. Fertility was relatively low and inversely related to body fatness of females. 5. The differences in lighting pattern did not influence performance. 6. For optimum reproductive performance during the rearing period dwarfs should not be restricted so severely as conventional breeders. Best chick production was obtained from birds with a bodyweight of 1.8 kg at 20 weeks of age, which were subjected to a 10% restriction of food during the breeding period. 相似文献
13.
Effect of a single injection of adrenaline on shell ultrastructure in a series of eggs from domestic hens 总被引：1，自引：0，他引：1
1. Adrenaline (1 mg in 1 ml water) was administered subcutaneously to three hens to determine whether any changes in the shell ultrastructure of subsequent eggs would occur. 2. The egg shells were examined in a scanning electron microscope after plasma etching. 3. The first three eggs laid by each bird after adrenaline injection were compared with previously-collected normal eggs from the same birds and also with control eggs collected over the same period from three hens which had received no adrenaline. 4. The first egg laid following adrenaline treatment was essentially normal but both the second and third eggs showed severe structural disorganisation at all levels, from the mamillary caps up to the cuticular layer. 5. Eggs laid 20 d or more after adrenaline treatment had reverted to normal. 6. The findings suggest that the abnormal eggs laid after hens have been exposed to disturbance or stress are likely to be affected in not only their external appearance but also to be of poor structural quality. 相似文献
14.
Several respiratory parameters were measured in five groups of hens to estimate the variation in respiratory function of the general hen population. A non-invasive technique was used to measure respiratory flow, with computer-aided analysis of the data, and the results were examined statistically. Using different groups of hens, additional information was obtained regarding possible sources of variation between individual hens, such as egg laying condition, age and health. Significant differences between individuals within the groups were observed, but there were also changes in breath-to-breath variation for individual hens. While some changes in the variation between birds were observed from one group to another, variation within individual birds made interpretation of the results difficult. Repeated measurements made on one group revealed significant changes in minute volume with time, but the changes were not related to learning. Significant interactions between hens and time of measurement occurred for certain parameters, showing that the individuals' responses changed with time in different ways. The groups of hens were compared to observe whether they represented the same or distinct populations, and were found to overlap to varying extents for different respiratory parameters. Single respiratory variables and weighted combinations of certain variables were also used to separate the groupings, as a possible diagnostic method for partitioning groups of hens. 相似文献
15.
16.
1. The effects of taking a blood sample from one bird in a caged group on plasma concentrations of corticosterone and glucose in birds from its own group and birds from other groups were investigated. 2. Two blood sampling protocols were used: successive (all birds within a group were sampled one immediately after another) and alternative (birds from different groups were sampled one after another until all birds in all groups had been sampled). 3. Neither sampling protocol nor between or within group sampling rank was related to plasma concentrations of corticosterone and glucose. 4. The time taken to remove a blood sample (generally more than 45 s but less than 2 min) did not influence circulating corticosterone and glucose. 5. In individual birds plasma concentrations of corticosterone and glucose were poorly correlated with one another. 6. It is concluded that it is possible to take blood samples from a bird, kept in a group, without affecting plasma concentrations of corticosterone and glucose in other birds from that group or in birds from other groups in other cages. 相似文献
17.
Metabolic bone disease in laying fowl has been associated with mortality and decreases in egg production. Recently there appears to have been an increasing incidence of the disease and the affected flocks have shown a variable response to dietary treatments. In 14 birds from eight recent submissions, avulsion of the patellar ligament together with part of its bony insertion was observed. Because the skeletons of the affected birds were judged from radiographs to be osteopenic, the lesions were probably pathological fractures. Histopathological studies of four birds revealed osteoporosis affecting cancellous bone trabeculae; in one bird, however, the medullary bone trabeculae were largely composed of unmineralized or poorly mineralised matrix, a finding which can be interpreted as osteomalacia. 相似文献
18.
1. A flock of laying hens was divided into two groups according to their fatness, which was estimated using abdominal fatness callipers.
2. A moult was induced in both groups by reducing day‐length and restricting food intake. The food restriction period lasted for 2, 3 or 4 weeks and the birds were given either 15 or 25 g of whole wheat/bird.
3. No differences were observed between the moulting treatments on post‐moult egg weights, shell strength or Haugh units, but maximum egg output (g/bird d) was obtained by the 4‐week food restriction period for the fat‐grouped birds but by the 3‐week food restriction for the lean‐grouped birds.
4. The birds restricted to 15 g wheat/bird d showed a more rapid regression of the ovary and oviduct, which may account for their increased egg numbers towards the end of the 22‐week laying period compared to the birds allocated 25 g/bird d. 相似文献
19.
Bronneberg RG Taverne MA Dieleman SJ Decuypere E Bruggeman V Vernooij JC Stegeman JA 《Domestic animal endocrinology》2007,32(1):15-28
In this study we investigated the temporal relationship between ovulation, egg formation, oviposition and the changes in plasma concentrations of progesterone, luteinizing hormone and estradiol-17beta during the egg laying cycle in farmed ostriches. In 10 egg-producing birds, transcutaneous ultrasound scanning was performed at 3h intervals and blood sampling at hourly intervals during a period of at least 48h (one egg laying cycle). In hens (n=8) that ovulated during the observational period, the ovulated egg was first detected 2h after oviposition; thus, ovulation occurred shortly after oviposition in all birds. During the period between two consecutive ovipositions, the developing egg remained for 9h in the proximal part (infundibulum, magnum or isthmus) and for 39h in the distal part of the oviduct (uterus). In ovulating hens, plasma progesterone concentrations showed a characteristic and consistent profile: from basal levels of around 0.1ng/ml concentrations started to increase 12h before oviposition, reached an average maximum of 3.5ng/ml at 3h before oviposition and returned to basal levels 3h and 30min after oviposition. Changes in plasma luteinizing hormone and estradiol-17beta concentrations showed comparable patterns of elevation and decline relative to the timing of oviposition and ovulation. However, variation in their individual basal concentrations was generally larger and peak values were less conspicuous than those of progesterone. In non-ovulating hens (n=2) neither progesterone, nor luteinizing hormone nor estradiol-17beta showed elevations to peak concentrations before oviposition. These data demonstrate that during the egg laying cycle of ostriches, events such as ovulation, egg development and oviposition evolve according to a rather strict time schedule, and that progesterone, luteinizing hormone and estradiol-17beta reach peak concentrations shortly before ovulation. Additionally, our findings also show that on-farm ultrasound scanning is a useful technique to discriminate between ovulating and non-ovulating hens. 相似文献
20.
Mycobacterium avium is an important veterinary pathogen causing avian tuberculosis in birds. The aim of the study was to evaluate the genetic relatedness in M. avium isolates from deep tissues of farmed lesser white-fronted geese with avian tuberculosis and in samples from the farm environment. The strains were analyzed by two PCR-based typing methods, inverted repeat (IR) typing and random amplified polymorphic DNA (RAPD) analysis. The primers for the inverted repeats of the insertion sequences IS1245 and IS1311 were used in IR typing, and the RAPD analysis was performed with six primers. Seven of the nine avian strains yielded an identical pattern in the IR typing, but they could be divided into two groups in the RAPD analysis. The remaining two bird isolates had an identical IR pattern (IR cluster II) which they shared with two environmental isolates. However, the RAPD analysis revealed that these environmental isolates had a RAPD pattern (RAPD cluster VI) distinct and different from either of the bird isolates (RAPD clusters II and IV). In all, four M. avium strains were verified as being inducers of avian tuberculosis in birds, and all were distinct from the three environmental strains identified. Thus, the results did not confirm the preliminary idea that a single strain had caused the epidemic. The polymorphism among M. avium strains highlighted the great biodiversity among an M. avium population even in a limited environmental setting during a short time span, and indicated the high susceptibility to avian tuberculosis of lesser white-fronted geese. 相似文献