Changes in structure of the limiting membrane and in oxygen permeability of the chicken egg integument during incubation

1. Oxygen permeabilities (K_O2 ) of the shell and shell membranes of fertile and infertile chicken eggs were measured at 37.5 °C and a relative humidity of 0.60 throughout 14 d incubation, with turning. The K_O2 of the shell and membranes of infertile eggs was around 1.0 × 10^?7 cm³ O₂STP sec^?1 cm^?2 Torr^?1 (1 Torr = 133.322 Pa) throughout incubation. With fertile eggs, from which there was a linear loss of water during incubation, the K_O2 of the shell and shell membranes was about 1.0 × 10^?7 cm³ O₂STP sec^?1 cm^?2 Torr^?1 for the first four days of incubation. Thereafter the majority of shells and membranes had a K_o2 of about 1.0 × 10^?6 cm³ O₂STP sec^?1 cm^?2 Torr^?1.

2. A diminution of the Na⁺ and K⁺ content of the shell membranes of fertile eggs was not associated with changes in the dimensions of the glyco‐protein mantle on the cores of the individual fibres of the membranes. There was, however, a progressive deterioration in the limiting membrane of fertile but not of infertile eggs.

3. It was concluded that changes in the O₂ resistance of the integument of fertile eggs were not a product of change in either of the shell membranes but of damage caused to the limiting membrane by the chorioallantois.     

Disorders of the avian integument.

The avian integument consists of highly specialized structures that show extreme variations between species. Feathers are the most obvious part of the integument, and their color and beauty forms an important basis for the attraction of birds to humans. Any disorder in the feathers can be distressing for a client and frustrating for the avian practitioner. The cause of some disorders may be apparent, but others have a complex pathogenesis involving management, human-bird interaction, malnutrition, psychologic factors, disease, or hormone imbalances.     

种蛋的人工孵化技术

自然条件下,鸡产下一定数量蛋后就会进行自然孵化,敷衍后代,但鸡在孵化期间即停止产蛋.为了延长鸡的产蛋时间,提高鸡的产蛋量,保证蛋的孵化率,提高生产效率和经济效益,蛋的人工孵化技术得到运用和全面推广.     

珍珠鸡蛋重和蛋形指数对孵化效果的影响

珍珠鸡具有生长快、食性广、适应性强、肉质细嫩、味道鲜美等特点,是纯天然的绿色滋补保健食品.随着市场经济的发展和膳食结构的改变,常规禽类养殖已经难以满足人们对更高经济利润和珍稀动物食品的需求,各类野生及经济动物的养殖正应势兴起.     

Optimum incubation conditions of the domestic guinea fowl egg

1. During artificial incubation of 8000 guinea fowl eggs, the effects of temperature, relative humidity, rate of inflowing air and age of the laying flocks were determined.

2. Total duration of incubation was divided into setter (0 to 24 days) and hatcher (25 to 28 days) periods. Eggs transferred at the end of the setter period, (ET, % of fertile eggs) and hatching rate (HR, % of transferred eggs) were calculated, as well as the total hatching rate expressed as percentage of fertile eggs.

3. In the range 36 to 39°C, temperature affected significantly (P< 0.001) ET and HR, with optima at 37.2 and 37.0°C ± 0.1°C respectively.

4. During incubating period, relative humidity in the range 40 to 64% (water vapour partial pressure, Ph₂o ⁼ 17 to 34 Torr at 36 to 39°C), significantly (P< 0.001) affected the total diffusive water loss and hatchling mass, both expressed as percentage of fresh egg mass. ET was significantly affected by water loss, the highest ET being for water loss of 13.3 ± 0.5%. Optimal relative humidity was calculated to be 48 to 52% (Ph₂o = 23 to 25 Torr at 37.2°G).

5. The rate of inflowing air significantly (P< 0.001) affected HR, with an optimum at 3.1 Lstpd/(h . egg).

6. The age of the laying flock significantly (P< 0.001) increased water loss; this was explained by a parallel increase of the mass specific shell conductance to water vapour.

7. Finally optimum incubation conditions were deduced, giving total hatching rates of 78 to 81% of fertile eggs, improving by 5 to 8% the best results obtained routinely in commercial practice.     

Importance of sub-embryonic fluid and albumen in the embryo's response to turning of the egg during incubation

1. The effects of removal of sub-embryonic fluid and albumen on the development of the fowl embryo were investigated. 2. A deficiency of sub-embryonic fluid on day 7 of incubation resulted in a reduction in the volume of the yolk sac and of allantoic fluid, and a reduction in the mass of the embryo later in incubation. 3. A deficiency of albumen on day 3 of incubation led to a reduction in allantoic fluid and embryo mass after day 12 incubation. 4. The results suggest that the physiology of embryos in unturned eggs is better modelled by eggs deprived of albumen than by eggs deprived of sub-embryonic fluid.     

自控技术在蚕种催青上的应用研究

通过对电自控升温补湿设备与传统的火缸(杠炭)升温补湿的温、湿度分布均匀度和催青成绩比较,结果说明电自控升温补湿催青质量明显优于火缸(杠炭)升温补湿,具有较高的经济、环保及生态效益.     

Studies on the avian shell gland during egg formation: mucosal intracellular pH.

1. The intracellular pH and the extracellular fluid volume of the shell gland mucosa were determined. 2. The pH value varied little during egg formation, the overall mean being 7.11 +/- 0.02 (n = 34). 3. The lowest pH, 7.01, was found 10 h after oviposition and the highest, 7.22, 18 h after oviposition.     

Studies on the avian shell gland during egg formation: Aqueous and electrolytic composition of the mucosa 1

1. The intracellular composition of the avian shell gland mucosa was studied at six stages of egg formation.

2. Total water content of the mucosa before shell calcification was 4.8 kg/kg dry weight (dw) and rose to 6.6 kg/kg dw during shell formation; 60% of the increase was intracellular and 40% extracellular.

3. The potassium concentration of the mucosa remained constant during egg formation.

4. Chloride was removed constantly from the mucosal cells during egg formation.

5. A model was constructed for the glandular cells which depicts them as primarily NaHCO₃‐secreting cells towards the luminal side and HC1‐secreting cells towards the serosal side, their main function being to provide CO^2‐ ₃ for shell formation. In this model, the columnar mucosal cells are responsible for the calcium used in shell formation.     

优质肉鸡早期利用种蛋的研究

蛋重对孵化率、雏鸡的出生重有显著地影响，出生重对雏鸡前期的成活率影响显著，对生长速度、饲料转化率的影响不显著，认为提前利用种蛋是可行的。     

Studies on the avian shell gland during egg formation: The effect of acetazolamide on the composition of the mucosa

1. The effect of acetazolamide, an inhibitor of carbonic anhydrase activity, on the intracellular composition of the shell gland mucosa was determined.

2. The normal cyclic hydration of the mucosal cells was found to be reduced when the egg was in the uterus and the partition of the water between the intra‐ and extracellular compartments was modified.

3. Acetazolamide decreased the accumulation of Na+ within the cells, inhibited the Na+‐independent movement of Cl‐ and reduced the transfer of Cl‐ linked with Na+.

4. It is concluded that acetazolamide blocks the intracellular generation of HGO₃‐ and the reabsorption of Cl‐.     

Comparative antibacterial activity of avian egg white protein extracts

1. Egg white proteins from the eggs of domestic chicken (Gallus gallus), turkey (Meleagris gallopavo), duck (Anas platyrhynchos) and goose (Anser anser) were analysed in order to compare the antimicrobial activity of these products. 2. Albumen from each species was sampled and analysed by SDS-PAGE and Western blotting. Antimicrobial activity and lysozyme activity were measured. 3. Ovotransferrin and ovalbumin were identified in all species while c-type lysozyme was present in chicken, turkey and duck egg white samples, but not in goose. 4. Galliformes appear to possess albumens with greater antimicrobial activity than those of the Anseriformes. This can be attributed to higher concentrations of ovotransferrin and the broad acting c-type lysozyme.     

Effects of egg mass and percentage mass loss during incubation on hatchability of eggs of the rock partridge (Alectoris graeca)

1. The effects of initial egg mass (IEM) and percentage mass loss during incubation (%ML) on hatchability of rock partridge eggs were investigated. 2. Eggs at the extremes of IEM had lower fertility and embryonic mortality. 3. Eggs at the extremes of %ML also had low fertility and hatchability was disproportionately reduced in eggs that had lost less mass during incubation. 4. Chick mass was a function of both IEM and mass lost during incubation. 5. In these respects rock partridge eggs are similar to that of other domesticated species of poultry.     

The outer membrane of the avian egg shell as a reticular structure

The shell membranes of fowl, duck, quail and turkey eggs were examined by electron microscopy. A proportion of the outer membrane fibres from all sources were interconnected by lamellae about 90 A thick. The lamellae, which are probably protein, endow the outer membrane with a secondary reticulum reinforcing the reticulum formed by the fibres themselves.     

蛋鸡低致病性禽流感(H9亚型)的防制体会

一 临床诊断新特点 1 冬春季节易流行,夏秋季节照样发病,切不可误认为天热时就不得禽流感了。     

The air space and embryonic respiration. I. The pattern of gaseous exchange in the fertile egg during the closing stages of incubation

Covering the whole shell or the shell over the chorio‐allantoic membrane with liquid paraffin resulted in the diffusion of oxygen through the shell over the air space before the onset of pulmonary respiration being reduced to a level insufficient to keep the embryo alive. During the parafoetal period respiratory exchange through the air space becomes progressively more important than that through the allantois with the result that the embryo can survive a blocking of the whole shell or allantoic shell during this period, provided that pulmonary respiration has been developed sufficiently and that the shell is pipped within a certain time limit. After pipping respiratory exchange can be effected by pulmonary respiration alone, without great danger to the embryo.

It was found that diffusion through the shell over the air space could be abolished, by a covering of liquid paraffin, for at least 2 days without causing the death of the embryo. On the other hand, increasing the gaseous exchange through the air space by drilling a hole through the shell did not improve hatch‐ability. It may therefore be concluded that the respiratory exchange through the allantoic shell is greater than through the air space shell up to the time of pipping.

By measuring directly the gaseous exchange through the shell over the air space and allantoic shell it was shown that the amount of the diffusion through the shell over the air space was in proportion to the total diffusion, at least until the onset of pulmonary respiration. After that moment the absolute as well as the percentage exchange via the air space increased. This was, however, attended by only a relative and not an absolute decrease in respiratory exchange through the allantoic shell.

The allantois did not begin to degenerate until pipping had taken place. Lung function then increased and soon took over completely the function of the allantois. As soon as the allantoic respiration had been practically abolished hatching activities started with the result that hatching often followed within half an hour.     

不同品种鹅蛋机摊结合孵化方法的研究

以莱茵鹅、籽鹅种蛋为研究对象，在种蛋孵化至20、24、27胚龄时，随机取部分种蛋，从孵化器移至摊床继续进行孵化直至出雏完毕，比较上摊孵化与全程机器孵化的效果，并研究最佳的上摊胚龄。通过试验证明：莱茵鹅全程机器孵化的孵化率为84．80％，上摊孵化的平均孵化率为86．93％，提高2．13％（P〈0．05）；籽鹅机器孵化的孵化率为85．84％，上摊孵化的平均孵化率为89．23％，提高3.39％（P〈O．05）。莱茵鹅在20、24、27胚龄上摊孵化率分别为86．46％、88．17％、86．15％（P〉0．05）；籽鹅在20、24、27胚龄上摊孵化率分别为87．41％、91．03％、89．19％（P〉0．05），可见机器孵化鹅胚蛋至24胚龄时上摊孵化效果最好。     

An outbreak of avian urolithiasis on a large commercial egg farm

A significant outbreak of avian urolithiasis was observed on a large commercial egg farm. From the initial outbreak site (a single laying house), the incidence of urolithiasis slowly spread in the ensuing months to numerous other laying houses. Increasing mortality associated with urolithiasis commenced during late growout to early lay and then leveled off when egg production peaked. At the height of the outbreak, mortality was typically 0.5% per week; 75% of this mortality was due to urolithiasis. The clinical and pathologic features of this condition are described. Both infectious bronchitis virus (IBV) and fowl adenoviruses were isolated from organ homogenates of sampled birds. A clone of the IBV strain was found to induce nephritis in specific-pathogen-free white leghorns.     

鸡脑脊髓炎高免卵黄抗体的制备及治疗试验

鸡脑脊髓炎是由鸡脑脊髓炎病毒引起的主要侵害雏鸡的一种传染病 ,其主要特征是共济失调 ,头颈部震颤和非化脓性脑炎 ,近年来河南许多鸡场有本病的发生 ,为找到本病的有效治疗措施 ,我们开展了此项研究 ,报告如下。1　材料与方法1 .1　试验鸡　选择健康蛋用鸡 50只 ,经检查没有白痢等垂直传播的疾病 ,由郑州牧专微生物教研室饲养。1 .2　疫苗　鸡 AE弱毒苗 ,购自河南兽医防治站 ,鸡AE油乳剂灭活苗 ,由郑州牧专微生物教研室自制。1 .3　鸡 AE琼扩抗原及阳性血清　由郑州市畜牧工作总站提供。1 .4　试验鸡免疫　一免 ,每只鸡分别肌注 AE弱…