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1.
A clear positive correlation was evident between egg weight at setting and embryo weight at 18 d of incubation for eggs laid at or after 32 weeks of age. The weight of embryos from the same size eggs were found to depend upon a curvilinear function of the age of parent flock, with the largest increase in embryo weight occurring between 28 and 32 weeks of age. Hatching weight was highly correlated with egg size at setting. Flock age had no effect on hatching weight from a particular sized egg. Within any of the five ages studied, chicks from smaller eggs tended to hatch slightly (but not significantly) earlier than those from larger eggs.  相似文献   

2.
1. An experiment was conducted utilising 480 eggs from broiler breeder hens to determine the effect of oviposition and parental age on 1-d-old chick weight when egg weight remained constant. 2. Neither the age of the breeder flock nor the time of oviposition had a significant effect on egg weight loss during the 18 d of incubation. Nor was there any effect on chick weight: egg weight ratio and 1-d-old chick weight when chicks were removed and weighed at the same time. 3. Hatching time was significantly affected by time of oviposition and age of parents. Afternoon eggs or eggs from older hens tended to hatch earlier than morning eggs or eggs from younger ones.  相似文献   

3.
Jackass penguins Spheniscus demersus hatch two different-sized eggs asynchronously: the second-hatched chick, being, on average, 59% of the weight of the first-hatched chick on hatching. We examined the effect of hatching order on growth rates of mass, culmen length and culmen depth by comparing: (i) growth rates of first-and second-hatched chicks, and (ii) chicks from experimentally synchronized broods to chicks from normal asynchronous broods. Only growth rates in mass showed significant variation. Within a brood, B chicks grew more slowly than A chicks. The effect of synchronizing a brood was to lower the growth rate of both chicks to that of a B chick, suggesting that equal-sized siblings feed less efficiently. Chicks hatching from larger A eggs, that had been synchronized for age and size with chiçks from B eggs, did not grow faster, indicating that chicks hatching from A and B eggs do not have intrinsically different growth rates. Single-chick nests result usually from egg infertility. Singletons showed only a non-significant trend towards faster growth in mass than offspring in two-chick broods, even though food availability in one-chick nests should be better than in two-chick nests. Overall, hatching order had more impact on growth rates of mass than did brood size or egg dimensions.  相似文献   

4.
1. The object of this research was to investigate the effects of high altitude with supplementary oxygen during the last stage of incubation of broiler eggs laid at low altitude and incubated at low and high altitude. We analysed thyroid hormones and haematological variables. 2. The treatment groups were: low altitude (LA), high altitude with oxygen supplementation in the hatcher (HA-OX) and high altitude non-oxygen-supplemented (HA-NOX). 3. High altitude affected relative egg weight loss and early embryonic mortality. The hatchability of fertile eggs was lower at high than at low altitude. 4. Oxygen supplementation into the hatcher cabinet during the last stage of incubation decreased late embryonic mortality ratio (LEM(1)) and improved survival rates of embryos incubated at high altitude. 5. Eggs incubated at low altitude had a higher hatched chick weight and relative chick weight than those incubated at high altitude. Hatched chick weight and relative chick weight did not change with oxygen supplementation at high altitude. 6. High altitude caused an increase in plasma T(3) and T(4) concentrations as well as in the ratio of T(3):T(4) in embryos. High altitude newly hatched chicks showed a higher T(3):T(4) ratio than low altitude chicks; this ratio decreased with oxygen supplementation at high altitude. Altitude and oxygen supplementation did not affect the mean plasma T(4). 7. Newly-hatched chicks incubated at high altitude showed a higher plasma haematocrit (PCV) than the newly-hatched chicks from eggs incubated at low altitude. High altitude without supplementation increased haemoglobin (Hb), while oxygen supplementation returned the value to low altitude values.  相似文献   

5.
1. The present study evaluated developmental characteristics in the chick embryo throughout incubation following cell removal from the freshly laid egg. 2. Between 10 and a few hundred cells of the blastoderm were removed for sex diagnosis. Incubation of the treated embryos was then continued in an open egg shell culture system. 3. Cell recovery from different regions within the blastoderm was performed. 4. The experiments presented here demonstrate the persistence of the developmental potential of chicken embryos in an in ovo culture system after removal of different numbers of cells from the germinal disc prior to incubation. 5. No deviations in developmental characteristics were recorded when compared to untreated control cultures. 6. No detrimental effects of double cell biopsies could be observed. 7. A similar number of chicks developed to hatch regardless of the location of manipulation within the blastoderm.  相似文献   

6.
Production of quail-chick chimaeras by blastoderm cell transfer   总被引：2，自引：0，他引：2  
1. Quail-chick chimaeras were produced by injecting dissociated quail blastoderm cells into chick embryos. 2. Quail blastoderms were removed from the yolk and the cells were dispersed by trypsin treatment or pipetting. The cell suspension (1 to 5 microliters) was injected into the subgerminal cavity of unincubated chick embryos. The chick embryos were then cultured in recipient eggshells. 3. Quail blastoderm cells injected into the chick embryos adhered to the chick embryonic cells. The rates of hatching were 8.6% (38 chicks from 441 eggs) and 40.3% (48 chicks from 119 eggs) when the volumes of the cell suspension injected were 3 to 5 microliters and 1 microliter, respectively. 4. Seven out of 86 hatched birds were clearly identified as being chimaeric because part of the feather colouring was of quail specificity. In addition to these chimaeric birds, there were 8 chimaeric embryos which died before hatching. The distribution patterns of the quail feathers were varied among the chimaeric birds and embryos. 5. This technique provides a basis for the investigation of chick embryo cryopreservation, genetic transformation and analysis of cell lineage of chickens.  相似文献   

7.
(1) This research was carried out to investigate changes in egg production and hatchability as influenced by age and breeding season of 10 trios (two females, one male) of ostrich (Struthio camellus) during 1998 to 2002. (2) Breeding season affected number of eggs laid per female per season, average egg weight, length of laying period and clutch sequence. (3) The number of eggs laid per female per season was 25 in the first breeding season and 57 by the fifth breeding season. The laying period lasted 169 d in the first season whereas it was 210 d by the fifth season. The breeding season became longer year by year. (4) The number of clutches was two in the first season, three in the second and 4 in the later breeding seasons: the mean interval between cycles was 9 to 10.6 d and the mean number of eggs in one cycle varied from 12 to 14.4. (5) The breeding season affected the hatchability of fertile eggs, chick weight at hatching, hatchability of total eggs, fertility, malpositioned embryos, deformed chicks and assisted chicks during hatching. The first 4 variables increased and the last three decreased, with each breeding season. (6) Weight loss of eggs and length of incubation were unaffected by the breeding season. Hatchability which was 64.3% in the first season increased progressively and reached 73.1% in the fifth breeding season.  相似文献   

8.
1. Eggs were stored for two different times at varying temperatures. The effects on hatchability, chick weight at hatch and hatching time were examined in two broiler breeder lines from 33 to 58 weeks of age. 2. Short storage (1 to 3 d). Storage at 20 degrees C compared with 16.5 degrees C reduced hatchability of all eggs set. No effect was observed on hatchability of fertile eggs, hatching time or chick weight. 3. Long storage (9 to 11 d). Storage at 16.5 degrees C compared with 10 degrees C decreased both hatchability of fertile eggs and chick weight at hatch. Incidence of early embryonic death increased and incubation time decreased at 16.5 degrees C compared with 10 degrees C. 4. Chicks from morning eggs were heavier than those from afternoon eggs irrespective of storage conditions. 5. Hatchability (all eggs set and fertile eggs) and chick weight varied with hen age irrespective of storage conditions. During long storage, hatching time varied with hen age independently of breeder line, storage temperature or egg laying time. 6. Hatchability (all eggs set and fertile eggs) was higher in line A than in line B. Line B eggs hatched later and produced heavier chicks than line A eggs irrespective of storage time.  相似文献   

9.
An Escherichia coli causing negligible mortality in embryonated chicken eggs was adapted to grow in media containing nalidixic acid. This isolate (EcNAL) was inoculated into 12-day-old embryonated eggs. Additional embryos inoculated with tryptose phosphate broth (TPB) served as controls. Six days later, all surviving eggs were moved to hatching units. One hatcher contained half of the TPB-inoculated eggs; the chicks hatching from these eggs served as negative controls. The EcNAL-inoculated eggs and the remaining TPB-inoculated eggs were moved to a second hatcher and allowed to hatch together; chicks hatching from these TPB-inoculated eggs served as contact controls. On day of hatch and at intervals thereafter, chicks from each of the treatment groups were sampled. Their body and yolk weights were recorded, and various tissues were cultured for the presence of the EcNAL bacterium. Hatchability of the EcNAL-inoculated embryos was markedly lower than that of either control group. Chicks from EcNAL-inoculated embryos also had low but detectable levels of mortality, lowered body weights, and increased yolk-to-body weight ratios. These same chicks had persistently high levels of EcNAL in the yolk and lower but detectable levels of the organism in the lungs and tracheas, which lasted a few days. The contact controls, on the other hand, were similar to the negative controls as far as having negligible mortality, steadily increasing body weights, and declining yolk-to-body weight ratios. However, in contrast to the negative controls, EcNAL was recovered primarily from the respiratory tract of the contact controls for a brief period of 3-4 days after hatch.  相似文献   

10.
1. Variation in chick weight at the moment of escape from the shell is accounted for by the fresh weight of the egg, the weight lost from the egg during the incubation period and the weight of the shell and residues at hatch.

2. Over 97% of the variation in chick weight at hatch can be explained by two factors, fresh egg weight and weight loss during incubation. These two factors still account for a high (87%) proportion of the variation in chick weight at 21 d after setting when chicks would normally be removed from the hatcher.

3. The water content of the true chick and the residual yolk sac are both affected by water loss from the egg during incubation and account for the differences in the weight of the whole chick at hatch from eggs of the same size.

4. When the fluid reserves within the egg become exhausted in the few days before hatch, the water: dry weight ratio of the yolk rather than embryo is maintained despite variation in water losses between eggs.  相似文献   


11.
1. Chick embryos, obtained from the anterior portion of the magnum of the oviduct 60 to 80 min after the preceding egg had been laid, were cultured in vitro in small and large recipient eggshells until hatching.

2. Of 82 embryos cultured, 46.3% had survived to day 4 of incubation, and 19.5% survived to hatching.

3. The method for culturing embryos used in this experiment could facilitate research on the in vitro manipulation of early chick embryos.  相似文献   


12.
1. Chick embryo cells and halved embryos were successfully implanted into unfertilised eggs. Yolks containing implants were placed in recipient eggshells, covered by transparent vacuum-formed plastic cones and incubated for 72 h. 2. Dispersed cells were obtained from eggs expelled from the uterus or from eggs that had been laid. Implantation of these cells often resulted in aggregation and epithelial growth, in several cases with axial development. 3. Growth of implanted halved embryos of different ages was often observed, including one 10-somite embryo. Non-axial epithelia, sometimes with a central hole, a central fluid-filled cellular vesicle or a vesicle only, were also observed. 4. In another culture system, whole and halved embryos obtained from laid eggs were cultured on a vitelline membrane stretched across semi-solid egg albumen. During the 72 h incubation, axial development was observed only in whole embryos, while halved embryos grew either into epithelia containing fluid-filled cellular vesicles or into vesicles only. 5. It was found that daily drainage of the accumulating fluid from the embryo compartment encouraged axial development in halved embryos, and almost abolished vesicle formation. Holes were formed in half the embryos cultured on a vitelline membrane. 6. It appeared that physical and biological conditions could inflict serious malformations on the implants.  相似文献   

13.
The objective of the present study was to determine the effect of broiler breeder egg weight on egg quality, chick quality, and broiler performance using Hubbard Classic broiler breeder flock. Hatching eggs from a commercial broiler breeder flock (Hubbard classic strain) were obtained at the age of 60 wk and divided into 3 egg-weight categories, namely small, medium, and large. For this purpose, 930 eggs having weights 63.09 ± 0.21, 68.85 ± 0.23, and 74.81 ± 0.11g were divided into 3 egg categories labeled small, medium, and large respectively. We further divided these eggs into 2 categories, eggs for quality parameters and eggs for incubation and posthatch performance parameters. Eggs from the small egg category had greater proportion of the shell weight and more shell strength. Egg weight did not significantly affect the albumen and yolk weight percentage. Egg weight affected the shape index and specific gravity for which lower values were observed for large eggs. Egg weight positively affected the chick weight, chick yield, and chick length (P < 0.05) of both male and female chicks. Results of the body weight gain showed that effect of egg weight on the posthatch performance of chick diminishes with the age of broilers. Egg weight significantly affected the body weight gain of male and female chicks up to 3 wk of age. Egg weights did not significantly affect the feed intake and mortality of broiler. Different egg-weight categories significantly affected the feed conversion ratio of female chicks at wk 2 and 3 of age and did not affect the feed conversion of male and female chicks at the end of wk 5. In conclusion, egg weight positively affected the chick characteristics (e.g., chick weight, chick length) and did not affect the final live body weight, feed conversion ratio, feed intake, and mortality in broilers.  相似文献   

14.
Twenty-four 70-week-old and sixteen 27-week-old white leghorn hens were challenged with R strain Mycoplasma gallisepticum (MG) by injection into the caudal thoracic air sac and infraorbital sinus. Eggs were collected daily and cultured within 7 days or incubated for 18 days. Vitelline membranes of eggs were cultured directly; in 18-day-old embryos, cultures were taken from the yolk sac, air sacs, and oral cavity. Culture of vitelline membrane of eggs within 2 days was compared with culture of eggs stored 10 days post oviposition. The first MG-positive egg was laid 2 days postinfection (PI). Hens continued to lay positive eggs to the end of the experiments. There was no significant difference in MG recovery between eggs cultured within 2 days and those cultured 10 days post oviposition. MG was isolated at a significantly higher rate from eggs than from 18-day-old embryos. MG was isolated at a higher rate from the yolk sac of 18-day-old embryos than from the air sacs or oral cavity of the same embryos.  相似文献   

15.
1. The objective of the study was to investigate the effects of breeder age and egg weight on hatching performance and morphological changes in segments of the small intestine of broiler chicks during a 21 h hatch window.

2. Eggs from Ross broiler breeder flocks aged 29 (young) and 48 weeks (old) were classified as light (LE) or heavy (HE) and incubated at the same conditions. At 475 h of incubation, eggs were checked every 3 h to determine time of external pipping and hatching. The first 42 chicks to emerge from each group were weighed and chick length was measured and 14 chicks from each group were sampled to collect residual yolk and intestine segments. The rest of chicks were placed back in the incubator and chick weight and length were measured individually at 9, 15 and 21 h after chicks hatched. At the end of 21 h, 14 chicks from each group were sampled again and the same procedure was followed.

3. The HE chicks pipped and hatched later than LE, regardless of breeder age. From hatch to the end of the hatch window, chick weight, but not yolk-free chick weight, gradually reduced. Relative residual yolk weight of chicks from both egg weights was similar at hatch, however, yolk sac utilisation was higher for LE chicks during the 21 h post-hatch period. At hatch, jejunum and ileum villus development was very similar for HE and LE chicks but greater development was observed for villus area with an increase in the jejunum villus length, width and goblet cell numbers in HE chicks.

4. The longest jejunum villus and the widest duodenum and jejunum villus were obtained for HE chicks from old breeders indicating that HE chicks from old breeders would have a greater surface area for nutrient absorption.  相似文献   


16.
Erysipelas was diagnosed in a layer breeder flock in Sweden in 2002. Although vertical transmission of Erysipelothrix rhusiopathiae has not been previously described in chickens, the potential of erysipelas infection to adversely affect hatching eggs was of concern. To clarify the possible impact of erysipelas on hatching eggs and their progeny, an experiment was done using 200 hatching eggs collected from the infected flock. The eggs were incubated for 21 days, and the egg shells, infertile eggs, dead-in-shell embryos, and a sample of day-old hatched chicks and blood samples from 5-day-old chicks were cultured for E. rhusiopathiae. In addition, after 28 days of grow-out, the male chickens were euthanatized and cultured for the bacterium, and the remaining female chickens were placed as a backyard flock and observed over a 4-mo period. Bacteriological test results of the above-mentioned samples were negative for E. rhusiopathiae. Mortality rates were not excessive, and no clinical symptoms of erysipelas were observed during the period of observation. The result of the investigation suggests that in layer breeder chickens, E. rhusiopathiae is not vertically or egg transmitted and that the disease outbreak in the parent stock had no adverse impact on the quality of hatching eggs in terms of increased embryo mortality.  相似文献   

17.
This study was to investigate the effects of in ovo feeding (IOF) L‐arginine (Arg) solution on the development of digestive organs, the duodenal mucosa of broiler embryos and hatchlings, and the growth performance of chicks during the first week post‐hatch. A total of 720 fertilized eggs with similar weight were randomly allocated to three groups, consisting of eight replicates of 30 eggs each. Three treatments were arranged as non‐injected control, diluent‐injected (0.75% NaCl solution) group and Arg solution‐injected group containing 1% Arg, dissolved in diluent. At 17.5 days of incubation, 0.6 ml of IOF solution was injected into amniotic fluid of each egg of injected groups. Results showed IOF of Arg solution increased (p < .05) the chick embryo weight at 19 days of incubation; the body weight gain of post‐hatch broilers during 1–7 days; the weights of liver, pancreas, proventriculus and gizzard; the concentrations of duodenal ghrelin, vasoactive intestinal peptide and glucagon‐like peptide 2; and the duodenum mucosal enzyme activities of alkaline phosphatase, maltase, sucrase and inducible nitric oxide synthase of 7‐day‐old post‐hatch broilers compared with other groups. The IOF of Arg solution also increased (p < .05) the villus height (VH) and the ratio of VH to crypt depth (CD) and decreased (p < .05) the CD in duodenum of broiler embryos and post‐hatch hatchlings, except for the CD at 19 days of incubation. In conclusion, IOF of 1% Arg solution into the amnion at 17.5 days of incubation could improve the development of digestive organs, the duodenal morphology, the releasing of gastrointestinal hormones and mucosal enzyme activities of broiler embryos and hatchlings and finally the growth performance of chicks during the first week post‐hatch. Therefore, IOF of appropriate Arg solution could be an effective technology for regulating early nutrition supply and subsequent growth development in poultry industry.  相似文献   

18.
为了研究蛋形指数对拉萨白鸡种蛋孵化效果的影响,在相同孵化条件下,选用3世代47周龄拉萨白鸡种蛋,按蛋形指数分组进行孵化,并对蛋形指数与孵化效果的相关性进行了分析。结果表明,蛋形指数(横径/纵径)在0.68~0.72时,0胚龄蛋重、纵径均值、头照(第11日胚龄)蛋重、二照(第20日胚龄)蛋重最大,分别为:(51.92±5.27)g、(57.71±1.97)mm、(48.95±4.67)g、(45.47±3.97)g;蛋形指数(横径/纵径)在0.73~0.77时,入孵蛋孵化率、受精蛋孵化率和雏鸡的初生重最大,分别为:82.65%、86.60%、(36.31±4.71)g;蛋形指数(横径/纵径)在0.78~0.82时,头照(第11日胚龄)失重、头照(第11日胚龄)失重率、二照(第20日胚龄)失重、二照(第20日胚龄)失重率最大,分别为:(3.35±0.93)g、(6.64±1.54)%、(6.70±1.47)g、(13.47±2.56)%;蛋形指数(横径/纵径)在0.83~0.87时,橫径均值、受精率、健雏率、雏鸡初生重占入孵蛋重的百分比最大,分别为:(42.82±1.23)mm、97.26%、95.96%、(70.23±3.58)%;雏鸡初生重与雏鸡初生重占入孵蛋重的百分比呈极显著正相关(P<0.01)。该研究为拉萨白鸡今后的选育提供了理论依据。  相似文献   

19.
为研究拉萨白鸡种蛋蛋重和蛋形指数（纵径/横径）对孵化效果的影响,在相同孵化条件下,选用3世代47周龄拉萨白鸡种蛋,按蛋重分组进行孵化,Ⅰ组（≤45.0 g）蛋形指数为（1.27±0.05）,Ⅱ组（45.1-50.0 g）蛋形指数为（1.27±0.05）,Ⅲ组（50.1-55.0 g）蛋形指数为（1.27±0.05）,Ⅳ组（55.1-60.0 g）蛋形指数为（1.28±0.05）,Ⅴ组（〉60.0 g）蛋形指数为（1.31±0.05）。结果表明,种蛋的蛋重越大,其纵径均值、横径均值、蛋形指数均值、受精率、入孵蛋孵化率、受精蛋孵化率和雏鸡初生重越大,即Ⅴ组（〉60.0 g）种蛋的蛋重均值、纵径均值、横径均值、蛋形指数均值、受精率、入孵蛋孵化率、受精蛋孵化率和雏鸡初生重均最大,分别为（61.03±0.82）g、（58.13±1.68）mm、（44.59±0.79）mm、（1.31±0.05）、98.15%、85.19%、86.79%和（42.48±1.98）g;Ⅱ组（45.1-50.0 g）的健雏率最高,为96.09%;Ⅰ组（≤45.0 g）的雏鸡初生重占入孵蛋重的百分比最大,为（69.91±2.71）%;蛋重与纵径、横径、蛋形指数呈极显著正相关（P〈0.01）。因此,蛋重和蛋形指数对拉萨白鸡种蛋的孵化率影响较大,应选择较大种蛋（〉45.0 g）,蛋形指数的范围则较宽,在≥1.27时即可以达到较理想的孵化效果。  相似文献   

20.
1. The effect of egg weight on the subsequent performance of individual growing chicks was studied. Eggs from commercial broiler breeder hens were collected at 52, 55 and 57 weeks of age and incubated. The chicks were reared for 18 d. 2. Egg weight and hatched chick weight were not affected by the age of the hens during the 52 to 57-week period, but there was a close correlation between egg weight and hatching weight, irrespective of the age of the hens (r = 0.89). Chick:egg weight ratio at hatching was about 0.71 and independent of hen age. One d after hatching, chick weights had decreased by about 1.5 g. 3. The initial high correlation between egg weight and chick weight decreased markedly during post-hatching growth, becoming insignificant 5 d after hatching. At 18 d of age, however, chicks from eggs of older hens tended to be heavier than those from younger birds. The greater 18-d weights appeared to be associated more with higher food intake during that period, than with greater egg weight. 4. It was concluded that, in individual broiler chicks, the advantage of the initially higher weight attributable to a larger egg diminishes rapidly after hatching, and the main factor affecting final body weight is food intake.  相似文献   

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