Influence of egg storage on hatchability, embryonic development and vitamin status in hatching broiler chicks

Effects of pre-incubation storage duration and nonventilation incubation procedure on embryonic physiology and post-hatch chick performance

This study investigated the effects and possible interactions of storage and nonventilation during incubation for eggs from Sasso broiler breeder flock on pre- and post-hatch incubation results.

A total of 1,260 Sasso eggs from a 58-wk-old broiler breeder flock were individually numbered, weighed and stored for 7 d or for 18 d in a climate-controlled room (16°C, 75% RH). After storage, eggs were weighed, and randomly assigned equally into 2 incubators. One of the incubators was ventilated (V) for the entire incubation and the second was nonventilated (NV) for the first 12 d. At d 18, the eggs were weighed, candled, and fertile eggs were transferred from the turning trays to hatching baskets. During the last 3 d of incubation, hatching eggs were checked individually every 3 h for hatching events and hatchability of fertile eggs. After pull out at d 21.5, post-hatch performances was determined until 1 wk of age.

Results showed that, embryo weights from eggs in NV incubator was significantly higher (P < 0.05) in both stored eggs compared to those from eggs in ventilated incubator, but embryos from eggs stored for 18 d were smaller (P < 0.05) than those from eggs stored for 7 d. Hatchability was higher (P < 0.0001) in NV incubator compared to V incubator in both 7 d and 18 d stored eggs and an interaction was found between incubation ventilation and storage duration on both hatchability and embryonic mortality (P < 0.0001). Chick weights from NV incubator at 7 d post-hatch was greater (P = 0.0009) than those from V incubator. Serum Tri-iodothyronine (T₃) and Thyroxin (T₄) concentrations were significantly higher (P < 0.05) in NV compare to V group.

It was concluded that the effect of long-term pre-incubation storage on embryonic physiology and post-hatch growth interacted significantly with incubation ventilation and that nonventilation can compensate for the negative effects of storage on some hatching and post-hatch performances.

Surgical repair of a meningoencephalocoele in a kākāpō (Strigops habroptilus)

CASE HISTORY

A kākāpō (Strigops habroptilus) chick hatched on an off-shore island of New Zealand with a small white mass protruding through the cranial skin of the head. The chick's growth followed a normal pattern for kākāpō but at 3 weeks of age the cranium mass was non-reducible and fixed in place and the chick was removed from the island for diagnostic imaging and hand-rearing.

CLINICAL FINDINGS AND TREATMENT

A computed tomography (CT) examination revealed a full-thickness circular defect in the central cranium with suspected herniation of brain and dura. Surgery was performed at 37 days of age, and the herniated dura was dissected from the open fontanelle. Attempts to reduce the herniated tissue were unsuccessful, so the herniated dura and cortex were clamped and resected. The dura was closed and the periosteum of the skull was scarified and monofilament polypropylene mesh was secured tautly over the fontanelle. The mesh graft was infused with autologous bone marrow harvested from the ulna in an attempt to stimulate osteogenesis in the mesh repair. The skin flap was then closed. Post-operative recovery and healing were without complication. A CT examination 4 weeks after surgery showed no recurrence of the hernia, and a composite of mesh and scar over the open fontanelle which had reduced in diameter. The chick was released back onto an off-shore island with a radio transmitter and it continues to be monitored regularly.

PATHOLOGICAL FINDINGS

The tissue resected at surgery consisted of a cylindrical core of cerebral parenchyma overlain by a mildly hyperplastic epidermis, and large amounts of oedematous fibrovascular tissue arising from the leptomeninges.

DIAGNOSIS

Rostral parietal meningoencephalocoele.

CLINICAL RELEVANCE

This is the first report of successful surgical resolution of a meningoencephalocoele in any bird. Techniques from human neurosurgery were adapted for the unique anatomical features of the avian skull. The risks of the procedure included increased intra-cranial pressure resulting in anaesthetic complications or death, cerebrospinal fluid leakage, meningitis or recurrence of the meningoencephalocoele. In the longer term, there was a risk of developmental deficits in cognition or behaviour. None of these complications eventuated in the short to medium term, probably due to the small size of the meningoencephalocoele.

Effect of guinea fowl egg storage duration on embryonic and physiological parameters, and keet juvenile growth

This study investigated the effects of guinea fowl hatching eggs storage time on embryo parameters and post-hatch juvenile growth. A total 1,800 eggs of guinea fowl were used. They were numbered, weighed, and divided into four groups of 450 eggs each according to storage time of 3, 7, 11, and 15 D before storage at a temperature of 18°C. Then, they were incubated at 37.7°C and 55% relative humidity for 28 D in a forced-draft incubator. Egg weight loss, albumen pH and weight, embryo weight, hatching events, and keet growth up to 7 D post-hatch were recorded. In addition, thyroid hormone and corticosterone levels were determined. The results indicate that during storage, relative egg weight loss increased with storage duration. However, albumen pH increased with storage time up to 11 D of storage and remained unchanged between 11 and 15 D. In addition, from 19 to 22 D of incubation, albumen weight was higher for eggs stored for 15 D compared to that of eggs stored for 3 to 11 D. But, from 16 D of incubation, embryos from eggs stored for 3 D grew faster than those from eggs stored for 7 to 15 D. Incubation durations up to internal pipping (IP), external pipping (EP), and hatching events increased with egg storage duration. At IP, corticosterone and triiodothyronine (T3) concentrations of eggs stored for 15 D had the lowest (P < 0.05) compared to those of eggs stored for 3 to 11 D. Moreover, the levels of thyroxine (T4) decreased with storage duration (P < 0.05). At hatch, corticosterone levels increased while T4 levels decreased with storage duration (P < 0.05). Also, hatchability decreased with egg storage duration. In addition, 7-day-old keets from eggs stored for 3 and 7 D had comparable weight and were heavier than those from eggs stored for 11 D. It was concluded that storage of guinea fowl hatching eggs more than 7 D negatively affects egg quality and subsequently depresses embryo and post-hatch growth.

Divergent selection for shape of growth curve in Japanese quail. 6. Hatching time, hatchability and embryo mortality

1. Hatching time, hatchability of fertile eggs and embryo mortality under standard egg storage (1 or 5 days at 12 ± 1°C and 55% relative humidity) and incubation conditions (37.5 ± 0.2°C and 50% relative humidity) were analysed in lines long-term selected for high (HG) and low (LG) relative weight gain between 11 and 28 d of age, respectively, and constant body weight at 49 d of age. 2. Egg storage duration did not have an effect on average hatching time. LG quail, characterised by a fast postnatal growth rate immediately after hatching, hatched earlier than HG quail with a low early growth rate (about 391 vs. 406 h after egg setting, respectively). 3. In contrast to hatching time, the hatchability of fertile eggs was influenced by line as well as egg storage duration. Extended storage decreased hatching success in both lines. However, LG eggs exhibited a higher hatchability than HG eggs (1 d storage: 96.0 vs. 82.5%; 5 d storage: 88.7 vs. 72.7%, respectively). 4. Lower hatchability resulted mostly from a higher frequency of embryo death during early (up to d 7) and late (d 14 and later) phases of incubation. 5. An inadequate nutrient supply to embryos in consequence of developmental delay seems to be a key factor decreasing viability of embryos during incubation.

Egg storage and the embryo

In domestic avian species, eggs are stored at cool temperatures until they can be placed into an incubator. The low temperature-induced diapause enables the embryo to survive until optimal temperature and humidity incubation conditions can be provided to support embryonic growth. Egg storage is a logistical necessity for the hatching egg industry both at the breeder farm and at the hatchery. However, it is well known that egg storage longer than 7 d negatively influences hatchability. At the cellular level, long-term egg storage induces cell death. This appears to be occurring both via necrosis and apoptosis. The result is higher embryonic mortality and, consequently, lower hatchability. In addition, long-term egg storage influences embryonic development and metabolism. Embryos of eggs stored long-term can be affected such that they do not initiate growth after proper incubation temperatures are provided; they initiate growth, but grow at a slower rate than eggs stored short term; and they are affected in both of the previously mentioned ways. Development of equipment to measure the embryonic metabolism of individually incubating eggs over the entire 21 d of incubation has provided further evidence that embryo metabolism has changed due to storage. One of the methods to reduce the negative effects of long-term storage has been to incubate eggs for short periods before storage. In both turkey and chicken eggs, this technique has been successful in improving the hatchability of long-term stored eggs. It is hypothesized that particular embryonic developmental stages are better able to survive long-term storage. Future research should focus on the mechanisms behind this improved ability to survive storage.

A model for failure of a chicken embryo to survive incubation

Proper assessment of factors contributing to failure of an egg to hatch, i.e., infertility and embryonic mortality, is important in poultry production. A model consisting of the sum of two cumulative logistic distributions was proposed previously to describe the distribution for time of mortality during incubation; model parameters, including probabilities of infertility and mortality, were estimated by the method of least squares. The objective of this paper was to improve the previous model and method of estimation by evaluating alternative distributions and methods; we propose four recommendations. First, probabilities of infertility and mortality should be estimated as observed proportions rather than as model parameters. Second, parameters of the distribution for time of mortality should be estimated using a diphasic Weibull distribution rather than a diphasic logistic distribution. Third, parameters of the distribution for time of mortality should be estimated using noncumulative proportions rather than cumulative proportions. Fourth, parameters of the distribution for time of mortality should be estimated by maximum likelihood rather than by least squares. The minimum Hellinger distance, however, is a good alternative to maximum likelihood to estimate distribution parameters if the distribution of mortality is not known exactly or if the data contain outliers.

Mineral status of embryos of domestic fowl following exposure in vivo to the carbonic anhydrase inhibitor acetazolamide

Eggs of domestic fowl were given daily injections of vehicle (DMSO) or vehicle plus acetazolamide, a potent inhibitor of the enzyme carbonic anhydrase, beginning on day 12 of incubation. Embryos were removed from eggs on days 16 and 18, and carcasses and yolks were analyzed for calcium, magnesium, and phosphorus. Treatment with acetazolamide did not affect the quantity of calcium or phosphorus in carcasses and the effect, if any, on magnesium in carcasses was small. However, calcium content of yolk was reduced substantially by acetazolamide both on day 16 and day 18. The reduction in calcium content of yolk led, in turn, to a reduction in the total quantity of calcium in eggs on days 16 and 18. Embryos exposed to acetazolamide seemingly mobilized less calcium from the eggshell than did control embryos. When faced with a shortfall in the availability of calcium from the eggshell, embryos defended carcass calcium, and the shortfall was reflected in a reduction in the quantity of calcium deposited in yolk. The results of this study support the concept that the enzyme carbonic anhydrase plays a role in solubilization of the eggshell and provision of calcium to embryos.

Influence of storage days on the distribution for time of embryonic mortality during incubation

Breakout analysis of 11,254 chicken eggs that failed to hatch was used to assess the influence of storage days on the distribution for time of embryonic mortality during incubation and on reproductive efficiency. Eggs were collected over 30 d, stored from 2 through 18 d, and incubated in two hatches. For each storage day within hatch, proportions of embryonic mortality during each of the 21 d of incubation, among embryos that did not survive incubation, were fitted by a diphasic Weibull distribution. Multivariate analysis was used to assess the influence of hatch and storage days within hatch on parameters of the distribution and on two measures of reproductive efficiency, proportions of embryonic mortality during incubation among all eggs incubated P(mort) and among fertile eggs incubated P(mort/fert), and to obtain partial correlation coefficients. Storage days influenced the distribution for time of embryonic mortality in each hatch, but the effect was different for each hatch. As the number of storage days increased, P(mort) and P(mort/fert) increased. Partial correlations showed that P(mort) and P(mort/fert) decreased as the proportion of embryos that died during the first phase decreased and as duration of the second phase increased. The shape of the distribution for time of mortality during incubation influenced reproductive efficiency. Factors that influence the shape of this distribution, other than hatch and storage days within hatch, should be studied to increase reproductive efficiency in the poultry industry.

Observations on the patterns of embryonic mortality over the laying season of pheasants

1. Embryonic mortality of domestic pheasant (Phasianus colchinus) eggs was recorded for a 10-week laying season for two groups of laying hens maintained under mating ratios of 8:1 and 12:1 (females:males). 2. Mating ratio had no significant effect on embryonic mortality between 1 and 4 or 5 and 20 d but values for these categories doubled as the laying season progressed, both rising to 8% to 9% of fertile eggs. 3. Higher embryonic mortality was observed between 21 and 25 d for the eggs from the 8:1 mating ratio (14.5% of fertile eggs compared with 12.1%) but this was unaffected by week of setting. 4. Reasons for these patterns of embryonic mortality were not clear and further research is needed to determine the factors affecting embryonic mortality in pheasants.

Effect of hatch on the distribution for failure of an embryo to survive incubation

The objectives of this paper were to validate an improved model to describe failure to hatch by using data obtained from two hatches of a line of chickens and to examine the effect of hatch on the distribution for time of failure of an embryo to survive incubation. Breakout analysis of 11,254 eggs that failed to hatch was used to characterize the distribution for time of failure to survive and the probability of failure to hatch. The distribution for time of failure to survive was modeled by a diphasic Weibull distribution, corresponding to the two phases of increased embryonic mortality during incubation. Distribution parameters for time of failure to survive were estimated by maximum likelihood and minimum Hellinger distance. Goodness-of-fit statistics validated the appropriateness of the diphasic Weibull distribution. Overall, the proportion of infertility was 0.213, and the proportion of embryonic mortality by the end of incubation was 0.086. Among embryos that suffered mortality during incubation, the proportion that died during Phase 1 was 0.77; therefore, 0.23 died during Phase 2. For Phase 1, mean time of mortality was 2.6 d, and standard deviation was 3.3 d. For Phase 2, mean time was 17.4 d, and standard deviation was 2.0 d. Time of mortality was distributed differently in the two hatches; this difference occurred mostly during Phase 1. Failure rates of the two hatches were different during the first 3 d of incubation. The model is useful to assess probability of failure to hatch and the distribution for time of failure to survive during incubation.

Examining the effects of prestorage incubation of turkey breeder eggs on embryonic development and hatchability of eggs stored for four or fourteen days

Thirty-six hundred British United Turkey hatching eggs were used in two separate trials to test whether prestorage incubation (PRESI) treatments of 0, 6, and 12 h (Trial 1) or 0, 7, and 14 h (Trial 2) could improve the hatchability of eggs stored (17 C) for 14 versus 4 d. The development of the embryos (n = 30) was staged before and after exposing eggs to the various PRESI treatments. Embryonic development was also established after storage to ascertain whether embryonic development was occurring during storage. The remaining eggs in each trial were split into three groups (n = 500) and incubated for 28 d to examine embryonic mortality and hatchability. No changes were observed in embryonic development due to egg storage. Embryos were significantly more developed as the number of PRESI h increased; therefore, embryos from different PRESI treatments were placed in storage at different stages of development. Early mortality (1 to 7 d of incubation), mortality at internal and external pipping, and hatchability of fertile eggs were significantly reduced in eggs stored for 14 versus 4 d. The various PRESI treatments did not significantly affect the mortality or hatchability of eggs stored for 4 d. However, the hatchability of eggs incubated prior to storage for 12 h and then stored for 14 d was restored to the levels reported for eggs subjected to the treatment that represents the industry norm (0 h of PRESI and 4 d storage). These results indicate that embryos of eggs stored for 14 d, which have developmentally advanced to the stage of complete hypoblast formation (PRESI for 12 h), have a survival advantage over eggs stored for 14 d that have not been subjected to any PRESI.

Preincubation storage of turkey eggs: impact on rate of early embryonic development

1. The effect of cooling and storage on preincubation development of turkey embryos was examined. 2. Fresh laid eggs were stored at 15 degrees C for 3, 7, or 14 d (group 1) or held initially at room temperature (21 degrees C) for 6 to 9 h and subsequently stored at 15 degrees C for 3, 7, or 14 d (group 2). 3. Most embryos in eggs from both groups progressed developmentally to Stage-8, just prior to onset of hypoblast formation. There were no significant differences in embryo development either within or between groups. 4. It is concluded that under the conditions of this study, egg cooling and storage augment development of the embryo, albeit only slightly.

Effects of maternal nutrition on hatchability

The effects of dietary factors on the development and viability of avian embryos have been extensively documented. A good nutritional status of the parent birds is crucial to the transfer to the egg of an adequate, balanced supply of nutrients required for normal development of the embryo. The consequences to the embryo may be lethal if the egg contains either inadequate, excessive, or imbalanced levels of nutrients. As nutritional deficiencies or excesses occur, it is common for the effects on the embryo to also become more severe and to occur at earlier stages of development. The type of nutritional stress signs visible in the embryo often depend upon the severity of the maternal nutritional stress. Diseases, parasitic infections, toxins, poisons, or drugs may also cause nutritional or pseudonutritional problems with hatchability.

Research note: variability in preincubation embryonic development in domestic fowl. 2. Effects of duration of egg storage period

Embryos of eggs from Single Comb White Leghorn hens were analyzed to determine whether duration of egg storage significantly affects embryonic development prior to incubation. Eggs were gathered over a period of 5 days from 25-wk-old hens that were naturally inseminated and housed in floor pens. Within 1 h of oviposition the eggs were collected and assigned randomly to one of five storage treatment groups of 0, 4, 7, 14, or 21 days. Fresh egg weight was recorded and the eggs were placed on plastic egg flats and stored at 14 C. Weight of each egg was measured after storage to determine amount of weight lost during storage. A total of 500 embryos were examined after storage. Viable embryos were staged for development using a modified Eyal-Giladi and Kochav classification. The incidence of embryonic mortality was noted. Duration of storage (P = .5815) collection date (P = .5815), and fresh egg weight (P = .3789) did not affect embryonic development significantly. A significant linear relationship was observed between duration of the storage period and loss of egg weight (P = .0001). Embryonic mortality was significantly related to loss of egg weight (P = .0001). Mortality was highest in eggs that were stored for a longer period of time. The data from the current study indicate that storing fertile eggs below physiological zero inhibits embryonic development. One of the reasons for the increased incidence of embryonic mortality in eggs that were stored for longer periods may be related to the increased egg weight loss in these eggs.