Ducks are waterfowl belonging to the Anatidae family of cosmopolitan distribution. In duck production systems, obtaining ducklings at one-day-old is determinant for the productive chain. The egg production in some species of ducks reaches about 250 to 300 eggs per year. Obtaining one-day-old ducklings can be done by natural incubation with a broody female duck or artificially in an incubator. During artificial incubation, fertility and hatchability are the most important indicators that must be controlled, because they influence the supply of ducklings to the farm. Many factors are related to fertility and hatching, such as environmental conditions, production system, season, nutrition, management of broodstock, storage time of egg and cleaning of eggs before the incubation. According to some reports, Pekin eggs have greater hatchability than Muscovy eggs. The eggs of Muscovy have presented values lower than 22.7% of hatchability. The hatchability of Pekin duck eggs was 78.0% in the spring, while in summer it was around 46.5%. The best hatchability is observed during the winter (57.68%), as in the summer it decreases to 54.14%. The reproductive characteristics of flocks, age, external and internal quality of the egg, male female relation, and presence of lethal genes are factors that directly involve breeders. Larger sexual ratios between males and females of 1:4.3 to 1: 10 cause reduced egg fertility from 75.9% down to 49.6%. Successful production of day-old ducklings starts with the proper selection and management of breeding stock, proper post-lay handling of fertile eggs and the correct incubation process. There are different methods used to improve the hatchability such as dipping eggs in nutrients during the incubation period.

Egg storage longer than 7 days is associated with negative effects on hatchability traits. Pre-storage incubation has been a suggested method to reduce the negative effects of long-term storage times by enhancing the developmental stage of the embryo and probably reducing the embryonic stress. The objective of the present study was to investigate the effects of pre-storage incubation and storage time on hatchability characteristics, chick quality and serum thyroid hormones, antioxidative properties and immunoglobulin Y (IgY) concentrations of newly hatched chicks at two breeder flock ages. A total of 8000 fertile eggs were obtained from two different ages of chicken breeder hens (Egyptian local cross, Inshas). Half of the eggs were collected from young breeder hens (28 weeks old) and the other half from old breeder hens (50 weeks old). In each breeder flock age, eggs were distributed in a completely randomized experimental design in a 2×4 factorial arrangement, with two storage periods (4 or 14 days) and four pre-storage incubation durations (0, 4, 6 or 8 h at 37.5°C). At 28 and 50 weeks of age, pre-storage incubation and its interaction with storage period influenced significantly the apparent fertility, hatchability of set eggs and hatchability of fertile eggs and this improvement in hatchability is attributed to the reduction in embryonic mortality (early, intermediate and late). Pre-storage incubation for 6 or 8 h elevated significantly the grade A chicks and reduced the grade B chicks in comparison with non-heated controls. Interestingly, for eggs stored for 14 days, pre-storage incubation for 6 or 8 h enhanced serum triiodothyronine, thyroxine, glutathione peroxidase activity, total antioxidant capacity and IgY concentrations significantly and decreased serum malondialdehyde concentration significantly in the newly hatched chicks. It could be concluded that pre-storage incubation enhanced the hatching results, improved the antioxidative properties, reduced lipid peroxidation and elevated the humoral immunity in the newly hatched chicks. Hence, several benefits might be gained by pre-storage incubation when fertilized eggs will be stored for long periods.

A number of studies have indicated that there is a relationship between the colour of pheasant eggshells and their quality, as well as hatchability results. For example, eggs with light coloured shell colour have higher water and cholesterol content than darker eggs. At the same time, blue and light-brown eggs contain more lysozyme in their albumen, compared to the eggs with different shell colours. On comparing the microbiological contamination, it was found that the dark-brown and olive eggs had a similar and higher total bacteria count (TBC) in the shell compared to the blue ones. Similarly, these eggs had lower ergosterol (EGR) content in the shell (indicator of microscopic fungi presence) compared to the eggs of blue colour. Also it was demonstrated that poorer hatchability of fertilised and set eggs with blue shell is the result of factors mentioned earlier. In summary, it appears that, from an economic viewpoint, the start of breeding in ring-necked pheasant should be considered and the eggshell colour should be included in the selection index. In addition, it is worth paying attention to the possibilities of environmental factors and nutritional modification in order to improve hatchability parameters in pheasants.

In the post-antibiotics era, prebiotics are proposed as alternatives to antibiotic growth promoters in poultry production. The goal of this study was to compare in ovo method of prebiotic delivery with in-water supplementation and with both methods combined (in ovo+in-water) in broiler chickens. Two trials were conducted. Trial 1 was carried out to optimize the doses of two prebiotics, DN (DiNovo®, extract of beta-glucans) and BI (Bi2tos, trans-galactooligosaccharides), for in ovo delivery. The estimated parameters were hatchability and bacteriological status of the newly hatched chicks. Prebiotics were dissolved in 0.2 ml of physiological saline, at the doses: 0.18, 0.88, 3.5 and 7.0 mg/embryo; control group (C) was injected in ovo with 0.2 ml of physiological saline. Trial 2 was conducted to evaluate effects of different prebiotics (DN, BI and raffinose family oligosaccharides (RFO)) delivered in ovo, in-water and in a combined way (in ovo+in-water) on broiler chickens performance. The results of the Trial 1 indicated that the optimal dose of DN and BI prebiotics delivered in ovo, that did not reduce chicks’ hatchability, was 0.88 mg/embryo (DN) and 3.5 mg/embryo (BI). Both prebiotics numerically increased number of lactobacilli and bifidobacteria in chicken feces (P>0.05). In Trial 2, all prebiotics (DN, BI and RFO) significantly increased BW gain compared with the C group (P<0.05), especially during the first 21 days of life. However, feed intake and feed conversion ratio were increased upon prebiotics delivery irrespective of method used. Injection of prebiotics in ovo combined with in-water supplementation did not express synergistic effects on broilers performance compared with in ovo injection only. Taken together, those results confirm that single in ovo prebiotics injection into the chicken embryo can successfully replace prolonged in-water supplementation post hatching.

Ladakh, the Trans Himalayan part of the Jammu Kashmir State of India, is located between the Greater Himalaya and the Karakoram Range, known as the ‘cold desert’, and is comprised of two districts, Leh (45110 km2) and Kargil (14,086 km2). This area has several peculiar climatic conditions characterised by prolonged sub-zero temperatures, unfertile sandy soils with very low water holding capacities, dryness (less than 30% humidity), low oxygen content, intense solar radiation, low atmospheric pressure, high wind velocity and rugged terrain. In winter the temperature falls to -35°C and the altitude varies from 10,000 to 12,000 feet from mean sea level (MSL). The atmospheric oxygen pressure is 30% lower than of MSL. This type of cold arid desert isn't akin to the natural environment of poultry, and hatchability is a big problem due to the climatic conditions in this region. For normal hatchability at sea level, the oxygen concentration, barometric pressure, humidity and temperature should be 21%, 740 mm Hg, 65% and 99.8°F, respectively. However in this cold desert area O2 concentration is 30% lower than at sea level, barometric pressure is only 510 mm Hg, humidity is less than 30% and temperature ranges from -30C to +30°C.

In the last two decades, India has reached a level of self-sufficiency in chicken production, and the poultry industry has become more sophisticated, but the situation in the cold arid part of Leh-Ladakh in India remains challenging. The main reasons for this are the non-existence of any commercial hatcheries, problems transporting day old chicks, poor availability of poultry feed ingredients and the fact that the majority of the population are Buddhist, and consequently largely vegetarian and generally avoid killing animals. The following paper reviews some of the issues of raising poultry in such inhospitable conditions, and how these can be resolved.

Egg storage is a common and important practice in the poultry industry. Knowledge of the effects of storage on the egg, the embryo and incubation yield is important for planning incubation by hatcheries. Recommendations for storage environmental conditions depend mainly on the breeder age and storage time. Storage from seven days or more alters the characteristics of albumen, reduces incubation yield, increases incubation period and can damage embryonic development. When working with long storage periods, the adoption of management practices such as storing the egg with the thin tip down, egg turning during storage and pre-storage incubation should be considered to reduce the negative effects on the incubation yield.

Adding value to eggs, being a very old concept in foods, is practiced for supplementing nutritive values along with provision for ease of handling too. Some of the value-added egg products include tea/century eggs (for extended shelf life of egg products); low cholesterol eggs (preferred by health conscious customers); and ‘super’ eggs produced through use of either herbal supplements, inclusion of drugs, manipulation of dietary protein and energy content, poly unsaturated fatty acids (PUFA), or additional vitamins and minerals in the poultry diet. These are considered helpful in reducing the risk of heart diseases and in some cancerous conditions.

However, the focus of this review is to concentrate on the production of salted eggs and the process of brining. Sales of salted eggs have been quite encouraging for on its own merits. People in many parts of the globe, prepare and market salted eggs as part of their preservative/extra value but very little scientific information has been available regarding the standardised brining technology and storage quality of salted chicken eggs. Apart from this, no information has been available on the hatching performance of salted eggs, subsequent growth performance of progeny, broiler chick quality and their immune-competence against disease. In view of the requirement for information, it was deemed imperative to consolidate the relevant information to determine future research needs.

The incubation-limitation hypothesis suggests that clutch size in some birds is limited by incubation capacity. However, this remains disputed amongst ornithologists. This study aimed to test whether incubation capacity limits the maximum clutch size to two eggs in south polar skuas (Catharacta maccormicki Saunders) by comparing the egg and nest temperatures as well as hatchability between two-egg and three-egg clutches. Although the vast majority of clutches contained one or two eggs, four naturally occurring three-egg clutches were found at Barton Peninsula, King George Island over three breeding seasons (2004–2005, 2005–2006 and 2006–2007). Regardless of clutch size, all incubating parents exhibited two discernible brood patches. The mean egg and nest temperatures of the three-egg clutches were significantly lower than were those of the two-egg clutches. The accumulated time that egg temperature decreased below 30°C in three-egg clutches was approximately eight times longer than that in two-egg clutches. The hatchability of natural one-egg (89.5%) and two-egg clutches (95.4%) were significantly higher than that of the three-egg clutches, which was zero. Our results suggest that the maximum clutch size in south polar skuas is probably restricted by incubation capacity.

The physical characteristics of the egg play an important role in the processes of embryo development and successful hatching. The most influential egg parameters are: weight, shell thickness and porosity, shape index, described as maximum breadth to length ratio, and the consistency of the contents. The average values of the physical characteristics mostly meet the requirements for the embryo's development. For those eggs, whose parameters do not fall in to the average range, the incubation process is more successful if the shell is thicker than average, the eggs are more pointed rather than round, and the contents firm. The results reported for investigations into incubating eggs, whose weights are not within the average values, are contradictory. Both thick shells and firm interiors, which are accepted as being higher than average, lead to an increase in egg weight, which probably results in the more successful hatching of embryos from heavier eggs.

The quality of the day-old broiler chick is foremost in the minds of many poultry managers. From fertilised ovum to the placement at the broiler farm, some factors such as the characteristics of the incubating eggs, the egg holding conditions, the incubation conditions and the conditions that exist between hatching and placement at the farm and their interactions may affect chick quality. It may be questioned if maximal hatchability is the best indicator for chick quality and/or post-hatching viability, even if optimal hatchability is considered a prerequisite for successful incubation. The environmental conditions during incubation (e.g. the temperature, humidity and ventilation rate (carbon dioxide concentration)) are not set independently from each other, although each may have its own optimum for hatchability and chick quality. These optima for each incubation factor may alter differentially according to the characteristics of the incubating egg. It is concluded that more independent control as well as more control of the variability of the classical physical conditions in the incubator are required in order to improve hatchability and chick quality.

This paper considers some of the factors affecting the fertility and hatchability of guinea fowl eggs. In addition to genetic components there is a wide range of environmental influences that affect these two measures of performance. These include severe nutritional deficiencies, certain drugs and feed contamination with pesticides and mycotoxins. After eggs are laid, faulty handling and storage conditions and incorrect fumigation procedures have harmful effects on hatchability, while correct incubation temperature, humidity and ventilation rates during the setting and hatching stages are essential for optimum results. The causes of low levels of hatchability can be identified by the careful examination of eggs which fail to hatch. However, accurate and complete records relating to the breeder flock and the history of the eggs from the nest through to the completion of incubation are essential for problem solving and in helping to obtain optimum results.

The paper addresses all feasible applications of long ahemeral light cycles in breeding flocks and reviews the limited published studies. Long cycles are likely to be most beneficial towards the end of the production cycle – when eggshell quality is often poor – and at the beginning of lay to increase the proportion of eggs exceeding the minimum weight for incubation. Published reports show an improvement in both fertility and hatchability of breeding flocks under long cycles.

The time between a hatching egg being produced and set in an incubator can be divided into a laying house period and a storage period. The period in the laying house affects hatching results by the stage of embryonic development at oviposition as well as by the subsequent environmental conditions. Advanced embryonic development at oviposition or prior to storage seems to improve hatchability, especially when storage is prolonged. Stage of embryonic development at oviposition is influenced by parental age, strain, individual bird variation and clutch length. After oviposition and before storage embryonic development can be influenced by the type of nest, egg collection pattern and temperature.

During storage, hatchability is influenced by the length of the storage period, temperature, humidity, gaseous environment and the orientation of the eggs. A decrease in hatchability can be detected in eggs stored for 2–3 days or more. Storage temperature should be decreased with extended length of storage. Temporary heating before incubation and enclosing eggs in plastic bags during storage improves hatchability, especially when storage is prolonged. A high humidity during storage also improves hatchability, probably due to a reduction in water loss. The changes in albumen pH during storage are discussed in so far as they provide a possible explanation for relationships between environmental conditions during storage and hatching results.

Several interrelationships are apparent between egg weight, chick weight, chick growth and other parameters. The hatchability of intermediate size eggs is better than that of very large or very small eggs. Decreased hatchability, hatchling weight, chick growth and chick viability have been associated with the first few eggs produced by young pullets. Incubation time is positively correlated with egg size. Embryo weight is not correlated with egg weight during the first half of the incubation period. Thereafter the correlation increases and reaches a maximum at the time of hatching (0.5–0.95). Chick weight is primarily determined by initial egg weight, normally being 62–78% of egg weight, and is secondarily determined by weight loss during incubation, shell and residue weight, strain, incubation time and conditions, breeder age and chick sex. The correlation of egg weight to posthatching chick weight decreases with increasing age of the chick. A 1 g change in egg weight has been shown to result in a corresponding change of 2–13 g in broiler weight at 6 to 8 weeks of age. This effect is much greater in eggs from young breeders than in those from old breeders. The effects of egg weight on chick feed conversion have been variable with no clear conclusion. Improved growth and uniformity may be obtained by growing chicks separately according to hatchling size. Therefore, sorting eggs by weight prior to incubation might be advantageous in some production operations to improve broiler or pullet uniformity and efficiency.

The effectiveness of Bacillus thuringiensis var. galleriae HD-129 against the moths and egg masses of the cotton leafworm, Spodoptera littoralis, has been demonstrated in laboratory experiments. The longevity and egg production were significantly affected when the moths were fed on a sucrose diet containing 17.2 × 103 IU of the tested formulation/mg or higher rates. At lower concentrations (4.4−8.7 × 103 IU/mg), the females gave normal egg production, but the longevity was adversely affected. Investigations show that a formulation with spores alone affects the egg production and hatching, while a formulation with active crystals alone had no effect on egg production. Sprays of B. thuringiensis combined with sucrose on flowering cotton plants seem to affect the biology of the moths released on it. Egg masses sprayed with B. thuringiensis hatched normally, but the survival of the hatched larvae was reduced when treatment was made shortly before egg hatching. Based on the results obtained, B. thuringiensis showed a promising effect in the control of the moth S. littoralis as well as an ovicide larvicide agent.