Ovo Feeding Research Articles

A Review: Nutrition Stimulation with in Ovo Feeding Technology for Optimization of Growth and Development of Prenatal and Postnatal Periods of Chicken

The improvement in broiler chicken performance is currently thanks to the genetic selection, nutrition, maintenance management, and health and biosecurity programs that have succeeded in improving the maintenance performance of broilers. Such rapid development in the cycle after hatching is undoubtedly also influenced by the embryo's development or the prenatal phase. Unlike other mammals, the process of breeding poultry has its characteristics where the process of embryonic development occurs outside the body of livestock or inside poultry eggs. Chicken embryos rely heavily on the nutrients inside the egg, which provide the energy and amino acid makeup needed for the metabolic needs of the growing embryo during the 21-day incubation process. Chicken embryos are susceptible to a lack of energy during the hatching process. This deficiency can result in weak embryos and, in more severe conditions, embryo death and failure to hatch. The nutritional needs of embryos during incubation can be added to the egg with the in ovo feeding technique. The in ovo feeding technique is a technique that allows the addition of outside nutrients injected into the egg during incubation for the developmental and metabolic needs of the embryo, as well as to improve the nutritional status of the egg. Nutrition stimulation with in ovo feeding technique produces many benefits, such as increasing hatchability, hatching weight, immunity level, reduced bone system disorders, reduced morbidity and mortality after hatching, feed efficiency and weight gain.

The influence of in ovo feeding of black cumin extract on the physiological responses of broilers under hot tropical environments

An experiment was conducted to investigate the influence of in ovo feeding of black cumin extract (BC) on the intestinal morphology and physiological responses of broilers thermally challenged during incubation. The study involved the use of seven hundred Marshall broiler hatching eggs, which were assigned to 7 in ovo feeding treatments at embryonic day 17.5, as follows: eggs injected with 8 mg (EN), 6 mg (SN), 4 mg (FN), 2 mg (TN)BC, no in ovo feeding (NI), 0.9 % saline solution (SS), and 3 mg vitamin C (VC). Juvenile growth performance, plasma malondialdehyde (MDA), triiodothyronine (T3), superoxide dismutase (SOD), and haematological and serum biochemical indices were evaluated. The results revealed that the juvenile growth performance of SN birds was better than those of the NI, SS, FN and TN groups. The plasma SOD and T3 of the birds of SN and VC were significantly higher (p < 0.05) than the chickens of NI and SS treatments. The ileal crypt depth recorded in SN birds was lower (p < 0.05) compared to SS and NI values. To conclude, in ovo black cumin extract enhanced the gut health and lymphoid organs of broiler chickens with no pronounced effect on the thermotolerance of the birds at market age.

Effect of in ovo feeding of folic acid on Disabled-1 and gga-miR-182-5p expression in the cerebral cortex of chick embryo.

Folate (vitamin B9) has been shown to reduce the prevalence of neural tube defects (NTDs). Many genes comprising Disabled-1 (DAB1) and miRNAs have been shown to play important role in normal brain development. Reelin-signalling has been shown to play key role in regulating of neuronal migration during brain development. The aim of this study was to evaluate the effects of in ovo administration of folic acid (FA) on DAB1 and gga-miR-182-5p expression in the cerebral cortex of chick embryo. A total number of 30 hatching eggs were used in this study. The number of 10 eggs were injected into the yolk sac with FA(150 µg/egg), 10 eggs by normal saline (sham group) on embryonic day 11 and 10 eggs were left without injection as control. Then the cerebral cortices were collected on E19 and the expression of DAB1 and gga-miR-182-5p was studied by Real-Time PCR. The results showed that DAB1 expression in the cerebral cortex of FA-treated, sham and control were 2.51 ± 0.13, 1.01 ± 0.04and 1.03 ± 0.04 fold changes, respectively, and this amount for gga-miR-182-5p were 0.54 ± 0.03, 1.09 ± 0.07 and 1.00 ± 0.06-fold changerespectively. Statistical analysis showed that there is a significant increase in DAB1 and a decrease in gga-miR-182-5p expression in FA injected cerebral cortex as compared either with either SHAM or control (p < 0.0001). But, no significant change in DAB1 and gga-miR-182-5p expression was observed between sham and the control group (p = 0.99 and p = 0.57respectively). It is concluded that in ovo feeding of FA increases DAB1 and decreases gga-miR-182-5p expression in the developing chick cerebral cortex.

Exploring the Confluence of In-Ovo Mineral Supplementation and Hatching Attributes in Broiler Chick Progeny: A Symphony of Nutritional Enrichment and Broiler Chicks Development

Embryonic nutrition is a key factor that influences broiler progeny performance with long-lasting nutritional adequacies or insufficiencies in the developmental phase. Objective: To explores the effects of in-ovo mineral supplementation or day in-ovo feeding on the hatching attributes and chick quality in broiler breeders. Methods: About 1400 hatching eggs of broiler breeders were selected, categorized into seven experimental groups: one control group, three macro mineral (P, Mg, and Ca) groups, and three micro-mineral (Zn, Mn, and Cu) groups. During the 12th and 18th day of incubation, eggs received in-ovo injections of their respective mineral (5% of the total mineral content in a 50g egg) solutions, prepared by dissolving the corresponding salts in deionized water. Post-injection, eggs were placed in the setter, and upon completion of incubation, hatching trays were removed to evaluate hatchability performance and chick quality parameters for each group. Results: The results showed that Zn, Ca, and Mg-supplemented eggs demonstrated the highest (P&lt;0.05) hatchability rates for settable and fertile eggs at day 12 of in-ovo feeding. The chick weight, hatch window, and hatchling size were significantly influenced (P&lt;0.05) by in-ovo feeding and the day of in-ovo feeding. However, no effect of in-ovo mineral feeding and day of in ovo feeding was observed on chick quality (chick grades, navel area, retracted yolk, and membrane score) and post-hatch chick activities (activity, down-appearance, vitality, eye score, and gait score). Conclusions: In conclusion, Zn, Ca, and Mg in ovo feeding improve the hatchability traits when administered at day 12 of incubation.

The use of ascorbic acid in ovo feeding for poultry embryos and its effect on egg hatchability, embryo mortality, chicks’ weight, and gastrointestinal tract development

The use of ascorbic acid in ovo feeding for poultry embryos and its effect on egg hatchability, embryo mortality, chicks’ weight, and gastrointestinal tract development

In ovo feeding of vitamins in broilers: A comprehensive meta-analysis of hatchability and growth performance.

In ovo feeding has been introduced as a cost-effective method to improve hatchability and broiler performance. Specifically, several studies have focused on the impact of vitamins. However, due to variations in experimental conditions across all trials, drawing general conclusions appears challenging. Therefore, we conducted a meta-analysis of 17 published papers, including a maximum of 134 sample size to evaluate the potential effects of in ovo feeding of vitamins in broilers. Studies were retrieved by consulting scientific repositories such as Pubmed, Scopus, Scielo, Web of Science, and Google Scholar. A binary logistic model was used to determine the parameters influencing hatchability. To assess variations in hatchling weight and growth parameters based on the vitamin category, a mixed model analysis of variance was performed, considering the study as a random effect and the vitamin category as a fixed effect. Finally, a linear mixed model was used to develop equations that explain the evolution of growth parameters based on vitamin concentration, volume, and day of injection. The results revealed that for better hatchability, it is preferable to consider heavier eggs (p = 0.007), lower volumes (p = 0.039), and late injection (p = 0.022). Vitamin E was associated with higher hatchling weight (p = 0.037), while vitamin C exhibited the lowest overall feed conversion ratio (p = 0.042). Interactions were observed between the day of injection and vitamin concentration or volume of injection for all studied growth parameters. In summary, the findings of this study suggest that hatchability during in ovo feeding is influenced by technique-related parameters, whereas growth parameters can be modulated by the category of vitamin injected. Consequently, this study lays the groundwork for future investigations assessing the effects of in ovo feeding in broilers, as it highlights the relationship between the methodology and potential outcomes.

Effect of in ovo feeding using albumin to Rhode Island Red poultry embryos

This study aimed to evaluate the effects of in ovo feeding using albumin on hatchability, hatching weight, embryo mortality, as well as on organ development of Rhode Island Red chicks. A total of 245 fertile eggs with viable embryos were randomly distributed in seven treatments with 35 replicates (eggs) each. The treatments were untreated eggs and eggs treated with a buffered solution (0.50% saline) or solutions containing increased levels of albumin (0.5, 1.0, 1.5, 2.0, and 2.5%). On d 17 of incubation, eggs were injected with solutions containing albumin dissolved in 200 μL of 0.5% sterile saline. After solutions injection, the pinholes in the eggs were sealed with molten paraffin and moved to a hatching machine. Evaluation of the chicks’ weight, hatchability, and embryo mortality was made immediately post hatch. Five viable chicks of each treatment were randomly selected and slaughtered by cervical dislocation in order to evaluate the heart, gastrointestinal organs and region development. Data collected were subjected to polynomial regression (p≤0.05) after a significant ANOVA result. In ovo feeding using albumin directly affected (p&lt;0.05) the hatching characteristics of injected eggs. When eggs were injected with increased levels of albumin, there was a linear decrease (p&lt;0.05) on hatchability and increase on embryo mortality. The increased supplementation of albumin resulted in a linear growth (p&lt;0.05) of gastrointestinal tract areas responsible to digestion (oropharynx + oesophagus, duodenal loop and cecum), and a linear decrease of heart, liver, pro-ventricle, gizzard and gastrointestinal tract areas responsible to absorption (jejunum + ileum and colon + rectum).

Improvement in growth performance and digestive function from amniotic injections of N-acetylglutamate in broiler chickens.

N-acetylglutamate (NAG) is the initial and essectial substrate in the process of de novo arginine synthesis, plays an important role in intestinal development. The aim of this study was to determine the effects of in ovo feeding of NAG, 1.5 mg/egg at 17.5 days of incubation (DOI) via amnion, on hatching performance, early intestinal histomorphometry, jejunal barrier, digestive function, and growth performance of broiler chickens between 1 and 14 days of age. Amniotic injection of NAG had no significant effect on hatching characteristics compared with the non-injected control group (NC group). Birds in the NAG solution-injected group (NAG group) exhibited lower average daily feed intake and better feed efficiency during a period of 1-14 days. In comparison with the NC group, the NAG group had decreased crypt depth (CD) in the ileum and increased villus height (VH) / CD in the jejunum at 7 days, and decreased CD in duodenum and significantly increased VH in the jejunum at 14 days. However, the effects of in ovo supplementation with NAG on the density of goblet cells, and gene expression of mucin 2 and alkaline phosphatase were not significant. Chicks in the NAG group had a significantly higher mRNA expression level of trypsin and maltase in jejunum at 7 days than the NC group but not at 14 days. Amniotic injections of NAG (1.5 mg/egg) at 17.5 DOI could improve early growth performance of broilers during 1-14 days after hatching by accelerating the development of the intestine and enhancing jejunal digestive function. © 2023 Society of Chemical Industry.

A Review: The Use of In Ovo Feeding in Various Types of Poultry

In ovo feeding is one way to increase poultry productivity by providing additional nutrition during the incubation period and can increase embryo growth. Many implementations of in-ovo feeding techniques have been carried out on various types of poultry, but a summary of the use of in-ovo feeding on various types of poultry has never been reported, therefore this study was conducted. This review article aims to determine the use of in-ovo feeding in various types of poultry. This study was conducted based on literature studies by analyzing secondary data and synthesizing research from various data sources originating from nationally accredited journals and reputable international journals that discuss the use of in-ovo feeding in various types of poultry. The study shows that the implementations of in-ovo feeding for various types of poultry have been mostly applied to broiler chickens and native chickens, but only a few in geese, ducks, and quails. In-ovo feeding has several advantages for enhancing nutrition and health, including preserving normal physiological status and preventing disease, so that poultry productivity can be increased.

In ovo feeding technique of probiotics in broiler chickens: Achievements, Prospective and Challenges

In ovo feeding technique of probiotics in broiler chickens: Achievements, Prospective and Challenges

Embryonic modulation through thermal manipulation and in ovo feeding to develop heat tolerance in chickens.

Healthy chickens are necessary to meet the ever-increasing demand for poultry meat. Birds are subjected to numerous stressful conditions under commercial rearing systems, including variations in the environmental temperature. However, it is difficult to counter the effects of global warming on the livestock industry. High environmental temperature is a stressful condition that has detrimental effects on growth and production performance, resulting in decreased feed intake, retarded growth, compromised gut health, enhanced oxidative stress, and altered immune responses. Traditional approaches include nutritional modification and housing management to mitigate the harmful effects of hot environments. Currently, broiler chickens are more susceptible to heat stress (HS) than layer chickens because of their high muscle mass and metabolic rate. In this review, we explored the possibility of in ovo manipulation to combat HS in broiler chickens. Given their short lifespan from hatching to market age, embryonic life is thought to be one of the critical periods for achieving these objectives. Chicken embryos can be modulated through either temperature treatment or nourishment to improve thermal tolerance during the rearing phase. We first provided a brief overview of the harmful effects of HS on poultry. An in-depth evaluation was then presented for in ovo feeding and thermal manipulation as emerging strategies to combat the negative effects of HS. Finally, we evaluated a combination of the two methods using the available data. Taken together, these investigations suggest that embryonic manipulation has the potential to confer heat resistance in chickens.

A deep learning-based automated image analysis for histological evaluation of broiler pectoral muscle

Global market demand for chicken breast muscle with high yield and quality, together with the high incidence rate of breast muscle abnormalities in recent years highlights the need for tools that can provide a rapid and precise evaluation of breast muscle development and morphology. In this study, we used a novel deep learning-based automated image analysis workflow combining Fiji (ImageJ) with Cellpose and MorphoLibJ plugins to generate an automated diameter and cross-sectional area quantification for broiler breast muscle. We compared data of myofiber diameter from 14-day-old broiler chicks, generated either by manual analysis or by automated analysis. Comparison between manual and automated analysis methods exhibited a striking accuracy rate of up to 99.91%. Moreover, the automated analysis method was much faster. When the automated analysis method was implemented on 84 breast muscle cross-section images it characterized 59,128 myofibers within 4.2 h, while manual analysis of 27 breast muscle cross-section images enabled analysis of 17,333 myofibers in 54 h. The automated image analysis method was also more productive, producing data sets of both diameter and cross-sectional area at an 80-fold higher rate than the manual analysis (26,279 vs. 321 data sets per hour, respectively). In order to demonstrate the ability of this automated image analysis tool to detect differences in breast muscle histomorphology, we applied it on cross sections from chicks of control and in ovo feeding group, injected with a methionine source [2-hydroxy-4-(methylthio) butanoic calcium salt (HMTBa)], known to effect skeletal muscle histomorphology. Analysis was performed on 19,807 myofibers from the control group and 21,755 myofibers from the HMTBa group and was completed in less than 1 h. The clear advantages of this automated image analysis workflow characterized by high precision, high speed, and high productiveness demonstrate its potential to be implemented as a reproducible and readily adaptable research or diagnostic tool for chicken breast muscle development and morphology.

Evaluation of In Ovo Cinnamon, Ginger or Anise Extract Injection on Broiler Hatching Performance

Firstly, this study aimed to evaluate the effects on hatchability and relative weights of yolk, metabolic organ (heart, liver, breast muscle, and thigh muscle) and total digestive system (GUT) of in ovo feeding of cinnamon, ginger or anise extract. Secondly, it was investigated to determine the appropriate dose of cinnamon, ginger or anise extract in in ovo feeding. For this purpose, 480 fertilized broiler eggs were randomly distributed into 12 groups with four replicates as a factorial arrangement of three extracts (cinnamon, ginger, anise) x 4 doses (0, 3, 9, 12 mg/egg) to hatching trays. On the 18th day of incubation, 1 ml of 0.9% saline solution containing 0, 3, 9, 12 mg of cinnamon, ginger or anise extract was injected into the eggs with a 19 mm and 27-gauge needle. The cinnamon and ginger groups had higher hatchability, chick quality and proventriculus weight, while the anise group had higher thigh muscle weight. Chick weight was 12 mg/egg, chick quality was 0 and 3 mg/egg, breast muscle weight was 9 mg/egg, and liver, gizzard and GUT weights were higher at 0, 3 and 9 mg/egg in ovo extract doses. In ovo anise injection increased the number of non‐pipped dead embryos. The interaction effect of factors on the hatchability and chick quality were found significant. The results of this study indicate that 9 mg/egg cinnamon, 12 mg/egg ginger, and 3 mg/egg anise extract can be used in in ovo injection without negative effects on the investigated parameters. The role of in ovo cinnamon, ginger or anise extract injection in broiler needs further research.

Effect of in ovo injection of DL-methionine on hatchability, embryo mortality, hatching weight, blood biochemical parameters and gastrointestinal tract development of breeder chicks

The current investigation was conducted to test the potential effects of in ovo feeding of DL-methionine (MET) on hatchability, embryonic mortality, hatching weight, blood biochemical parameters and development of heart and gastrointestinal (GIT) of breeder chick embryos. 224 Rhode Island Red fertile eggs were randomly distributed into seven experimental treatments: untreated egg (control), buffered saline (0.5% NaCl), and five solutions containing increased levels of MET (0.5, 1.0, 1.5, 2.0 and 2.5%) + 0.5% NaCl, being separated into four groups/replicates (each one with 8 eggs), totaling 32 eggs/treatment. All embryos submitted to in ovo injection with MET presented a decrease in the hatchability results and an increase in the results of intermediary embryonic mortality. Chicks hatched from eggs injected with until to 1.0% MET were heavier and presented better development of the heart and GIT, especially important organs and regions for digestion and nutrient absorption. Conclusively, the in ovo feeding using MET showed positive impacts on hatching weight and GIT development of breeder chicks. However, caused negative impacts on hatchability when used at high levels.

Effect of IOF and its interaction with post-hatch feeding procedure on hatchability, some organs development and post-hatch performance in broiler chickens.

Under commercial conditions, chickens are fasted for the first 36 to 72h post-hatch. Delayed access to feed and water causes delayed development of the intestinal tract and retarded performance. This study focused on the chick's life as affected by in ovo feeding (IOF) and the animal's interaction with the feeding procedure. The birds in a factorial arrangement (2 × 3) were placed into six treatment groups in a completely randomised design. The treatment groups differed in feed procedure, 6h [early feeding (EF)] or 36h [common feeding (CF)] post-hatch, with or without IOF with beta-hydroxy-beta-methyl butyrate (HMB) or calcium gluconate (CG) in a saline solution, and were examined for hatchability and performance parameters until 24h post-hatch. In addition, physical and histological characteristics of breast, jejunum and serum indices in 14 days post-hatch and performance criteria until 35 days of age were recorded. On day 17 of the incubation period, eggs were subjected to the IOF procedure. One mL of sterile IOF solution including 0.1% HMB or 0.4% CG dissolved in 5% saline solution was injected into the eggs. Results showed that IOF groups had lower (p < 0.05) FCR than the control group. The highest mortality rate was noted in the control-CF group. The lowest myofibril density was related to the HMB-CF group. Myofibril periphery, area and diameter for the HMB-CF group were larger (p < 0.05) than those of the other groups. Results indicated that injection of HMB increased hatchability by almost 15%. The IOF of HMB improved the digestive tract and breast muscle development and improved FCR.

Effects of in ovo Administration of Zinc Oxide Nanoparticles and Vitamin C on Hatchability Performance and Redox Status in Day Old Kadaknath Hatchlings

Background: In poultry industry, hatcheries play a vital role in connecting the poultry production chain and are expected in the productive performance, with an impact on company profits. The use of in ovo feeding support poultry embryonic development and offers the production efficiency and welfare of commercial poultry. Methods: This study investigated the impact of in ovo administration of normal saline, Zinc oxide nanoparticles and Vitamin C on hatchability, chick growth and redox status in Kadaknath hatchlings. Zinc oxide nanostructures were synthesized by chemical method and characterized for size determination. A total of 150 fertile eggs of the Kadaknath poultry breed were divided into five groups (T0 to T4) and treated with in ovo administration of 200 μl each of normal saline, zinc oxide nanoparticles (5 and 10 ppm) and Vitamin C respectively on the 18th day of incubation through air sac into amniotic fluid. Result: Rod shaped nanostructures ranging from 45 to 98 nm were synthesized and showed sharp peak positioned at 436.59 cm-1. Zinc nano composite 5 ppm and vitamin C administration had significantly (p less than 0.05) improved hatchability, hatch weight, chick weight and egg weight ratio and antioxidant status.

The Effects of In Ovo Feeding of Selenized Glucose on Selenium Concentration and Antioxidant Capacity of Breast Muscle in Neonatal Broilers.

This study aims to investigate the impacts of in ovo feeding (IOF) of selenized glucose (SeGlu) on selenium (Se) level and antioxidant capacity of breast muscle in newborn broilers. After candling on 16day of incubation, a total of 450 eggs were randomly divided into three treatments. On the 17.5th day of incubation, eggs in a control treatment were injected with 0.1mL of physiological saline (0.75%), while the 2nd group and 3rd group were supplied with 0.1mL of physiological saline containing 10μg Se from SeGlu (SeGlu10 group) and 20μg Se from SeGlu (SeGlu20 group). The results showed that in ovo injection in both SeGlu10 and SeGlu20 increased the Se level and reduced glutathione concentration (GSH) in pectoral muscle of hatchlings (P < 0.05). Compared with the control group, the SeGlu20-treated chicks significantly enhanced the activity of the superoxide dismutase (SOD) and mRNA expression of NAD(P)H quinone dehydrogenase 1 (NQO1) in breast muscle, while there was upregulation in mRNA expressions of glutathione peroxidase 1 (GPX-1) and thioredoxin reductase 1 (TrxR1) and higher total antioxidant capacity (T-AOC) in SeGlu10 treatment (P < 0.05). However, no significant difference on enzyme activities of glutathione peroxidase (GR), glutathione reductase, thioredoxin reductase, concentration of malondialdehyde, and free radical scavenging ability (FRSA) of superoxide radical (O2-•) and hydroxyl radical (OH•) was observed among the three treatments (P > 0.05). Therefore, IOF of SeGlu enhanced Se deposition in breast muscle of neonatal broilers. In addition, in ovo injection of SeGlu could increase the antioxidant capacity of newborn chicks possibly through upregulating the mRNA expression of GPX1, TrxR1, and NQO1, as well as the SOD activity.

Developmental changes in lipid and fatty acid metabolism and the inhibition by in ovo feeding oleic acid in Muscovy duck embryogenesis.

Hepatic lipid and fatty acid (FA) metabolism are critical for regulating energetic homeostasis during embryogenesis. At present, it remains unclear how an exogenous FA intervention affects embryonic development in an avian embryo model. In Exp. 1, 30 fertilized eggs were sampled on embryonic days (E) 16, 19, 22, 25, 28, 31 and the day of hatch (DOH) to determine the critical period of lipid metabolism. In Exp. 2, a total of 120 fertilized eggs were divided into two groups (60 eggs/group) for in ovo feeding (IOF) procedures on E25. Eggs were injected into the yolk sac with PBS as the control group and with oleic acid (OA) as the IOF-OA treatment group. Samples were collected on E28 and E31. In Exp. 1, hepatic triacylglycerol (TG) and cholesterol (CHO) contents increased while serum TG content decreased from E16 to DOH (P<0.05). Both serum and liver displayed an increase in unsaturated FA and a decrease in saturated FA (P<0.05). There was a quadratic increase in the target gene and protein expression related to hepatic FA de novo synthesis and oxidation (P<0.05), whose inflection period was between E22 and E28. In Exp. 2, compared with the control embryos, IOF-OA embryos had an increased yolk sac TG content on E28 and E31, and a decreased serum TG and CHO content on E28 (P<0.05). The IOF-OA embryos had less OA in the yolk sac and liver on E28, and less unsaturated FA in the serum and liver on E31 than did the control embryos (P<0.05). Hepatic gene mRNA expression related to FA uptake, synthesis, and oxidation on E28 was lower in IOF-OA than in control embryos (P<0.05), not on E31 (P>0.05). Maximal metabolic changes in lipid and FA metabolism occurred on E22-E28 in Muscovy duck embryogenesis, along with the altered target gene and protein expression related to lipogenesis and lipolysis. IOF-OA intervention on E25 could inhibit the target gene expression related to FA uptake, synthesis, and oxidation, which may influence the normal FA metabolism on E28 during embryogenesis.

In ovo feeding of carbohydrates for broilers: A meta-analysis

The objective of this meta-analysis was to evaluate the effect of inoculating fertilized eggs with carbohydrates on the hatching and posthatching characteristics of broilers. The search for scientific articles was conducted in September 2021 in different databases using the keywords (carbohydrate OR carbohydrates OR glucose OR dextrose OR dextrin OR maltodextrin OR fructose OR maltose OR isomaltose OR isomaltulose OR sucrose OR galactose OR trehalose OR sorbitol OR mannitol OR starch OR amylose OR amylopectin) AND ("in ovo") AND (broilers OR broiler). Only articles that evaluated the effect of in ovo feeding of carbohydrates on hatching (hatchability and hatch weight) and/or posthatching (performance) parameters in broilers were used. The meta-analysis was performed using the random effects model, considering the differences between the group inoculated with carbohydrates and the placebo control. The inoculation of carbohydrates did not influence (P > 0.05) hatchability. Glucose ranging from 50 to 125 mg/egg increased (P < 0.01) hatch weight. As for the post-hatching performance, only studies with glucose were found. Glucose at 75 mg/egg increased (P < 0.01) the weight gain and decreased (P < 0.01) the feed conversion ratio, although only a single study has evaluated this dose. Inoculation of solutions between the 7th and 10th days of incubation in the albumen using deionized water as vehicle increased (P < 0.01) hatching weight and weight gain and decreased (P < 0.05) the feed conversion ratio without to affect (P > 0.05) hatchability. In conclusion, the in ovo feeding of carbohydrates can be used to improve broiler performance, with glucose at 75 mg/egg being the most appropriate carbohydrate. Deionized water should be used as a dilution vehicle, and the albumen is the recommended site for inoculation. The solutions should be inoculated between the 7th and 8th days of incubation.

Emerging in ovo technologies in poultry production and the re-discovered chicken model in preclinical research

Abstract Prenatal programming is a concept based on assumptions that the events occurring in critical points of embryonic development may pose epigenetic changes resulting from chemical rearrangements on the DNA structure. Epigenetic changes may pose life lasting phenotypic effects in the animal, or can be heritable, like gene silencing associated with methylation in gene promoters regions. The technical advancements in biotechnology, bioinformatics, molecular techniques and robotization have brought to new technological applications in poultry production. Intentional stimulation of embryonic development and determination of the future health of the hatched organism is possible by in ovo application of natural antioxidants and prebiotics, gut stabilizers like probiotics and other immunological enhancements, including vaccines. In parallel, the fine-tuned and generally accessible techniques of chicken embryo incubation along with the novel tissue engineering tools have led to focus the attention of scientists on chicken embryo as the alternative animal model for some pre-clinical approaches, in the context of reducing and replacing the experiments on animals. In this chapter, some key highlights are provided on current achievements in poultry embryonic applications, with the attention put to the emerging in ovo technologies (in ovo feeding, immunological stimulation and in ovo oncological tools), that address the societal challenges in food production and health management.