Methods for early nutrition and their potential

Supporting dataset on the content of Cu, Ni Cd, Pb, Zn, Ag, Mg, Fe, Co and Ca in the carcass, gastrointestinal tract tissues and the whole body of nestlings of a small passerine bird, the Eurasian Reed Warbler Acrocephalus scirpaceus from an intensively fertilized fishpond habitat

The dataset presented in this data paper supports "The prenatal assimilation of minerals and metals in the nestlings of a small passerine bird" (Orłowski et al. 2024) [1]. The article includes raw data on dead nestlings of a small passerine bird, the Eurasian Reed Warbler Acrocephalus scirpaceus breeding in an extensive reedbed (with dominating plant species, the Common Reed Phragmites australis) located in an intensively fertilized fishpond habitat, the Stawy Milickie [Milicz Ponds] Nature Reserve (SW Poland). The data include the description of concentrations of Cu, Ni Cd, Pb, Zn, Ag, Mg, Fe, Co and Ca measured in the isolated, emptied gastrointestinal tract, the whole body, and carcass of the each of 26 individual nestlings of a different age (1-9 days old) and hence a different stage of post-natal development. The dataset includes also some additional information on the breeding biology of the focal species.

In ovo delivery of carvacrol triggers expression of chemotactic factors, antimicrobial peptides and pro-inflammatory pathways in the yolk sac of broiler chicken embryos

BACKGROUND

Broiler chickens are most vulnerable immediately after hatching due to their immature immune systems, making them susceptible to infectious diseases. The yolk plays an important role in early immune defence by showing relevant antioxidant and passive immunity capabilities during broiler embryonic development. The immunomodulatory effects of phytogenic compound carvacrol have been widely reported. After in ovo delivery in the amniotic fluid during embryonic development carvacrol is known to migrate to the yolk sac. However, it is unknown whether carvacrol in the yolk could enhance defence responsiveness in the yolk sac. Therefore, the aim of this study was to improve early immune function in chicken embryos, and it was hypothesized that in ovo delivery of carvacrol would result in immunomodulatory effects in the yolk sac, potentially improving post-hatch resilience.

METHODS

On embryonic day (E)17.5, either a saline (control) or carvacrol solution was injected into the amniotic fluid. Yolk sac tissue samples were collected at E19.5, and transcriptomic analyses using RNA sequencing were performed, following functional enrichment analyses comparing the control (saline) and carvacrol-injected groups.

RESULTS

The results showed that 268 genes were upregulated and 174 downregulated in the carvacrol group compared to the control (P < 0.05; logFC < -0.5 or log FC > 0.5). Functional analyses of these differentially expressed genes, using KEGG, REACTOME, and Gene Ontology databases, showed enrichment of several immune-related pathways. This included the pathways 'Antimicrobial peptides' (P = 0.001) and 'Chemoattractant activity' (P = 0.004), amongst others. Moreover, the 'NOD-like receptor signaling' pathway was enriched (P = 0.002). Antimicrobial peptides are part of the innate immune defence and are amongst the molecules produced after the nucleotide oligomerization domain (NOD)-like receptor pathway activation. While these responses may be associated with an inflammatory reaction to an exogenous threat, they could also indicate that in ovo delivery of carvacrol could prepare the newly hatched chick against bacterial pathogens by potentially promoting antimicrobial peptide production through activation of NOD-like receptor signaling in the yolk sac.

CONCLUSION

In conclusion, these findings suggest that in ovo delivery of carvacrol has the potential to enhance anti-pathogenic and pro-inflammatory responses in the yolk sac via upregulation of antimicrobial peptides, and NOD-like receptor pathways.

Effects of Formula Product Injection on Hatching Parameters, Small Intestinal Development and Ileum Histology in Breeder Chicken Eggs

BACKGROUND AND OBJECTIVE

This study aimed to determine the effects of in ovo formula product injection on hatching parameters, chick quality, small intestinal development and ileum histology of breeder hen eggs.

METHODS

A total of 400 fertilised eggs were obtained from the Atak-S parent flock at 42 weeks of age for the experiment. The experiment was designed in two groups: a control group (C), in which no injection was performed, and the other group in which a solution containing formula products at concentrations of 1.25% (F1), 2.5% (F2) and 5% (F3) was injected into 0.5 mL/egg air sac. The hatching rate, embryonic mortality and discard chick rate were examined at the end of the trial.

RESULTS

The best result of the hatching rate was found in the Group F2, while there was no difference between the control and Group F1 regarding these parameters. The weight and length of the quality chicks were promoted in the Group F1. In Group F3, the injection of the formula product at a rate of 5% had a negative effect on parameters such as hatchability, embryonic mortality, chick length, Pasgar score and yolk sac weight compared to the other groups. Otherwise, in Group F2, there was a significant increase in villus height, crypt depth and lamina muscularis mucosa thickness compared to the other groups (p < 0.01).

CONCLUSIONS

As a result, it has been concluded that the appropriate rates for the formula product application on chicks are 1.25% and 2.5%, considering the positive effects of the 1.25% and 2.5% rates and the negative effects of the 5% rate.

The in ovo screening of 27 single essential oils showed selective effects on hatchability, performance and gene expression relevant to gut functions in broilers at hatch

The early post-hatching phase remains to be one of the most vulnerable phases in broiler production. Some essential oils have been reported to improve gut health and growth in broiler chickens when applied to post-hatching diets. However, in-feed applications are unable to prevent the health challenges observed immediately after hatching. Thus, pre-hatch interventions need to be considered. A research project was developed with the aim of investigating the impact of in ovo application of 27 selected essential oils (EOs) on foetal development with emphasis on gut integrity in broiler hatchlings. The eggs were incubated under standard conditions until day 17.5, when 1 mL of each EO preparation (5 µL EO + 5 µL polysorbate-80 + 990 µL saline) was injected into the amnion. Hatchability, body weight and organ weights (residual yolk, gizzard-proventriculus, intestines, liver, and heart) were measured at hatch. Five essential oils eugenol, clove, tea tree, lemongrass, and thyme, significantly (P < 0.05) reduced hatchability (66.67 %, 58.33, 83.30 and 83.30 %) compared to the saline (96.80 %), were discarded from the rest of the study. The other 22 essential oils were investigated in a second phase to assess their impact on expression of gut biomarkers including: a) jejunum integrity; b) digestive enzymes and nutrient transporters; and c) immune system. The results indicated that lemon myrtle significantly increased and oregano EO decreased body weight at hatch (BW0) compared to the saline (P < 0.05). Ylang ylang, clary sage, bergamot, lemon myrtle, and black pepper upregulated the expressions of biomarkers regulating gut integrity and barrier functions (ZO-1, ZO-2, CLDN1, MARVELD2, EGFR and EGF), nutrients transporters (EAAT3, PEPT1, I-FABP1, SGLT1), and digestive enzymes (APN, SI). Ylang ylang, turmeric acid, star anise, clary sage, and black pepper upregulated the expression of gut immunity biomarkers IL1B, IL10, IGMH, CD3D, and BU1 compared to the saline. In conclusion, in ovo delivery of selected EOs has the potential to improve embryonic development relevant to nutrient digestion and absorption, gut integrity and immunity in broilers.

Ontogeny and function of the intestinal epithelial and innate immune cells during early development of chicks: to explore in ovo immunomodulatory nutrition

Intestinal epithelial cells (IECs) and innate immune cells in the gastrointestinal tract (GIT) of chickens play crucial roles in pathogens defense and maintaining gut health. However, their effectiveness influenced with their developmental and functional stages during pre and post hatch periods of chick. During embryonic development, differentiation and migration of these innate immune systems are tightly regulated by diverse cellular and molecular factors. The maturation and functionality of IECs are histologically evident starting embryonic day (ED) 14. Moreover, the innate immun cells, such as dendritic cells (DCs), macrophages, natural killer (NK) cells, and gamma-delta (γδ) T cells have showed developmental expression varation, while most identified by the 3rd days of incubation and capable of responsing to their cognate ligands of pathogens by ED 17, it may not efficient during posthatch period. In modern poultry production, in ovo feeding of bioactive substances is a topic of interest to maximize the protection capability of hatched chicks by enhancing improvement on the development of innate immune systems. However, their actions and effects on each distinct innate immune involved response are inconsistent and not clearly understood. Thus, summarizing the ontogeny and function of IECs, innate immunity systems, and interaction mechanisms of in ovo feeding of bioactive substances could provide baseline information for designing targeted in ovo feeding interventions to modulate cell waise specific innate immune systems.

The Expressions of the Immunity- and Muscle Development-Related Genes of 40-Day-Old Broilers Are Promoted in Response to the In Ovo and Dietary Supplemental Administration of Calcidiol in Conjunction with the In Ovo Administration of Marek's Disease Vaccine

Effects of in ovo and dietary sources of calcidiol (25(OH)D3), combined with Marek's disease vaccine (MDV), on the expression of genes involved with the antioxidant activity, muscle deposition, and immunity in the pectoralis major (P. major) muscle and spleen of 40 d of age (doa) broilers were investigated. The in ovo treatments were as follows: (1) non-injected; (2) the injection of 50 μL of commercial MDV, (3) MDV + 1.2, or (4) 2.4 μg of 25(OH)D3. All birds received either a commercial diet containing no supplemental 25(OH)D3 (control) or the same diet supplemented with an additional 69 µg of 25(OH)D3 per kg of feed (Hy-D diet). At 40 doa, the pectoralis major (P. major) muscle and spleen of 48 birds (six replicates per diet x in ovo treatment combination) were collected. When compared to un-supplemented commercial diet-fed birds, in birds that were fed the Hy-D diet, the expression of the TGF-β4 gene in the spleen and P. major muscle, and the GSH-P1, GSH-P7, SOD2, MyoG, MyoD1, and Pax3 genes in the P. major muscle were up-regulated, whereas the expression of the IL-1β, IL-8, and CYP24A1 genes in the spleen and P. major muscle were down-regulated. Nevertheless, birds that received any of the in ovo injection doses of 25(OH)D3 exhibited a higher expression of the IL-10, TGF-β4, and CYP27B1 genes in the spleen and P. major muscle. Furthermore, in comparison to the MDV-injected control group, the CAT, MyoD1, and Pax3 genes in the P. major muscle were up-regulated, and the expression of the INF-γ, IL-1β and CYP24A1 genes in the spleen and the IL-8, and IL-1β genes in the P. major muscle were down-regulated. In conclusion, a significant improvement in the expression of genes responsible for enzymatic antioxidant activity, protein synthesis, and inflammatory reactions in 40-day-old broilers occurred in response to in ovo and dietary supplemental 25(OH)D3, and supplemental 25OHD3 provided via either route was used to enhance the expression of genes linked to vitamin D activity (CYP27B1, CYP24A1).

Gene ontology defines pre-post- hatch energy dynamics in the complexus muscle of broiler chickens

BACKGROUND

Chicken embryos emerge from their shell by the piercing movement of the hatching muscle. Although considered a key player during hatching, with activity that imposes a substantial metabolic demand, data are still limited. The study provides a bioenergetic and transcriptomic analyses during the pre-post-hatching period.

METHODS

Weight and morphology alongside content determination of creatine and glycogen were analysed. Transcriptome identified differentially expressed genes and enriched biological processes associated with hatching muscle development, catabolism, and energy provision. Using gene set enrichment, we followed the dynamics of gene-sets involved in energy pathways of oxidative phosphorylation, protein catabolism, glycolysis/gluconeogenesis, and glycogen metabolism.

RESULTS

Results show several significant findings: (A) Creatine plays a crucial role in the energy metabolism of the hatching muscle, with its concentration remaining stable while glycogen concentration is depleted at hatch and placement. (B) The hatching muscle has the capacity for de-novo creatine synthesis, as indicated by the expression of related genes (AGAT, GAMT). (C) Transcriptome provided insights into genes related to energy pathways under conditions of pre-hatch oxygen and post-hatch glucose limitations (oxidative phosphorylation: NDUF, MT-ND, SDH, UQCR, COX, MT-CO, ATP5, MT-ATP; glycolysis/gluconeogenesis: FBP,G6PC, PFKM; glycogen metabolism: PPP1, PYGL, GYG1). (D) The post-hatch upregulation of protein catabolic processes genes (PSMA, RNF, UBE, FBX), which align with the muscle's weight dynamics, indicates a functional shift from movement during hatching to lifting the head during feeding.

CONCLUSIONS

There is a dynamic metabolic switch in the hatching muscle during embryo-to-hatchling transition. When glycogen concentration depletes, energy supply is maintained by creatine and its de-novo synthesis. Understanding the hatching muscle's energy dynamics is crucial, for reducing hatching failures in endangered avian species, and in domesticated chickens.

Research Note: Effects of on-farm and hatchery hatching on broiler performance, intestinal lesions, and immune response during a subclinical necrotic enteritis challenge

The effects of traditional and on-farm hatching systems on broiler performance and health under a subclinical necrotic enteritis (NE) challenge were evaluated in this study. A 2×2 factorial study explored the effects of place of hatch (on-farm hatched [OFH] vs. hatchery hatched [HH]) and NE challenge (nonchallenged vs. challenged) on broilers. Cobb 500 eggs (∼E19) were acquired from a commercial hatchery; 840 eggs were placed in pens on clean shavings in prewarmed floor pens and allowed to hatch out, while 927 eggs were placed in a hatcher set under standard practices. On day (d) of hatch, all chicks were weighed and randomly distributed to 4 treatments (8 replicate pens each and 30 birds/pen). The OFH birds were placed immediately after sorting while HH birds were placed back in the hatcher overnight to simulate commercial hatchery procedures. After placing HH birds, feed and litter in the challenge group pens were sprayed with a live oocyst coccidia vaccine as a predisposing factor to NE. The small intestines of 3 male chicks per pen were scored for NE lesions (n = 24) on d 8 (peak NE challenge) and jejunal samples were collected from 1 bird per pen for RNA extraction and qPCR on d 8 and d 14. Data were analyzed using JMP Pro17 and significance between treatments was identified by LSD (P ≤ 0.05). Regardless of the hatching system, the subclinical NE challenge caused a significant reduction in average daily gain (ADG) and average daily feed intake (ADFI), and increased feed conversion ratio (FCR) until d 28 (P ≤ 0.05). Moreover, OFH birds exhibited significantly better growth (P ≤ 0.05) through d 28 but had similar performance to HH birds by d 42. There were no significant differences in NE lesion scores between HH and OFH groups. In conclusion, OFH system resulted in better broiler performance compared to HH system under both no-challenge and challenge conditions during the starter and grower periods. This practice may hold potential for further exploration by the industry as an alternative to traditional hatching, aiming to improve the welfare and productivity of broilers.

The prenatal assimilation of minerals and metals in nestlings of a small passerine bird

Although certain metals can reach their highest concentrations in tissues of newly hatched nestlings, their sources have yet to be fully elucidated. Evidence for the differentiation of body reserves, including some chemical elements, during avian embryonic life and early post-hatching period is limited mostly to studies on poultry. Here, we present novel findings on the bioaccumulation and egg-to-nestling transfer of 10 minerals and metals, including non-essential potentially toxic chemical elements (Cu, Ni Cd, Pb, Zn, Ag, Mg, Fe, Co and Ca) in the tissues of the gastrointestinal tract (GT), whole body (WB) and carcass (CA) of nestlings of a small passerine bird, the Eurasian Reed Warbler Acrocephalus scirpaceus, breeding in an intensively fertilized fishpond habitat. Our findings show that concentrations of metals that are relevant to contaminated systems (Cu, Ni, Cd, Pb, Zn, Fe and Co) are the highest in GT tissues across all the nestling age classes examined (from hatching to day 9 of life). The important question emerged from our findings: why the hatchlings were characterized by higher metal concentrations in GT, WB and CA compared to older nestlings. We suggest that the prenatal accumulation of chemical elements assimilated from egg contents, and their subsequent utilization for building various tissues/internal organs by the growing embryo, is a reasonable explanation for this finding. More specifically, the potential functional mechanism explaining the highest concentrations of some trace metals in hatchlings seems to be associated with an extremely high rate of utilization of residual yolk metal resources that survived from the embryonic until the post-natal period. On the basis of our own work and literature data, we identified a presumable significant discrepancy in the actual rate of egg-to-nestling and egg-to-embryo metal transfer due to the eggshell being ignored (a commonly occurrence), and only the egg contents being treated as the basic repository of chemical elements for developing embryos. Much more research is needed on the prenatal assimilation and subsequent accumulation of chemical elements in a developing avian embryo, representing both the transition from near-to-hatching embryos to hatchlings, and then to older nestlings.

Effects of surface sterilization of fertile eggs on the yolk microbiota during the chicken embryo development

Surface sterilization of the fertile eggs is a common process for commercial broiler breeding to avoid pathogenic bacterial infections before incubation. However, it is also possible to remove the beneficial microbes that might contribute to the development of chicken embryos. Thus, we established a model to mimic surface sterilization in the laboratory by rubbing fertile eggs with 70% ethanol and investigated the effect of eggshell surface sterilization on the yolk microbiota and its potential role in chicken (Gallus gallus) embryo development. In total, 460 Ross 308 fertile eggs were randomly divided equally into the eggshell surface sterilized group (CS, commercial egg sterilization group) and the eggshell surface unsterilized group (CC, commercial egg control group). The shell surface of group CS was sterilized with 70% alcohol before incubation (E0, embryonic stage), while that of group CC was not sterilized before incubation. At each sampling day (E0, E07, E15, and E21), 24 fertile eggs from each of the two groups were randomly selected to collect the yolk samples and weigh the embryos. The results showed that the surface sterilization of eggshells before incubation improved the development of chicken embryos from E15 to E21 but reduced the diversity of the yolk microbiota. In the whole process of embryogenesis, the relative abundance of Firmicutes, Bacteroidetes, and Actinobacteria in the egg yolk of group CS was lower than that of group CC before incubation. Indeed, the surface sterilization of fertile eggs significantly reduced the relative abundance of Staphylococcus saprophyticus and other pathogenic bacteria in the yolk, which may result in the better development of chicken embryos.

Benefit and potential risk: Effects of in ovo copper oxide nanoparticles supplementation on hatchability traits, organ weights and histological features of newly hatched chicks

This investigation was directed to examine the influence of copper oxide nanoparticles (CuO-NPs) on the hatchability traits, and chick quality of newly hatched broiler chicks. A total of 480 eggs were randomly divided into four treatment groups, each consisting of three duplicates. As a negative control (NC), the first group was not injected; the second group was injected with saline and served as a positive control (PC), the third and fourth groups were injected with 30 and 60 ppm of (CuO-NPs)/egg. Eggs were injected into the amniotic fluid on the eighteenth day of the incubation period. Results showed that the hatchability, chick yield %, yolk free-body mass (YFBM), chick length, shank length (SL), and relative weight of the heart, gizzard and intestine of day-old broiler chicks were all unaffected by the in ovo injection of CuO-NPs. The Pasgar Score was slightly improved compared to the NC and PC groups. Also, the in ovo administration of CuO-NPs (60 ppm/egg) significantly increased the intestine length. Both levels of CuO-NPs significantly increased the concentration of Cu ions in the hepatic tissue. Additionally, different levels of tissue damage were seen in the liver of the birds that were given low or high dosages of CuO-NPs. Conclusively, the in ovo injection of CuO-NPs has a good result on the appearance of the chicks (Pasgar score). However, negative effect of CuO-NPs on liver tissue may raise concerns about the potential risks of applying CuO-NPs in ovo administration.

Neonatal α-Ketoglutaric Acid Gavage May Potentially Alleviate Acute Heat Stress by Modulating Hepatic Heat Shock Protein 90 and Improving Blood Antioxidant Status of Broilers

This study investigated the effect of neonatal α-ketoglutaric acid (AKG) gavage feeding on broilers. The first experiment was conducted to determine the effect of AKG on day-old broilers. A total of seventy-two-day-old Ross 308 broiler chicks were divided into four treatment groups: (i) Two groups of chicks with gavage feeding of 0.6 mL of distilled water (DDW) for four consecutive days (CON); (ii) chicks fed with 0.6 mL of 0.1% AKG dissolved in DDW on the day of hatch (AL) followed by 0.2%, 0.3%, and 0.4% for three consecutive days; and (iii) chicks fed with 0.6 mL of 0.2% AKG dissolved in DDW on the day of hatch (AH) followed by 0.4%, 0.6%, and 0.8% for three consecutive days. Twenty-four hours after the first gavage feeding, six birds per treatment were slaughtered to study the organ development. Chicks fed with AKG showed higher absolute (p = 0.015) and relative (p = 0.037) weights of the gizzard. The AH group had higher absolute (p = 0.012) and relative (p = 0.035) heart weights. The second experiment was carried out to determine the effect of AKG on 15-day-old broilers under acute heat stress (AHS) for 3.5 h at 33 ± 1 °C. Forty-eight birds (12 per treatment) were raised until 15 days of age, divided into four treatments with equal numbers (n = 12), and given one of the following four treatments: (i) CON group reared at standard temperature (25 ± 1 °C) (CON-NT); (ii) CON group subjected to AHS (33 ± 1 °C) for 3.5 h (CON-HT); (iii) AL group subjected to AHS (33 ± 1 °C) for 3.5 h (AL-HT); and (iv) AH group subjected to AHS (33 ± 1 °C) for 3.5 h (AH-HT). There was a significant reduction in the change in BW (ΔBW, p = 0.005), an increase in the final rectal temperature (RTf) (p = 0.001), and a decreased final body weight (BWf) for all the treatments under AHS. Further, AHS led to an increased expression of hepatic heat shock protein (HSP)70 (p = 0.009), nicotinamide adenine dinucleotide phosphate hydrogen oxidase (NOX)1 (p = 0.006), and NOX4 (p = 0.001), while nuclear factor erythroid 2-related factor (NRF2), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase 1 (GPX1) remained significantly unaffected. Hepatic expression of HSP90 decreased in the AL-HT treatment as compared to CON-HT (p = 0.008). Plasma antioxidant status measured by malondialdehyde (MDA) concentration and antioxidant balance (AB) improved linearly (p = 0.001) as the concentration of AKG increased. Neonatal gavage feeding of AKG could potentially alleviate heat stress in broilers by enhancing plasma antioxidant levels and modulating HSP90 expression in the liver.

The effect of methionine and folic acid administered in ovo on the blood biochemical parameters of chickens (Gallus gallus domesticus)

Methionine is one of the most frequently supplemented amino acids in raising of poultry. However, an overdose of methionine can cause hyperhomocysteinemia. Folic acid, taking part in the process of homocysteine remethylation, is a factor affecting the reduction of the concentration of this amino acid. The study was carried out in 2 stages. The experiment of step I was to investigate the effect of methionine and/or folic acid administration in ovo in the early stage of embryogenesis (E4), and the experiment of the second stage - in the late stage of embryogenesis (E17) on the following biochemical parameters of chicken blood: glucose concentration in whole blood and concentration of homocysteine and uric acid in plasma of domestic chickens (Gallus gallus domesticus). Our results confirm that methionine supplementation may increase the concentration of uric acid and homocysteine. Moreover, we demonstrated that folic acid administered during embryogenesis decreased homocysteine concentration, also in groups simultaneously supplemented with methionine, especially in the initial stage of postnatal life of the bird.

Significance of successive feeding of sources of n-3 fatty acids to broiler breeders and their progeny on growth performance, intestinal lesion scores, lymphoid organs weight and plasma immunoglobulin A in broiler chickens challenged with Eimeria

The study examined the effects of successive feeding of sources of n-3 PUFA to broiler breeders (BB) and their progeny in broiler chickens challenged with Eimeria. The BB were fed: 1) control (CON), corn-soybean meal diet, 2) CON + 1 % microalgae (DMA), as a source of DHA and 3) CON + 2.50% co-extruded full fat flaxseed (FFF), as a source of ALA. Eggs were hatched at 34, 44, and 54 wk of age. Posthatch treatments (BB-progeny) were: CON-CON, DMA-CON, FFF-CON, DMA-DMA and FFF-FFF with diets formulated for starter (d 1-10) and grower/finisher (d 11-42) phases. All chicks were orally challenged with Eimeria (E. acervulina and E. maxima) on d 10. Relative to CON, DMA and FFF increased concentration of n-3 PUFA by ≥ 2-fold in hatching eggs and progeny diets. There were no (P > 0.05) interactions between treatment and BB age on d 0 to 10 growth. In general, BB age affected (P < 0.05) growth performance throughout the study. In the starter phase, successive exposure to DHA and ALA improved FCR over CON-CON (P < 0.01). The interaction between treatment and BB age in grower/finisher was such that DHA exposure to younger BB resulted in poor growth performance (P < 0.05) relative to exposure to older BB. In contrast, exposure to ALA had similar (P > 0.05) growth performance irrespective of BB age. Moreover, successive exposure to ALA resulted in higher BWG, breast weight and lower FCR compared to successive exposure to DHA (P < 0.05). There were no (P > 0.05) interactions between treatment and BB age on the intestinal lesion scores, lymphoid organ weights and concentration of plasma immunoglobulin A (IgA). Successive exposure to DHA resulted in higher (P = 0.006) jejunal lesion scores than CON-CON birds. The results showed that successive exposure of DHA and ALA improved FCR relative to non-exposed birds in the starter phase. However, responses in the grower/finisher phase depended on n-3 PUFA type, with birds on successive ALA exposure supporting better growth and breast yield than birds on successive DHA exposure.

In ovo probiotic supplementation supports hatchability and improves hatchling quality in broilers

In modern broilers, the period of embryonic development constitutes a greater proportion of a broiler's productive life. Hence, optimum embryonic development can exert a significant influence not only on chick hatchability and hatchling quality but also on overall broiler growth and performance. Further healthy and active hatchlings are correlated with improved posthatch performance. In this regard, probiotics are good candidates to mediate early-life programming. Therefore, we evaluated the effect of In ovo probiotic spray application on broiler hatchability and hatchling quality. The experiment was set out as a completely randomized study with 2 independent trials. In each trial, 540 eggs (Ross 308) were either sprayed with phosphate buffered saline (PBS; control) or probiotics [∼9 log CFU/egg of Lactobacillus rhamnosus NRRL B-442(LR) or Lactobacillus paracasei DUP 13076 (LP)] during incubation. On day 18, eggs were transferred to the hatcher and set up for hatching. Starting on day 19, eggs were observed for hatching to determine the spread of hatch and hatchability. Hatched chicks were then assessed for quality using the Tona and Pasgar score and morphometric measurements including hatchling weight, yolk-free-body-mass and hatchling length were measured. Further, chicks were reared in floor pens for 3 wk to assess posthatch growth. Overall, In ovo probiotic supplementation improved hatchability and hatchling quality. Specifically, the spray application of LP improved hatchability by ∼ 5% without affecting the spread of hatch. Further, both LR and LP significantly improved Pasgar and Tona score, indicating an improvement in hatchling quality. Also, LP and LR significantly improved hatchling weight, yolk-free-body-mass, and posthatch growth in chicks. LR significantly improved hatchling weight and hatchling length (P < 0.05). Moreover, this increase in posthatch growth was positively correlated with hatchling weight in the probiotic groups. Overall, our study demonstrates that In ovo probiotic application exerts a positive effect on hatchability, hatchling quality, and subsequent posthatch growth.

ß-Hydroxy-ß-methylbutyrate: A feed supplement influencing performance, bone metabolism, intestinal morphology, and muscle quality of laying hens: a preliminary one-point study

Laying hens, selectively bred for high egg production, often suffer from bone fragility and fractures, impacting their welfare and causing economic losses. Additionally, gut health and muscle quality are crucial for overall health and productivity. This study aimed to evaluate the effects of ß-Hydroxy-ß-methylbutyrate (HMB) supplementation on performance, bone metabolism, intestinal morphology, and muscle quality in laying hens. Forty-eight Bovans Brown hens were divided into a control group and an HMB-supplemented group (0.02% HMB in diet). The study spanned from the 31st to the 60th wk of age. Assessments included bone mechanical testing, serum hormonal analysis, histological analysis of bone and intestine, and muscle quality analysis. The HMB supplementation led to decreased feed intake without affecting body weight or laying rate in laying hens. It caused an increase in both mean daily and total egg weight, indicating improved feed utilization, without influencing the feed intake to egg weight ratio. Enhanced bone formation markers and altered intestinal morphometric parameters were observed, along with improved trabecular bone structure. However, no changes in measured other bone quality indices, including geometric, densitometric, or mechanical properties were observed. Muscle analysis revealed no significant changes in overall meat quality, except for a decrease in cholesterol content and alterations in the fatty acid profile, notably a reduction in total n-3 polyunsaturated and total polyunsaturated fatty acids (PUFA). In conclusion, although not all effects of HMB supplementation were unequivocally beneficial, the positive changes in performance data and trabecular bone microarchitecture support further research into various doses and durations of supplementation. Such studies are necessary to fully understand and optimize the benefits of HMB for enhancing the health and productivity of laying hens.

Effects of the Marek's Disease Vaccine on the Performance, Meat Yield, and Incidence of Woody Breast Myopathy in Ross 708 Broilers When Administered Alone or in Conjunction with In ovo and Dietary Supplemental 25-Hydroxycholecalciferol

The effects of the Marek's disease vaccine (MDV) on the live performance, breast meat yield, and incidence of woody breast myopathy (WBM) of Ross 708 broilers were investigated when administered alone or in conjunction with in ovo and dietary supplemental 25-hydroxycholecalciferol (25OHD3). At 18 d of incubation (doi), four in ovo injection treatments were randomly assigned to live embryonated Ross 708 broiler hatching eggs: (1) non-injected; (2) commercial MDV alone; or MDV containing either (3) 1.2 or (4) 2.4 μg of 25OHD3. An Inovoject multi-egg injector was used to inject a 50 μL solution volume into each egg. The birds were provided a commercial diet that contained 250 IU of cholecalciferol/kg of feed (control) or a commercial diet that was supplemented with an additional 2760 IU of 25OHD3/kg of feed (HyD-diet). In the growout period, 14 male broilers were placed in each of 48 floor pens resulting 6 replicated pens per in ovo x dietary treatment combination. Live performance variable were measured at each dietary phases from 0 to 14, 15 to 28, and 29 to 40 d of age (doa). At 14 and 40 doa, pectoralis major (P. major) and pectoralis minor (P. minor) muscles were determined for one bird within each of the six replicate pens. At 41 doa, WBM incidence was determined. No significant main or interaction effects occurred for WBM among the dietary or in ovo injection treatments. However, in response to in ovo 25OHD3 supplementation, BW and BWG in the 29 to 40 doa period and BWG and FCR in the 0 to 40 doa period improved. In addition, at 40 and 41 doa, breast meat yield increased in response to in ovo and dietary 25OHD3 supplementation. Future research is needed to determine the possible reasons that may have been involved in the aforementioned improvements.

Carvacrol in ovo delivery optimization and flow dynamics in broiler chicken eggs

In ovo delivery of carvacrol, the primary active compound in oregano essential oil (OEO) has the potential to enhance gut development in broilers. This study aimed to optimize in ovo application of OEO by investigating day and site of injection and delivery of carvacrol to different embryonic tissues. In Experiment 1, 2 d of injection (embryonic day (E) 12 or 17.5) and 3 sites of injection for OEO (air cell, amniotic fluid, or yolk) were evaluated based on hatchability and posthatching performance. Experiment 2 aimed to examine the impact of combining OEO with the nonionic surfactant polysorbate 80 (p80) at ratios to carvacrol of 0:0, 0:1, 0.5:1, and 1:1 on carvacrol concentration in amniotic fluid, blood, and yolk. The concentration of carvacrol was measured at 3, 6, and 9 h after OEO injection either without (0:1) or with (1:1) p80. Injection of OEO on E12 led to a significant lower hatchability compared to E17.5 (P ≤ 0.01; Δ = 9.2%). Injecting OEO into the air cell, amniotic fluid, or yolk at E17.5 did not significantly affect hatchability and posthatching performance. The highest concentrations of carvacrol found in egg tissues were observed when injected together with surfactant at the 1:1 ratio (P ≤ 0.001; 14.45 µM, 16.64 µM, and 124.82 µM, for air cell, amniotic fluid, and yolk, respectively) compared to the 0:0, 0:1 or 0.5:1 ratios. Carvacrol was highest in the amniotic fluid and blood at the first time point (3 h postinjection) and decreased afterward (P ≤ 0.001), whereas the concentration in yolk remained elevated up to 9 h postinjection. In conclusion, the optimization of the in ovo delivery of carvacrol resulted in that early injection (E12) had negative effects on hatchability and should be avoided. The findings also suggest that using a nonionic surfactant was crucial for an effective delivery of carvacrol in ovo and the migration from amniotic fluid to yolk within 3 h. In addition, carvacrol's persistence in yolk may serve as a route for delivery into the gastrointestinal tract via the yolk stalk during the peri-hatching phase, potentially influencing gut 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.

In-ovo feeding with creatine monohydrate: implications for chicken energy reserves and breast muscle development during the pre-post hatching period

The most dynamic period throughout the lifespan of broiler chickens is the pre-post-hatching period, entailing profound effects on their energy status, survival rate, body weight, and muscle growth. Given the significance of this pivotal period, we evaluated the effect of in-ovo feeding (IOF) with creatine monohydrate on late-term embryos' and hatchlings' energy reserves and post-hatch breast muscle development. The results demonstrate that IOF with creatine elevates the levels of high-energy-value molecules (creatine and glycogen) in the liver, breast muscle and yolk sac tissues 48 h post IOF, on embryonic day 19 (p < 0.03). Despite this evidence, using a novel automated image analysis tool on day 14 post-hatch, we found a significantly higher number of myofibers with lower diameter and area in the IOF creatine group compared to the control and IOF NaCl groups (p < 0.004). Gene expression analysis, at hatch, revealed that IOF creatine group had significantly higher expression levels of myogenin (MYOG) and insulin-like growth factor 1 (IGF1), related to differentiation of myogenic cells (p < 0.01), and lower expression of myogenic differentiation protein 1 (MyoD), related to their proliferation (p < 0.04). These results imply a possible effect of IOF with creatine on breast muscle development through differential expression of genes involved in myogenic proliferation and differentiation. The findings provide valuable insights into the potential of pre-hatch enrichment with creatine in modulating post-hatch muscle growth and development.

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 16 day 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 0.1 mL of physiological saline (0.75%), while the 2nd group and 3rd group were supplied with 0.1 mL of physiological saline containing 10 μg Se from SeGlu (SeGlu10 group) and 20 μg 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.

In ovo feeding of creatine monohydrate increases performances of hatching and development in breeder chicks

The current investigation was conducted to test the potential effects of in ovo feeding of creatine monohydrate (CMH) on hatchability, embryonic mortality, hatching weight, and development of heart and gastrointestinal tract (main organs and regions) of breeder chick embryos. Rhode Island Red fertile eggs were randomly distributed into seven experimental treatments: untreated egg (control), a sterile buffered solution (0.50% NaCl), and five solutions containing increased levels of CMH (0.50, 1.00, 1.50, and 2.00%) + 0.50% NaCl, being separated in four groups/replicates (three with 15 eggs and one with 16 eggs), totaling 61 eggs/treatment and a total of 427 fertile eggs used. All-in ovo injected groups with CMH decreased the hatchability and increased the intermediary embryonic mortality. At hatching, all-in ovo injected groups with CMH also increased the hatching weight and stimulated the development of the heart and the total length of the gastrointestinal tract, especially important organs for digestion of nutrients (yolk sac, pro-ventricle and gizzard) and regions for nutrient absorption (jejunum + ileum and colon + rectum). Conclusively, the in ovo feeding using CMH showed positive impacts on hatching weight and the development of gastrointestinal tract of chicks. However, caused negative impacts on hatchability.

Factors influencing the development of gastrointestinal tract and nutrient transporters' function during the embryonic life of chickens-A review

Intestinal morphology and regulation of nutrient transportation genes during the embryonic and early life of chicks influence their body weight and feed conversion ratio through the growing period. The intestine development can be monitored by measuring villus morphology and enzymatic activity and determining the expression of nutrient transporters genes. With the increasing importance of gut development and health in broiler production, considerable research has been directed towards factors affecting intestine development. Thus, this article reviews (1) intestinal development during embryogenesis, and (2) maternal factors, in ovo administration, and incubation conditions that influence intestinal development during embryogenesis. Conclusively, (1) chicks from heavier eggs may have a better-developed intestine than chicks from younger ones, (2) in ovo supplementation with amino acids, minerals, vitamins or a combination of several probiotics and prebiotics stimulates intestine development and increases the expression of intestine mucosal-related genes and (3) the long storage period, improper incubation temperature and imbalanced ventilation can negatively influence intestinal morphology and nutrient transporters gene expression. Finally, understanding the intestine development during embryonic life will enable us to enhance the productivity of broilers.

Potential Implication of in ovo Feeding of Phytogenics in Poultry Production

Hatchery's goals include maximizing revenue by achieving high hatchability with day-old birds of excellent quality. The advancement of technology has benefited the poultry sector since breeding and genetics technology have increased the rates of meat maturation in developing birds in a short period of time. Excessive use of in-feed antibiotics has been shown in studies to increase the chance of resistance to human infections. Bacterial resistance and antibiotic residues in animal products raised concerns about using antibiotics as growth promoters, eventually leading to a prohibition on using in-feed antibiotics in most industrialized nations. In ovo technology is a novel method for delivering bioactive chemicals to developing avian embryos. In ovo feeding technologies may provide additional nutrients to the embryos before hatching. The introduction of bioactive compounds has the potential to assist in decreasing and eventually eliminating the problems associated with traditional antibiotic delivery in chicken production. Phytobiotics were advocated as an alternative by researchers and dietitians. So far, several studies have been conducted on the use of phytogenic feed additives in poultry and swine feeding. They have primarily demonstrated that phytobiotics possess antibacterial, antioxidant, anti-inflammatory, and growth-stimulating properties. The antioxidant effect of phytobiotics can improve the stability of animal feed and increase the quality and storage duration of animal products. In general, the existing documentation indicates that phytobiotics improve poultry performance. To effectively and efficiently use the in ovo technique in poultry production and advance research in this area, it is important to have a thorough understanding of its potential as a means of nutrient delivery during the critical stage of incubation, its effects on hatching events and posthatch performance, and the challenges associated with its use. Overall, this review suggests that in ovo feeding of phytobiotics has the potential to improve the antioxidant status and performance of chickens.

Notch mediates the glycolytic switch via PI3K/Akt signaling to support embryonic development

BACKGROUND

Energy metabolism disorder or insufficient energy supply during incubation will affect the development and survival of avian embryos. Especially, β-oxidation could not provide the continuous necessary energy for avian embryonic development due to the increasing energy demand under hypoxic conditions during the mid-late embryonic stages. The role and mechanism of hypoxic glycolysis replacing β-oxidation as the main source of energy supply for avian embryonic development in the mid-late stages is unclear.

RESULTS

Here, we found that in ovo injection with glycolysis inhibitor or γ-secretase inhibitor both decreased the hepatic glycolysis level and impaired goose embryonic development. Intriguingly, the blockade of Notch signaling is also accompanied by the inhibition of PI3K/Akt signaling in the embryonic primary hepatocytes and embryonic liver. Notably, the decreased glycolysis and impaired embryonic growth induced by the blockade of Notch signaling were restored by activation of PI3K/Akt signaling.

CONCLUSIONS

Notch signaling regulates a key glycolytic switch in a PI3K/Akt-dependent manner to supply energy for avian embryonic growth. Our study is the first to demonstrate the role of Notch signaling-induced glycolytic switching in embryonic development, and presents new insight into the energy supply patterns in embryogenesis under hypoxic conditions. In addition, it may also provide a natural hypoxia model for developmental biology studies such as immunology, genetics, virology, cancer, etc.

Slow and Fast-Growing Chickens Use Different Antioxidant Pathways to Maintain Their Redox Balance during Postnatal Growth

The evolution of parameters known to be relevant indicators of energy status, oxidative stress, and antioxidant defense in chickens was followed. These parameters were measured weekly from 1 to 42 days in plasma and/or muscles and liver of two strains differing in growth rate. At 1-day old, in plasma, slow-growing (SG) chicks were characterized by a high total antioxidant status (TAS), probably related to higher superoxide dismutase (SOD) activity and uric acid levels compared to fast-growing (FG) chicks whereas the lipid peroxidation levels were higher in the liver and muscles of SG day-old chicks. Irrespective of the genotype, the plasma glutathione reductase (GR) and peroxidase (GPx) activities and levels of hydroperoxides and α- and γ-tocopherols decreased rapidly post-hatch. In the muscles, lipid peroxidation also decreased rapidly after hatching as well as catalase, GR, and GPx activities, while the SOD activity increased. In the liver, the TAS was relatively stable the first week after hatching while the value of thio-barbituric acid reactive substances (TBARS) and GR activity increased and GPx and catalase activities decreased. Our study revealed the strain specificities regarding the antioxidant systems used to maintain their redox balance over the life course. Nevertheless, the age had a much higher impact than strain on the antioxidant ability of the chickens.

Physiological effects of in ovo delivery of bioactive substances in broiler chickens

The poultry industry has improved genetics, nutrition, and management practices, resulting in fast-growing chickens; however, disturbances during embryonic development may affect the entire production cycle and cause irreversible losses to broiler chicken producers. The most crucial time in the chicks' development appears to be the perinatal period, which encompasses the last few days of pre-hatch and the first few days of post-hatch. During this critical period, intestinal development occurs rapidly, and the chicks undergo a metabolic and physiological shift from the utilization of egg nutrients to exogenous feed. However, the nutrient reserve of the egg yolk may not be enough to sustain the late stage of embryonic development and provide energy for the hatching process. In addition, modern hatchery practices cause a delay in access to feed immediately post-hatch, and this can potentially affect the intestinal microbiome, health, development, and growth of the chickens. Development of the in ovo technology allowing for the delivery of bioactive substances into chicken embryos during their development represents a way to accommodate the perinatal period, late embryo development, and post-hatch growth. Many bioactive substances have been delivered through the in ovo technology, including carbohydrates, amino acids, hormones, prebiotics, probiotics and synbiotics, antibodies, immunostimulants, minerals, and microorganisms with a variety of physiological effects. In this review, we focused on the physiological effects of the in ovo delivery of these substances, including their effects on embryo development, gastrointestinal tract function and health, nutrient digestion, immune system development and function, bone development, overall growth performance, muscle development and meat quality, gastrointestinal tract microbiota development, heat stress response, pathogens exclusion, and birds metabolism, as well as transcriptome and proteome. We believe that this method is widely underestimated and underused by the poultry industry.

The effects of in ovo injected with sodium borate on hatching performance and small intestine morphology in broiler chicks

The objective of this study was to investigate the effects of in ovo injection of sodium borate on hatching power, chick weight, chick length in fertile broiler eggs. A total of 256 fertile broiler eggs were incubated in the study. On Day 18 of incubation, two groups were injected with 0.1 mL of 0.5 mg and 1 mg of sodium borate dissolved in saline, and two groups were used as sham control (injected with 0.1 mL of saline) and uninjected control. Hatching power was apparently increased (P ≤ 0.05) by in ovo injection of sodium borate (0.5 mg) rather than control groups and sodium borate (1 mg) group. While there was no significant difference between the groups in terms of chick weights, a significant difference was found between group B and other experimental groups in terms of chick length (P < 0.05). In ovo sodium borate injection (0.5 mg) had a positive effect on villus length, crypt width, villus absorption surface (HASA), and the number of proliferating cell nuclear antigen positive crypt cells.

Supply and demand of creatine and glycogen in broiler chicken embryos

Optimal embryonic development and growth of meat-type chickens (broilers) rely on incubation conditions (oxygen, heat, and humidity), on nutrients and on energy resources within the egg. Throughout incubation and according to the embryo's energy balance, the main energy storage molecules (creatine and glycogen) are continuously utilized and synthesized, mainly in the embryonic liver, breast muscle, and the extraembryonic yolk sac (YS) tissue. During the last phase of incubation, as the embryo nears hatching, dynamic changes in energy metabolism occur. These changes may affect embryonic survival, hatchlings' uniformity, quality and post hatch performance of broilers, hence, being of great importance to poultry production. Here, we followed the dynamics of creatine and glycogen from embryonic day (E) 11 until hatch and up to chick placement at the farm. We showed that creatine is stored mainly in the breast muscle while glycogen is stored mainly in the YS tissue. Analysis of creatine synthesis genes revealed their expression in the liver, kidney, YS tissue and in the breast muscle, suggesting a full synthesis capacity in these tissues. Expression analysis of genes involved in gluconeogenesis, glycogenesis, and glycogenolysis, revealed that glycogen metabolism is most active in the liver. Nevertheless, due to the relatively large size of the breast muscle and YS tissue, their contribution to glycogen metabolism in embryos is valuable. Towards hatch, post E19, creatine levels in all tissues increased while glycogen levels dramatically decreased and reached low levels at hatch and at chick placement. This proves the utmost importance of creatine in energy supply to late-term embryos and hatchlings.

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.

Early Post-Hatch Nutrition Influences Performance and Muscle Growth in Broiler Chickens

The poultry industry is under pressure to produce safe and good quality meat in the welfare conditions. Many areas such as genetics, biosecurity, and immunoprophylaxis were improved, and hatchery is one of the areas in which welfare could be improved for better production output. The aim of the study was to investigate the effect of early post-hatch nutrition providing body weight and muscle development in broiler chickens. The experiment involving two groups (chicken hatched with access to water and feed in the hatcher, and chicken without feed and water in hatcher) was replicated three times, and the body weights and breast-muscle index of the randomly chosen 30 chickens per group in each term were measured on the 1st, 7th, 21st, and 35th day of life. The breast-muscle sample was taken for genetic examination (the expression of the myoD, myoG, and MRF4 genes) and histological examination. The results showed that the positive effect of early nutrition was observed on the seventh day of bird life with higher expression of myoG and MRF4 and higher body weight of the birds. The positive effect of early nutrition on the diameter of the breast-muscle fibers was visible on days 21 and 35 of chicken life. The average final body weight in groups with early access to food and water was 5% higher than in groups hatched under classic conditions. Conclusions: early feeding in the hatcher improves performance and muscle growth in broiler chickens.

Effect of In Ovo Vitamin C Injection against Mobile Phone Radiation on Post-Hatch Performance of Broiler Chicks

This study aimed to investigate the effect of in ovo injection of vitamin C to reduce the harmful effects of electromagnetic waves (EMWs) emitted from mobile phones on chicken embryos. In this study, a total of 750 fertilized eggs of Ross 308 were exposed to EMWs for 1050 min during the incubation period. On the 17th day of incubation, the eggs were divided into three groups and solutions were injected into the amnion sac of embryos. The chicks were housed separately in accordance with in ovo treatments for 5 wk after hatching. An in ovo vitamin C injection resulted in a lower hatching weight. The post-hatch mortality or production efficiency factor of birds in the in ovo vitamin C injection group and the intact egg group were comparable, and were better than that of the other negative control group. In ovo vitamin C injection in eggs subjected to EMWs significantly increased their body weight gain, carcass weight, abdominal fat weight, and AST levels, but reduced spleen weight and PON-1 levels. In conclusion, an in ovo vitamin C injection in eggs subject to mobile phone EMWs improved the post-hatch performance of chicks, but low PON and high AST activities indicate an increase in oxidative damage among broiler chicks.

Evaluation of in ovo feeding of low or high mixtures of cysteine and lysine on performance, intestinal morphology and physiological responses of thermal-challenged broiler embryos

The objective of this study was to evaluate the effect of in ovo feeding cysteine, lysine or their combinations on the perinatal and post-hatch physiological responses of broiler embryos exposed to heat stress during incubation. A total of two thousand fertile eggs of broiler breeders (Ross 308) flock (at 38 weeks of age) were used for this study. In the first 10 days, the eggs were incubated using the conventional protocol of relative humidity and temperature of 55% and 37.8°C respectively. From day ten onward, the temperature was increased to 39.6°C for 6 h per day. On day 17.5, 1,500 eggs with the evidence of living embryos were randomly selected and assigned to 6 treatments having five replicates of 50 eggs each. The treatments were: un-injected eggs (UI), eggs injected with only 0.5 ml distilled water (DW), 3.5 mg/egg cysteine (CY), 2mg/egg lysine (LY), 3.4 mg cysteine+2 mg lysine (CLH) and 1.7 mg cysteine+1 mg lysine (CLL). On day 21, the hatchability, anatomical characteristics, chick quality and the antioxidant status of the chicks were evaluated. During the post-hatch phase, data were collected on the haematology, biochemical parameters, growth performance and intestinal morphology of the birds. The results revealed that the hatchability of CY chicks was higher (p &lt; 0.05) than in the other treatments, while the lowest values were recorded in CLH. The hatching muscle of the chicks of CLL was similar to those of CY but higher (p &lt; 0.05) than the others. The MDA of DW and UI chickens was similar and higher than birds in the other treatment groups. The serum SOD of CLL birds was comparable to that of CY but higher than the values recorded in the other treatments. The final weights of CLL chickens were similar to those of LY but significantly higher (p &lt; 0.05) than those of the other treatments. The duodenal villus heights of the birds of CLL were higher than those of the other treatment groups, whereas the villus height of the birds of CLH was higher than those of UI, DW and CY. Overall, in ovo feeding of cysteine alone improved the hatchability of thermally-challenged broiler embryos. In contrast, a low-dose mixture of cysteine plus lysine improved the post-hatch growth performance.

Intestinal microbiota of layer hens and its association with egg quality and safety

The intestinal microbiota has attracted tremendous attention in the field of the poultry industry due to its critical role in the modulation of nutrient utilization, immune system, and consequently the improvement of the host health and production performance. Accumulating evidence implies intestinal microbiota of laying hens is a potential mediator to improve the prevalent issues in terms of egg quality decline in the late phase of laying production. However, the regulatory effect of intestinal microbiota on egg quality in laying hens remains elusive, which requires consideration of microbial baseline composition and succession during their long lifespans. Notable, although Firmicutes, Bacteroidetes, and Proteobacteria form the vast majority of intestinal microbiota in layer hens, dynamic intestinal microbiota succession occurs throughout all laying periods. In addition to the direct effects on egg safety, intestinal microbiota and its metabolites such as short-chain fatty acids, bile acids, and tryptophan derivatives, are suggested to indirectly modulate egg quality through the microbiota-gut-liver/brain-reproductive tract axis. These findings can extend our understanding of the crosstalk between intestinal microbiota and the host to improve egg quality and safety. This paper reviews the compositions of intestinal microbiota in different physiological stages of laying hens and their effects on egg quality and proposes that intestinal microbiota may become a potential target for modulating egg quality and safety by nutritional strategies in the future.

Intra-amniotic administration of l-glutamine promotes intestinal maturation and enteroendocrine stimulation in chick embryos

Initial nutritional stimulation is a key driving force for small intestinal maturation. In chick embryos, administration of l-glutamine (Gln) into the amniotic fluid stimulates early development of the small intestinal epithelium by promoting enterocyte differentiation. In this study, we evaluated the effects of intra-amniotic administration of Gln on enterocyte morphology and function, and elucidated a potential enteroendocrine pathway through which Gln stimulates small intestinal maturation. Our results show that Gln stimulation at embryonic day 17 significantly increased enterocyte and microvilli dimensions by 10 and 20%, respectively, within 48 h. Post-hatch, enterocytes and microvilli were 20% longer in Gln-treated chicks. Correspondingly, Gln stimulation significantly upregulated mRNA expression of brush border nutrient transporters PepT-1 and SGLT-1 and tight junction proteins TJP-1 and TJP-2, before and after hatch (P < 0.05). Since GLP-2 signaling from intestinal L-cells is associated with enterocyte growth, functionality and integrity, we examined the effects of Gln stimulation on mRNA expression of key hormones and receptors within this enteroendocrine pathway and found significant increases in GLP-2R, IGF-1 and IGF-1R expression before and after hatch (P < 0.05). In conclusion, our findings link primary nutrient stimulation in the developing small intestine with enterocyte morphological and functional maturation and enteroendocrine signaling.

Effects of in ovo feeding of disaccharide and/or methionine on hatchability, growth performance, blood hematology, and serum antioxidant parameters in geese

A completely randomized design employing a 2 × 2 factorial experiment was designed in this study to evaluate the effects of in ovo injection of disaccharide (DS) and/or methionine (Met) on hatchability, growth performance, blood hematology, and serum antioxidant parameters in geese. A total of 600 fertilized geese's eggs containing live embryo were randomly assigned into 4 groups with 6 replicates and 25 eggs per replicate. Factors in four groups comprised noninjection, DS injection (25 g/L maltose + 25 g/L sucrose + 7.5 g/L NaCl), Met injection (5 g/L Met + 7.5 g/L NaCl), or DS plus Met injection (25 g/L maltose + 25 g/L sucrose + 5 g/L Met + 7.5 g/L NaCl), respectively. We found that the administration of DS in embryo increased hatching time, yolk sac-free carcass weight, yolk sac-free carcass indexes and decreased assisted hatching ratio, yolk sac weight, yolk sac indexes, but did not affect hatchability and mortality. Moreover, higher body weight and serum glucose concentrations in DS injection group compared with noninjection group were observed on day of hatching. The body weight and average daily gain (ADG) of geese in DS injection group were higher than noninjection group after incubation. In ovo injection of Met increased hatching time and yolk sac-free carcass indexes, but decreased yolk sac indexes. In addition, the strategy of in ovo feeding of Met led to higher body weight, ADG, serum uric acid, glutathione (GSH), and glutathione peroxidase concentrations, as well as lower GSSG/GSH ratio, serum glutathione disulfide (GSSG), and malondialdehyde (MDA) concentrations than the noninjection group on day of hatching. The post-hatching body weight, ADG, serum total protein, albumin, and uric acid concentrations increased, whereas post-hatching serum GSSG and MDA concentrations and GSSG/GSH ratio decreased when injected with Met. In addition, synergistic effects of in ovo injection of DS plus Met on hatching time as well as post-hatching body weight and ADG were observed. Therefore, in ovo injection of DS plus Met was demonstrated to be a way to improve the development of geese during early incubation stages.

Early Phenotype Programming in Birds by Temperature and Nutrition: A Mini-Review

Early development is a critical period during which environmental influences can have a significant impact on the health, welfare, robustness and performance of livestock. In oviparous vertebrates, such as birds, embryonic development takes place entirely in the egg. This allows the effects of environmental cues to be studied directly on the developing embryo. Interestingly, beneficial effects have been identified in several studies, leading to innovative procedures to improve the phenotype of the animals in the long term. In this review, we discuss the effects of early temperature and dietary programming strategies that both show promising results, as well as their potential transgenerational effects. The timing, duration and intensity of these procedures are critical to ensure that they produce beneficial effects without affecting animal survival or final product quality. For example, cyclic increases in egg incubation temperature have been shown to improve temperature tolerance and promote muscular growth in chickens or fatty liver production in mule ducks. In ovo feeding has also been successfully used to enhance digestive tract maturation, optimize chick development and growth, and thus obtain higher quality chicks. In addition, changes in the nutritional availability of methyl donors, for example, was shown to influence offspring phenotype. The molecular mechanisms behind early phenotype programming are still under investigation and are probably epigenetic in nature as shown by recent work in chickens.

Non-Antibiotics Strategies to Control Salmonella Infection in Poultry

Salmonella spp. is a facultative intracellular pathogen causing localized or systemic infections, involving economic and public health significance, and remains the leading pathogen of food safety concern worldwide, with poultry being the primary transmission vector. Antibiotics have been the main strategy for Salmonella control for many years, which has allowed producers to improve the growth and health of food-producing animals. However, the utilization of antibiotics has been reconsidered since bacterial pathogens have established and shared a variety of antibiotic resistance mechanisms that can quickly increase within microbial communities. The use of alternatives to antibiotics has been recommended and successfully applied in many countries, leading to the core aim of this review, focused on (1) describing the importance of Salmonella infection in poultry and the effects associated with the use of antibiotics for disease control; (2) discussing the use of feeding-based (prebiotics, probiotics, bacterial subproducts, phytobiotics) and non-feeding-based (bacteriophages, in ovo injection, vaccines) strategies in poultry production for Salmonella control; and (3) exploring the use of complementary strategies, highlighting those based on -omics tools, to assess the effects of using the available antibiotic-free alternatives and their role in lowering dependency on the existing antimicrobial substances to manage bacterial infections in poultry effectively.

In ovo threonine supplementation affects ileal gene expression of nutrient transporters in broilers inoculated post-hatch with Salmonella Enteritidis

The effect of in ovo threonine (Thr) supplementation on the ileal expression of glucose, peptide and amino acid transporters was assessed in Salmonella Enteritidis-challenged broiler chicks. At 17.5 days of incubation, fertile eggs were supplemented in the amniotic fluid with sterile saline or 3.5% threonine. Hatchlings were individually weighed, and Salmonella Enteritidis negative status was confirmed. At 2 days of age, half of the birds of each group were inoculated with sterile nutrient broth or Salmonella Enteritidis inoculum. Relative expression of sodium-dependent glucose transporter 1 (SGLT1), glucose transporter 2 (GLUT2), di- and tri-peptide transporter 1 (PepT1) and alanine, serine, cysteine, threonine transporter (ASCT1) was assessed at hatch, 2 and 9 days of age, i.e., before inoculation and 7 days post-inoculation (dpi). At 9 days of age (7dpi), threonine increased SGLT1 and GLUT2 expression, whereas GLUT2 expression decreased in Salmonella-challenged birds. There was a significant interaction between threonine and Salmonella for PepT1 and ASCT1. Threonine increased PepT1 expression only in non-challenged birds. In addition, in ovo supplementation increased expression of ASCT1 regardless of post-hatch inoculation; Salmonella inoculation resulted in decreased expression of ASCT1 only in supplemented birds. The results suggest that while intra-amniotic threonine administration in broiler embryos increases the expression of genes related to the absorption of monosaccharides and amino acids, Salmonella challenge may negatively affect the expression of protein related transporters in the ileum of broilers.

Histological alterations of small intestine and growth performance of broiler chicks after in ovo copper injection at 10 days of embryogenesis period

This study aimed to assess impacts of early in ovo injection (at 10 days of incubation) of copper (sulfate, acetate, or nanoparticles) on histomorphometric parameters of small intestine and growth performance of post-hatched chicks. Fertile eggs (n = 462) were distributed to seven groups (3 replicates, 22 eggs in each). The first group as a control, the 2nd, 3rd and 4th groups injected with 100 µL deionized water containing 8 μg/egg of Cu (sulfate, acetate and nanoparticles, respectively), and the 5th, 6th and 7th groups injected with 100 µL deionized water containing 16 μg/egg of the same Cu sources above. Results illustrated that in ovo administration of Cu sulfate and Cu acetate significantly improved histological parameters of small intestine parts of newly hatched chicks compared with the control. Cu sulfate and nano-Cu significantly augmented body weight gain compared with the control. In ovo Cu injection showed a nonsignificant improvement in feed conversion ratio. The highest level (16 μg/egg) of different sources was better than the lowest level (8 μg/egg) in most results. In conclusion, it is recommended that in ovo injection of Cu (16 μg/egg) can improve the growth performance (Cu sulfate and nano-Cu) and the small intestine histomorphometry parameters (Cu sulfate and Cu acetate) of broiler chicks.

Effects of Early Nutrition of Hatched Chicks on Welfare and Growth Performance: A Pilot Study

Simple Summary

It is common practice that one-day-old chicks can be deprived of feed for about 48 h or more before they are housed on farms. Thus, we hypothesized that early nutrition on-farm hatched chicks might overcome the adverse effects of delayed nutrition on-hatchery hatched chicks regarding some animal welfare issues such as foot pad health as well as growth performance of birds. Our results confirmed that early nutrition on-farm hatched chicks together with using new fresh litter at d 7 of life led to a reduction in the severity of foot pad lesions and improved the growth performance of broiler chickens.

Abstract

This study aimed to investigate the possibility of rearing newly hatched chicks with immediate access to feed and water in the same hatching unit one week prior to transferring them to the conventional broiler house with special regards to foot pad health and growth performance. Two trials were performed with a total of 6900/6850 (trials 1/2) broiler chickens (ROSS 308). A total of 3318/3391 chicks (trials 1/2) were transported from the hatchery (duration of about 3 h) and reared in a conventional broiler house (control group: delayed nutrition on-hatchery hatched). The control group did not receive any form of nutrition until they were taken to conventional broiler housing. Additionally, a total of 3582/3459 (trials 1/2) embryonated eggs (d 18) were obtained from the same parent flock of the same commercial hatchery and taken to the farm facility. After on-farm hatch, the chicks had immediate access to water and feed (experimental group: early nutrition on-farm hatched). After d 6/7 of life, the on-farm hatched chicks (trials 1/2) were transferred to the broiler house on the same facility. The delayed nutrition on-hatchery hatched groups displayed a significantly lower dry matter content in the litter compared to the early nutrition on-farm hatched groups (two-factorial analysis) at d 6/7 and d 14 of life. However, thereafter, no significant differences were noted. Based upon two-factorial analysis, the early nutrition on-farm hatched groups revealed lower foot pad lesions from d 14 of life onwards and showed a higher body weight (BW) throughout the rearing period compared to the delayed nutrition on-hatchery hatched groups (p < 0.05). Overall, early nutrition on-farm hatched chickens is of critical importance together with using new litter at d 7 to maintain healthy foot pads as well as to enhance nutrient utilization and optimize the growth performance.

Nutrition and Digestive Physiology of the Broiler Chick: State of the Art and Outlook

Simple Summary

The first week after hatch is the most challenging period in the life of broilers. The digestive tract of the newly hatched chick is immature and must undergo dramatic changes before it can efficiently digest and absorb nutrients. The gut is the vital organ where nutrient digestion and absorption take place. Ontogenic changes that accompany improved digestion and absorption include increased secretion of digestive enzymes, increase in the gut absorptive surface area, and enhanced nutrient transporters. The obvious limiting factors are the secretion and activities of digestive enzymes, and the surface area for absorption. These limitations are overcome as the birds grow older, with concurrent improvements in nutrient utilization. In addition, substantial changes also take place in the physical and functional development of the immune system and intestinal microbial ecology. However, the focus of the current review was on nutrition-related challenges and nutritional approaches to assist the chick during this highly demanding period.

Abstract

Because the intestine is the primary nutrient supply organ, early development of digestive function in newly hatched chick will enable it to better utilize nutrients, grow efficiently, and achieve the genetic potential of contemporary broilers. Published data on the growth and digestive function of the gastrointestinal tract in neonatal poultry were reviewed. Several potential strategies to improve digestive tract growth and function in newly hatched chick are available and the options include breeder nutrition, in ovo feeding, early access to feed and water, special pre-starter diets, judicious use of feed additives, and early programming.