Effects of Ascorbic Acid Injection in Incubated Eggs Submitted to Heat Stress on Incubation Parameters and Chick Quality

Bibliographical Mapping of Research into the Relationship between In Ovo Injection Practice and Hatchability in Poultry

Recent advances in poultry practice have produced new tools enabling the poultry industry to increase productivity. Aiming at increasing production quality, varying protocols of in ovo injection facilitate the introduction of exogenous substances into the egg to complement the nutrients that support embryonic development up to hatching, which are already available in the internal and external compartments. Due to embryonic sensitivity, adding any substance into the egg can be either advantageous or disadvantageous for embryonic survival and can influence hatch rates. Thus, understanding the relationship between poultry practices and production rates is the first step towards successful commercial application. This review aims to assess the influence on hatch rates of injecting different substances in ovo, including effects on embryo and chick health parameters where these are reported. Bibliographic mappings of co-authorship of citations, co-occurrence of keywords, and bibliographic coupling based on the in ovo injection technique and hatchability parameters were also performed. Using the Scopus database, 242 papers were retrieved, reviewed, and submitted for bibliographic mapping using the VOSviewer^® software. This review provides a broad overview of just over 38 years' research on the subject, revealing that studies have significantly increased and peaked in 2020, being produced primarily by US researchers and published primarily in the journal Poultry Science. It also reveals that despite negative reports relating to some substances in the embryo, in ovo delivery of substances may possibly change the poultry industry for the better in terms of production rates (hatchability) and/or poultry health.

Impact of spraying eggs with betaine after exposure to short-term thermal stress during early embryogenesis on pre and post-hatch performance of Japanese quail

It is essential to understand and manage environmental factors for good quail production and welfare. One of the most important environmental stressors that hinder quail productivity is heat stress. This study aimed to evaluate the impact of spraying Japanese quail (Coturnix coturnix japonica) eggs with betaine after exposure to short-term high temperature during early embryogenesis on pre and post-hatch performance of quail. A total of 750 eggs were equally divided into two groups. Eggs in the first group were incubated at normal incubation temperature (37.5 °C/NIT), while those in the second group were incubated at high incubation temperature (39.0 °C/HIT) for 3 h daily from day 4-6 of incubation. Eggs in both groups were subjected to five treatments, NC (negative control), PC sprayed distilled water (positive control), while B0.5, B1, and B2 treatments were sprayed with distilled water supplemented with 500, 1000, and 2000 mg betaine/L, respectively. The chick weight at hatch, slaughter weight, and first egg weight was significantly impaired by the HIT treatment. The HIT group revealed a significant increase in cloacal temperature, H/L ratio, liver enzymes, triglyceride, and cholesterol and a significant decrease in hatchability, T3 hormone, and blood protein levels than the NIT group. Regarding betaine effects, the embryonic mortality rates, hatchability, hatched chick weight, and oviduct percentage in groups treated with 1000 or 2000 mg betaine/L were significantly improved compared with the control. Also, spraying betaine at 1000 or 2000 mg/L significantly increased blood protein and triiodothyronine (T3) hormone levels and significantly decrease liver enzyme levels and total feed consumption compared with the untreated group. The right/total ventricle ratio (RV/TV) of quail in HIT group was significantly increased, while betaine treatment significantly decreased this ratio. Considering these results, it is strongly suggested that spraying of betaine on eggs at 2000 mg/L optimizes Japanese quail performance.

Thermal manipulation modifies embryonic growth, hepatic free amino acid concentrations, and hatching performance in layer-type chicks

Thermal manipulation (TM) of incubation temperature has been demonstrated to alter metabolism and post-hatch thermotolerance in broiler strains (meat-type chickens). Fewer reports were focused on layer-type chickens and there was no report on amino acid metabolism during TM in layer-type embryos. In this study, we investigated the effects of TM on embryonic development, hepatic amino acid metabolism, and hatching performance in layer-type chickens. Fertilized eggs were incubated under control thermoneutral temperature (CT, 37.6°C) and TM with high temperature (TMH, 39°C, 8 h/day) or low temperature (TML, 20°C, 1 h/day) from embryonic day (ED) 8 to ED 15. The embryonic weight and relative embryonic weight (yolk-free embryonic weight to the initial egg weight) significantly declined in the TML group at ED 13 (P < 0.01) and ED 16 (P < 0.0001), and were significantly increased (P < 0.001) in the TMH group at ED 16, in comparison with the embryos in the CT group. The concentrations of all hepatic free amino acids were significantly increased (P < 0.01) with embryonic development. Interestingly, TMH and TML caused similar effects on hepatic amino acid metabolism, in which most of the essential and non-essential amino acids were significantly declined (P < 0.05) under TM treatments at ED 13 but not affected at ED 16. Until hatching, TML, but not TMH, caused a significant (P < 0.05) delay (31-38 min/day from ED 8) in incubation duration. The hatchability in the TML group was lower than the other two groups, which indicated that 20°C as cold stimulation was not suitable for layer embryos. The body weight, yolk weight, yolk-free body mass, and chick quality were not affected by TM treatments. However, the relative weight of the liver, but not the heart, was significantly reduced (P < 0.05) at hatching by TML treatment. In conclusion, TML, but not TMH, caused to delay in embryogenesis and affected the internal organ of chicks at hatch. Similar changes in amino acid metabolism under TMH and TML indicated that thermal stress induced by both high and low extreme ambient temperatures influences embryonic amino acid metabolism in a similar fashion in layer-type embryos.

Impact of Treating Hatching Eggs with Curcumin after Exposure to Thermal Stress on Embryonic Development, Hatchability, Physiological Body Reactions, and Hormonal Profiles of Dokki-4 Chickens

Simple Summary

Curcumin has been used as a suitable feed supplement for poultry to improve several hematological and biochemical indicators, diminish heat stress, and increase antioxidant activity. This experiment evaluated the effects of incubation temperatures and spraying hatching eggs with curcumin during the incubation phase on chick embryo development, hatchability, physiological body reactions, and hormonal profiles of Dokki 4 chickens. The findings indicated that the relative water loss and dead after piping in the chronic incubation temperature group were significantly increased compared with the normal incubation temperature group. Post-hatch, the triiodothyronine level in the high incubation temperature group was significantly decreased than in the control group. Regarding curcumin treatments, relative water loss from eggs and the hatchability of fertile eggs in treated groups significantly increased, while body surface temperature significantly decreased compared with the control.

Abstract

This study evaluated the impact of incubation temperature and spraying hatching eggs with curcumin during the early embryogenesis phase on chick embryo developments, hatchability, physiological body reactions, and hormonal profiles of Dokki 4 chickens. A total of 720 fertile eggs were equally distributed into two groups. In the first group, the eggs were incubated at normal incubation temperature/NIT (37.8 °C and 55–60% RH) for up to 19 days of incubation, whereas those in the second group were incubated in the same conditions except from 6 to 8 day, in which they were daily exposed to chronic incubation temperature/CIT (39.0 °C) for 3 h. Each group was classified into four curcumin treatment doses; the 1st treatment (control) was sprayed with distilled water, while the 2nd, 3rd, and 4th treatments were sprayed with 250, 500, and 1000 mg curcumin/liter distilled water. The results indicated that the lowest hatchability of fertile eggs (%) was obtained in the CIT group (p = 0.02), whereas the highest body surface temperature/BST compared in the NIT group (p = 0.01). Regarding curcumin treatments, the percentages of heart, gizzard, spleen, and T3 hormone levels in the treated group were significantly increased, while the H/L ratio was significantly reduced (p = 0.001) compared with the control. At 8 weeks of age, the testes and ovary percentages in treated groups were significantly (p = 0.05) increased compared with the control. In conclusion, exposure of hatching eggs to high thermal stress (39 °C) during the incubation phase had deleterious effects on chick performance and T3 hormone level. Moreover, spraying hatching eggs had beneficial impacts on growth, reproductive organs, T3 hormone level, and reducing H/L ratio.

Impact of acute short-term high thermal stress during early embryogenesis on hatchability, physiological body reaction, and ovarian follicles development of quails

This experiment aimed to evaluate the impact of continuous and intermittent thermal stress during early embryogenesis on hatchability, physiological body reaction, ovary weight, and follicle development of quails. A total of 540 eggs were divided into 3 equal groups (3 groups × 6 replicates × 30 eggs). In the first group (control), eggs were incubated at normal incubation conditions (37.5°C and 50–55% relative humidity) from day 0 till hatching. In the second group (continuous thermal stress [CTS]), eggs were daily exposed to 39.5°C and 50 to 55% during the early embryogenesis for 3 successive days (E4–E6) for 3 h (12:00–15:00). In the third group (intermittent thermal stress [ITS]), eggs were daily exposed to 39.5°C and 50 to 55% during the early embryogenesis for 90 min (12:00–13:30) then temperature was returned to 37.5°C for 60 min (13:30–14:30) after that the temperature was raised again for 39.5°C for 90 min (14:30–16:00) daily for 3 successive days (E4–E6). The findings showed that the highest relative water loss form egg (RWL/%) at 6 d of incubation was obtained in the CTS group (P ≤ 0.05). The hatchability rate was significantly (P ≤ 0.05) decreased in the thermal-treated groups compared with the control group. The body surface temperature and cloacal temperature in the CTS and ITS groups significantly (P ≤ 0.001) increased compared with the control group. Chick weight (g) at 5 wk old, total weight gain, daily weight gain were significantly lower (P ≤ 0.05) in the CTS group compared with the control group. Triiodothyronine (T3) hormone concentration and globulin level were significantly (P ≤ 0.05) lower in the CTS and ITS groups compared with the control. The ovarian follicle weights (first, second, third, fourth, and fifth) and the diameter of the large follicle (fifth follicle) were significantly (P ≤ 0.01) decreased by increasing incubation temperature. From these findings, it could be concluded that the hatchability and body weight at sexual maturity for quails produced from eggs exposed to CTS and IST were significantly decreased by 8 and 2.1% as well as 2.98 and 2.1%, respectively, compared with the control group.

Efeito da manipulação térmica durante a incubação sobre as variáveis hematológicas, bioquímica sérica e morfometria da bolsa cloacal de codornas japonesas submetidas ao estresse crônico por calor

RESUMO Objetivou-se avaliar os efeitos da manipulação da temperatura de incubação sobre a resposta imune de codornas desafiadas termicamente após eclosão. Para isso, foram utilizados 540 ovos, distribuídos em três incubadoras, com temperatura de 37,8°C e umidade de 60%. A partir do sexto dia de incubação até a eclosão, as temperaturas foram ajustadas em 37,8°C (padrão), 38,5°C (intermediária) e 39,5°C (alta). Após a eclosão as codornas foram pesadas e distribuídas, em delineamento inteiramente ao acaso, com três temperaturas de incubação (37,8, 38,5 e 39,5°C) e duas temperaturas de ambiente (estresse e termoneutro). Aos 10, 20, 30 e 40 dias, quatro codornas por tratamento foram eutanasiadas para coleta da bolsa cloacal, do fígado e do coração, para se determinar o peso absoluto (g), o peso relativo (%) e a área dos folículos bursais. Sangue foi coletado para realização do hemograma, do leucograma e da bioquímica sérica. Os dados foram analisados e as diferenças entre as médias foram determinadas pelo teste de Tukey a 5%. O estresse térmico por calor, a partir dos 20 dias, promove redução no peso absoluto do fígado, do coração, da bolsa cloacal e na área dos folículos bursais, além de heterofilia, linfopenia e aumento da relação heterófilo/linfócito. Em conclusão, o estresse térmico por calor após 10 dias de idade pode causar imunossupressão.

In ovo injection of ascorbic acid and higher incubation temperature modulate blood parameters in response to heat exposure in broilers

1. This study analysed whether in ovo injection of ascorbic acid before incubation and at high incubation temperature influenced blood characteristics and performance in broilers reared in different temperature conditions. 2. A total of 3,000 fertile eggs from broiler breeders (Cobb®) were randomly divided into three incubation treatments: no ascorbic acid injection and egg incubation at 37.5°C (control); no ascorbic acid injection and egg incubation at 39°C; in ovo ascorbic acid injection prior to incubation (6 µg AA/100 µl water) and egg incubation at 39°C. 3. Male chicks hatched from the three incubation treatments were submitted to three distinct rearing temperatures (control, cold and hot) from the third week of age onwards (540 chicks were divided into 6 treatments with 5 replicates per treatment). 4. Measurements at 42 d showed that, after egg incubation at 39°C, the haematocrit, haemoglobin values, ionised calcium and glucose concentrations were increased and base excess values were reduced. However, in ovo injection of ascorbic acid normalised all these parameters. 5. Partial CO₂ and O₂ pressure were higher with increased rearing temperature. Blood pH was lower when eggs were incubated at 39°C and injected with ascorbic acid. In ovo injection of ascorbic acid induced leucocytosis due to lymphocytosis and heterophilia, restored basophils rate and led to monocytopoenia. Leucocytosis was triggered by hot rearing temperature due to lymphocytosis, eosinophilia and heterophilia. 6. The results obtained in this study showed that in ovo injection of ascorbic acid before incubation may serve as a long-term stimulator and modulator of the broiler immune system, and that high incubation temperatures induce adaptations in the electrolytic balance, minimising or avoiding the occurrence of respiratory alkalosis under hot rearing temperature.

Influence of in Ovo Administration of Some Water-Soluble Vitamins on Hatchability Traits, Growth, Carcass Traits and Blood Chemistry of Japanese Quails

A total of 450 fertile Japanese quail eggs were used to determine the impacts of in ovo administration of water-soluble vitamins (C, B6 and B12) on the growth performance, carcass traits, hematological and biochemical blood parameters as well as the immune response of Japanese quails. On the 7th day of incubation, the eggs were allocated to five groups: un-injected, 0.1 ml/egg saline, 1 mg/egg vitamin C, 150 µg/egg vitamin B6 and 20 µg/egg vitamin B12. The percentage of early embryonic mortality was increased (P≤0.001) in all treated groups versus the control group. Chicks that hatched from eggs injected with 1 mg/egg vitamin C exhibited a significantly greater (P≤0.05) live body weight (LBW) than those from the control and saline groups. During 0–2 weeks of age, the chicks hatched from eggs injected with vitamins displayed better feed conversion than the positive or negative controls. In ovo injection of vitamins had no significant effect on all carcass traits. In ovo injection with vitamins C, B6 and B12 increased plasma total protein and its fractions compared with the control. Plasma levels of total lipids and cholesterol were decreased in chicks hatched from eggs injected with 1 mg/egg vitamin C, 150 µg/egg vitamin B6 or 20 µg/egg vitamin B12 compared with those hatched from control eggs. Plasma T3 and T4 were increased in chicks hatched from eggs injected with vitamin C, vitamin B6 and vitamin B12. The relative weights of the bursa of Fabricius and thymus were significantly (P=0.002 or 0.003) increased in the birds hatched from eggs injected with vitamins compared with those in the control or saline group. Thus, in ovo injection of vitamins C, B6 and B12 improved the blood profile and immune response of Japanese quail.

Effects of In Ovo Methionine-Cysteine Injection on Embryonic Development, Antioxidant Status, IGF-I and TLR4 Gene Expression, and Jejunum Histomorphometry in Newly Hatched Broiler Chicks Exposed to Heat Stress during Incubation

Sulfur amino acids are typically the first-limiting amino acids (AA) used in protein metabolism in poultry. Therefore, we hypothesized that their utilization in the pre-hatch period would affect embryonic development, IGF-I and TLR4 gene expression, antioxidant status, serum biochemical profile, and jejunum histomorphometry of newly hatched Ross broiler chicks incubated under heat stress conditions. A total of 150 fertile broiler eggs were subjected to heat stress (39.6 °C for 6 h/d) from d10 until d18 and injected at d 17.5 of incubation with methionine and cysteine (Met-Cys) at a dose of 5.90 mg l-methionine plus 3.40 mg l-cysteine. The effects of Met-Cys administration were examined and compared with the control (Non-injected group) and 0.75% NaCl injected group. The results showed that no significant differences among all groups in serum protein profiles (total protein, albumin, globulin, and albumin/globulin ratio) and creatine kinase were observed. The level of heat shock protein-90 was decreased with Met-Cys In ovo injection. The In ovo injection of Met-Cys also improved the values of total antioxidants capacity and glutathione in examined tissues. At the same time, an increase in fold change mRNA abundance of IGF-I and TLR4 was observed after Met-Cys injection in tested tissues. Finally, an increase of 29% in villus area was found after Met-Cys injection compared to the control group. In conclusion, the In ovo injection of Met-Cys resulted in improved embryonic development, IGF-I and TLR4 gene expression, antioxidant status and jejunum histomorphometry of newly hatched broiler chicks exposed to heat stress during incubation.