In Ovo and Early Chick Nutrition
Sarita Mahicha1, Monika Karnani2, Sheela Choudhary3 and Manju4
Department of Animal Nutrition
Post Graduate Institute of Veterinary Education and Research (PGIVER), Jaipur
1PhD Scholar, Department of Animal Nutrition, PGIVER, Jaipur
2Assistant professor, Department of Animal Nutrition, PGIVER, Jaipur
3 Professor & Head, Department of Animal Nutrition, PGIVER, Jaipur
4Assistant professor, Department of Animal Nutrition, PGIVER, Jaipur
Abstract- During the first several days after hatching, the gastrointestinal system of a broiler chick experiences considerable morphological and physiological changes. In ovo feeding is a strategy used during embryonic development to anticipate the chick’s requirements and to adapt them to their new diet after hatching, as well as to provide extra energy for the energy-demanding action of hatching. In ovo feeding can provide early nutrients and additives to embryos, stimulate gut microflora and mitigate the adverse effects of starvation during pre- and post-hatch periods. In ovo applications of bioactive compounds like vaccines, nutrients, antibiotics, prebiotics, probiotics, synbiotics, creatine, follistatin, L-carnitine, CpG oligodeoxynucleotide, growth hormone, polyclonal antimyostatin antibody, peptide YY and insulin-like growth factor-1 have been used. These compounds affect hatchability, body weight at hatch, physiological functions, immune responses, gut morphology, gut microbiome, production performance and overall health of birds.
Introduction:-
Early nutrition programming using both in ovo and post-hatch feeding as a means to modulate the early growth and development of GIT and found to be an effective strategy. In ovo feeding is possible through the perforation of egg shell and inoculation of nutrients into the amniotic or the allantoic fluid, with a syringe and needle. The late term embryo acquires nutrients through the allantoic fluid (Gonzales et al., 2003), and extra nutrients delivered to this location may be used to compensate for any energy deficits during hatching. There are five potential injection sites via which an in ovo injection may be administered during the different stages of embryonic development: the air sac, the allantois, the amnion, the yolk sac and the embryo body. In ovo feeding has the objective of promoting the early development of the digestive tract, in which interaction between nutrients and the immature intestine induces the development of absorptive epithelium and the enzymatic activity, mainly for digesting carbohydrates. The aim of the in ovo injection of prebiotics, probiotics, and synbiotics is to facilitate the early colonization of the embryonic gut with the native microbiota to establish the beneficial microbiome. Dietary supplementation with some bioactive compounds, such as probiotics, enhanced the growth performance of broiler chickens by improving gut health. Furthermore, the early intervention with some bioactive substances may provide early bacterial colonization in the gut of newly hatched chicken and improve the gut microbiota and, consequently, improve gut health and growth performance. Overall, in ovo supplementation with various nutrients and substances appears to promote earlier development of the digestive tract and muscle tissues, improve digestive efficiency and enhance the immune system of hatchlings, thus contributing to the maintenance of glycogen stores and posthatch survivability.
Nutrients used by broiler chicks:-
On the first day of life, the digestion and absorption of amino acids and carbohydrates by broiler chicks is very low and mainly confined to glucose uptake. On the day of hatch the absorption of glucose and amino acids can vary from 43 to 53%, however, as the bird grows, absorption increases, and on day four glucose and amino acids absorption reach over 80% (Noy and Sklan, 1999; 2001). According to Noy and Sklan (1999) the best use of proteins and carbohydrates occurs when appropriate conditions are reached, including enzymatic activity and sufficient sodium for glucose and amino acids cotransporters in the gut lining.
In ovo feeding of carbohydrate- Physiological and morphological changes occur mostly during in ovo feeding because birds switch from a diet based on fatty acids from the yolk sac to a diet based on carbohydrates, provided by commercial feeds, often formulated with corn and soya bean meal. Sklan (2003) attributed low intestinal absorption of carbohydrates on the day of hatch to the presence of fatty acids from the yolk sac. As the yolk sac nutrients are hydrophobic, these inhibit the absorption of hydrophilic compounds.
As a result of carbohydrate supplementation, higher body weight and pectoral muscle weight have been observed at hatch. The appropriate level of glucose available in ovo reduces the use of muscle protein to produces energy via gluconeogenesis.
In ovo feeding of amino acid and protein– The amino acid balance remains stable throughout the development of embryo and the amino acids ratio to lysine in egg compounds and embryo are similar during the incubation period. However, during embryonic development, crude protein and fat concentrations decrease in the egg components and increase in the embryo, due to nutrient transfer. The amino acid concentration on the 19th day of incubation is higher in the egg than in the embryo, indicating that the egg amino acid pool is larger than needed for embryo development until hatch (Ohta et al., 1999). These latter researchers evaluated the injection of 0.5 ml of an amino acid solution (similar to standard egg amounts) into fertile eggs at days zero and seven of incubation through the air-chamber and into the yolk sac. The hatchability of eggs submitted to in ovo injection of amino acids at day zero was 13%, while in control group hatchability was 87%. No beneficial effect of in ovo injection with amino acids was observed irrespective of incubation day (0 or 7) or inoculation route, on broiler chick body weight at the day of hatch.
In ovo supplementation of vitamin- IOF of ascorbic acid increased hatchability but did not affect feed intake and growth parameters during starter phase. It improved jejunal morphology and decreased cholesterol. In another study, IOF of ascorbic acid increased post-hatch growth, improved leg muscle development and increased plasma antioxidant level in broilers. Ascorbic acid also improved both the antioxidant and the immune systems in hatchlings (El-Senousey et al., 2018).
In ovo vitamin E inoculation improves newly hatched chicks oxidative state, thus enabling better physical quality. In ovo vitamin E improved hatchling quality and the oxidative status of chicks, resulting in better performance (Araujo et al., 2019). Improvement of neonatal chick characteristics enabled better initial broiler chicken performance. Therefore, VE is indicated for routine inoculation in industrial hatchery to improve the initial production of broilers.
Vitamin D has two forms—vitamin D2 and vitamin D3. In ovo vitamin D2 inoculation lowered late embryo mortality, feed intake and feed conversion ratio as compared with injection of diluent or vitamin D3.
In ovo supplementation of hormone- The In ovo injection of TRH (Thyrotropin Releasing Hormone) improved hatchability and elevated embryonic blood plasma T3 and T4 when injected either through the air cell membrane or through the small end of the eggs.
In ovo injection of of corticosterone on ED (Embryonic Day) 11 suppressed the post-hatch growth rate during the first 21 days of life, increased the aggressive behaviors (Day 28), elevated plasma corticosterone (Day 42) and downregulated hypothalamic expression of arginine vasotocin and CRH.
The injection of thyroxine and manipulation of temperature increased the number of first-grade chicks, decreased yolk sac weight, but increased body weight at hatch.
In ovo injection of CpG Oligodeoxynucleotides- The in ovo injection of this immuno-stimulant showed immuno-protection against E. coli in neonatal chicks. Encapsulated CpG was used as an adjuvant to check the effects of this in enhancing the efficacy of the herpes virus of turkey (HVT) vaccine for boosting immunity against Marek’s disease (MD).
In ovo injection of prebiotic, probiotic and synbiotic- In ovo stimulation by prebiotics causes early-life microbial modulation, which can persistently affect intestinal histomorphology, nutrient uptake and immunity. Galactooligosaccharide showed a bifidogenic effect by increasing the relative abundance of Bifidobacterium spp in the cecum and decreased the number of Lactobacillus spp in the ileum by competitive exclusion in 42 days adult broiler chickens. In addition, the in ovo stimulation increased mRNA expression of cytokine genes (IL-1β, IL-10, IL-12p40) in jejunum and cecum, expression of MUC6 responsible for mucin production in goblet cells in jejunum and cecum, genes of intestinal integrity (CLDN1 and TJAP1), nutrient sensing genes (free fatty acid receptors–FFAR 2 and FFAR4) and showed a variation in the expression of glucose transporter genes (GLUT1, GLUT2, GLUT5) in the large intestine.
The Bifidobacterium bifidum ATTC 29521 and B. longum ATTC 15707, when using injected in-yolk route, improved live body weight, BWG, FCR, various hematological indices and villi height without hampering carcass traits and liver and renal functions. In vivo stimulation of probiotics produce vitamin B complex, different acids which lowered the pH that increased iron absorption from the small intestine, and the availability of vitamin B.
The in ovo injection of bioactive compounds can induce epigenetic change by modulating embryonic gut microbiota. In ovo injection of L. plantarum and RFO as synbiotics improved metabolic gene expression (downregulated ANGPTL4, upregulated NR4A3) in the liver, and the change obtained was better than in ovo injection of other synbiotics (L. salivarius and GOS).
Conclusion- In ovo feeding is one of the latest and successful methods to feed embryos for improved performance and health during pre-hatch and post-hatch periods. It is crucial as it provides the chicks with sufficient nutrients and supplements during the lag period (from hatch to first feed in the production farm). Currently used materials for in ovo feeding include nutrients like glucose, amino acids, and vitamins, and supplements like probiotics, prebiotics, exogenous enzymes, hormones, vaccines, drugs, and other nutraceuticals. Several studies have shown that the in ovo injection of different compounds can increase the number of quality hatched chicks, decrease yolk sac weight, increase body weight at hatch and post-hatch period, reduce mortality, increase carcass yield, improve metabolism of nutrients, improve gut morphology, change blood histology, modify the regulation of transcription of different genes, boost immunity and protect against harmful gut microbes through competitive exclusion. In ovo feeding of pre-, pro- and synbiotics and CpG-ODN can reduce bacterial loads in the gut and reduce pathological conditions caused by bacteria in the challenged birds. Some studies have been done to evaluate the effect of a combination of compounds where the conclusion cannot be drawn which compound could be credited for the beneficial effects. This method has been found to be effective in raising the body weight of chicks on the day of hatching and at various periods throughout the bird’s life. These compounds can be opted for in ovo inoculation to initiate the effect earlier in life. But to replace antibiotic growth promoter throughout the post-hatch period, the effects of in ovo injection should be ensured through long-time trials expanding from the perinatal period to the marketable age of the poultry. The outcomes of an in ovo injection of a biological compound may vary according to species, strain, time and route of injection. For commercial adaptation, the optimum injection procedures must be established to get reproducible results and broader application in commercial production systems.
References-
Araújo, I. C., Café, M. B., Noleto, R. A., Martins, J. M., Ulhoa, C. J., Guareshi, G. C., and Leandro, N. S. (2019). Effect of vitamin E in ovo feeding to broiler embryos on hatchability, chick quality, oxidative state and performance. Poultry Science, 98(9), 3652-3661.
El-Senousey, H. K., Chen, B., Wang, J. Y., Atta, A. M., Mohamed, F. R., and Nie, Q. H. (2018). In ovo injection of ascorbic acid modulates antioxidant defense system and immune gene expression in newly hatched local Chinese yellow broiler chicks. Poultry Science, 97(2), 425-429.
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