Volume 15, Issue 1 (4-2024)
Res Anim Prod 2024, 15(1): 83-94 |
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Shokrani F, Daneshyar M, Ansari Pirsaraei Z, Mirghelenj S A. (2024). Effects of In ovo Injection of L-carnitine and Betaine on Hatchability, Blood Metabolites Concentration, Carcass Characteristics, Expression of Some Growth Associated Genes and Development of One Day Old Chicks. Res Anim Prod. 15(1), 83-94. doi:10.61186/rap.15.43.75
URL: http://rap.sanru.ac.ir/article-1-1374-en.html
URL: http://rap.sanru.ac.ir/article-1-1374-en.html
1- Department of Animal Science, Urmia University, Urmia, Iran
2- Department of Animal Science, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
2- Department of Animal Science, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
Abstract: (1223 Views)
Extended Abstract
Background: In ovo feeding of nutrients into the egg can reduce nutrient limitations within the egg, thereby improving embryo quality and chick growth. Therefore, significant attention should be given to the growth and development of the embryo to maximize performance after hatching. Additionally, providing nutrients to the embryo (embryo nutrition) may enhance growth performance and help overcome developmental limitations during the late embryonic period and early life of the chick. Administering certain nutrients during the incubation period can improve metabolism in chick embryos and yield beneficial effects on post-hatching performance. L-carnitine is a dipolar compound soluble in water, and its in ovo injection may benefit chickens due to their limited capacity to synthesize L-carnitine. Betaine, a derivative of the amino acid trimethylglycine, acts as a methyl group donor, and its beneficial effects on the performance of various bird species have been documented in numerous studies. This study aimed to investigate the effects of in ovo feeding of L-carnitine and betaine, either alone or in combination, on hatchability, carcass traits (drumstick, breast, liver, and egg yolk), blood indices (cholesterol, triglycerides, and total protein), and the expression of growth-associated genes (liver IGF-1 and muscle MyoD and MyF5) in chicks.
Methods: A total of 630 fertile eggs (Ross 308 strain from a 34-week-old breeder flock) were randomly assigned to six treatments, with five replicates and 21 eggs per replicate. The mean weight of the eggs was 56.64 ± 1.18 g. Treatments included a control group (non-injected), dry punch, physiological saline injection (100 µL), in ovo injection of L-carnitine (8 mg), in ovo injection of betaine (2.5 mg), and in ovo injection of both L-carnitine and betaine (8 mg L-carnitine + 2.5 mg betaine). Treatment solutions were injected into the amniotic sac on day 14 of incubation. A total of 100 µL of the injection solution was injected with an insulin syringe into the upper third of the egg, reaching a depth of 19 mm. The injection solution was maintained at 30°C, while the environmental temperature was kept at 35°C, with each treatment lasting approximately 15 minutes. After injection, the injection site was sealed. The eggs were then placed in an incubator set at 37.5°C and 61% humidity. Infertile eggs and those with dead embryos were transferred to the laboratory for examination of embryonic mortality. After hatching, the chicks were weighed using a digital scale with an accuracy of 0.01 g to determine post-hatch weight. Two chicks from each replicate were selected and slaughtered to assess carcass traits (drumstick, breast, liver, and egg yolk). Blood samples were taken from the neck to determine blood parameters (cholesterol, triglycerides, and total protein). The liver and breast muscle of the one-day-old chicks were collected to measure relative gene expression. Relative gene expressions were quantified using Real-Time PCR with gene-specific primers. Data obtained from gene expression were analyzed using the Livak method. The remaining chicks were reared for seven days, during which weight gain, feed consumption, and feed conversion ratio were determined. Data were analyzed using the general linear model procedures of SAS 9.1.
Results: The results indicated that in ovo injection of 8 mg L-carnitine decreased mortality and increased hatchability (P<0.05). However, injection of 2.5 mg betaine increased embryo mortality during the final stage of incubation and decreased the percentage of hatched chicks (P<0.05). In ovo injection of L-carnitine and betaine, both alone and in combination, reduced serum triglyceride and cholesterol concentrations (P<0.05) but did not significantly affect total protein concentration (P>0.05). Furthermore, in ovo injection of L-carnitine and betaine, alone or in combination, increased the percentage of breast and thigh yield in newly hatched chicks (P<0.05). However, there was no effect on yolk sac and liver weights (P>0.05). The injections did not influence the functional characteristics of the chickens at 7 days of age (P>0.05). Additionally, L-carnitine and betaine, either alone or in combination, increased the relative expression of the IGF-1 gene in the liver and the MyoD and MyF5 genes in the breast muscle of hatched chicks (P<0.05).
Conclusion: The results of this research indicate that L-carnitine may reduce embryo mortality during incubation by mitigating oxidative stress, thereby increasing the hatching rate. Overall, the findings suggest that in ovo injection of L-carnitine and betaine can stimulate IGF-1 secretion and subsequently enhance the expression of muscle regulatory genes (MyoD, MyF5), promoting the proliferation and maturation of satellite cells during the embryonic stage. Therefore, L-carnitine and betaine can be recognized as positive stimulants of the IGF-1 signaling pathway, contributing to muscle growth and overall chicken development.
Methods: A total of 630 fertile eggs (Ross 308 strain from a 34-week-old breeder flock) were randomly assigned to six treatments, with five replicates and 21 eggs per replicate. The mean weight of the eggs was 56.64 ± 1.18 g. Treatments included a control group (non-injected), dry punch, physiological saline injection (100 µL), in ovo injection of L-carnitine (8 mg), in ovo injection of betaine (2.5 mg), and in ovo injection of both L-carnitine and betaine (8 mg L-carnitine + 2.5 mg betaine). Treatment solutions were injected into the amniotic sac on day 14 of incubation. A total of 100 µL of the injection solution was injected with an insulin syringe into the upper third of the egg, reaching a depth of 19 mm. The injection solution was maintained at 30°C, while the environmental temperature was kept at 35°C, with each treatment lasting approximately 15 minutes. After injection, the injection site was sealed. The eggs were then placed in an incubator set at 37.5°C and 61% humidity. Infertile eggs and those with dead embryos were transferred to the laboratory for examination of embryonic mortality. After hatching, the chicks were weighed using a digital scale with an accuracy of 0.01 g to determine post-hatch weight. Two chicks from each replicate were selected and slaughtered to assess carcass traits (drumstick, breast, liver, and egg yolk). Blood samples were taken from the neck to determine blood parameters (cholesterol, triglycerides, and total protein). The liver and breast muscle of the one-day-old chicks were collected to measure relative gene expression. Relative gene expressions were quantified using Real-Time PCR with gene-specific primers. Data obtained from gene expression were analyzed using the Livak method. The remaining chicks were reared for seven days, during which weight gain, feed consumption, and feed conversion ratio were determined. Data were analyzed using the general linear model procedures of SAS 9.1.
Results: The results indicated that in ovo injection of 8 mg L-carnitine decreased mortality and increased hatchability (P<0.05). However, injection of 2.5 mg betaine increased embryo mortality during the final stage of incubation and decreased the percentage of hatched chicks (P<0.05). In ovo injection of L-carnitine and betaine, both alone and in combination, reduced serum triglyceride and cholesterol concentrations (P<0.05) but did not significantly affect total protein concentration (P>0.05). Furthermore, in ovo injection of L-carnitine and betaine, alone or in combination, increased the percentage of breast and thigh yield in newly hatched chicks (P<0.05). However, there was no effect on yolk sac and liver weights (P>0.05). The injections did not influence the functional characteristics of the chickens at 7 days of age (P>0.05). Additionally, L-carnitine and betaine, either alone or in combination, increased the relative expression of the IGF-1 gene in the liver and the MyoD and MyF5 genes in the breast muscle of hatched chicks (P<0.05).
Conclusion: The results of this research indicate that L-carnitine may reduce embryo mortality during incubation by mitigating oxidative stress, thereby increasing the hatching rate. Overall, the findings suggest that in ovo injection of L-carnitine and betaine can stimulate IGF-1 secretion and subsequently enhance the expression of muscle regulatory genes (MyoD, MyF5), promoting the proliferation and maturation of satellite cells during the embryonic stage. Therefore, L-carnitine and betaine can be recognized as positive stimulants of the IGF-1 signaling pathway, contributing to muscle growth and overall chicken development.
Keywords: Betaine, In ovo injection, Insulin like growth factors, L-carnitine, Myogenic regulator factors
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