Dynamic alterations in early intestinal development,microbiota and metabolome induced by in ovo feeding of L-arginine in a layer chick model

Background:Prenatal nutrition is crucial for embryonic development and neonatal growth,and has the potential to be a main determinant of life-long health.In the present study,we used a layer chick model to investigate the effects of in ovo feeding(IOF)of L-arginine(Arg)on growth,intestinal development,intestinal microbiota and metabolism.The treatments included the non-injected control,saline-injected control,and saline containing 2,6,or 10 mg Arg groups.Results:IOF Arg increased early intestinal index and villus height,and enhanced uptake of residual yolk lipid,contributing to subsequent improvement in the early growth performance of chicks.Prenatal Arg supplementation also increased the early microbialα-diversity,the relative abundance of Lactobacillales and Clostridiales,and decreased the relative abundance of Proteobacteria of cecum in chicks.Furthermore,the shift of cecal microbiota composition and the colonization of potential probiotics were accelerated by IOF of Arg.Simultaneously,metabolomics showed that metabolisms of galactose,taurine-conjugated bile acids and lipids were modulated to direct more energy and nutrients towards rapid growth of intestine at the beginning of post-hatch when embryos received IOF of Arg.Conclusions:Prenatal Arg supplementation showed beneficial effects on the early intestinal development,cecal microbiota and host metabolism of layer chicks,contributing to subsequent improvement in the early growth performance.These findings provide new insight into the role of IOF of Arg in the establishment of the gut microbiota of newly-hatched layer chicks,and can expand our fundamental knowledge about prenatal nutrition,early bacterial colonization and intestinal development in neonate.

Exploring the effectiveness of in ovo feeding of vitamin C based on the embryonic vitamin C synthesis and absorption in broiler chickens

Background:Many researches about in ovo feeding(IOF)of vitamin C(VC)are gradually carried out to explore physiological development in chicken,but little studies focus on VC synthesis capacity of the embryo itself,the selection of injection site and the effectiveness of IOF of VC.This study aims to explore the above problems.Results:Kidney and yolk sac were the main organs for VC synthesis and L-gulonolactone oxidase(GLO)expression was lower during pre-hatch development than that during post-hatch development.Sodium-dependent vitamin C transporter 1(SVCT1)expression was increased continuously in yolk sac from embryonic age 19(E19)to post-hatch day 1(D1)and in intestine(duodenum,jejunum and ileum)from E17 to D1.Plasma VC content was higher at D1 than that at D21 and D42.IOF of VC significantly reduced GLO expression in liver,kidney and yolk sac as well as SVCT1 expression in duodenum,jejunum and ileum,but increased the VC content in plasma,brain,kidney and liver.In addition,IOF of VC obviously reduced the embryonic morality and increased the hatchability under heat stress.Conclusions:This study suggested that IOF of VC at E11 in yolk was effective for embryonic VC supplementation.These findings provide a theoretical reference about the method of embryonic VC supplementation and effective methodology on embryonic VC nutrition in broiler chickens.

The effects of in ovo feeding of selenized glucose on liver selenium concentration and antioxidant capacity in neonatal broilers

Selenium is an essential trace element for humans and animals.As the active center of selenoproteins,the addition of selenium is beneficial to enhance the antioxidant ability.However,the high cost limits the application of organic Se in agriculture animal production.Selenized glucose(SeGlu)is a newly invented organoselenium material with good stability,low toxicity and low cost.This assay found that SeGlu was able to increase selenium deposition in liver of newborn broilers,and enhance the antioxidant capacity of liver by elevating the activities of antioxidant enzymes such as total superoxide dismutase and glutathione peroxidase.This paper as the first example clarifying the mechanism of SeGlu to enhance the antioxidant ability of chicks,shows that SeGlu can be used as an organic selenium enrichment additive for early nutrition of poultry.As a cross-discipline study involving chemistry,biology and agriculture animal science,the work may be beneficial for studies in related fields and prompt the development of the selenium science.

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 envi-ronmental 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 po-tential to confer heat resistance in chickens.