Effects of in ovo feeding of L‐arginine on the development of digestive organs, intestinal function and post‐hatch performance of broiler embryos and hatchlings
However, during the late period of incubation, the deficiency of glycogen and albumen caused by huge energy expenditure would force the chicken embryo to mobilize more muscle proteins coming from the pectoral muscle and then mainly produce amino acids (AA) used for gluconeogenesis, which might result in the deficiency of AA to meet embryonic requirements (De Oliveira, Uni, & Ferket, 2008). Another realistic issue under hatchery practices is that newly hatched chicks cannot get access to feed and water within the first 24–72 hr post‐hatch owing to management factors (Moran & Reinhart, 1980). This delay access to feed further aggravates the poor nutritional status and blocks the muscle deposition, the GIT maturation and function, and the growth development of chicks (Foye, Uni, McMurtry, & Ferket, 2006; Kadam, Barekatain, Bhanja, & Iji, 2013).
Increasing experimental evidences suggested that in ovo feeding (IOF) exogenous nutrients could provide nutrients to bridge the gap between hatch and first feeding and must be applied while the embryo orally consumes amniotic fluid. By this way, the nutrients were delivered to the intestine for utilization, which was vital for early development of small intestine (Willemsen et al., 2010; Kadam et al., 2013). Birds have the greatest requirement of L‐arginine (Arg) among the studied animals, and as an essential AA, Arg serves numbers of important biological and physiological functions (Ball, Urschel, & Pencharz, 2007). However, in the late phase of incubation, the content of Arg decreased in embryonated egg, which easily resulted in Arg insufficiency (Ohta, Tsushima, Koide, Kidd, & Ishibashi, 1999). Nouri Sanami, Ghaedi, Salary, and Hemati Matin (2014) reported that IOF of 0.5 ml Arg solution (60 mg/egg) increased the feed intake and body weight gain of broilers during 1–21 days post‐hatch than the control group. Therefore, we conducted this study to investigate the effects of IOF of Arg solution into the amnion of fertilized eggs at 17.5 days of incubation on the development of digestive organs, the duodenal mucosa of broiler embryos and hatchlings, and the growth performance of broiler chickens during the first week post‐hatch.