Effect of in ovo ghrelin administration on hatching results and post-hatching performance of broiler chickens

The aim of this study was to investigate the effects of in ovo ghrelin administration on hatching weight, hatchability, and post-hatch performance of broiler chickens. One thousand fifty fertilized eggs were divided into 7 treatments (150 eggs/treatment): treatment C (control, intact without injection), treatment G50d5 (50 ng ghrelin/egg at day 5), treatment G100d5 (100 ng ghrelin/egg at day 5), treatment G50d10 (50 ng ghrelin/egg at day 10), treatment G100d10 (100 ng ghrelin/egg at day 10), treatment G0d5 (vehicle without ghrelin at day 5), and treatment G0d10 (vehicle without ghrelin at day 10). Hatchability in all of the injected treatments was lower than C (P<0.01), indicating an influence of injection that was augmented. Hatchability of treatments G50d10 and G100d10 were greater than treatment G0d10 (P<0.01). Hatching weight was greater in all injected treatments than intact. Healthy hatched chicks from each treatment were allocated to 21 floor pens with three replicate pens pretreatment and 7 chicks per pen. Chicks were fed common starter and grower diets, and BW and feed intake were recorded weekly. At day 42 post-hatch, one chick from each replicate that had BW close to the mean was selected. Blood samples were collected, and, then, chicks were harvested to evaluate carcass quality. There was a decrease in feed intake and feed conversion ratio (FCR) for treatments subjected to in ovo ghrelin (P<0.01). There were increases in thigh, breast, and gizzard weights, and abdominal fat deposition in 42-d old chickens on treatment G100d10 (P<0.01). The results indicated that in ovo administration of exogenous ghrelin can improve hatching weight and post-hatch performance, and in ovo administration of 100 ng ghrelin/egg, can be efficient in increasing breast and thigh yields. When suitable hatching weight, performance, and carcass yield are the main focus of broiler production, in ovo injection of 50 ng ghrelin/egg can be beneficial.