Changes in ghrelin mRNA level, plasma growth hormone concentration and performance in different dietary energy and protein levels in broiler chicken

Abstract

We studied the effects of different energy and protein contents of the diet on performance, growth hormone concentration and ghrelin gene expression in broiler chicken. Two experiments were conducted to determine whether different dietary energy and protein levels alter growth hormone concentration and ghrelin mRNA abundance in broiler chicks. Body weight and feed intake were recorded weekly. Blood, carcass traits and proventriculus samples were collected at 21, 42 and 56 days of age. Blood samples assayed for growth hormone (GH) concentration by radio immuno assay (RIA) and ghrelin gene expression from proventriculus tissue was measured by Real Time polymerase chain reaction (PCR). Feed intake and body weight gain increased in broilers fed on low-energy diets compared with those fed on high-energy diets at 21 days of age (P<0.0001). Also, increasing dietary energy improved feed conversion (FCR) at 22-42 days of age in broiler chicken (P<0.0001). Increasing levels of protein increased feed intake, body weight gain and improved FCR as compared with low level of protein. Carcass percentage and breast percentage increased in broilers fed on high protein diets compared with those fed on low-protein diets during different periods. High-energy and low-protein diets increased abdominal fat percentage in broiler chickens. The result of this experiment indicated that there was no effect of different dietary energy and protein levels on growth hormone concentration and ghrelin gene mRNA expression for broiler chicken.

Effect of ghrelin peripheral administration on growth performance, carcass quality, and selected serum parameters in broiler chickens

“…As already pointed out, ghrelin is mainly considered as a "hunger signal" in chicken, similar to its function in mammalian systems (Kaiya et al, 2007. This function is referred to the endogenous ghrelin (Kaiya et al, , 2007 and is possibly not connected with the peripherally administered exogenous ghrelin that was applied in the present study.…”

“…As already pointed out, ghrelin is mainly considered as a "hunger signal" in chicken, similar to its function in mammalian systems (Kaiya et al, 2007. This function is referred to the endogenous ghrelin (Kaiya et al, , 2007 and is possibly not connected with the peripherally administered exogenous ghrelin that was applied in the present study. The administration of exogenous ghrelin has different effects on appetite or feed intake in chickens (Stimulation/No effect/Inhibition) as reviewed by Kaiya et al, (2013).…”

“…In a study with in ovo (pre-hatching) administration of ghrelin in chicken, a significant decrease in post-hatching feed intake was observed . However, after a post-hatch treatment the results were different (Kaiya et al, (2007), since plasma ghrelin levels in laying hens were not affected by its administration. Also in other study, the plasma level of ghrelin was not correlated with the laying-performance of layer-type birds (Höhne et al, 2017).…”

Broiler Tavuklarda Probiyotik ve Değişik Kaynaklı Yağların Performans, Karkas Özellikleri, Barsak Morfolojisi, Bağışıklık Sistemi, Karaciğer Enzimleri, Kan Parametreleri ve Grelin Gen Ekspresyonu Üzerine Etkisi

“…1 shows the lowest level of ghrelin expression in broiler chickens was in the treatment which only had tallow in their diet. Ghazanfari et al [25] stated in their research that ghrelin plasma concentration decreases when fat is included in the diet indicating that ghrelin secretion is sensitive to diet composition. Salehi et al [26] found that ghrelin secretion decreased when fat was included in the diet.…”

“…Research on animals was conducted in Rudsar, Iran (37.1378° N, 50.2836° E) and all the procedures used were approved by the Ethics Committee in Animal Use (Approval date: 10/05/2016; No: 10038). The experiment, in a completely randomized design with 6 treatments and 4 replicates using 240 1-day-old male chicks of strain Ross 308, was conducted in the starter period (1-10 day), grower period (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28) and finisher period (29-42). Each replication included 10 chicks.…”