Productive performance and histological features of intestinal mucosa of broiler chickens fed different dietary protein levels

Abstract

To evaluate the effect of decreasing dietary protein on growth performance, carcass traits, and intestinal mucosal morphometry, 180 female Hubbard strain broiler chickens were divided into 3 groups and fed 3 isoenergetic diets ad libitum from 14 d of age until slaughter age (49 d). The treatments varied according to 3 protein levels: high-protein diet (HiP, 22.5% CP, DM basis), medium-protein diet (MedP, 20.5% CP), and low-protein diet (LowP, 18.5%). Diets were obtained by replacing wheat middlings with soybean meal and were formulated to meet or exceed broiler amino acid requirements of the NRC. Morphometric indices of duodenum, jejunum, and ileum were measured at the end of the feeding period and included villus height, crypt depth, villus-to-crypt ratio, and apparent villus surface area. The dietary protein level had a significant effect on final BW of birds, whereas ADG, ADFI, and feed efficiency remained unaffected by dietary treatment. The muscle (breast and drumstick) yields were significantly higher in birds fed the HiP diet compared with those of the MedP and LowP diets. Meat quality traits were not affected by the protein level. The villus surface area of all intestinal segments did not change among groups. Instead, reducing the dietary protein level to 20.5% resulted in a higher villus height and villus height to crypt depth ratio in the duodenum and ileum. On the basis of our findings, even if the high-protein diet promoted meat yield, a medium-protein diet could positively support broiler growth performance, as confirmed by favorable morphometric features of the intestine.

Effect of oregano oil dietary supplementation on production parameters, height of intestinal villi and the antioxidant capacity in the breast of broiler

“…Other researchers report no morphological changes at doses of 500 mg of oregano oil per kg of feed (Onderci et al 2008, Betancourt et al 2012, Emami et al 2012, Laudadio et al 2012, Wu et al 2013. Olnood et al (2015) mentioned that additives could favor the development of bacteria and improve growth of the anatomical structures.…”

“…The main function of the villi is the absorption of nutrients, an activity which is partially dependent on its size. In addition, villi can be considered as intestinal health indicator (Uni et al 1998, Laudadio et al 2012. Natural additives improve the epithelium surface structure and increase the enterocytes size Peng 2008, Incharoen et al 2010).…”

Serum antioxidants and trace minerals as influenced by vitamins, probiotics and proteins in broiler breeders

“…Previously, some of the authors have reported improved reproductive performance by feeding lower protein levels in male broiler breeders (Zhang et al 1999;Romero-Sanchez et al 2007). Similarly, Laudadio et al (2012) recently found that a lower protein level (20.5%) is a better choice for optimum level of growth in broilers than a higher protein level (22.5%). In all these reports, the antioxidants' status of the birds has not been measured; however, it is inferred that the improved performance achieved with the lower level of protein may have some association with enhanced anti-oxidant status, which needs to be further explored.…”

“…Previously, Lactobacillus and Bifadobacterium have been reported to improve the anti-oxidant status in birds (Sohail et al 2011) by decreasing the production of free radicals (Fuller 1989). The lower levels of crude protein (CP) control body weight gain and decrease blood urea, which is translated into improved reproductive performance of the birds (Zhang et al 1989;Romero-Sanchez et al 2007;Laudadio et al 2012). Some authors have indicated that different levels of dietary protein may affect the serum antioxidants in poultry (MachIn et al 2004).…”

Effects of crude protein levels on egg quality traits of brown layers raised in two production systems

“…The choice of the adequate level of protein is favorable both for the bird, which might perform its metabolic functions in a potentiated way, as well as for the producer, who might maximize its financial resources through saving with protein sources (Sakomura et al, 2002;Laudadio et al, 2012a;Laudadio et al, 2012b).…”