Effects of pellet diameter and crumble size on the growth performance and relative gizzard weight of broilers

Abstract

An experiment was conducted to compare the growth performance, gizzard and relative gizzard weight (RGW) of broilers fed a mash diet, micro-pellets, or coarse and fine crumbles with or without the fines removed. A total of 300 Cobb 500 one-day-old male broiler chicks were randomly distributed into 60 battery cages with 5 broilers per cage. Cages were randomly assigned to 1 of 6 dietary treatments to provide 10 replicates per treatment in a CRD. Treatments comprised of 1) mash (M); 2) micro-pellets (MP); 3) coarse-crumbles with fines (CCF); 4) coarse-crumbles with fines removed (CCNF); 5) fine-crumbles with fines (FCF); and 6) fine-crumbles with fines removed (FCNF). Overall BW, ADG, and ADFI were increased (P < 0.001), FCR improved (P < 0.001), and RGW decreased (P < 0.001) for broilers fed MP or crumbles compared to the M diet. Broilers fed MP, CCNF, and FCNF had increased (P < 0.05) BW compared to those fed CCF and FCF. Broilers fed the CCNF had improved (P < 0.05) FCR compared to those fed all other treatments. Gizzard weight (P = 0.0007) and RGW (P < 0.0001) were higher for birds fed M, FCF, and FCNF compared to other diets. The results of this study indicated that feeding MP or crumbles to broiler chicks improved feed intake, BW, and FCR but reduced RGW. Removing the fines resulted in further improvement in BW for broilers fed crumbles. Furthermore, feeding good quality crumbles yielded similar growth performance in chicks fed micro-pellets.