Effects of potato (Solanum tuberosum l. cv. golden valley) protein on performance, nutrient metabolizability, and cecal microflora in broilers

In this study, 600 Ross broiler chicks (initially 44.2 +/- 2.11 g) were used to investigate the use of potato protein (PP) as an alternative to antibiotics. The PP was obtained from the tubers of Solanum tuberosum L. cv. Golden valley potatoes known to have antimicrobial activity against gram positive and negative bacteria. Birds were randomly allotted to five dietary treatments, comprising 4 replicates in each with 30 birds per replicate. Dietary treatments were basal diet added with antibiotics (PC, Positive control), and basal diet added with 0.0, 0.25, 0.50 and 0.75% PP. Birds fed PC diet had greater body weight gain (P = 0.098) during starter period than birds fed 0.0 and 0.75% PP diet, while the apparent metabolisability of DM was higher (P = 0.037) in birds fed 0.50% PP and PC diet when compared with birds fed 0.0% PP diet. In general the population of total bacteria and coliforms in excreta and cecal contents was lowest in birds fed PC diet and highest in birds fed 0.0% PP diet. An increase in dietary PP resulted in an increase (quadratic, P = 0.051) in feed intake of birds during starter period, wherein the highest feed intake was noticed in birds fed 0.50% PP diet. In addition, linear reduction in the number of coliforms (d 21, P < 0.10, and d 42, P < 0.01) and total bacteria (d 42, P < 0.01) in excreta, and total bacteria (P < 0.01) and coliforms (P < 0.10) in cecal contents were noticed as the level of PP inclusion was increased in the diet of birds. Thus, potato protein obtained from tubers of Golden valley potatoes showed in-vivo antimicrobial activity being more effective at 0.75% inclusion level, while the feed intake, body weight gain and nutrient metabolisability were maximized when PP were included at 0.50% level in the diet of birds. Hence potato protein has the potential to be used as an alternative to antibiotics in the diet of broilers.