HomePhilippine Journal of Veterinary and Animal Sciencesvol. 26 no. 1 (2000)

Feeding Value of Protein-Enriched Sweet Potato Pulp for Broilers

Rodolfo A. Demo-os | Ma. Teresa SJ. Valdez | Mariano C. Mapili Jr.

Discipline: Veterinary Medicine, Animal Science



The study was conducted to develop a feed product from sweet potato pulp through the adoption of protein enrichment technology modified to suit farm level conditions. Specifically, the most appropriate degree of wetness of the pulp, fungal culture used in fermentation, non-protein nitrogen source/s for the nutrient mixture and technique of sterilizing the fermentation substrate to produce a protein-rich broiler feed from sweet potato pulp were investigated.

Sweet potato pulp (fiber), a solid waste from starch processing, was gathered from two commercial plants in the towns of Calasiao and Rosales, in Pangasinan. Protein-enriched sweet potato pulp was produced using three non-protein nitrogen sources (urea, ammonium phosphate, ammonium sulfate) in the preparation of nutrient mixture for the substrate; three fungal cultures (Trichoderma harzianum, Aspergillus niger, Rhizopus oligosporus) for substrate fermentation; two degrees of wetness (low-moisture vs. high-moisture) of the pulp; and two substrate sterilization techniques (aseptic vs. semi-aseptic). The protein-rich feed products resulting from various treatments were sampled for determination of proximate composition and test-fed to broilers through feeding trials.

There were 17 to 20-fold increases in the crude protein content of sweet potato pulp after protein enrichment, compared to the original material. High-moisture sweet potato pulp contained higher percentage of crude protein than low-moisture pulp. T. harzianum-fermented sweet potato pulp contained 7-9% more crude protein than protein-enriched sweet potato pulp fermented by R. oligosporus or A. niger.

Feeding trial results showed 0.7-3.8% improvement in gain in weight and 6.4-15.8% improvement in feed conversion when protein-enriched sweet potato pulp was incorporated in the finisher ration. Cost efficiency analysis revealed that savings on feed cost range from PhP2.54-3.81 per bird (finishing stage) and PhP0.49-3.06 per bird (growing-finishing stage).