Nutrient utilization in Papua New Guinean mixed-genotype growing pigs fed boiled sweet potato or cassava roots blended with a wheat-based protein concentrate

Michael T Dom, Roy Kirkwood, Workneh K Ayalew, Pikah J Kohun, Philip C Glatz, Paul E Hughes


Sweet potato (SP) and cassava roots are important feeds in Asia-Pacific countries where local mixed genotype (MG) pigs are bred for meat production. However, the impact of dietary fibre on nutrient digestibility and N balance when roots are boiled needs examination. Two consecutive 32 d metabolic trials (Exp1 and Exp2) in 0.7 m raised double-unit crates (1.0 m × 1.0 m × 1.5 m) allowing separate collection of urine and faeces in a 4 × 4 Latin Square design with eight MG growing pigs, four in each trial with mean starting body weights of 24.7 ± 0.74 kg (Exp1) and 30.5 ± 2.15 kg (Exp2), tested the hypothesis that there would be no differences in performance, nutrient digestibility and N balance from feeding a wheat-based pellet feed (STD), 570 g/kg DM boiled SP roots (SBR43), or 550 g/kg DM boiled cassava-roots (CBR45) or milled-roots (CMR45) blended with a complementary protein concentrate at 430 or 450 g/kg DM, respectively. DM intakes on SBR43 and CBR45 were much higher (p<0.05) than CMR45 or STD, however, the ADG and FCR shared statistical similarities. Coefficient of apparent total tract digestibility (CATTD) of DM (0.81-0.88), organic matter (OM) (0.88-0.92), and energy utilization (0.97-0.99) were superior (p<0.05) in pigs fed the root-based diets than STD. Fibre, protein and fat CTTAD were also improved on the root-based diets, but ash, Ca and total P CTTAD were reduced (p<0.05) compared with STD, and from Exp 1 to Exp 2. The N digestibility (NR-Intake %) and utilization (NR-Digested %) were lower for pigs fed the root-based diets due to very high urine N losses (p<0.05). However, the N retained (g/d) were comparable and provided MG pigs with 28.2-34.4 (CBR45), 16.4-23.9 (CMR45), 27.2-31.8 (SBR43) and 23.0-27.5 (STD) g N/d respectively. Digestible nutrients were in excess of the requirements of MG pigs, particularly for protein N, and further refinement of the nutrition provided by SP and cassava root-based diets is possible.


Cassava; sweet potato; digestibility; growing pigs; nitrogen balance

Full Text:



AN, L.V., HONG, T.T.T., & LINDBERG, J.E. 2004. Ileal and total tract digestibility in growing pigs fed cassava root meal diets with inclusion of fresh, dry and ensiled sweet potato (Ipomoea batatas L. (Lam.)) leaves. Animal Feed Science and Technology 114, 127–139.

AOAC, 2012. Official Methods of Analysis. 19thed. Association of Official Analytical Chemists, Gaithersburg, Maryland.

AYALEW, W., GARIBA, D., DOM, M., AMBEN, S., BESARI, F., MORAN, C., & NIDUP, K. 2011. Genetic and cultural significance of native pigs in PNG and their phenotypic features. FAO Animal Genetic Resources.

BACH KNUDSEN, K.E. & HANSEN, I. 1991a. Gastrointestinal implications in pigs of wheat and oat fractions 1. Digestibility and bulking properties of polysaccharides and other major constituents. British Journal of Nutrition 65, 217–232.

BACH KNUDSEN, K.E., JENSEN, B.B., ANDERSEN, J.O. & HANSEN, I. 1991b. Gastrointestinal implications in pigs of wheat and oat fractions 2. Microbial activity in the gastrointestinal tract. British Journal of Nutrition 65, 233–248.

BARAMPAMA, Z. & SIMARD, R.E. 1995. Effects of soaking, cooking and fermentation on composition, in-vitro starch digestibility and nutritive value of common beans. Plant Foods for Human Nutrition 48, 349–365.

BINDELLE, J., LATERME, P. & BULDGEN, A., 2008. Nutritional and environmental consequences of dietary fiber in pig nutrition: a review. Biotechnology, Agronomy and Society, and Environment 12, 69–80.

BRADBURY J.H. & HOLLOWAY, W.D. 1988. Chemistry of Tropical Root Crops: significance for nutrition and agriculture in the Pacific. Australian Centre for International Agricultural Research Monograph Series No.6.

BRADBURY, J.H., BRADSHAW, K., JEALOUS, W., HOLLOWAY, W.D. & PHIMPISANE, T. 1988. Effect of Cooking on Nutrient Content of Tropical Root Crops from the South Pacific. Journal of the Science of Food and Agriculture 43, 333–342.

CHOCT, M., DERSJANT-LI, Y., MCLEISH, J. & PEISKER, M. 2010. Soy Oligosaccharides and Soluble Non-starch Polysaccharides: A Review of Digestion, Nutritive and Anti-nutritive Effects in Pigs and Poultry. Asian-Australasian Journal of Animal Science 23, 1386–1398.

DOM, M. & AYALEW, W. 2009a. Adaptation and testing of ensiling sweet potato tuber and vine for feeding pigs: Digestibility and nitrogen retention of mixed silage diets. Journal of the Institute of Chemists Papua New Guinea 2, 77–88.

DOM, M. & AYALEW, W. 2009b. Adaptation and testing of ensiling sweet potato tuber and vine for feeding pigs: On-station growth performance on mixed silage diets. Papua New Guinea Journal of Research Science and Technology. 1, 86–96.

DOM, M., AYALEW, W. & AMBEN, S. 2010. Development of Improved Pig Feeding Systems Using Ensiled Material: On-farm testing of feeding Sweet Potato silage to growing pigs at Tambul in Western Highlands Province. Science in New Guinea. 30, 94–104.

DOM, M., AYALEW, W., GLATZ, P., KIRKWOOD, R. & HUGHES, P. 2014. Effect on Nutrient Digestibility and Nitrogen Balance in Grower Pigs Fed Three Forms of Blended Cassava Roots. Sustainable Livestock Production in the Perspective of Food Security, Policy, Genetic Resources and Climate Change, Proceedings of the 16th AAAP Animal Science Congress Vol. II, pp. 676–679.

DOM, M.T., AYALEW, W.K., GLATZ, P.C., KIRKWOOD, R.N. & HUGHES, P.E. 2017. Nutrient utilization in grower pigs fed boiled, ensiled or milled sweet potato roots blended with a wheat-based protein concentrate. Animal Feed Science and Technology 223, 82–89.

DOMINGUEZ, P.L. & LY, J. 1997. An approach to the nutritional value for pigs of sweet potato (Ipomoea batatas L. (Lam)), Livestock Research for Rural Development. 9, 2.

FREIRE, J.P.B., DIAS, R.I.M., CUNHA, L.F. & AUMAITRE, A. 2003. The effect of genotype and dietary fibre level in the caecal bacterial enzyme activity of young piglets: digestive consequences. Animal Feed Science and Technology 106, 119–130.

GIANG, H.H., LY, L.V. & OGLE, B. 2004. Digestibility of dried and ensiled sweet potato roots and vines and their effect on the performance and economic efficiency of F1 crossbred fattening pigs. Livestock Research for Rural Development. 16, 50.

GONZALÉZ, C., DÍAZ, I., MILAGRO, L., VECCHIONACCE, H., ALEXIA, B. & LY, J. 2002 Growth performance and carcass traits in pigs fed sweet potato (Ipomoea batatas L. (Lam.)) root meal. Livestock Research for Rural Development. 14, 6.

GUIXIN, Q., VERSTEGEN, W.A. & BOSCH, M.W. 1995. Variation of the digestive capacity between genetically different pig populations: a review. Journal of Animal Physiology and Animal Nutrition 73, 233–242.

HANG, D.T. 1998. Digestibility and nitrogen retention in fattening pigs fed different levels of ensiled cassava leaves as a protein source and ensiled cassava root as energy source. Livestock Research for Rural Development. 10, 24.

HANSEN, J.A., CHWALIBOG, A., TAUSON, A.H. & SAWOSZ, E. 2006. Influence of different fiber sources on digestibility and nitrogen and energy balances in growing pigs. Archives of Animal Nutrition 60, 390–401.

HEGARTY, R.S. 2012. Livestock nutrition – a perspective on future needs in a resource-challenged planet. Animal Production Science, 52: 406–415.

HEUZÉ, V., TRAN, G., HASSOUN, P., RENAUDEAU, D. & BASTIANELLI, D. 2015. Sweet potato (Ipomoea batatas) tubers. Feedipedia, a programme by Institut national de la recherche agronomique, Centre de coopération internationale en recherche, Association Française de Zootechnie and Food and Agriculture Organization.

HIDE, R. 2003. Pig Husbandry in New Guinea. A literature review and bibliography. Australian Centre for International Agricultural Research Monograph Series No. 108.

JOHANSEN, H. & BACH KNUDSEN, K.E. 1994. Effects of wheat-flour and oat mill fractions on jejunal flow, starch degradation and absorption of glucose over an isolated loop of jejunum in pigs. British Journal of Nutrition 71, 299–313.

JOHANSEN, H.N., BACH KNUDSEN, K.E.B., SANDSTROM, B. & SKJOTH, F. 1996. Effects of varying content of soluble dietary fibre from wheat flour and oat milling fractions on gastric emptying in pigs. British Journal of Nutrition 75, 339–351.

KYRIAZAKIS, I. 2011. Opportunities to improve nutrient efficiency in pigs and poultry through breeding. Animal 5, 821–832. doi:10.1017/S1751731110002545

LE GALL, M., WARPECHOWSKI, M., JAGUELIN-PEYRAUD, Y. & NOBLET, J. 2009. Influence of dietary fiber level and pelleting on the digestibility of energy and nutrients in growing pigs and adult sows. Animal 3, 352–359.

LINDBERG, J.E. 2014. Fiber effects in nutrition and gut health in pigs. Journal of Animal Science Biotechnol. 5, 15.

LOW, A.G. 1989. Secretory response of the pig gut to non-starch polysaccharides. Animal Feed Science and Technology 23, 55–65.

LY, J., TY, C. & SAMKOL, P. 2003. N balance studies in young Mong Cai and Large White pigs fed high fibre diets based on wheat bran. Livestock Research for Rural Development. 15, 1.

MALYNICZ, G. & NAD, H. 1973. The effect of level of feeding and supplementation with sweet potato foliage on the growth performance of pigs. Papua New Guinea Agriculture Journal. 24, 139–144.

MARFO, E.K., SOMPSON, B.K., IDOWU, J.S. & OKE, O.L. 1990. Effect of Local Food Processing on Phytate Levels in Cassava, Cocoyam, Yam, maize, Sorghum, Rice, Cowpea, and Soybean. Journal of Agricultural and Food Chemistry 38, 1580–1585.

MOORE, K.L., MULLAN, B.P., CAMPBELL, R.G., & KIM, J.C. 2013. The response of entire male and female pigs from 20 to 100-kg live weight to dietary available lysine. Animal Production Science 53, 52–56.

MOTER, V. & STEIN, H.H. 2004. Effect of feed intake on endogenous losses and amino acid and energy digestibility by growing pigs. Journal of Animal Science 82, 3518–3525.

NDINDANA, W., DZAMA, K., NDIWENI, P.N.B., MASWAURE, S.M. & CHIMONYO, M. 2002. Digestibility of high fibre diets and performance of growing Zimbabwean indigenous Mukota pigs and exotic Large White pigs fed maize based diets with graded levels of maize cobs. Animal Feed Science and Technology 97, 199–208.

NGOC, T.T.B, LEN, N.T. & LINDBERG, J.E. 2013. Impact of fiber intake and source on digestibility, gut development, retention time and growth performance of indigenous and exotic pigs. Animal 7, 736–745. doi: 10.1017/S1751731112002169

NHMRC, 2013. Australian code for the care and use of animals for scientific purposes, eighth ed. National Health and Medical Research Council, Canberra, Australia.

NOBLET, J., FORTUNE, H., DUPIRE, C. & DUBOIS, S. 1993. Digestible, metabolizable and net energy values of 13 feedstuffs for growing pigs: effect of energy system. Animal Feed Science and Technology 42, 131–149.

NOBLET, J., GILBERT, H., JAGUELIN-PEYRAUD, Y. & LEBRUN, T. 2013. Evidence of genetic variability for digestive efficiency in the growing pig fed a fibrous diet. Animal 7(8), 1259–1264.

NOBLET, J. & LE GOFF, G. 2001. Effect of dietary fiber on the energy value of feeds for pigs. Animal Feed Science and Technology 90, 35–52.

NOBLET, J. & VAN MILGEN, J. 2004. Energy value of pig feeds: Effect of pig body weight and energy evaluation system. Journal of Animal Science 82, 229–238.

NRC, 1998. Nutrient Requirements of Swine, tenth ed. National Research Council, National Academy Press, Washington DC, USA.

OCHETIM, S. 1993. Traditional pig farming on the South Pacific: Problems and opportunities for increasing productivity. Asian-Australasian Journal of Animal Science 6, 347–360.

OSPINA, L., PRESTON, T.R. & OGLE, B. 1995. Effect of protein supply in cassava root meal based diets on the performance of growing-finishing pigs. Livestock Research for Rural Development. 7, 2.

PASCUAL-REAS, B. 1997. A comparative study on the digestibility of cassava, maize, sorghum and barley in various segments of the digestive tract of growing pigs. Livestock Research for Rural Development. 9, 5.

PETERS, D., TINH, N.T., MINH, T.T., TON, P.H., YEN, N.T. & HOANH, M.T. 2001. Pig feed improvement through enhanced use of sweet potato roots and vines in Northern and Central Vietnam. International Potato Center (CIP), Hanoi, Vietnam.

Quartermain, A.R. & Kohun, P.J. 2002. Pig production in Papua New Guinea, in: Jones, R., (Ed), Priorities for Pig Research in Southeast Asia and the Pacific to 2010, ACIAR Working Paper No. 53, Australian Centre for International Agricultural Research, Canberra, pp. 40–47.

REGNIER, C., BOCAGE, B., ARCHIMÈDE, H., NOBLET, J. & RENAUDEAU, D. 2013. Digestive utilization of tropical foliages of cassava, sweet potatoes, wild cocoyam and erythrina in Creole growing pigs. Animal Feed Science and Technology 180, 44–54.

RENAUDEAU, D., BOCAGE, B. & NOBLET, J. 2006. Influence of energy intake on protein and lipid deposition in Creole and Large White growing pigs in a humid tropical climate. Journal of Animal Science 82, 937–945.

ROSE, C.J. & WHITE, G.A. 1980. Apparent digestibilities of DM, OM, CP, energy and ADF of chopped raw sweet potato (Ipomoea batatas) by village pigs. Papua New Guinea Agriculture Journal. 31, 69–72.

ROSE, C.J. & WILLIAMS, W.T. 1983. Ingestion of Earthworms, Pontoscolex corethrurus, by Village Pigs, Sus Scrofa papuensis, in the Highlands of Papua New Guinea. Applied Animal Ethology 11, 131–139.

SCHULZE, H., VAN LEEUWEN, P., VERSTEGEN, M.W.A., HUISMAN, J., SOUFFRANT, W.B. & AHRENS, F. 1994. Effect of level of dietary neutral detergent fiber on ileal apparent digestibility and ileal nitrogen losses in pigs. Journal of Animal Science 72, 2362–2368.

SCHULZE, H., VAN LEEUWEN, P., VERSTEGEN, M.W.A. & VAN DEN BERG, J.W.O. 1995. Dietary Level and Source of Neutral Detergent Fibre and Ileal Endogenous Nitrogen Flow in Pigs. Journal of Animal Science 73, 441–448.

SCOTT, G., ROSEGRANT, M.W. & RINGLER, C. 2000. Global projections for root and tuber crops to the year 2020. Food Policy 25, 561–597.

SCOTT, G.J.H. 1992. Sweet potatoes as animal feed in developing countries: present pattern and future perspectives, in: Machin, D., Nyvold, S., (Eds.), Roots, tubers, plantain and bananas in animal feeding, FAO Animal Production and Health Paper No. 95, Rome, pp. 183–202.

SPENCER, P.B.S., HAMPTON, J., LAPIDGE, S.A., MITCHELL, J., LEE, J. & PLUSKE, J.R. 2006. An assessment of the genetic diversity and structure within and among populations of wild pigs (Sus scrofa) from Australia and Papua New Guinea. Journal of Genetics 85, 63–66.

TEKA, A., EMIRE, A.A., HAKI, G.D. & GEZMU, T.B. 2013. Effects of processing on physicochemical and anti-nutritional factors of cassava (Manihot Esculenta Crantz) grown in Ethiopia. International Journal of Science Innovations and Discoveries 3, 212–222.

TETENS, I., LIVESEY, G. & EGGUM, B.O. 1996. Effects of the type and level of dietary fiber supplements on nitrogen retention and excretion patterns. British Journal of Nutrition 75, 461–469.

TOMITA, Y., HAYASHI, K. & HASHIZUME, T. 1985. Palatability of pigs to sweet potato-silage and digestion trial by them. Bulletin of the Faculty of Agriculture, Kagoshima University No. 35, 75–80.

TZUDIR, I., SAVINO, N. & DAS, K.C. 2012. Effect of replacement of maize with tapioca (Manihot esculenta) root meal on the performance of growing crossbred pigs. Livestock Research for Rural Development. 24, 197.

WENK, C. 2001. The role of dietary fibre in the digestive physiology of the pig. Animal Feed Science and Technology 90, 21–23.

WILFART, A., MONTAGNE, L., SIMMINS, H., NOBLET, J. & VAN MILGEN, J. 2007. Effect of fibre content in the diet on the mean retention time in different segments of the digestive tract in growing pigs. Livestock Science 107, 27–29.


  • There are currently no refbacks.

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.