Intake, digestibility, rumen protein synthesis, and growth performance of Malawi Zebu steers fed diets containing rangeland-based protein sources
The study evaluated effects of feeding Malawi Zebu steers with diets containing baobab (Adansonia digitata) seed meal and white thorn tree (Vachellia polyacantha) leaf-meal as alternative protein sources to soybean meal on dry matter intake (DMI), total tract nutrient digestibility, rumen microbial nitrogen supply and growth performance. Thirty Malawi Zebu steers (181 ± 21.4 kg and 29 months), put into individual pens, were randomly assigned to three treatments (10 steers per treatment) made up of rangeland hay and maize bran with either baobab seed meal (baobab diet), V. polyacantha leaf-meal (Vachellia diet), or soybean meal (soybean diet, control) as the protein source. Steers fed the soybean and baobab diets had higher (P ≤ 0.05) DMI, final BW, average daily gain (ADG), and total tract nutrient digestibility of DM, NDF, CP and crude fat than those fed the Vachellia diet. Steers fed the soybean diet had the highest feed conversion ratio followed by those fed the baobab and Vachellia diets, respectively (P ≤ 0.05). Steers fed the baobab diet had the highest rumen microbial N followed by the soybean- and Vachellia-fed steers in that order (P ≤ 0.05). Steers fed the baobab diet had higher microbial N supply, comparable DMI, ADG, FCR, and nutrient digestibility to the soybean diet. The baobab seed meal could be an alternative protein source to the soybean meal for beef production in Malawi.
KeywordsAdansonia digitata seed meal Beef production Vachellia polyacantha leaf-meal
This study was made possible through the financial assistance of the Royal Kingdom of Norway through the Capacity Building for Managing Climate Change Programme in Malawi.
Compliance with ethical standards
Ethical clearance (SU-ACUD14-00075) for the current research was provided by Stellenbosch University Human Research (Humanities) Ethics Committee.
Conflict of interest
The authors declare that they have no conflict of interest.
- AOAC International., 2002. Official methods of analysis of AOAC International. Gaithersburg: AOAC International.Google Scholar
- Assogbadjo, A.E., Chadare, F.J., Kakaï, R.G., Fandohan, B. and Baidu-Forson, J.J., 2012. Variation in biochemical composition of baobab (Adansonia digitata) pulp, leaves and seeds in relation to soil types and tree provenances. Agriculture, Ecosystems and Environment, 157, 94–99.CrossRefGoogle Scholar
- Chen, X.B. and Gomes, M.J., 1992. Estimation of microbial protein supply to sheep and cattle based on urinary excretion of purine derivatives - an overview of the technical details. Rowett Res. Institute, Bucksburn, Aberdeen AB2 9SB, UK 1–19.Google Scholar
- Dzanja, J., Kapondamgaga, P. and Tchale, H., 2013. Value Chain Analysis of Beef in Central and Southern Malawi (Case Studies of Lilongwe and Chikhwawa Districts). International Journal of Physical and Social Sciences 4, 92–103.Google Scholar
- FAOSTAT, 2017. Production data on live animals: Malawi. Food and Agriculture, Rome.Google Scholar
- Frutos, P., Hervás, G., Giráldez, F.J. and Mantecón, A.R., 2004. Review. Tannins and ruminant nutrition. Spanish Journal of Agriculture Research, 191–202.Google Scholar
- Goering, H.K. and Van Soest, P.J., 1970. Forage fiber analyses (Apparatus, reagants, procedures and some applications)- Agricultural handbook no.379. US Dept. of Agriculture, Washington DC., USA.Google Scholar
- Hall, M.B., 2009. Determination of starch, including maltooligosaccharides, in animal feeds: Comparison of methods and a method recommended for AOAC collaborative study. Journal of AOAC International, 92, 42–49.Google Scholar
- Makkar, H.P.S., 2000. Quantification of tannins in tree foliage, in: IAEA, Vienna. p. 6221.Google Scholar
- Mertens, D.R., 2009. Impact of NDF content and digestibility on dairy cow performance. Western Canadian Dairy Seminar (WCDS). Advances in Dairy Technology. 21, 191–201.Google Scholar
- Mertens, D.R., Allen, M., Carmany, J., Clegg, J., Davidowicz, A., Drouches, M., Frank, K., Gambin, D., Garkie, M., Gildemeister, B., Jeffress, D., Jeon, C.S., Jones, D., Kaplan, D., Kim, G.N., Kobata, S., Main, D., Moua, X., Paul, B., Robertson, J., Taysom, D., Thiex, N., Williams, J. and Wolf, M., 2002. Gravimetric determination of amylase-treated neutral detergent fiber in feeds with refluxing in beakers or crucibles: Collaborative study. Journal of AOAC International 85, 1217–1240.Google Scholar
- Mtimuni, J.P., 2013. Forages and feed resources, in: Smallholder Dairy Production in Malawi: Current Status and Future Solutions, Scoping Papers: Optimising Smallholder Dairying.Google Scholar
- NRC, 2001. Nutrient requirements of dairy cattle. 7th rev. ed. Natl. Acad. Sci., Washington, D.CGoogle Scholar
- Schalla, A., Meyer, L., Meyer, Z., Onetti, S., Schultz, A. and Goeser, J., 2012. Hot topic: apparent total-tract nutrient digestibilities measured commercially using 120-hour in vitro indigestible neutral detergent fiber as a marker are related to commercial dairy cattle performance. Journal of Dairy Science, 95, 5109–14.CrossRefGoogle Scholar