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\hypersetup{pdftitle={Evaluation of Drymatter Yields and Silage Quality of Sweetpotato Dual Purpose Varieties},pdfauthor={Lonita Manoa, Charles Gachuiri, Ben Lukuyu, Jane Wamatu},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={Animal nutrition , dual purpose sweet potato vines and roots, nutritive value, silage},pdfpagemode=None,colorlinks=true}
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\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 14-16, 2010, Zurich}}\\[1ex] \Large{``World Food System  ---\\A Contribution from Europe''\\[2ex]}}
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\begin{center}
\Large{\textbf{Evaluation of Drymatter Yields and Silage Quality of Sweetpotato Dual Purpose Varieties\footnote{\textbf{Contact Address:} Charles Gachuiri, University of Nairobi, Animal Production, 29053, 00625~Nairobi, Kenya, \mbox{e-mail}: \email{gachuiri@uonbi.ac.ke}}\\[0.8ex]}}
\normalsize{\textsc{Lonita Manoa$^{1}$, Charles Gachuiri$^{2}$, Ben Lukuyu$^{3}$, Jane Wamatu$^{4}$}}
\end{center}
\begin{itemize*}
\item[]{\small{\textit{$^{1}$University of Nairobi, Animal Production, }}}
\item[]{\small{\textit{$^{2}$University of Nairobi, Animal Production, Kenya}}}
\item[]{\small{\textit{$^{3}$International Livestock Research Institute, Improving Market Opportunities, }}}
\item[]{\small{\textit{$^{4}$University of Hohenheim, Institute of Aquaculture Systems and Animal Nutrition in the Tropics and Subtropics, Germany}}}
\end{itemize*}
\index[author]{Manoa, Lonita}
\index[author]{Gachuiri, Charles}
\index[author]{Lukuyu, Ben}
\index[author]{Wamatu, Jane}
\begin{center}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
Recently, sweet potato, \textit{Ipomoea batatas}, has attracted attention of various research organisations, governments, public and international developmental agencies and industries in the tropics and subtropics due to its adaptability to semi arid marginal sites and the possibility of using it both as human food and livestock feed. Two years ago, the International Potato Centre initiated a study to evaluate the role sweet potato can play in livestock production in East Africa (Peters, 2008). The study revealed that sweetpotato, can play a significant role in the partial replacement of napier grass or other pastures in the nutrition of dairy cows, goats and pigs. Dual purpose varieties (those with high biomass yield from both tubers and vines) are particularly preferred so as to give an opportunity to farmers to have enough fodder for livestock as well as tubers for human consumption. 



This study is evaluating six improved dual purpose sweet potato varieties namely Gweri, NASPOT$^{-1}$, Wagabolige, Kemb-23, Musinyamu and 10300.152. Cuttings for planting were obtained from the University of Nairobi Field Station from germplasm that had been planted by the International Potato Centre. They were planted on March 15\textsuperscript{th}.  



The objectives are to determine the dry matter yield of the six dual purpose sweet potato varieties harvested at 75 and 150 days, to determine the nutritional quality of the freshly harvested varieties and to determine the silage quality of the six varieties with and without additives after 30, 60 and 90 days. Additives will include combinations of cassava meal, molasses, fresh and sun"=dried chicken manure, all locally available and affordable materials. 



Proximate analysis, pH, \textit{in~vitro} gas production, ammonia, volatile fatty acids, metabolisable energy will be carried out on samples. Microbiological tests for aflatoxin, \textit{Salmonella }and \textit{E.~coli} will be performed on vines fermented with various types of chicken manure, to ensure feed safety. Aflatoxin analysis will be determined using thin layer chromatography for qualitative analysis and Elisa for quantitative analysis. \textit{E.~coli} and \textit{Salmonella }will be determined from enterobacteria diagnosis using culture methods.



}

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\noindent \textbf{Keywords:} Animal nutrition , dual purpose sweet potato vines and roots, nutritive value, silage
\index[key]{Animal!nutrition }
\index[key]{Dual purpose sweet potato vines and roots}
\index[key]{Nutritive value}
\index[key]{Silage}
\end{document}