Nutrient Value and In Vitro Gas Production of African Wild Cocoyam ( Colocasia esculentum )

• Published in: African journal of food, agriculture, nutrition, and development : AJFAND Vol. 9; no. 1; pp. 593 - 607
• Main Authors: Babayemi, O.J, Bamikole, M.A
• Format: Journal Article
• Language: English
• Published: Nairobi Rural Outreach Program 01-01-2009
• Subjects: Animal nutrition; Cocoyam, nutrients, metabolites, gas production; Colocasia; Flowers & plants; Food and nutrition; Food supply; Health and Medicine; Nutrition; Nutritional aspects; Ruminants; Saponins; Science and Technology; Scientific research; Nigeria
• ISSN: 1684-5358; 1684-5358; 1684-5374
• DOI: 10.4314/ajfand.v9i1.19215

Cost of feeding conventional feedstuffs to ruminants in Nigeria is
prohibitive. African wild cocoyam ( Colocasia esculentum ) is an
unconventional energy feed source and non human edible food. The study
determined the chemical composition and energy content, secondary
metabolites and in vitro gas production characteristics of the African
wild cocoyam (AWC). There were two main treatments which comprised
soaking in boiled water or cold water for 0 (raw as control) 3, 6 and 9
days. Dry matter (DM) of boiled water treated wild cocoyam (BWTAWC) and
DM in cold water treated wild cocoyam (CWTAWC) decreased from 64 % to
43 % in 9 day BWTAWC and 64 % to 52 % in 9 day CWTAWC. Crude fibre,
ether extract, neutral detergent fibre and gross energy contents
decreased with increasing days of soaking and ranged from 11 - 21 %
(BWTAWC) and 18 - 21 % (CWTAWC), 3.9 - 6.5 % (BWTAWC) and 5 - 6.5 %
(CWTAWC), 32.5 - 56.1 % (BWTAWC) and 38 - 56.1 % (CWTAWC) and 3.66 -
4.29 % (BWTAWC) and 4.10 - 4.29 % (CWTAWC), respectively. Method of
soaking and length of soaking marginally increased contents of crude
protein (range = 4.7 - 5.8 %) and ash (range = 8 - 13 %). Secondary
metabolites present were saponin and steroids, with no tannin. Medium
saponin content was detected and it decreased by soaking method and
duration of soaking. There were significant (P < 0.05) differences
in the metabolisable energy (ME) (Range = 4.33 - 9.62 MJ/Kg DM and 4.33
- 8.59 MJ/Kg DM for CWTAWC and BWTAWC respectively), organic matter
digestibility (OMD) (Range = 32.26 - 56.6 % and 32.26 - 43.55 % for
CWTAWC and BWTAWC, respectively) and short chain fatty acids (Range
0.65 - 0.97 for both CWTAWC and BWTAWC) among the treatment means.
Methane production increased with increasing days of soaking in water
but were not significantly (P > 0.05) different. Results showed that
with high energy value, medium saponin, enhanced organic matter
digestibility and relatively low methane production, African wild
cocoyam has potential to be used as energy feed for ruminants.
Treatment by soaking in water reduced the secondary metabolites and,
therefore, safe for livestock feeding.