Three experiments were conducted to evaluate the existing native
beef cattle production system and available resources in order to
develop, improve production, management and sustainable production
system and potential of production and utilization of cassava hay
(CH) as supplementation in native beef cattle.
In the first experiment, a formal survey were to collect
existing data and information concerning beef cattle production
system practiced by small holder farmers in Nasaythong district,
Vientiane Municipality. Two areas were selected, irrigated and
rain-fed areas involving 4 villages with 50 farmers/households. A
semi-structure questionnaire was used for interviews as well as
observations and feed samples were noted and collected. Based on
this survey, it was found that beef cattle raising has been closely
associated with farmers' livelihood where cattle provided as source
of protein food, important income, source and social value. Average
household numbers across the two areas were 5.6 members with 53.5 %
being females. Landholding ranges from 1.7-7.2 ha/household in
irrigated and 0.12-0.16 ha/household in rain-fed area. Rice is by
for the most abundant cash crop grown with 1.6 and 3.0 t/ha rice
yield in rain-fed and irrigated areas, respectively. Cattle raised
were 17 and 7 heads/household in rain-fed and irrigated areas,
respectively. It was also found that most of farmers in irrigated
area paid more attention and managed beef herd better e,g. use of
vaccination, better feedings and feed use. Grazing cattle on
roadside, forest area and paddy fields. A common for two sites.
Crop residues are available e.g. sugarcane tops, dried cassava leaf
particularly rice straw, which has been collected and used for
cattle. However, other sources have been limitedly used. Farmers
have been shown interested in improving feed use and better
management since market price of cattle is very attractive. Group
forming and support from government in relation to promoting and
supporting beef cattle raising as well as extension were highly
required by the interviewed farmers. Native beef cattle production
would be a sustainable system for village farmers it more local be
resources exploited in Nasaythong district, Lao PDR.
In the second experiment, local and introduced cassava varieties
were studied to compare yield and chemical composition using a 2x2
Factorial arrangement in a Randomized complete block design with 4
replications, the aims were to determine the effects of different
initial and subsequent cutting on yields and chemical compositions
of local and introduced variety (Rayong72; RY72) from Thailand. The
results revealed that fresh, dry matter (DM) and protein yields of
cassava variety RY72 at each harvest were significantly higher
(P<0.001) than local variety. As a consequence, 35.1, 7.7, 1.9
and 15.2, 3.5, 0.8 ton/ha for total fresh, DM and protein yield of
RY72 and local varieties, respectively.
The chemical analysis of cassava foliage (CF), CP percentages
were from 22.6 to 25.8% in RY 72 variety while 17.2 to 25% in local
variety. However, in this study it was found that local variety was
lower in CP content than RY 72 variety. Fiber components of cassava
foliage; NDF (54.2 to 58.8 % and 53.2 to 55.7 %), ADF (26.2 to 30.5
% and 24.7 to 34.2 %), ADL (9.4 to 11.6 % and 11.3 to 11.8 %), in
RY 72 and local varieties, respectively. Fiber components of CF in
local variety were slightly higher than RY 72 variety. In this
study, condensed tannin (CT) were 3.3 to 3.4 and 3.5 to 3.8 %, in
RY72 and local varieties, respectively. Concentration of chemical
composition was highly different among varieties and cassava
cultivation to produce cassava hay for ruminant feeding could be
practiced under Lao condition.
In the third experiment, four, 2-year old rumen fistulated bulls
were randomly assigned according to a 4 x 4 Latin square design to
receive four dietary treatments; Treatment (T1) = rice straw (RS)
(Control), T2 = RS + 200 g CH/head/d, T3 = RS + 400 g CH/head/d, T4
= RS + 600 g CH/head/d. All animals were dewormed and injected with
vitamin A, D3, E prior to commencement of
experimentation. Each feeding period consisted of 14 days for rice
straw intake measurement and followed by a 7-day collection period
of feed, rumen fluid, blood and fecal samples. Under this current
experiment, it was found that rice straw and CH contained 5.3 and
27.3% CP and 3.6% condensed-tannins (CH), respectively. Weight
changes of cattle were affected by CH supplementation and improved
weight gain were obtained at 400, 600 g CH/head/d supplementation.
Intakes of rice straw were significantly enhanced by CH
supplementation and were highest at 600g/hd/d supplementation. As a
consequence, total DM intakes were increased by CH supplementation
as compared to control. Ruminal temperature and pH were found in
normal range (38-39° C) (pH = 6.4-6.6). Ruminal
NH3-N and BUN were increased as CH level increased.
Bacterial and fungal zoospore populations were significantly
increased while protozoal population was decreased as a result of
CH supplementation. Digestion coefficients and digestible nutrient
intakes particularly those of DM, OM, and CP were remarkably
enhanced (P<0.05) by CH supplementation. Over all energy intake
with regards to ME (by calculation) was subsequently improved by
level of CH supplementation.
In summary, results from three experiments revealed that native
beef cattle production would be a sustainable system for village
farmers based on local resources in Nasaythong district, Lao PDR.
Cassava foliage harvested at 3 months and followed by 2 months to
produce CH resulted in higher DM and protein yields in RY72 than in
local variety. CH supplementation for native cattle can improve
rumen ecology by maintaining normal pH, temperature, increasing
bacterial and fungal zoospore population and decreasing protozoal
population particularly at 600 g/hd/d. The use of CH as a
supplement for cattle in Lao, PDR should be further
recommended.
Key Words: Native beef cattle; Village survey;
Management; Cutting; Cassava variety; Rice straw; Cassava hay;
Rumen ecology; Digestibility; Intake.