Dao
Lan Nhi, Mai Van Sanh and Le Viet Ly
National Institute of Animal Husbandry, Hanoi
Abstracts
Two experiments were
conducted to evaluate the effects of different levels of cassava root meal and
processed cassava leaves supplemented to the diets based on maize stover or
natural grasses and rice straw on performance of growing-fattening male
buffaloes. In each experiment, 20 male buffaloes 19-21 months of age and body
weight of 110-130 kg was divided into 4 groups of 5 each with a randomized
block design. In Expt. I, buffaloes were fed maize stover, rice straw and
supplemented mixture of cassava root meal (CRM) and cassava leaf meal (CLM)
(ratio 1:1) with the levels of 0.8, 1.6, 2.4 and 3.2 kg. In Expt. II, buffaloes
were fed natural grasses, rice straw and supplemented 0.5 kg cassava root meal
plus 1.4, 2.8, 4.2, 5.6 kg cassava leaf silage (CLS).
Increased the levels of
cassava root meal and cassava leaf meal or cassava leaf silage resulted in
increased dry matter (DM) intake and body weight gain. At the level of 2.4 kg
mixture of CRM and CLM or 0.5 kg CRM and 5.6 kg CLS, buffaloes gained 500-600
g/day, feed consumption was 10.5-11.0 kg DM. The profit per fattening head was
230-249 thousand VND during 3 months. Cassava leaf can be used as supplemented
feed for growing fatenning buffaloes in dry form or silage.
Introduction
The major feeds for buffalo are natural grasses and crop
residues as maize stover and rice straw which are low in protein and energy.
Supplementation of high protein and energy feeds is necessary for the
growing-finishing buffalo to maximze the potential of meat production. In
Vietnam, cassava is one of the important crops for farmers in mountainous
provinces. Cassava leaf has high crude protein concentration (from 16,7 to
39,8%, Allen, 1984). However, there were not much interest to use fresh cassava
leaves in animal feeding. Buitrago (1990) stated that the great limitation of
using cassava leaf as animal feed is its content of Cyanogenic glucosides. The
most common procedures for reducing the concentration of these substances are
sun-drying and ensiling (Wanapat, 1997; Pham Sy Tiep, 1999; Duong Thanh Liem et
al., 2000). The yield of cassava leaves was 2.5-3.0 tonnes (containing 500-600
kg dry matter and 110-130 kg crude protein per ha prior to root havesting Bui
Van Chinh et al., 1992).
The objective of
the experiments was to study the effects of different levels of cassava root
meal and processed cassava leaves supplementing to diets based on natural
grasses and crop residues on performance of growing-finishing male buffaloes.
Materials and methods
Location: The experiments were carried out at the Centre for
Livestock Research and Development in the moutainous region of Thai nguyen
province
Experimental design: Fourty male swamp buffaloes (19-21
months of age) with live weight of 110-130 kg were allocated into two
experiments. In each experiment, 20 buffaloes were block and divided into 4
groups (5 per each) with a randomized block design according to body weight and
age of animals.
Processing cassava leaves: The fresh cassava leaves were
collected before havesting.
- For cassava leaf meal:
Cassava leaves were dried under sun light and groud by machine.
- For ensiling: cassava leaves were mixed with 10% cassava
root meal and salt (1 kg salt for 1 tonne of cassava leaves), put in plastic
bags and incubated for 45-50 days before feeding.
|
Table 1. The
experimental design |
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|
Feed |
Treat. 1 |
Treat. 2 |
Treat. 3 |
Treat. 4 |
|
Exp. 1.
CLM |
||||
|
Fresh maize stover (kg) |
10-12 |
10-12 |
10-12 |
10-12 |
|
Rice straw* |
Ad lib. |
Ad lib. |
Ad lib. |
ad lib. |
|
Cassava root meal (kg) |
0.4 |
0.8 |
1.2 |
1.6 |
|
Cassava leaf meal (kg) |
0.4 |
0.8 |
1.2 |
1.6 |
|
Exp. 2. CLS |
||||
|
Natural grasses (kg) |
12-15 |
12-15 |
12-15 |
12-15 |
|
Rice straw* |
Ad lib. |
Ad lib. |
Ad lib. |
ad lib. |
|
Cassava root meal (kg) |
0.5 |
0.5 |
0.5 |
0.5 |
|
Cassava leaf silage (kg) |
1.4 |
2.8 |
4.2 |
5.6 |
CLM: Cassava leaf meal
CLS: Cassava leaf silage
Animal feeding and management: Maize stover or natural
grasses and rice straw were given at 7:00; 11:00; 15:00 and 18:00 h. Cassava
root meal and processed cassava leaves (meal or silage) were given at 7:00 and
15:00 h. Buffaloes were kept and fed individually indoor with exercise dailly
for a few hours outside. Water was available in the trough which was cleaned
every day.
Data collection procedure: Refusals were weighed daily in
the morning before supplying new feeds. Body weight was determined every month
(weighed in the morning before feeding and drinking). Feed composition was
analyzed twice a month by the procedure of Vietnam, 1986.
Experimental duration: The feeding period was 3 months
(excluding the feed adaptation time of 10 days)
Statistical analysis:
Data was analyzed by ANOVA, using the General Linear Model in the
Minitab programme release 12.21 (1998).
Results and discussion
Chemical composition of feeds
Composition of the diet
ingredients was in accordance with expectations (Table 2). The values of HCN
was 14.6 mg/kg in cassava leaf silage and 18.7 mg/kg in cassava leaf meal.
These data were lower than that of previous reports by Bui Van Chinh et al.,
1992 and Wanapat et al., 1997.
|
Table 2. Chemical composition of feeds |
||||||
|
Feed |
DM(%) |
CP* |
EE* |
CF* |
NEF* |
HCN mg/kg |
|
Cassava leaf meal |
91.5 |
21.1 |
4.5 |
13.9 |
39.7 |
18.7 |
|
Cassava leaf silage |
33.4 |
16.5 |
4.6 |
16.8 |
12.0 |
14.6 |
|
Cassava root meal |
92.8 |
1.2 |
2.4 |
4.3 |
77.1 |
- |
|
Natural grasses |
22.0 |
8.8 |
1.5 |
6.9 |
16.7 |
- |
|
Maize stover |
28.4 |
4.1 |
1.2 |
4.5 |
6.7 |
- |
|
Rice straw |
89.2 |
4.6 |
1.8 |
30.5 |
29.8 |
- |
(*):
percent in dry matter
Feed intake and body weight
gain of buffaloes in Experiment I
The buffaloes in all
treatments readily consumed most feeds supplied, indicated no toxin and
palatability problems, except the buffaloes in treatment 4, they consumed only
2.6 kg/day of mixed cassava leaf and root meal (Table 3).
Dry matter intake increased
following the increace of CRM and cassava processed leaves. The dry matter
intake (kg/day) were different significantly (P<0,05) between 1 and 2
and 3 but no difference between treatment 3 and 4. Higher supplemented level of
3.2 kg did not significantly give any intake and growth (0.600 kg/day) of
buffaloes.
Table 3. Daily feed intake and body weight gain of buffaloes
fed maize stver, rice straw and supplemented CRM/CLM
|
|
Supplemental levels (kg/day) |
|||
|
CRM/CLM |
0.4/0.4 |
0.8/0.8 |
1.2/1.2 |
1.3/1.3 |
|
Total DM intake (kg/day) |
5.5a |
5.9b |
6.3c |
6.4c |
|
% Body weight |
2.67 |
2.82 |
2.93 |
2.94 |
|
CRM and CLM intake (kg) |
0.67 |
1.08 |
1.67 |
2.17 |
|
Maize tover intake (kg) |
3.08 |
2.97 |
3.00 |
3.25 |
|
Rice straw intake (kg) |
1.75 |
1.85 |
1.60 |
0.98 |
|
Total crude protein (g) |
351a |
437b |
518c |
545c |
|
Metabolisable energy (MJ) |
42.0a |
48.9b |
54.9c |
56.4c |
|
Initial weight (kg) |
194.6 |
196.7 |
197.5 |
195.6 |
|
Final weight (kg) |
220.3 |
235.5 |
250.1 |
249.6 |
|
Total gain (kg) |
25.7 |
38.8 |
52.6 |
54.0 |
|
Live weight gain (kg/day) |
0.285a |
0.431b |
0.585c |
0.600c |
|
Feed conversion (kg DM/kg of
gain) |
19.2 |
13.7 |
10.7 |
10.6 |
abc Different superscript within
rows indicates significant diferences
Feed intake and body weight
gain of buffaloes in Experiment II
There was a trend towards increase of body weight gain
(kg/day) follow the increase levels of supplemental. Dry matter intake
increased following the increace of cassava leaf silage. The dry matter intake
(kg/day) were different significantly (P<0,05) between treatment 1 and 3 and 4. Body weight
gain also increased following the increase of cassava leaf silage.
|
Table 4. Daily feed intake and body weight gain of
buffaloes fed natural grasses, rice straw and supplemented CRM/CLS |
||||
|
|
CRM/CLS (kg/day) |
|||
|
|
0.5/1.4 |
0.5/2.8 |
0.5/4.2 |
0.5/5.6 |
|
Total DM intake (kg/day) |
5.3a |
5.6ab |
5.8b |
6.1c |
|
% Body weight |
2.78 |
2.84 |
2.80 |
2.90 |
|
CRM and ECL intake |
0.69 |
1.17 |
1.45 |
2.10 |
|
Natural grasses intake |
2.86 |
2.95 |
3.05 |
2.98 |
|
Rice straw intake |
1.75 |
1.47 |
1.30 |
1.05 |
|
Total crude protein (g) |
433a |
498ab |
535b |
563c |
|
Metabolis energy (MJ) |
43.0a |
46.9ab |
49.7b |
54.0c |
|
Initial weight (kg) |
193.4 |
195.8 |
192.1 |
196.9 |
|
Final weight (kg) |
223.5 |
230.4 |
235.7 |
247.0 |
|
Total weight gain (kg) |
20.5 |
34.6 |
43.6 |
50.1 |
|
Live weight gain (g/day) |
0.334a |
0.384b |
0.483c |
0.557c |
|
Feed conversion (kg DM/kg of
gain) |
15.5 |
14.4 |
11.8 |
10.9 |
abc Different superscript within
rows indicates significant diferences
The mean daily gain was
highest (0.550-0.600 kg/day) and the best feed conversion (about 11 kg DM/kg
weight gain) in the treatments with 30-35 % of CRM and cassava leaves in total
DM intake. These results were in agreement with the study of Wanapat and
Wachirapakorn (1990) who reported that the daily gain was 542-551 g and feed
conversion rate was 10.6-10.7 kg DM/kg weight gain of the feedlot buffaloes fed
on ure-treated rice straw based diet with supplement of concentrate.
Economic Efficiency
|
Table 5. Estimation of cost/benefit from feeding
growing-finishing buffalo (1,000 VND/head) |
||||||||
|
|
CRM/CLM (kg/day) |
CRM/ECL (kg/day) |
||||||
|
Supplemental levels |
0.4/0.4 |
0.8/0.8 |
1.2/1.2 |
1.6/1.6 |
0.5/1.4 |
0.5/2.8 |
0.5/4.2 |
0.5/5.6 |
|
Init.value of buffalo |
1654 |
1671 |
1678 |
1662 |
1643 |
1664 |
1632 |
1673 |
|
Total feed cost |
177 |
245 |
312 |
320 |
170 |
206 |
237 |
271 |
|
Other costs |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
|
Total |
1861 |
1946 |
2020 |
2012 |
1843 |
1900 |
1899 |
1974 |
|
Fin.value of buffalo |
1992 |
2119 |
2250 |
2246 |
2012 |
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