MEKARN Regional Conference 2007: Matching Livestock Systems with Available Resources |
Experiment 1. Four growing male goats fed ad-libitum
Tithonia diversifolia hay were allocated in a 4*4 Latin
square design to supplements of cassava chips (1% of BW), fresh
mulberry leaves (1% of BW as DM), both cassava chips and mulberry
leaves (0.5% BW of each on DM basis) or no supplement.
Supplementation did not affect the intake of the Tithonia hay thus total DM intake was higher on all the supplement treatments. Crude protein intake was highest for the treatment of mulberry leaves. N intake was lowest in the goats given Tithonia and Tithonia with cassava chips. Lowest N retention was on the Tithonia diet expressed as absolute amounts or as percentages of N intake or N digested. N intake on the diet with cassava chips was low, but the efficiency with which the N was retained was higher than on all the other diets. Live weight changes were in the same order as those for N retention with highest value on the diet with supplements of both cassava chips and mulberry leaves.
Experiment 2. Four growing male goats were assigned to a 2*2 factorial design in a 4*4 Latin square. The factors were: ad-libitum fresh tithonia foliage or tithonia hay; and supplementation with cassava root chips + mulberry leaves (1% BW of each on DM basis). Total DM intake for goats fed fresh Tithonia foliage was higher than when the Tithonia hay (plus jackfruit leaves) was fed. Supplementation with mulberry leaves and cassava chips increased DM intake compared with no supplement, reaching 46.5 g/kg live weight. Coefficients of apparent digestibility for DM, organic matter, crude protein and NDF were lowest when the Tithonia was fed as hay. Supplementation improved the coefficients on Tithonia hay but not on fresh Tithonia. Urine volume was much higher on fresh Tithonia than on sun-dried Tithonia. When the diets were supplemented the urine volume was decreased on the fresh Tithonia but not on the sun-dried Tithonia. N retention did not differ between fresh and sun-dried Tithonia but was increased when the Tithonia was supplemented with cassava chips and mulberry leaves.
Experiment 3. Four growing goats were assigned in a 4*4 Latin square to evaluate four sources of bypass protein (banana leaves, jackfruit leaves, erythrina leaves and mulberry leaves) at levels of 2% BW (DM basis) with a basal diet of ad libitum fresh Tithonia foliage. Urine volumes were highest on the banana and erythrina diets and reflected the rates of excretion of N in the urine. N retention was highest on the mulberry-supplemented diet which was not different from the diet with jackfruit. The lowest value was on the diet with banana leaves. N retention on the erythrina supplemented diet appeared to be only slightly less than on the diet with jackfruit. The weight gains broadly followed the values for N retention being much less on the Tithonia supplemented with banana leaves.
The findings of these three experiments support the hypothesis that, in goats fed tree foliages as the basal diet, digestibility indicates nutritive potential of the diet but actual performance is dependent on appropriate supplementation to increase the amino acids absorbed by the animal.
Nowadays, many new kinds of foliages, shrubs, and tree fodders
have been researched and introduced to farmers by scientists. Wild
sunflower (Tithonia diversifolia) is one of the new
foliages, which in Laos is considered to be a valuable green
manure. In Western Kenya, it is renowned as a component of
agro-forestry systems as it is rich in N, P and K which are
essential for soil fertility. Biomass from Tithonia has proven to
be valuable in improving soil fertility for crop production in
areas constrained by soil N, P and K deficiencies (Lijzenga 1998). It has been reported that addition of foliage of Tithonia
diversifolia to the cropping area leads to double the yield of
the crops and that it is more effective than urea when applied at
the same N rate (Jama et al 2000; Sanchez 2001).
In this study we are concerned with the potential use of the
Tithonia as forage for live stock. There were now several
researches relevant to its use for livestock production. Mahecha
and Rosales (2005) reported that the crude protein content in the
foliage of Tithonia was 24.2% in DM basis and that about 40% of the
protein was soluble. The percentage (in DM) of NDF was 35.3% and
ADF 30.4%. The rumen degradable protein (in sacco) was very
high (about 90% in 48h) (Rosales 1996, cited by Mahecha and
Rosales 2005). Recently, Wambui et al (2006) reported that the
daily weight gain of goats fed urea-treated maize stover as basal
diet and supplemented with Tithonia foliage was about 82.6g/day and
it was greater than when Caliandra and Sesbania foliages were used.
. The low content of tannins reported for Tithonia foliage (Wambui et al 2006) supports the idea that the protein may well be highly
soluble with poor "bypass" characteristics (Preston and Leng 1987). The fact that loss of nitrogen in the urine was higher for
Tithonia than for Calliandra or Sesbania in the study of Wambui et
al (2006) supports this suggestion that rumen ammonia levels are
high on Tithonia, resulting in high excretory levels of urea in the
urine. Similar high urine losses of nitrogen were reported for
water spinach (Ipomoea aquatica) fed at 40% (Pathoummalangsy
and Preston 2006) or as the sole diet of goats (Buntha and Ty
2006). Water spinach is similar to Tithonia in having high protein
content and high digestibility but low tannin content.
Based on the above observations it is hypothesized that the
limiting factors to efficient utilization of Tithonia as the sole
diet of goats is the high solubility of the protein resulting in
high rumen ammonia levels, which have to be excreted via the urine.
The final result is that the supply of metabolic protein to the
animal is reduced. The two ways to improve goat performance on
Tithonia foliage as the main feed would thus appear to be: to feed
easily fermentable carbohydrate to utilize the high ammonia levels
or to supplement with foliages with known rumen bypass
characteristics.
Cassava chips are reported to be excellent sources of rumen fermentable carbohydrate as they are rich (70-80%) in rapidly fermentable starch (Kearl 1982; Sommart et al 2000; Vearasilp and Mikled 2001; Gomez and Valdivieso 1983).). Chanjula et al (2003) found that cassava chips were better than cassava root waste, sweet potato roots, maize corn meal and rice bran, as a means to optimize use of NPN for rumen microbial protein synthesis. Sathapanasiri et al (1990) observed that starch of cassava is highly degraded in the rumen (94%) and completely digested in the whole tract. A similar result has been reported by Sommart et al (1991).
Mulberry leaves are traditionally used as food for silkworms in
sericulture (Subbarayappa and Bongale 1997). Mulberry leaves are
very rich in protein and minerals and low in fiber (Fotadar and
Dandin 1997). Jegou et al (1994) reported DM intakes in lactating
goats of 4.18 percent of live weight and that digestible DM was
from 78.4 to 80.8 percent. Growth rates in goats were improved when
the basal grass diet was replaced with ensiled mulberry leaves with
highest N retention when the ensiled mulberry leaves were the sole
content of the diet (Nguyen Xuan Ba et al 2005). Vu Chi Cuong et al (2005) reported
that fresh mulberry leaves could replace cottonseed meal in the
diets of growing cattle with no reduction in live weight gain. The
protein in cottonseed meal is known to be one of the best sources
of bypass protein for ruminants (Promkot and Wanapat 2003; Zhang et al 1994) thus it is reasonable to conclude that mulberry
leaves are also rich in bypass protein.
Mineral content is high in mulberry foliage and no anti-nutritional factors or toxic compounds have been identified (Makkar et al 1989; Makkar and Becker 1998, Singh et al 2002). Additionally, the mulberry samples analysed by the UFAG Laboratories in Switzerland, from the high zone of Cartago in the Central Plateau of Costa Rica, gave on a DM basis, 22 percent of crude protein (CP) 19 percent of crude fibre (CF), 2.3 percent of ether extract, 50 percent of by-pass protein and an estimated 1.48 Mcal/kg of net energy for lactation (cited by Boschini 2002)
Foliage from the Jackfruit (Artocarpus heterophyllus) has been recommended as a basal diet for lactating goats and growing kids, especially during the dry winter season when grasses are in short supply (Duyen et al 1996). Moreover, Phengvilaysouk and Kaensombath (2006) reported that the retention of N in goats only on Jackfruit foliage was 2.8 g/day which is equal to about 18 g/day of protein which, assuming the body contains 20% protein, would be reflected in a rate of live weight gain of the order of 100 g/day.
Camero and Franco (2001) presented that feeding leguminous
fodder that is high in protein can improve rumen fermentation
parameters leading to increased digestibility and intake of low
quality fibrous feeds, and hence improved animal production.
Erythrina variagata is a leguminous tree that is more
palatable than Gliricida sepium and supported higher milk
yields in goats due mainly due to differences in intake (Camero and
Franco 2001). Supplementing foliage of Erythrina
poeppigiana to goats fed King grass and banana fruit resulted
in linear increases in milk production (Esnaola et al 1990). In
an experiment with dairy cows, foliage of Erythrina
poeppigiana supported better economical returns than use of
soybean or fish meal as protein supplement (Pezo et al 1990).
In Laos, banana leaves are traditionally used as material for
packaging human food. Duyen et al (1996) fed banana leaves as
protein sources for lactating goats given a basal diet of rice
straw and sugarcane tops and concluded that leaves from banana
supported better milk production than the leaves of Trichanthera
gigantea but were inferior to foliage from Jackfruit.
The hypothesis that was tested in this study
was:
The nutritive value of Tithonia foliage for goats would be increased by supplementing it with: (i) a source of readily fermentable carbohydrate; and ii) a tree foliage that would supply bypass protein.
Three experiments were carried out using growing goats housed in
metabolism cages so as to measure feed intake, apparent
digestibility and N retention with different combinations of
cassava root chips and tree foliages. In Experiment 1, the basal
diet was sun-dried Tithonia foliage and the supplements were
cassava root chips and mulberry leaves. In Experiment 2: a
comparison was made of sun-dried Tithonia foliage and the fresh
foliage with and without cassava chips plus mulberry leaves. In
Experiment 3: the basal diet was fresh Tithonia foliage and four
different sources of leaves (from banana, Erythrina
variegata, mulberry and Jackfruit).
The experiments were conducted at The Faculty of Agriculture
farm, National University of Laos (Nabong campus), sited in
Parksarp Mai Village and 32 km from the City centre, Xaythany
District, Vientiane Capital, Lao PDR. The environmental temperature
during the experiments ranged from 18 to 32 degrees centigrade.
Four young goats about 5-7 months of age were purchased from local farmers for each of the experiments (different animals for each experiment). The animals were de-wormed with Ivomectin and vaccinated against Foot and mouth disease and Pasturellosis two weeks before the beginning of each experiment. They were housed and fed in individual metabolism cages built from wood and designed for collection of feed residues, faeces and urine separately. The floor area in each cage was 90*90 cm, and they were raised 85 cm from the floor.
Experiment 1. The treatments consisted of sun-dried Tithonia foliage, which was fed as basal diet (offered at 120% of recorded intake). The treatments arranged as a 4*4 Latin square were:
TH: Tithonia foliage hay
THC: TH supplemented with dried sliced cassava root at 1 % of body weight (BW) on DM basis.
THM: TH supplemented with mulberry leaves at 1% of BW on DM basis.
THCM: TH supplemented with cassava root chips at 0.5% of BW and
mulberry leaves also at 0.5% of BW, both on DM
basis.
Experiment 2.The factors compared in a 2*2 factorial arrangement within a 4*4 Latin square were:
Processing of Tithonia foliage
Sun-dried/hay (TH) or fresh (TF)
Supplementation
Mulberry (M) leaves plus cassava root chips (C) each at 1% of BW
DM basis
Experiment 3.The basal diet was fresh Tithonia foliage
supplemented with the following leaves each at 2% of BW (DM
basis):
M: Mulberry
E: Erythrina
J: Jackfruit
B: Banana
In each experiment there were 4 periods each of 12 days, the
first 7 days for adaptation to the new feed and the last 5 days for
data collection.
Tithonia foliage was collected from waste land at the sides of
the highway in Xiengkhouang province in the upland area of Laos.
The foliage, which comprised stems (about 50 cm long) with attached
leaves, was dried in the sun for 3 to 5 days. It was then packed
into polypropylene bags and transported by bus to the Experimental
farm in the University. Fresh cassava root was purchased from
local farmers in Vientiane province. The roots were sliced by hand
or machine and dried under sunlight for 4 to 5 days. Leaves of
mulberry and jackfruit were collected daily from trees in the Crop
Science department of NUOL.
The Tithonia hay, cassava chip, mulberry and jackfruit leaves were obtained according to the same procedure used in Experiment 1. Fresh Tithonia foliage was from shrubs which had been established 3 months previously, in an area close to the Goat house, using as plant material stem cuttings brought from Xiengkhouang province.
|
|
|
Photo 1. Goat fed Tithonia foliage hay in the feed
trough |
Photo 2. Goat fed Tithonia foliage hay and supplemented with
cassava root chips and mulberry |
Photo 3. Goat fed fresh Tithonia foliage (hanging outside the
pen) and supplemented with cassava root chips and mulberry
|
Tithonia foliage was harvested from the re-growth of the plants established in Experiment 2. Leaves of mulberry, jackfruit and banana were collected from the Crop Science Department. The leaves of Erythrina were from trees growing in the experimental area.
|
|
Photo 4. Tithonia diversifolia was grown beside the goat
house in the NOUL research farm |
Photo 5. The goats fed fresh Tithonia foliage and supplemented
with banana, mulberry, jackfruit or Erythrina leaves |
In all treatments in all experiments the goats had free access
to mineral blocks and clean water. The first feed at 7.00 am
comprised the supplements and part of the basal diet. The remainder
of the basal diet was offered in two feeds at 12.00 am and 4.00 pm.
The Tithonia hay was fed loose in the feed trough (Experiments 1
and 2), In the case of the fresh Tithonia foliage (Experiments 2
and 3), this was hung in bunches suspended in the feed trough.
Mulberry and Jackfruit were always given as leaves in the trough
(all experiments) as was the banana in experiment 3.
Live weight was recorded at the beginning of each 12 day period
and at the end of the experiment. During the data collection
period, samples of the Tithonia foliages offered and refused were
separated into stem and leaves (containing attached petioles).
Representative samples of each component were analysed daily for DM
and the dried material retained until the end of each period when
it was analysed for N, ash and NDF.
30 ml of 25% sulphuric acid was put into the urine collection container to maintain the pH below 4.0. Urine volume was measured daily. A representative sample of urine (10% of the total) was taken each day. At the end of the 5-day collection period, the urine samples were mixed and analysed for N.
Faeces were weighed and sampled twice a day in the morning (at 6:30) and late afternoon (16:30). The samples were combined for each animal and 10% of the total kept in the freezer at -18ºC for DM, N, NDF and ash determination at the end of the period.
Chemical analyses of diets and faeces were undertaken following the methods of AOAC (1990) for ash and N. The measurement of NDF followed the procedure of Goering and Van Soest (1970). The DM content was determined using the microwave method of Undersander et al (1993). Urine was analyzed for pH by a digital meter with glass electrode. The N content of urine was determined by the AOAC (1990) procedure.
The data were subjected to analyses of variance according to the general linear model of the Minitab software (Minitab release 13.31, 2000). When the "F" test was significant (P<0.05), the means were separated using the Turkey comparison option in the Minitab software. In Experiments 1 and 3, sources of variation were treatments, animals, periods and error. The model was as follows:
Yijk = µ + Ti + Pj + Ck + ijk
Where:
Yijk = observation,
µ = population mean,
Ti = diet effect,
Pj = periods effect,
Ck = goat effect, and
ijk = residual error.
For experiment 2, the 2 x 2 factorial analysis of
variance was used. The sources of variation were: periods, animal, processing,
supplements, interaction processing*supplements and error. The model was:
Y ijpsp*s = µ + Pi + Cj
+ Tpsp*s +
ijpsp*s
Where:
Yijkl = observation,
µ = population mean,
Pj = periods effect,
Cj = goat effect,
Tk = supplement effect,
Pl = processing effect,
Tk*Pl = interaction processing*supplements and
ijkl = residual error.
The proportion of leaf in the sun-dried Tithonia hay was 76.6%. The chemical composition of feeds is shown in Table 1.
Table 1. The chemical composition of feeds (Experiment 1) | ||||
|
DM, g/kg |
g/kg DM |
||
CP (N*6.25) |
OM |
NDF |
||
Tithonia leaves |
836 |
201 |
875 |
356 |
Tithonia stems |
795 |
87.5 |
854 |
418 |
Jackfruit leaves |
365 |
121 |
887 |
301 |
Mulberry leaves |
253 |
168 |
956 |
239 |
Cassava chips |
850 |
16.3 |
842 |
149 |
During the introduction of the goats to the experimental diets it was observed that they ate very little of the Tithonia hay. However, when some leaves of jackfruit were also offered the intake of the hay increased. It was therefore decided to include the Jackfruit leaves at the level of 0.5% of live weight (DM basis) in all the treatments.
Supplementation did not affect the intake of the Tithonia hay thus total DM intake was higher on all the supplement treatments (Table 2; Figure 1).
Table 2.
The mean values intake and digestibility for goats fed Tithonia
foliage hay (TH) and supplements |
||||||
|
TH |
THC |
THM |
THCM |
SEM |
Prob. |
Intake (in fresh basis), g/day |
|
|
|
|
||
Tithonia hay |
305 |
307 |
344 |
356 |
18.8 |
0.227 |
Jackfruit leaves |
171a |
173a |
167b |
172a |
1.07 |
0.038 |
Mulberry leaves |
0 |
0 |
436 |
225 |
|
|
Dried cassava root |
0 |
135 |
0 |
72.5 |
|
|
DM intake, g/day |
|
|
|
|
|
|
Tithonia hay |
257 |
260 |
300 |
289 |
15.2 |
0.222 |
Jackfruit leaves |
60.3 |
60.7 |
58.9 |
60.6 |
|
|
Mulberry leaves |
0 |
0 |
106 |
54.7 |
|
|
Dried cassava root |
0 |
115 |
0 |
61.6 |
|
|
Total |
317 b |
435a |
454a |
477a |
18.1 |
0.003 |
Total crude protein, g/day |
43.7b |
46.6b |
63.9a |
61.4a |
3.09 |
0.008 |
Crude protein, g/kg DM |
140a |
108b |
142a |
131a |
1.97 |
0.001 |
DM intake/LW, g/kg |
26.8b |
36.8a |
38.9a |
40.1a |
1.55 |
0.003 |
Apparent digestibility, g/kg |
|
|
|
|
|
|
Dry matter |
587b |
658a |
615b |
626b |
8.7 |
0.007 |
Crude protein |
864a |
818b |
841ab |
888a |
10.3 |
0.014 |
Organic matter |
600b |
676a |
629ab |
642a |
8.1 |
0.003 |
Neutral detergent fibre |
637b |
641b |
771a |
713ab |
23.1 |
0.018 |
ab Means without letter in common in the same row differ at P<0.05 |
|
|
As expected, intakes of crude protein were higher for the diets containing mulberry leaves; however, expressed as concentration in diet DM, the values were lower for the diets with cassava chips. Apparent digestibility of DM tended to be increased on all the supplemented diets, while coefficients for crude protein tended to be higher for those diets with mulberry foliage which contained more protein (Figure 2).
|
Figure 2. Apparent digestibility in goats fed Tithonia hay (and small amount of fresh jackfruit foliage) alone or supplemented with dried cassava root, fresh mulberry leaves or both cassava root and mulberry |
N intake was lowest in the goats given Tithonia and Tithonia with cassava chips (Table 3).
Table 3. Nitrogen balance of goats fed Tithonia foliage hay (TH) and supplements of cassava root (C) or mulberry (M) or both (CM) |
||||||
|
TH |
THC |
THM |
THCM |
SEM |
Prob. |
Waste output, g/day |
|
|
|
|
|
|
Faeces |
128b |
150ab |
173a |
178a |
6.26 |
0.004 |
Urine |
405b |
461b |
695a |
542ab |
31.6 |
0.003 |
Nitrogen balance g/d |
|
|
|
|
|
|
Intake |
6.99c |
7.46bc |
10.2a |
9.82ab |
0.49 |
0.008 |
Excreted in faeces |
0.89b |
1.35ab |
1.58a |
1.09b |
0.10 |
0.012 |
Excreted in urine |
3.11a |
1.49b |
3.00a |
2.95a |
0.27 |
0.017 |
Retention |
2.99b |
4.62ab |
5.64a |
5.79a |
0.42 |
0.021 |
N retained % N intake |
42.6b |
61.76a |
54.83ab |
54.13ab |
3.37 |
0.032 |
N retained % N digested |
49.3b |
75.3a |
64.9ab |
64.4ab |
4.28 |
0.028 |
ADG, g/d |
27.5 |
36.3 |
45.0 |
85.0 |
13.3 |
0.083 |
abc Means without letter in common in the same row differ at P<0.05 |
Lowest N retention was on the Tithonia diet (TF) expressed as absolute amounts or as percentages of N intake or N digested (Figure 3). Although N intake on the diet with cassava chips was low, the efficiency with which the N was retained was higher than on all the other diets.
|
|
A 12 day period is very short for measuring reliable data on live weight change. However, the values recorded were in the same order as those for N retention with highest value on the diet with supplements of both cassava chips and mulberry leaves.
The crude protein in the leaves of the dried Tithonia (20%) was similar to the value of 21% in DM reported by Mahecha and Rosales (2005) and the value of 22% recorded by Jama et al (2000) and Wambui et al (2006). In the case of mulberry the crude protein content was lower (14%) than the value (20 to 22% in DM) reported by Vu Chi Cuong et al (2005) and the value of 18% in DM observed by Nguyen Xuan Ba et al (2005).
Despite the high crude protein content and the relatively high
apparent digestibility of DM and crude protein of the Tithonia
foliage, the DM intake and N retention were low. Supplementation
with cassava chips increased both intake and N retention, despite
the fact that crude protein as percentage of DM was lower on this
diet than on the Tithonia (TH) diet. The implications are that the
effect of the cassava chips was to increase microbial protein
production in the rumen through the availability of easily
fermentable carbohydrate. Chanjula et al (2003) proposed that
cassava chips facilitate the achievement of optimal utilization of
energy and protein, especially NPN, for rumen microbial protein
synthesis. Hoover and Stoke (1991) and Khampha and Wannapat (2006)
also indicated that the high rate of digestion of carbohydrate in
cassava chips was a major factor controlling the energy for growth
of the rumen microbes.
The increase in voluntary intake and in N retention when the Tithonia hay was supplemented with mulberry leaves would appear to be a direct result of more protein becoming available at tissue level, presumably because part of the mulberry protein escaped the rumen fermentation and passed directly to the abomasum and intestine. Boschini (2002) on the basis of laboratory analysis claimed that 50% of the protein in mulberry leaves was by-pass protein. The fact that growth rates of cattle on a basal diet of molasses and rice straw were maintained at 550 g/day when mulberry leaves replaced whole cotton seeds (which are known sources of bypass protein) implies similar bypass properties in mulberry protein as in cotton seeds (Vu Chi Cuong et al 2005). Supporting evidence for the bypass protein characteristics of mulberry leaves are the reports of Oviedo (1995) (cited by Benavides et al 2000) that dairy heifers grazing star grass (Cynodon nlemfuencis) had the same growth rates when supplemented with concentrates or only mulberry leaves. Gonzalez et al (1996) (cited by Benavides et al (2000)) observed that young Romosinuano bulls in total confinement and fed a basal diet of elephant grass (Pennisetum purpureum) had growth rates of 40, 690, 940 and 950g/day when mulberry foliage intakes (as DM) were 0, 0.90, 1.71 and 2.11 percent of live weight.
The overall findings of this experiment support the original
hypothesis that "The nutritive value of Tithonia foliage for goats
would be increased by supplementing it with: (i) a source of
readily fermentable carbohydrate; and ii) a tree foliages that
would supply bypass protein".
The fresh leaves and stems of Tithonia had higher crude protein and lower NDF that the dried leaves and stems (Table 4). The leaves in both cases were richer in crude protein than the leaves of mulberry and jackfruit.
Table 4. The chemical composition of feeds |
||||
|
DM |
g/kg DM |
||
|
CP (N*6.25) |
NDF |
OM |
|
Dried Tithonia leaves |
826 |
209 |
359 |
889 |
Dried Tithonia stems |
781 |
88 |
499 |
893 |
Fresh Tithonia leaves |
187 |
227 |
333 |
866 |
Fresh Tithonia stem |
160 |
111 |
444 |
827 |
Mulberry leaves |
256 |
170 |
356 |
904 |
Jackfruit leaves |
374 |
160 |
322 |
899 |
Dried cassava root |
860 |
21.9 |
133 |
958 |
Total DM intake in the goats fed fresh Tithonia was higher (P<0.02) than when the Tithonia hay (plus jackfruit leaves) was fed (Table 5). The DM intake of fresh Tithonia was 371 g/day compared with 300 g/day for the combined Tithonia hay and Jackfruit leaves.
Table 5. Mean
values (main effects) of feed intake by goats fed Tithonia
diversifolia foliage in fresh and hay form |
|||||||
|
Tithonia foliage |
|
CM supplement |
|
|
||
Fresh |
Hay |
Prob. |
CM |
No CM |
Prob. |
SEM |
|
Intake in fresh basis, g/day |
|
|
|
|
|
|
|
Tithonia leaves |
1,604 |
0 |
|
707 |
897 |
|
|
Tithonia stems |
649 |
0 |
|
268 |
381 |
|
|
Tithonia hay leaves |
0 |
150 |
|
62.5 |
87.8 |
|
|
Tithonia hay stems |
0 |
69.6 |
|
32.7 |
36.9 |
|
|
Jackfruit leaves |
0 |
312 |
|
156 |
156 |
|
|
Mulberry leaves |
233 |
223 |
|
456 |
0 |
|
|
Cassava chip |
61.9 |
62.4 |
|
124 |
0 |
|
|
Intake, g/day dry matter basis |
|
|
|
|
|
|
|
Tithonia |
371 |
183 |
|
240 |
314 |
|
|
Jackfruit leaves |
0 |
116 |
|
57.9 |
58.3 |
|
|
Mulberry leaves |
59.8 |
57.0 |
|
117 |
0 |
|
|
Cassava chips |
53.5 |
53.6 |
|
107 |
0 |
|
|
Total |
484 |
410 |
0.02 |
522 |
372 |
0.001 |
16.7 |
Intake/LW, g/kg |
42.9 |
36.4 |
0.07 |
46.5 |
32.9 |
0.004 |
2.10 |
Supplementation with mulberry leaves and cassava chips (Table 6 and Figure 4) increased DM intake compared with no supplement, reaching 46.5 g/kg live weight, which is more than the maximum intake expected in young goats in the tropics (Devendra and McLeroy 1982; Steele 1996).
Table 6. Mean
values ‘interaction’ of feed intake by goats fed Tithonia
diversifolia foliage in fresh |
||||||
Intake as DM, g/day |
TH |
TF |
THCM |
TFCM |
SEM |
Prob. |
Tithonia |
206bc |
422a |
260b |
320ab |
29.3 |
0.003 |
Jackfruit |
117 |
0 |
116 |
0 |
|
|
Mulberry |
0 |
0 |
114 |
120 |
|
|
Cassava |
0 |
0 |
107 |
107 |
|
|
Total |
323c |
422b |
497ab |
547a |
23.6 |
0.002 |
In/LW, g/kg |
28.6b |
37.1a |
44.2a |
48.8a |
2.97 |
0.013 |
abc Means without letter in common in the same row differ at P<0.05 |
|
Figure 4. DM intake of goats fed Tithonia hay (with 1%
of LW as jackfruit leaves) or fresh Tithonia foliage
alone or
supplemented with cassava root chips plus mulberry
leaves |
There were significant interactions on apparent digestibility between effects of processing of the Tithonia foliage and supplementation with cassava root chips + mulberry leaves (Table 7). Coefficients of apparent digestibility for DM, organic matter, crude protein and NDF were lowest when the Tithonia was fed as hay (Figure 5). Supplementation improved the coefficients on Tithonia hay but not on fresh Tithonia (Figure 6).
Table 7. Mean values of apparent digestibility by goats fed Tithonia
diversifolia foliage in fresh (TF) and hay |
||||||
Apparent digestibility, % |
TH |
TF |
THCM |
TFCM |
Prob |
SEM |
DM |
55.0b |
82.7a |
74.6a |
84.3a |
2.5 |
0.001 |
CP |
64.1c |
89.9a |
74.7b |
89.4a |
2.0 |
0.001 |
OM |
49.3b |
82.9a |
73.6a |
85.1a |
2.9 |
0.001 |
|
|
Figure 5. Apparent digestibility of DM for goats fed Tithonia hay (plus 1% BW jackfruit leaves) or fresh Tithonia foliage, with or without supplements of cassava root chips and mulberry foliage |
Figure 6. Apparent digestibility of crude protein in goats fed Tithonia hay (plus 1% BW jackfruit leaves) or fresh Tithonia foliage, with or without supplements of cassava root chips and mulberry foliage |
There were significant interactions on urine output, N excretion and N retention between effects of processing of the Tithonia foliage and supplementation with cassava root chips + mulberry leaves (Table 8). Urine volume was much higher on fresh Tithonia than on sun-dried Tithonia. When the diets were supplemented the urine volume was decreased on the fresh Tithonia but not on the sun-dried Tithonia.
Table 8. Mean
values (main effects) of N balance in goats fed Tithonia
diversifolia foliage in fresh and hay form and |
|||||||
|
Tithonia foliage |
CM supplement |
|
||||
Fresh |
Hay |
Prob. |
Yes |
No |
Prob. |
SEM |
|
Waste output, g/day |
|
|
|
|
|
|
|
Faeces |
78.5 |
136 |
0.002 |
106 |
108 |
0.922 |
7.95 |
Urine |
961 |
387 |
0.003 |
650 |
698 |
0.696 |
81.6 |
Nitrogen balance, g/day |
|
|
|
|
|
|
|
N intake |
12.5 |
9.93 |
0.28 |
11.8 |
10.6 |
0.232 |
0.63 |
N in faeces |
1.20 |
3.02 |
0.001 |
2.00 |
2.22 |
0.51 |
0.21 |
N in urine |
7.14 |
3.30 |
0.001 |
4.81 |
5.63 |
0.218 |
0.42 |
N retained |
4.14 |
3.61 |
0.454 |
4.98 |
2.77 |
0.016 |
0.47 |
Faecal N was lower and urine N was higher for diets with fresh Tithonia than for those with Tithonia hay, the differences being greater in the absence of supplementation (Figure 7). N retention did not differ between fresh and sun-dried Tithonia but tended (P=0.059) to be increased when the Tithonia was supplemented with cassava chips and mulberry (Figure 8). When the ANOVA analysis was done for main effects (Table 8) the effect of supplementation on N retention was significant (P=0.016). As was to be expected, changes in live weight (Figures 9 and 10) mirrored the changes in N retention.
|
|
Figure 7. Nitrogen balance of goats fed Tithonia in hay or fresh form |
Figure 8. Nitrogen balance of goats fed Tithonia in hay and fresh form supplemented with cassava root plus mulberry (CM) or no supplement (NCM) |
|
|
Figure 9. Live weight gain of the goats fed
Tithonia in hay or fresh form |
Figure 10. Live weight gain of goats fed Tithonia in hay and fresh form supplemented with cassava root chips plus mulberry (CM) or no supplement (NCM) |
The higher crude protein content in the fresh compared with
sun-dried Tithonia foliage, and the lower values for apparent
digestibility, were probably due to chemical changes resulting in
losses of valuable nutrients during the drying process (McDonald et
al; 2002). The higher intakes of Tithonia foliage fed fresh rather
than as hay probably reflected in part the way these two feeds were
offered (the hay was loose in the trough; fresh foliage was hung in
bunches). It has been shown in several experiments that intakes and
often digestibility are higher when tree foliages are hung as
bunches rather than being offered only as leaves (Kouch et al 2003; Keopaseuht et al 2004; Van et al 2006; Phengvilaysouk and
Kaensombath 2006).
The higher urine volume on fresh compared with sun-dried Tithonia appears to be related to the need to excrete a greater quantity of N on the fresh Tithonia as the N content of the urine was similar in both (about 0.8%).
The greater responses to supplementation on the fresh compared with the sun-dried Tithonia indicates that the fresh foliage has a high potential as ruminant feed (high crude protein content and high digestibility) but that the expression of the potential (in N retention and live weight gain) requires supplementation to improve rumen microbial growth (addition of cassava chips) and to increase the supply of bypass protein (mulberry leaves).
The situation presented by fresh Tithonia foliage is similar to what happens when a low digestibility forage (eg: cereal straw) is treated with urea or supplemented with rumen nutrients, or a high digestibility diet (eg: molasses or sugar cane juice) is supplemented with urea and minerals.
In such cases the potential
nutritive value is increased but the expression of this improvement
in live weight gain requires supplementation with bypass protein
(Zhang et al 1994 and Sath
2007 in the case of cereal straw;
Martin and Preston (1968), cited by Preston and Leng (1987) for
molasses and Sanchez and Preston (1980) for sugar cane juice).
The chemical composition (Table 9) of the diet ingredients indicated that the CP content in fresh Tithonia leaf was the highest but lower than in Experiment 2 with similar high values in Erythrina leaves. The level of condensed tannins was highest in the banana and jackfruit leaves. The level in the Tithonia leaves (57.1 mg/kg DM) is much higher than was reported for Tithonia foliage (5.6 mg/kg DM) in Kenya (Wambui et al 2006).
Table 9. The chemical composition of dietary components (Experiment 3) |
|||||
|
DM, g/kg |
g/kg DM |
|||
N*6.25 |
OM |
NDF |
Condensed tannin |
||
Tithonia leaves |
222 |
188 |
864 |
333 |
57.1 |
Tithonia stems |
208 |
113 |
893 |
399 |
19.4 |
Jackfruit leaves |
344 |
138 |
896 |
338 |
130 |
Banana leaves |
180 |
140 |
906 |
638 |
133 |
Mulberry leaves |
362 |
19 |
873 |
316 |
50.3 |
Erythrina leaves |
285 |
194 |
881 |
336 |
45.8 |
There were no differences in intake and apparent digestibility among the diets, except for crude protein apparent digestibility which was lowest for the jackfruit supplemented diet (Table 10).
Table 10.
Mean values for
intake and apparent digestibility for goats fed fresh Tithonia
foliage (T) supplemented with leaves of banana (B), jackfruit (J), erythrina (E) and mulberry (M) |
||||||
|
TB |
TJ |
TE |
TM |
SEM |
Prob |
Intake in fresh basis, g/d |
||||||
Tithonia leaves |
1,062 |
1,011 |
1,009 |
946 |
53.5 |
0.542 |
Tithonia stems |
340 |
387 |
389 |
414 |
35.8 |
0.563 |
Jackfruit leaves |
0 |
629 |
0 |
0 |
|
|
Banana leaves |
1,105 |
0 |
0 |
0 |
|
|
Mulberry leaves |
0 |
0 |
0 |
631 |
|
|
Erythrina leaves |
0 |
0 |
764 |
0 |
|
|
DM intake, g/d |
||||||
Tithonia |
283 |
287 |
286 |
277 |
17.3 |
0.971 |
Jackfruit leaves |
0 |
216 |
0 |
0 |
|
|
Banana leaves |
203 |
0 |
0 |
0 |
|
|
Mulberry leaves |
0 |
0 |
0 |
228 |
|
|
Erythrina leaves |
0 |
0 |
218 |
0 |
|
|
Total |
481 |
503 |
504 |
505 |
18.9 |
0.780 |
DM, g/kg BW |
37.4 |
39.6 |
39.3 |
39.9 |
1.56 |
0.589 |
Apparent digestibility, % |
||||||
DM |
76.3 |
74.0 |
74.8 |
78.5 |
1.29 |
0.177 |
Crude protein |
86.6ab |
81.6b |
88.6a |
87.2ab |
1.38 |
0.048 |
OM |
76.9 |
75.8 |
76.5 |
80.0 |
1.21 |
0.176 |
NDF |
76.8 |
68.3 |
75.6 |
70.4 |
3.03 |
0.242 |
abc means without letter in common are different at P<0.05 |
Urine volumes were highest on the banana and erythrina diets and reflected the rates of excretion of N in the urine which were also highest for these two diets (Table 11).
Table 11.
Mean values for N balance in goats fed fresh Tithonia foliage (T)
supplemented with |
||||||
|
TB |
TJ |
TE |
TM |
SEM |
Prob |
Waste output |
||||||
Faeces, g/d |
103 |
126 |
126 |
104 |
6.75 |
0.083 |
Urine, ml |
962a |
688b |
817a |
507b |
38.5 |
0.001 |
N balance |
||||||
N intake |
12.3 |
12.5 |
14.5 |
13.1 |
0.490 |
0.387 |
N in faeces |
1.41 |
1.99 |
1.56 |
1.34 |
0.14 |
0.072 |
N in urine |
9.01a |
6.23b |
9.23a |
6.02b |
0.49 |
0.005 |
N retention |
1.92b |
4.31ac |
3.71bc |
5.69a |
0.46 |
0.006 |
Live weight gain, g/day |
21.0b |
72.0a |
80.0a |
95.0a |
10.5 |
0.011 |
Faecal N did not differ among the diets. N retention was highest on the mulberry-supplemented diet which was not different from the diet with jackfruit. The lowest value was on the diet with banana leaves. N retention on the erythrina-supplemented diet appeared to be only slightly less than on the diet with jackfruit (Figure 11). The weight gains broadly followed the values for N retention being much less on the Tithonia supplemented with banana leaves (Figure 12).
|
|
Figure 11. N balance of goats fed fresh Tithonia foliage
supplemented with leaves of banana, jackfruit, erythrina or mulberry |
Figure 12. Daily weight gain of goats fed Tithonia
foliage supplemented with leaves of banana, jackfruit, erythrina or mulberry |
There was a close relationship between N retention and live weight gain (Figure 13).
|
Figure 13. The relationship between live weight gain and
N retention of goats fed Tithonia foliage supplemented with leaves
of banana, jackfruit, erythrina or mulberry |
It was observed that the goats consumed the jackfruit and mulberry leaves within 30 to 40 minutes. In contrast they took most of the day to eat the banana and erythrina leaves. These observations are different from those reported by Kongmanila et al (2007) when intakes, N retention and live weight gain were always better for erythrina than other foliages. The difference was that in the present study only the leaves of the erythrina were fed while Kongmanila et al (2007) hung the complete foliage (leaves attached to the stems) in the feed trough. It has been shown that for most foliages the intakes and digestibility are higher when the foliage is hung in the trough than when only the leaves are fed (Kouch et al 2003; Keopaseuht et al 2004; Van et al 2005; Phengvilaysouk and Kaensombath 2006).
The finding that N retention was highest with mulberry leaves as the supplement is in agreement with the results reported by Bakshi and Wadhwa (2006) where, in a comparison of a range of tree leaves as the sole diet, the highest N retention was observed with mulberry leaves.
The fact that there was a poor relationship between coefficients of apparent digestibility and the N retention (R2 = 0.25; P = 0.068) indicates that digestibility was not the constraint to goat performance on Tithonia foliage. This conclusion is similar to the one drawn in experiment 2 that: digestibility is indicative of the nutritive potential of the diet but that appropriate supplementation to improve protein flow to the intestine is the real determinant of performance. In experiment 3. apparent digestibility on the Tithonia foliage supplemented with banana leaves was high and similar to that on the other diets. However, N retention and live weight gain with the banana-supplemented diet were significantly lower than for the diets supplemented with jackfruit, erythrina and mulberry leaves. All of these latter foliages are considered to have protein in a form which allows it to bypass the rumen to the lower gut (Preston and Leng 1987).
The close relationship between the quantities of N retained and the observed changes in live weight (Figure 13) is an indication that the experimental procedures were an appropriate means of assessing the nutritive value of the experimental diets.
There was no relationship between DM intake and coefficients of apparent digestibility and the N retention in goats fed fresh Tithonia foliage supplemented with leaves from banana, jackfruit, erythrina and mulberry.
N retention for diets with banana leaves was less than 50% of the values recorded with the other leaf supplements. This supports the findings in the two previous experiments that digestibility only indicates nutritive potential of the diet and that actual performance is dependent on appropriate supplementation to increase the amino acids absorbed by the animal.
The senior author would like to express sincere thanks to the
MEKARN Master Course project financed by Swedish International
Development Authority (SIDA), Department for Corporation SAREC.
Besides, she expresses her gratitude to National Agriculture and
Forestry Research Institute and Faculty of Agriculture, National
University of Laos particularly Department of Livestock and
Fisheries for the facilities to carry out the
experiment.
AOAC 1990 Official Methods of Analysis. Association of Official Analytical Chemists. 15th edition (K Helrick editor). Arlington pp 1230
Bakshi M P S and Wadhwa M 2006 Tree leaves as complete feed for goat buck. Sciendirect. Small ruminant research 69: 74-78
Benavides J, Hernández I, Ésquivel J, Vasconcelos, Gonzáles J and Espinosa E 2000 Supplementation of Grazing Dairy Cattle with Mulberry in the High Part of Central Valley of Costa Rica. In: FAO Electronic Conference on "Mulberry for Animal Production"
Boschini C F 2002 Nutritional quality of mulberry cultivated for ruminant feeding. Mulberry for animal production. FAO Animal Production and Health Paper 147 http://www.fao.org/DOCREP/005/X9895E/x9895e0g.htm
Buntha P and Ty C 2006 Water-extractable dry matter and
neutral detergent fibre as indicators of whole tract digestibility
in goats fed diets of different nutritive value. Livestock
Research for Rural Development. Volume 18, Article # 33.
Retrieved , from
Camero A and Franco M 2001 Improving rumen fermentation and milk production with legume-tree fodder in the tropics. Biomedical and life science and earth environmental science 51 (2): 157-166
Chanjula P, Wannapat M, Wachirapakorn C, Uriyapongson S and Rowlinson P 2003 Ruminal degradability of tropical feeds and their potential use in ruminant diets. Asian-Autralasian Association of Animal Production Societies, Kwachon-Shi,Kyunggi-Do, COREE, REPUBLIQUE DE (1988) (Revue). Asian-australasian journal of animal sciences Asian-australasian.Journal of Animal Science 16 (2): 211-216
Devendra C and McLeroy G B 1982 Goat and sheep
production in the tropics. Intermediate Tropical Agriculture
Series, Longman, London.
Duyen N T, Bien L T, Mui N T, Binh D V and Preston T R
1996 Foliage of Trichantera gigantea, Jack fruit
(Artocarpus heterophyllus), banana (Musa sp) and
Acacia mangium as protein sources for lactating goats fed a
basal diet of rice straw and sugarcane tops. Livestock Research for
Rural Development volume 8, Number 3, September
1996.
Esnaola M A and Rios C 1990 Hojas de "Poro"(Erythrina
poeppigiana) como suplemento proteico para cabras lactantes.
Livestock Reseach for Rural Development volume 2, Number 1.
http://www.cipav.org.co/lrrd/lrrd2/1/esnaola.htm
Fotadar R K and Dandin S B 1997 Chemical composition and feeding studies of different elite mulberry genotypes under temperate conditions. Indian Journal of Sericulture 36: 22-26
Goering H and Van Soest P 1970 Forage fiber analysis.
Agricuture hand book No. 379. United States Department of
Agriculture, Washington D.C, USA.
Gomez G and Waldivieso M 1983 Cassava meal for baby pig
feeding. Nutrition Reports International 28(3): 547
Hoover W H and Stokes S R 1991 Balancing carbohydrate and proteins for optimum rumen microbial yield. Journal of Dairy Science 74: 3640-3644 http://jds.fass.org/cgi/reprint/74/10/3630
Jama B, Palm C A, Buresh R J, Niang A, Gachengo C, Nziguheba G and Amadalo B 2000 Tithonia diversifolia as a green manure for soil fertility improvement in western Kenya: A review. Agroforestry Systems. pp 201-221
Jegou D, Waelput J J and Brunschwig G 1994 Consumo y
digestibilidad de la materia seca y del nitrógeno del follaje
de Morera (Morus sp.) y Amapola (Malvabiscus
arboreus) en cabras lactantes. In: Arboles y arbustos
forrajeros en América Central. p.155-162. Vol.I.
Turrialba, Costa Rica. CATIE
Kearl L C 1982 Nutrient requirment of ruminants in developing countries. Longan: International Feedstuffs Institute. Utah State University, Utah
Keopaseuht T, Ty C, Bouahom B and Preston T R 2004 Effect
of method of offering foliages of Gliricida sepium and Stylosanthes
guianensis CIAT 184 (Stylo) to goats on intake and digestibility.
Livestock Research for Rural Development. 16, Art. No. 31.
http://www.cipav.org.co/lrrd/lrrd16/5/toum16031.htm
Khampa S and Wannapat M 2006 Influences of Energy Sources and Levels Supplementation on Ruminal Fermentation and Microbial Protein Synthesis in Dairy Steers. Pakistan Journal of Nutrition 5(4):294-300 http://www.pjbs.org/pjnonline/fin469.pdf
Kongmanila Daovy , Preston T R and
Ledin Inger 2007 Chemical composition, digestibility and intake of some tropical
foliage species used for goats
Kouch T, Preston T R and Ly J 2003 Studies on utilization of trees and shrubs as the sole feedstuff by growing goats; foliage preferences and nutrient utilization. Livestock Research for Rural Development 15(7) http://www.cipav.org.co/lrrd/lrrd15/7/kouc157.htm
Lijzenga M 1998 Maize response to NPK in relation to soil
fertility indices in western Kenya. MSc thesis. Wageningen
Agricultural University, Wageningen, The Netherlands
Mahecha L and Rosales M 2005 Nutritional value of of the
foliage of Wild Sunflower (Botón de Oro; (Tithonia
diversifolia [Hemsl]. Gray) for tropical animal production.
Livestock Research for rural Develoment 17(9)2005.
McDonald P, Edwards R A, Greenhalgh J F D and Morgan C A
2002 Animal nutrition. Pearson education limited, Sixth
edition published 2002.
Minitab 2000 GLM In Minitab reference manual Release
13.31 for window. Minitab Inc., State College, USA, http://www.minitab.com
Makkar H P S and Becker K 1998 Do tannins in leaves of
trees and shrubs from African and Himalayan regions differ in level
and activity? Agroforestry Systems, 40: 59-68
Makkar H P S, Singh B and Negi S S 1989 Relationship of rumen degradability with microbial colonization, cell wall constituents and tannin levels in some tree leaves. Animal Production 49: 299-303
Nguyen Xuan Ba, Vu Duy Giang, Le Duc Ngoan and Vu Chi Cuong 2005: Ensiling of mulberry foliage (Morus alba) and the nutritive value of mulberry foliage silage for goats in central Vietnam. Workshop-seminar "Making better use of local feed resources" (Editors: Reg Preston and Brian Ogle) MEKARN-CTU, Cantho, 23-25 May 2005. Article #24. RetrievedJune 22, 107, from http://www.mekarn.org/proctu/ba24.htm
Pathoummalangsy K and Preston T R 2006 Effect of a
supplement of fresh water spinach (Ipomoea aquatica) on feed
intake and digestibility in goats fed a basal diet of cassava
foliage. Livestock Research for Rural Development. Volume 18,
Article # 35. Retrieved , from
Pezo D, Kass M, Benavides J, Romero F and Chaves C 1990
Potential of legume tree fodders as animal feed in Central America.
In: Devendra C (editor), Shrubs and Tree Fodders for Farm
Animals. Proceedings of a workshop held in Denpasar, Indonesia.
IDRC, Ottawa, Canada, pp. 163-175
Phengvilaysouk Ammaly and Kaensombath Lampheuy 2006: Effect on intake and digestibility by goats given jackfruit (Artocarpus heterophyllus) leaves alone, the whole branch or free access to both. Livestock Research for Rural Development. Volume 18, Article No. 38. http://www.cipav.org.co/lrrd/lrrd18/3/amma18038.htm
Promkot C and Wanapat M 2003 Ruminal degradation and
intestinal digestion of crude protein of tropical protein resources
using nylon bag technique and three-step in vitro procedure in
dairy cattle; Livestock Research for Rural Development (15)
11 Retrieved , from
Preston T R and Leng R A 1987 Matching Ruminant
Production Systems with Available Resources in the Tropics and
Subtropics. PENAMBUL Books Ltd: Armidale NSW,
Australia.
Sanchez P 2001 The climate change-soil fertility-food
security Nexux. In: Sustainable food security for all by
2020. Sept 4-6 2000 Bonn, Germany.
Sanchez M and Preston T R 1980 Sugar cane juice as cattle
feed: comparisons with molasses in the presence or absence of
protein supplement. Tropical Animal Production 5 (2): 117-124
Sath K 2007 Feed utilization for cattle production and
effect of levels of sun-dried cassava foliage on growth performance
of cattle fed rice straw. Master Thesis of Mekarn project.
Departmnt of Animal Nutrition and Management. Swedish University of
Agricultural Sciences.
Sathapanasiri K, Vearasilp T and Vjarabukka C 1990
Digestibility of starch of cassava, whole rice seed meal and broken
rice in whole gastrointestinal tract of dairy cattle. Kaset Journal
6(4):265-280
Singh B, Goel G C and Negi S S 1984 Effect of supplementing mulberry (Morus alba) leaves ad libitum to concentrate diets of Angora rabbits on wool production. Journal of Applied Rabbit Research 7: 156-160
Singh B, Hanrinder P and Makkar S 2002 The potential of mulberry foliage as a feed supplement in India. Food and Agriculture Organization of United Nations. Proceedings of an electronic conference carried out between May and August 2000 http://www.fao.org/DOCREP/005/X9895E/x9895e0d.htm
Sommart K, Wanapat M, Wachirapakorn C, Chanthai S and Toburan V 1991 Degradability of organic matter of various energy sources in the rumen of Brahman crossbreds and swamp buffalo. In: Proceedings the 29th Kasetsart University Annual Conference. pp. 233. Kasetsart University, Bangkok, Thailand
Sommart K, Wanapat M, Parker D S and Rowlinson P 2000 Cassava chips as an energy source for lactating dairy cows fed rice straw. Asian-Australasian Journal of Animal Science 13. 1094-1101
Steele M 1996 The tropical agriculturist, Goats. Technical Centre for Agriculture and Rural Co-operation, pp 24
Subbarayappa C T and Bongale U D 1997 Nitrogen nutrition of mulberry-a review. Indian Journal of Sericulture 36: 92-98
Undersander D, Mertens DR and Theix N 1993 Forage analysis procedures. National Forage Testing Association. Omaha. pp 154
Van D T T, Mui N T and Ledin I 2006 Tropical foliages:
effect of presentation method and species on intake by goats.
Doctoral Thesis No. 2006:32. Faculty of Veterinary Medicine and
Animal Sciences. Department of Animal Nutrition and Management.
Swedish University of Agricultural Sciences.
Vearasilp T and Mikled C 2001 Site and extent of cassava starch digestion in ruminants. In: Preston T R, Ogle B and Wanapat M (Editors), In: International Workshop Current Research and Development on Use of Cassava as Animal Feed. Khon Kaen, Thailand. July 23-24, 2001. pp. 73-76 http://www.mekarn.org/procKK/choc.htm
Vu Chi Cuong, Pham Kim Cuong and Pham Hung Cuong 2005: The nutritive value of mulberry leaf (Morus alba) and effects of part replacement of cotton seed with fresh mulberry leaf in diets for growing cattle. Workshop-seminar "Making better use of local feed resources" (Editors: Reg Preston and Brian Ogle) MEKARN-CTU, Cantho, 23-25 May 2005. Article #14. RetrievedJune 22, 107, from http://www.mekarn.org/proctu/cuon14.htm
Wambui C C, Abdulrazak S A and Noordin Q 2006 The effect
of supplementing urea treated maize stover with Tithonia,
Calliandra and Sesbania to growing goats. Livestock
Research for Rural Development 18 (5) 2006
Zhang Weixian, Gu Chuan
Xue, Dolberg F and Finlayson P M 1994
Supplementation of ammoniated wheat straw with hulled cottonseed
cake. Livestock Research for Rural Development Volume 6, Number 1.
http://www.cipav.org.co/lrrd/lrrd6/1/china1.htm