A total of eight
castrate male pigs, either Mong Cai
or Large White growing animals with an average weight of approximately 30 kg
were used in a factorial arrangement 2x4 according to a 4x4 Latin square design
to study N utilization from a high fibrous diet consisting of fresh, chopped
water spinach and
graded levels of partially defatted rubber seeds (rubber seed cake, 0, 20, 30
and 40 % of the daily feed intake respectively).
There was no
significant interaction in any of the estimated indices. There was no treatment
effect on voluntary fresh material intake (average, 135.9 g/kg body weight).
Rubber seed cake determined a significant increase (R2 0.369,
P<0.002) in voluntary DM intake. There was a significant genotype effect on
DM (P<0.05) and organic matter (P<0.01) digestibility with lower values
in Mong Cai
than in Large White pigs. N balance indices appeared to favor Large White
animals as compared to Mong Cai animals. Water spinach given alone to pigs had a
relatively very high DM, organic matter and N digestibility (68.6, 71.2 % and
75.0% respectively). Rubber seed cake had no significant effect on any
digestive indices. Nevertheless a sensible urinary loss of N suggested a
potential imbalance of amino acids contained both in water spinach and rubber
seed cake.
Results from the
present experiment suggest that the total tract digestibility of water spinach
for pigs is high in spite of its high fibrous content. In contrast, rubber seed
cake has a rather low nutritive value for pigs. It is probable that improving
amino acid profile of water spinach could necessarily influence N balance in a
positive form. Besides, N requirement of Mong Cai pigs must probably be lower than that recommended for
improved genotypes for lean meat.
Cambodia is a tropical country where some
fibrous feeds which have a moderate to high N content are locally available. In this
connection, it is a popular practice in Cambodia to raise pigs with water
spinach (Ipomoea aquatica) as one of the major
feedstuffs, and furthermore, this vegetable is commonly seen everywhere in
local markets as a merchandise destined to pig production. On the other hand, although there are
available information in South East Asia (see for example Le Thi Men 1999)
related to the feeding value of water spinach, there are no consistent data
concerning the use of the locally available water spinach in the diets of
growing pigs.
Cambodian rubber (Hevea
brasiliensis) plantations can provide yearly
enough amounts of rubber seeds so as to be taken into account as potential
feedstuffs in the country. Rubber seeds in turn are commonly used in animal
feeding either intact or partially defatted. There are some preliminary
evidence that full-fat rubber seeds can be used with advantage for feeding pigs
in Cambodia (Ly et al 2001; Bun Tean et al 2002;
Nguyen Thi Thuy and Ly 2002), but there are no experimental
evidence about the nutritive value for pigs of Cambodian rubber seeds partially
defatted, otherwise called rubber seed cake.
Experimental evidence has been accumulated suggesting that the scheme of N utilization in Mong Cai pigs is somewhat different fom that observed in improved pig genotypes for lean meat (Molenat and Tran 1991; Hoang and Nguyen 1996). In fact body composition of Mong Cai pigs indicates that fat is predominant (Molenat and Tran 1991). Therefore, a minor requirement of alimentary N for protein accretion in the animal could greatly explain a lesser N utilization, if rations are formulated according to non local standards of common use in those area where the improved breeds are usually fed to express the maximum potential of growth of body mass (see for example, NRC 1998) which in turn have been selected for a high protein to fat ratio.
The aim of the present experiment was to obtain
information of the characteristics of N balance in Mong
Cai pigs as compared to that of Large White animals,
fed locally available, highly fibrous diets.
A total of eight castrate male pigs, either Mong Cai or Large White growing pigs in equal number with an average live weight of approximately 30 kg were used according to a factorial arrangement in a 4x4 Latin square design to study N utilization from a high fibrous diet consisting of partially defatted rubber seeds and water spinach as the major dietary components. The Mong Cai pigs were of Vietnamese origin (Thu Duc, near Ho Chi Minh City) and the Large White pigs were of commercial origin, locally available in the Phnom Penh environment. Both types of animals had been born from parents raised in the University pig herd.
The diet was composed by rubber seed cake and water spinach. Rubber seed cake was a by-product after partial oil extraction of rubber seeds locally available in Cambodia. Water spinach was daily obtained from the market at Chamcar Daung and was from the type usually sold for rising pigs. Feeds were given to the animals resembling the Lehman feeding system. Ground rubber seed cake was daily given at 7:00 am and after totally consumption of the seeds, the water spinach was given fresh and chopped to the animals. Daily feed intake was calculated as being 30 g DM/body weight, in dry basis, and rubber seed cake was calculated as 0, 10, 20 and 30 % of total feed intake. Some characteristics of the feeds are shown in Table 1.
Details of animal housing, feeding and routine work
related to daily collection of feed refusals, faeces
and urine is available elsewhere (Chiev Phiny and
Rodriguez 2001). DM content of feeds and faeces was
determined according to Undersander et al (1993) by
microwave radiation until constant weight, and N in feeds, faeces
and urine was as indicated by the AOAC (1990) by the wet oxidation procedure
outlined by Kjeldahl. Other proximal analyses from
representative samples of feedstuffs
were also carried out according to AOAC (1990) procedures.
|
Table 1. Chemical composition of the feeds (Per cent in dry basis, except for dry matter) |
||
|
|
Rubber seed cake |
Water spinach |
|
Dry matter |
90.71 |
11.24 |
|
Ash |
2.32 |
11.50 |
|
Organic matter |
97.68 |
88.50 |
|
Crude fibre |
61.58 |
28.34 |
|
Crude fat |
7.09 |
4.65 |
|
Nx6.25 |
8.31 |
29.58 |
Statistical analysis was carried out using Minitab software (Ryan et al 1985) by analysis of variance for treatments (Steel and Torrie 1980). Regression analysis was utilized in the required cases.
Although the cyanide content of rubber seed cake was not determined, during the conduction of the experiment there was any symptom of animal intoxication due to rubber seed cake intake. Furthermore, all the pigs showed a good health and gained in live weight. Feed refusals were commonly found throughout the trial, due to the bulky characteristics of fresh water spinach. Therefore, it was considered that the animals were fed ad libitum. On the other hand, calculation of rubber seed cake and water spinach revealed that animals adjusted the proportion of both feeds in the 0:1, 1:4, 3:7 and 2:3 ratio in dry basis respectively, rubber seed cake accounted for 0, 20, 30 and 40 % of feed intake, in dry basis. Some characteristics of the rations given daily to the pigs are presented in Table 2.
|
|
|||||
|
|
Rubber seed cake, % dry basis |
SE ± |
|||
|
0 |
20 |
30 |
40 |
||
|
Feed intake,
g/kg body weight |
|
|
|
||
|
Fresh basis |
136.1 |
134.5 |
134.8 |
138.5 |
24.4 |
|
Dry basis |
15.2a |
17.9ab |
20.5ab |
23.9b |
3.0*** |
|
Chemical
composition, % DM |
|
|
|||
|
Organic matter |
88.50 |
90.11 |
91.15 |
91.70 |
- |
|
Crude fibre |
28.34 |
34.18 |
37.95 |
39.94 |
- |
|
Crude fat |
4.65 |
5.08 |
5.36 |
5.50 |
- |
|
Nx625 |
29.58 |
25.83 |
23.69 |
22.16 |
- |
|
*** P<0.01 |
|||||
In general, the rations given to the animals were rather bulky, from the point of view of it high water content, due to the fact that water spinach was offered in natura. Mean daily feed intake of fresh material was 136.0 ± 32.9 g/kg body weight. On the other hand, mean daily DM intake was 19.4 ± 5.2 g/kg body weight. A great variability amongst animals was observed in both forms of expression of feed intake. In this connection, it was not observed any change in voluntary feed intake due to genotype influence, and daily DM intake was 19.8 and 19.0 g/kg body weight for Mong Cai and Large White animals respectively.
In spite of the fact that the introduction of graded levels of rubber seed cake in the diet determined a substantial increase in the crude fibre contained in the ratio (see Table 1), a sustained positive response of the animals was encountered, with daily DM intake from15.2 to 23.9 g/kg body weight. When the analysis of variance technique was applied to these values, a highly significant effect was found (P<0.001) and a linear influence due to the dietary rubber seed cake (R2 0.369; P<0.002) was observed. This animal response could only be explained if an important contrast between the nature of the fibre fraction in the water spinach and the rubber seed cake could be evident, mainly from the point of view of its water holding capacity. It has been claimed that water holding capacity of the cell fraction of forage could be a decisive index for predicting voluntary feed intake of roughage in the pig (Kyriziakis and Emmans 1995; Tsaras et al 1998). If this was true in the present experiment, then it follows that the water holding capacity of water spinach in substantially higher than in rubber seed cake.
There was no significant interaction (P>0.05) in any of the estimated indices.Table 3 lists digestibility data for DM and organic matter. A great variability amongst animal response was observed. Since it is well known that feed intake may be inversely proportional to digestibility indices (see for example, Roth and Kirchgessner 1984; Oude et al 1986), an attempt to search any DM feed intake effect (see Table 2) on digestion parameters. Nevertheless this investigation resulted in a not significant (P>0.10) influence of feed intake level in any digestion.
|
|
|||
|
|
Faecal DM, % |
Digestibility, % |
|
|
DM |
Organic matter |
||
|
Genotype |
|
|
|
|
Mong Cai |
34.83 |
63.4 |
64.4 |
|
Large White |
34.30 |
69.3 |
72.4 |
|
SE ±
|
8.91 |
3.16* |
3.29** |
|
Rubber seed
cake, % |
|
|
|
|
0 |
30.14a |
68.6 |
71.2 |
|
20 |
29.12a |
68.8 |
70.0 |
|
30 |
34.30ab |
63.7 |
67.2 |
|
40 |
45.22b |
63.4 |
65.1 |
|
SE ± |
5.75*** |
6.79 |
7.23 |
|
* P<0.05; ** P<
0.01; *** P<0.001 |
|||
There was no genotype effect on faecal DM concentration. On the other hand, a significant influence was found in DM (P<0.05) and organic matter (P<0.01) digestibility, in favor of the Large White genotype. A so clear advantage of Large White animals over Mong Cai pigs was not observed in a previously reported experiment (Nguyen Thi Thuy and Ly 2002).
A highly significant (P<0.001) interdependence was found between DM (x, %) and organic matter digestibility (y, %), and the resulting equation was as follow:
y = 3.22 + 0.982 x (Syx = ± 4.15; R2 = 0.834)
Similar relationships have been found in somewhat near conditions of experimentation (Bun Tean et al 2002; Nguyen Thi Thuy 2002)
When pigs were given water spinach alone (rubber seed cake, 0%), a relatively high DM and organic matter digestibility was obtained (68.6 and 71.2 % respectively). Other approach to the nutritive value of water spinach has indicated that this aquatic plant is a rather satisfactory fibrous local resource for pigs in South East Asia (Le Thi Men 1999; Ly et al 2001). However, in the author’s knowledge, there were no previous reports concerning the nutritive value of water spinach given alone to growing pigs.
The inclusion of graded levels of rubber seed cake in the diet determined an increase in faecal DM content (P<0.001) and a decrease in DM and organic matter digestibility. However, there was neither linear nor quadratic effect (P>0.10) of dietary rubber seed cake on DM and organic mater digestibility. These results probably were a consequence of the high fibre fractions content of rubber seed cake (see Table 1). In this connection, Bun Tean et al (2002) observed only a slight decrease in digestibility parameters when growing Large White pigs were fed diets where wheat bran was partially substituted by graded levels of full fat rubber seeds up to 30%. On the other hand, Nguyen Thi Thuy and Ly (2002) found a slight but not significant advantage in DM and organic matter digestibility when growing female pigs were given 27.3 of full-fat rubber seeds in the diet, whereas Ly et al (2001) observed that digestibility of nutrients of feeds prepared with sugar palm syrup and dried fish was not impaired by the incorporation of either 17.8 or 40.5% of full-fat rubber seed meal in the diet.
The information concerning the effect of genotype on the balance of N is presented in Table 4. In spite of a somewhat high N intake in Large White pigs, this effect was not significant (P>0.10) when compared to that of Mong Cai animals. Total amount of daily N digested was significantly higher (P<0.01) in Large White pigs as compared to the Mong Cai animals. However, this genotype effect was only a not significant trend (P<0.09) for N digestibility. Similarly, a not significant tendency (P<0.12) between both breeds was observed for total amount of N retained per day, this index appearing to be higher in Large White than in Mong Cai pigs. Nevertheless, N balance, expressed either as N retained:N consumed ratio or as N retained:N digested ration was not significant when both genotypes were contrasted.
|
|
|||
|
|
Mong Cai pigs |
Large White pigs |
SE ± |
Number of animals |
4 |
4 |
- |
|
N intake, g/day |
20.26 |
22.94 |
2.23 |
|
N excretion, g/day |
|
|
|
|
Faeces |
5.03 |
4.91 |
0.61 |
|
Urine |
9.10 |
10.01 |
0.95 |
|
Total excretion |
14.13 |
14.92 |
1.38 |
| N digestion, g/day |
15.23 |
18.03 |
1.89** |
|
N digestibility, % |
74.9 |
78.1 |
2.15+ |
|
N retention g/day |
6.13 |
8.02 |
1.19+ |
|
N balance |
|
|
|
|
As % of intake |
30.1 |
35.0 |
3.26 |
|
As % of digestion |
40.2 |
44.5 |
3.69 |
|
+ P<0.10; ** P<0.01 |
|
|
|
In spite of a relatively high N digestibility of water spinach, considerable losses of urinary losses were observed in pigs fed the water spinach alone. It is possible that the primary cause of these findings could be the amino acid composition of water spinach. In fact, it have been claimed that water spinach is low in methionine content (National Institute of Animal Husbandry of Vietnam, quoted by Le Thi Men 1999; Bui Huy Nhu Phuc 2000). In this connection, Le Thi Men (1999) found a somewhat decrease in N retention when either growing or finishing pigs were fed with graded levels of water spinach up to 21% of diets prepared with broken rice and rice bran.
The introduction of rubber seed cake in the diets of the present study determined higher, although not significant values for N digestibility and retention. Very little is known about the N balance in pigs fed rubber seeds products. Babatunde et al (1990) have suggested that an impairement in N balance could occur in pigs fed rubber seeds due to a deficiency in certain essential amino acid. With regard to amino acid composition of different products obtained from rubber seeds, it has been reported a relatively low sulphur amino acid conten in the rubber seed protein (Orok and Bowland 1974; Bressani et al 1983; Narahari and Kothandaraman1983; Nwokolo 1987) and lysine (Bressani et al 1983).
|
|||||
|
|
Rubber seed cake, % |
SE ± |
|||
|
0 |
20 |
30 |
40 |
||
|
Number of observations |
8 |
8 |
8 |
8 |
- |
|
N intake, g/day |
20.25 |
20.93 |
21.80 |
23.41 |
4.64 |
|
N excretion, g/day |
|
|
|
|
|
|
Faeces |
5.06 |
5.16 |
4.88 |
5.10 |
2.06 |
|
Urine |
9.38 |
9.44 |
10.51 |
8.88 |
1.95 |
|
Total excretion |
14.44 |
14.60 |
15.39 |
13.98 |
2.87 |
N digestion, g/day |
15.19 |
15.77 |
16.92 |
18.31 |
3.97 |
|
N digestibility, % |
75.0 |
75.4 |
77.6 |
78.2 |
3.97 |
|
N retention g/day |
5.81 |
6.33 |
6.41 |
9.43 |
2.48 |
|
N balance |
|
|
|
|
|
|
As % of intake |
28.7 |
30.2 |
29.4 |
40.3 |
6.81 |
|
As % of digestion |
38.2 |
40.1 |
37.9 |
51.5 |
8.56 |
Results from the present experiment suggest that
the nutritive value of water spinach for pigs is high in spite of its high
fibrous content. In contrast, rubber seed cake has a rather low nutritive value
for pigs.
It is probable that improving amino acid balance
of water spinach could necessarily influence N balance in a positive form. This
same assumption appears to be true for rubber seed cake.
N requirement of Mong Cai pigs must probably be lower than that recommended for
improved genotypes for lean meat.
The authors are very grateful to the staff
of the Tropical Agricultural Foundation for their support and help during the conduction
of the experiment. Special thanks are given to Mr. Keo
Saeth for the care and management of the animals and
to Mr. Pok Samkol for his
assistance in the conduction of analyses in the laboratory.
Bressani R, Elias L G, Ayuso
T, Rosal O, Braham J E and Zuniga J 1983 Nutritional value of protein and oil in
rubber seed (Hevea brasiliensis).
Turrialba 33:61-66
Bun Tean, Keo Saeth,
Pok Samkol and Ly J 2002 The utilization of diets containing
increasing levels of Cambodian rubber seed meal by growing pigs. Livestock
Research for Rural Development 14(1): httm://www.cipav.org.co/lrrd/lrrd14/1/ly141.htm
Bui Huy Nhu Phuc
2000 Tropical forages
for growing pigs: digestion and nutritive values. Doctoral thesis. Swedish
University of Agricultural Sciences. Uppsala pp 131
Chiev Phiny and Rodriguez L 2001 Digestibility and N retention in Mong Cai pigs fed sugar palm (Borassus flabellifer)
juice and ensiled fresh water fish. Livestock Research for Rural Development
13(2): http://www.cipav.org.co/lrrd/lrrd13/2/phiny132.htm
Hoang N D and
Nguyen K D 1996 Pig
breeding in Central Vietnam and its improvement. In: Exploring Approach to
Research in the Animal Science in Vietnam (W J Pryor, editor) Australian Centre
of International Agricultural Research. Camberra p
123-126
Kyriazakis I and Emmans G
C 1995 The voluntary
food intake of pigs given feeds based on wheat bran, dried citrus pulp and gras meal, in relation to measurements of food bulk.
British Journal of Nutrition 73:191-207
Le Thi Men
1999 Evaluation of water
spinach (Ipomoea aquatica) for Baxuyen and Large White sows and fattening crossbred pigs.
Master in Science Thesis. Swedish University of Tropical Agriculture. Uppsala
pp 71
Ly J, Chhay Ty and Chiev Phiny 2001 Evaluation of nutrients of rubber seed
meal in Mong Cai pigs.
Livestock Research for Rural Development 13(2):
http://cipav.org.co/lrrd/lrrd13/2/ly132.htm
Ly J, Pok Samkol and Preston T R 2001 Nutritional evaluation of aquatic plants
for pigs. Pepsin/pancreatin digestibility of six
plant species. Livestock Research for Rural Development http://www.cipav.org.co/lrrd/lrrd13/6/ly136.htm
Molenat M and Tran T T
1991 La production
porcine au Vietnam et son amelioration. World Animal Review 68(3):26-36
Narahari D and Kothandaraman
P 1984 Chemical
composition and nutritional values of para-rubber
seed and its products for chickens. Animal Feed Science and Technology
10:257-267
Nguyen Thi Thuy and Ly J 2002
A short-term study of growth and digestibility indices in Mong
Cai pigs fed rubber seed meal. Livestock Research for
Rural Development 14(2): http://www.cipav.org.co/lrrd/lrrd14/2/thuy142.htm
NRC 1998 Nutrient Requirement of Swine. National
Academy of Science. 9th edition. National Academy of Science Press.
Washington D C
Nwokolo E 1987 Biochemical and nutritional qualities of rubber-seed meal.
Tropical Agriculture (Trinidad) 64:170-171
Orok E J and Bowland
J P 1974 Nigerian para rubber seed meal as an energy and protein source for
rats fed soybean meal- or peanut meal-supplemented diets. Canadian Journal of
Animal Science 54:239-246
Oude E G, Mentink
A, Everts H, Smits B and Jongbloed A W 1986
Digestibility in swine depending on several factors: literature research and
report of a number of trials, IVVO) Report 174. Lelystad
pp 83
Roth F X and Kirchgessner M 1984 Verdaulichkeit der Energie und Rohnahrstoffe beim Schwein in abhangigkeit von Futterungsniveau und Lebendgewicht.
Zeitchrift Tierphysiologie,
Tierernahrung und Futtermittelkunde
51:79-87
Ryan B F,
Joiner B L and Ryan Jr T A 1985 Minitab (2nd edition) Hilliday Lithigraph
Steel
T G D and Torrie J H 1980. Principles and Procedures of Statistics: a Biometrical
Approach. McGraw-Hill Book Company (second edition)
Tsaras L N, Kyriazakis
I and Emmans G C 1998 The prediction of the voluntary feed
intake of pigs on poor quality foods. Animal Science 66:713-723
Undersander D, Mertens D R and Theix N 1993 Forage analysis procedures. National Forage
Testing Association.