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| Mini-project Research
protocol |
MSc in Tropical Livestock System (2005-2007) |
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| Mini-project Research
protocol |
MSc in Tropical Livestock System (2005-2007) |
| Contents |
In tropical countries such as Laos, Vietnam or Cambodia, most farmers keep livestock production for their main source of income. In this case, rabbits are also used for home consumption (Honthong Phimmasan et al 2004).
Water spinach (Ipomoea aquatica) appears to have a high
potential as a feed source for rabbits according to the preliminary
report of Hongthong Phimmasan et al (2004). It is a
vegetable that is consumed by people and animals; it has a short
growth period, is resistant to common insect pests and can be
cultivated either in dry or flooded soils and moreover, it has been
found that water spinach is a vegetable with a high potential to
efficiently convert nitrogen from biodigester effluent into edible
biomass with high protein content (Kean Sophea and Preston 2001).
Water spinach has high digestibility indices of DM, ash, organic
matter and crude protein (84.7, 76.7, 88.4, and 79.6%,
respectively) for growing rabbits but rabbit husbandry is not an
exception in this context, and there are some recent reports
concerning the use of tropical foliage as source of protein for
this specie (Akinfala et al 2003; Sarwatt et al 2003). Water
spinach (Ipomoea aquatica) is coming to play an important
role for farmers and animal in rural areas, because it is easy to
plant and has a very high yield of biomass, which is rich in
protein. The crude protein content in the leaves and stems can be
as high as 32 and 18 % in dry basis, respectively (Ly Thi Luyen
and Preston 2004). Some preliminary researches have been conducted on the use
of water spinach as a basal diet for rabbit production ( Honthong
Phimmasan et al 2004; Vo Thi Tuyet Nga 2004; Samkol 2005) which ndicates the potential of this feed as an
alternative to conventional diets, which usually consist of pelleted mixtures of concentrates and forages such as alfalfa
(Lebas et al 1997).
Rice bran is an excellent energy source for rabbits, and is
available in large quantities in many developing countries.
However, it is susceptible to rancidity, which can reduce
palatability, and care should be taken to avoid rancid rice bran in
feed (Raharjo 1987). Rabbits can be raised successfully without the use of grain
in the diet, for example, using a diet in which all of the protein and energy
was provided by alfalfa meal and wheat
milling by-products, and it was found that production of does over
several parities was adequate (Raharjo et al 1986a).
Because energy and protein needs are highest during lactation, a
concentrate supplement could be used for lactating does, while the
weaned rabbits could be raised entirely on forage and agricultural
by-products such as wheat bran or rice bran (Raharjo 1987).
Digestion in rabbits begins in the mouth. The food is mashed up by
the teeth and mixed with saliva, which begins breaking down the food
which then moves out of the stomach into the small intestine where
nutrients are absorbed into the body, and it continues on into the
large intestine where the food particles are sorted by size. The
larger particles of indigestible fiber drive the smaller fragments
of digestible fiber backwards into the cecum, which is a
large blind-ended sac located at the junction of the small and
large intestines. The indigestible particles are then passed out in
the fecal pellets (regular faeces) and then begins the fermentation
process that will produce what is commonly referred to as night
feces or cecotropes, which a rabbit will ingest directly from the anus (Anon No
date).
The hard pellets of rabbit are expelled, but the soft pellets are recovered by the rabbit directly upon being expelled from the anus. To do this the rabbit twists itself round, sucks in the soft faeces as they emerge from the anus, then swallows without chewing them. The soft pellets consist half of imperfectly broken-down food residues and what is left of the gastric secretions and half of bacteria.
The hard faeces, which are produced in the large intestines, are the faecal pallets commonly seen. The faeces that are consumed via coprophagy are the soft faeces, produced in the caecum. McNitt et al (1996) fed rabbits with different feed sources, which were either balanced concentrate feeds, or green and dry forage, and measured the nutrients in the hard and soft faeces. The major difference in composition was in the DM content (lower in soft faeces) and crude protein (much higher in the soft faeces) ( Proto 1980).
The objectives were to evaluation of the feed intake and growth rate of rabbits with or without access to the soft faeces, and with access or not to rice bran, on a basal diet of water spinach.
Rabbits will have a lower feed intake and lower growth rate when they are prevented from consuming the soft faces, and that growth rate will be improved when they access to rice bran, when the basal diet is water spinach.
This experiment will be conducted in the Livestock Research Center, Nam Xuang. The experiment will be carried out from 17 Sep 2005 to 17 Oct 2005.
Twelve young rabbits with average live weight of 713g will be used in the experiment.. The design has four treatments in 2*2 factorial arrangement with three replications in a completely randomized block design (see Table1). The rabbits will be confined in individual cages constructed from wood and iron net. The treatments are:
Y-WS : Water spinach only with access to soft faeces
Y-WSRB : Water spinach and rice bran separately with access to soft faeces
N-WS: Water spinach only without access to soft faeces
N-WSRB : Water spinach and rice bran separately without access to soft faeces
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Table 1: Layout of experiment |
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Block |
I |
II |
III |
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Cages |
Y-WS |
N-WS |
Y-WSRB |
Y-WS |
N-WS |
N-WSRB |
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N-WSRB |
Y-WSRB |
N-WSRB |
N-WS |
Y-WS |
Y-WSRB |
|
The composition of the feeds is in Table 2. Rice bran is an agricultural by-product which is not suitable for humans; however, it has an important role for pig, poultry and rabbits. On the other hand, the leaves from the water spinach will be rich in crude protein, nearly twice the value corresponding to the stems from this same plant. The leaves and stems from water spinach used in the experiment will be the terminal branches.
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Table 2: Feed characteristics (% in dry basis, except for DM which is on fresh basis) |
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DM |
Ash |
Crude protein |
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Rice bran |
87.3 |
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Water spinach |
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Whole plant |
7.32 |
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Leaves |
12.9 |
11.2 |
31.9 |
|
Stem |
8.43 |
14.4 |
18.2 |
Water spinach will be harvested at level of 1cm above soil in order to let them re-grow. The leaves combined with the stems of the water spinach will be hung in the cage, by tying as a bunch at the side of the cage. Rice bran will be put in a small feeder, made up from wood and will be tied into the individual cage wall.
The rice bran will be bought from farmers outside of the station of Nam Xuang Center. The two kind of feed will be offered to the rabbits at least two times a day, beginning in the morning at 6:00 am. Observations will bemade, mainly at midday (12:00 m) and in the evening (4:30 pm), in order to ensure the permanent availability of water spinach and rice bran. The proportions of leaves and stems (fresh basis) in the water spinach will be recorded daily in the feed that will be offered and refused. Water will not be provided.
The cages are made from wood and iron net with dimension of length 0.5m, width 0.5m and height 0.7m. There are holes in the cage floor of approximately 1cm2 (See Photo1).
Photo 1:
Rabbit in the individual
cage
Chemical analyses of the diets, refusals, normal faeces and soft faeces will be undertaken following the methods of AOAC (1990) for Ash, N and CF. DM will be determined using the microwave method of Undersander et al (1993). Water extractability of DM and N is determined by the methods described by Ly and Preston (2001).
The data will be subjected to analysis of variance (Steel and Torrie 1980) using the General Linear Model (GLM) option of the MINITAB software (Release 13.31, 2000). Sources of variation are: blocks, access to faeces, rice bran, interaction access to faeces*rice bran and error
Anon1 No date
Rabbit diet and Nutrition. http://www.mybunny.org/info/rabbit_Nutrition.htm.
Anon 2 No date Nutrition and Feeding http://www.fao.org/docrep/x5082e/x5082E05.htm
Akinfala E O, Matanmi O and Aderibigbe A O
2003. Preliminary studies on the response of weaned rabbits to
whole cassava plant meal basal diets in the humid tropics.
Livestock Research for Rural Development 15(4): http://www.cipav.org.co/lrrd/lrrd154/akin154.htm
AOAC 1990. Official methods of analysis.
Association of Official Analytical Chemists. 15th edition.
Arlington pp1290
Hongthong Phimmmasan, Siton
Kongvongxay, Chhay Ty and Preston T R 2004:
Water spinach (Ipomoea aquatica) and Stylo 184 (Stylosanthes
guianensis CIAT 184) as
basal diets for growing rabbits.
Kean Sophea and Preston T R 2001 Comparison of biodigester effluent and urea as fertilizer for water spinach vegetable. Livestock Research for Rural Development (13) 6; http://www.cipav.org.co/lrrd/lrrd13/6/Kean136.htm
Lebas, F Coudert, P Rochambeau H de and Thebault R
G. 1997. The rabbit husbandry, Health and Production. Fao
Animal Production and Health Series No. 21.
Ly Thi Luyen
Ly J and Preston T R 2001. In vitro estimates
of nitrogen digestibility for pigs and water-soluble nitrogen are
correlated in tropical forages feeds. Livestock Research for Rural
Development 13(11): http://www.cipav.org.co/lrrd/lrrd13/1/ly131.htm
McNitt, J I Patton, N M Lukefahr, S D And Cheeke,
P R 1996. Rabbit production ( 7th edition). Interstate
Publishers Inc. Danville, Illinois. Pp 144-278.
Proto V 1980 Alimentazione del coniglio da
carne. Coniglicoltura, 17(7): 17-32.
Raharjo Y C, Cheeke P R, Patton N M
and Supriyati K 1986b Evaluation of tropical forage and
by-product feeds for rabbit production. I. Nutrient digestibility
and effect of heat treatment. J. Appl. Rabbit Res., 9: 56-66.
Ramchurn R and Raggoo J and Ruggoo A 2000 Digestibility and growth in the domestic rabbit using multi-nutrient blocks as a feed supplement. Livestock Research for Rural Development. 12 (1): http://www.cipav.org.co/lrrd/lrrd12/1/ram121b.htm
Raharjo, Y C 1987. Evaluation of tropical
forages and byproduct feeds for rabbit production (Ph.D.
dissertation). Corvallis, OR, Oregon State Univ.
Steel R G D and Torrie J A 1980. Principles
and Procedures of Statistics: a Biometrical Approach. McGraw-Hill
Book Company (second edition) Toronto
Undersander D, Mertens D R and Lewis B A 1993.
Forage analysis procedures. National Forage Testing Association.
Omaha pp 154