REPORT ON POST DOCTORAL F'ELLOWSHIP ...
REPORT
ON
POST DOCTORAL F'ELLOWSHIP
YEARLY ACTIVITIES
EXBRUARY 1996
Dr. CHEIK23 MBAYE BOYE
2
INTRODUCTION
In mid-June 199@ the Senegalese government received an application form for
KOSEF (Korea Science and Engineering Foundation) post doctoral fellowship for foreign
researchers fiom the government of the Republic of Korea, and transmitted it to ail
research institutes and universities for applicants. Our institute (the Senegalese
Agricultural Research Institute) selected candidate for the fellowship and 1 was chosen. 1
filled out the application form and put together a research plan which outlined the area 1
wanted to be involved in and have research undertaken on . The plan stated:
“ a _ undertake experiments and courses on nutritional physiology for small
ruminants to better understand how to analyze and make inference on feeding behavior of
short cycle reproductive animals (small ruminants and poultry) and on response under
feeding with agricultural by-products under extensive or intensive feeding”;
” b -finding ways to optimize the value of those by-products in the feeding strategy
to be recommended”.
In December 1994, we received confirmation that the application sent was
accepted and that 1 Will be working with Dr. J. K. Ha (my host scientist) from the Seoul
National University College of Agriculture and Life Sciences. 1 made contact with him and
proposed to put together a program and schedule of activities upon my arriva1 in Korea.
Upon my arriva1 in Korea on the 24th of February 1995 and alter a first meeting
with my host scientist and a brief visit to the members (graduate students and post
doctorate assistant) of his laboratory, we decided that 1 Will take some times to hand out
the proposal on the experiments 1 intended to work on for the duration of my stay. A
month later 1 came up with two topics:
“study of the nutritive value of a non conventional foodstuffs: cardboard” and
“test on potential for native chicken to use high fiber ration”.
ACTIVITIES UNDERTAKEN
Upon my arrival, 1 was sheltered during the first month at the guest house of the
College of Agriculture and Life Sciences then moved to a room at the farm station.
The day of my arrival, 1 had a meeting with my host scientist and the graduate
students and post doctorate assistant of his laboratoty during which 1 was given a
summary on their works; afier the meeting 1 was introduced to the head of the Animal
Science and Technology Department dr. 1. K. Han with whom 1 took about my work and
my expectations then to the Dean of the College and his staff.
Mer settling down, 1 soon was faced with the fact that ail activities were
undertaken in Korean language which 1 could not read, Write or speak; this was and still is
an handicap in the pursuit of my activities because 1 could not use my files brought with
me and communicate or search for references on research works done by my fellows
Korean researchers in my field. 1 did overcome some of it by buying a computer and some
software in English which did allow me to Write my proposa1 and be able to perform the
analysis needed on the data 1 gather in the course of my experiments here.
The proposal on “study of the nutritive value of a non conventional foodstuff:
cardboard” was carried out on five experiments:
1) comparative digestibility of treated cardboard (sodium hydroxide: NaOH) and
rice straw using ‘Yumen collection” and “KNGF-SNU” a fùngi isolated by the research
team of the ruminant nutrition laboratory from the rumen of Korean native goat;
2) effect of chemical treatment i.e. sodium hydroxide, ammonium hydroxide,
hydrogen peroxide and soaked with running water) on in vitro dry matter digestibility
(IVDMD) of cardboard;
3) effect of protein supplement (cottonseed meal) on in vitro dry matter
digestibility (IVDMD) of cardboard;
4
4) effect of chemical treatment (i.e. NaOH or NI&OH) on in situ dry matter
digestibility (ISDMD) of cardboard;
5) biochemical rumen characteristics (volatile fatty acids and ammonia
concentration of sheep fed diets with different levels of substitution of rice straw by
cardboard.
Recycling waste products has received attention in recent years due to shortages of
food (roughage, cereal and cereal by-products) for feeding of animal especially in
developing countries where there is competition between humans and animals in the use of
some foodstuffs. This lead to the tria1 of non conventional foodstuffs. Wood products and
residues have been receiving consideration as possible energy sources for ruminants. Their
use could tiee more additional foodstuffs for man and allow recycling of wood products
such as waste paper into productive use (meat and milk) in ruminants, Feeding waste
paper to ruminants has created interest because it utilizes a waste product which has the
potential to become an economically feasible roughage substitute in ruminants diets.
Early works have shown that varieties of waste papers cari be consumed and
digested by ruminants, that dry matter disappearance (DMD) rate varies depending on the
nature of waste papers(i.e. brown cardboard and brown wrappings paper have higher
DMD than glossy or silk magazine which have higher DMD than newsprint paper). The
variation could be the effect of difference in manufacturing process. Chen&al treatment
(mainly NaOH) of cardboard have shown to improve IVDMD and the same is true for
nitrogen supplement. Complete diets incorporating cardboard have been well digested by
ruminants.
TO be successfùl in the promotional use of cardboard, one may show how well it
cari be a substitute to low quality forage and roughage. Our objective in the different trials
done was to evaluate the digestibility value of cardboard and its ability to be a good
substitute to low quality forage as basa1 diet in a feeding strategy of areas where there is
shortage of conventional foodstuffs for animals.
5
Experiment 1
200 g of cardboard were treated with a 2000 ml solution of 4% sodium hydroxide
(NaOH) into a becher, sealed for 96 hours at room temperature, then air dried for 48
hours. The treated cardboard and a same amount of rice straw and non treated cardboard
were grinned (1 mm) separately. 2 g of triplicates samples of each treatments were put
into test tubes and 10 ml of Lowe’s medium were added under CO1 and autoclaved for 45
mn. Rumen content fiom a fistulated sheep fed rice straw and concentrate (ratio 30:70)
was collected by aspiration through a rubber tube and under anaerobic conditions
(Hungate anaerobic system COz) was filtered using a four layer cheesecloth, the rumen
fluid was them centrifuged at 10000 rpm for 15 mn at 10°C, the supernatant and the Upper
white layer were collected and the ‘“rumen collection” which was homogenized using a
vortex and then diluted at 10% with a Bryant’s solution under COZ. Culture of “KNGF-
SNU” fungi was also homogenized using a vortex and then diiuted at 10% with a Bryant’s
solution under CO2. Samples were then inoculated with 1 ml of one of the treatments
(“rumen collection” or “KNGF-SNU”) and incubated for 7 days at 39’C. Rephcates were
taken out at day 4 and 7, dried for 48 hours at 7O*C then weighed for dry matter
disappearance (DMD).
The results show at 4 days of incubation a DMD rate of 8.8, 16.5 and 30.0 by
“rumen collection” for treated cardboard, non treated cardboard and rice straw
respectively 10.0, 20.5 and 29.2 by “KNGF-SNU” for treated cardboard, non treated
cardboard and rice straw respectively. At 7 day incubation the DMD rates were 13.2, 17.0
and 32.5 by “rumen collection” for treated cardboard, non treated cardboard and rice
straw respectively and 8.9, 21.9 and 31.8 by “KNGF-SNU” for treated cardboard, non
treated cardboard and rice straw respectively.
These data suggest that rice straw is more digested than cardboard and that
chemical treatment did not improve the digestibility of cardboard. The ‘KNGF-SNU”
shows higher (p < 0.05) potential for digesting cardboard than ‘%umen collection” but no
difference in digestibility potential between “‘KNGF-SNU” and ‘Yumen collection” was
found for rice straw. This may be due to the fact that ‘KNGF-SNU’” is cultured and
6
conserved under filter paper which may increase its potential for wood by-product
degradation.
Experiment 2
200 g of cardboard and 2000 g of a solution of one of the chemical treatments
(4% NaOH, 3% mOH, 1% Hz02 and running water) were put into a becher which was
then sealed and allowed the chemical treatments to react for 96 hours, then air dried for 48
hours, then grinned (1 mm). The rumen fluid was obtained in the same way than in
experiment 1 without the centrifugation. The first phase of the Tilley and Terry in vitro
digestibility method was then undertaken which consists of a 48 hours incubation of 2 g
sample with 20 ml rumen fluid at 39’C.
The in vitro dry matter disappearance (IVDMD) rates were 65.5, 59.3, 40.7, 52.2
and 54.4 for non treated cardboard, NILOH treated cardboard, NaOH treated cardboard,
Hz02 treated cardboard and soaked cardboard (running water treatment) respectively.
Non treated cardboard has higher (p < 0.05) IVDMD rate than NaOH treated
cardboard, but no Sign&ant difference in IVDMD rate was found between non treated
cardboard and the other chemical treatments. The overall finding is that chemical
treatment does not improve the IVDMD rate of cardboard.
Experiment 3
Cottonseed meal (CSM) was use as protein source in a trial to evaluate the effect
of protein supplement level in the digestibility improvement of cardboard. Three levels
were used: 10, 15 and 20%. The rumen fluid was obtained in the same way than in
experiment 2 and the Tilley and Terry in vitro digestibility method done also in the same
way than in experiment 2.
The IVDMD rates at 24 hour incubation were 25.7, 25.2 and 32.7 for non
supplemented cardboard, lO%, 15% and 20% CSM supplemented cardboard respectively,
and 45.8, 48.3, 46.4 and 44.5 at 48 hour incubation for non supplemented cardboard,
1 O%, 15% and 20% CSM supplemented cardboard respectively.
7
The results suggest that supplernented CSM at 15 and 20% levels improves
IVDMD rate of cardboard at 24 hour incubation but not at 48 hour incubation.
Experiment 4
The treated cardboard (NaOH and Nl&OH) tiom experiment 2 were used in the in
situ tria1 conducted using the facilities of the National Livestock Research Institute.
Triplicates of nylon bags containing 2 g of samples of one of the treatments (non treated
cardboard, NaOH treated cardboard and NI&OH treated cardboard) were incubated into
the rumen of a four years old fistulated Holstein cow fed concentrate and alfalfa hay.
Samples were removed at 0, 3, 6, 9, 12, 16, 24, 48, 72 and 96 hour; alter removal nylon
bags are washed gently under warm running water then agitated for more washing into a
bucket full with running water for 30 to 35 mn until the water is clear. the bags are then
dried for 48 hours at 70°C and weighed for dry matter disappearance rate. a11 replicates of
a given removal time and treatment are then mixed and sent for ADF and NDF analysis.
The in situ dry matter disappearance (ISDMD) rate were 29.7, 38.1 and 41.5 for
non treated cardboard, NaOH treated cardboard and WOH treated cardboard
respectively at 24 hour incubation time and 48.7, 47.9 and 44.4 for non treated cardboard,
NaOH treated cardboard and m0H treated cardboard respectively at 48 hour incubation
time.
The results suggest that chemical treatments (mainly NaOH or mOH) improves
(p < 0.05) ISDMD rate at 24 incubation but not at 48 hour incubation.
Experiment 5
Three fistulated adult sheep were used in a Latin square design 3 x 3 with 3 diets:
rice straw and concentrate (Tl)(ratio 40:60), cardboard, rice straw and concentrate (T2)
(ratio 20:20:60) and cardboard and concentrate (T3)(ratio 40:60). The adjustment period
was 4 days and the collection period 3 days. Every 7 days each sheep was fed a new diet
different fkom the one for the last week. Rumen content samples were taken using a
rubber tube 4 hours alter the morning feeding of every day of the collection period. Upon
8
arriva1 at the laboratory, the samples are filtered using a four layer cheesecloth and 10 ml
of the rumen fluid are collected into test tubes where are added 1 ml of a 2% HgC12
solution and 2 ml of a 25% HP03 solution, then the mixture is centrifùged at 3000 rpm for
15 mn at 10°C. 2 ml of the supernatant were collected for fùrther ammonia analysis using
the Chaney and Marbach method with a spectophotometer at 630 mn. Duplicates of 1 ml
of the supernatant are then centrifùged again at 14000 rpm for 15 mn at 1OoC and the new
supernatant collected for VFA analysis at Kon Kuk university using a Gas Chromatograph
( Hewlett Packard Gas Chromatograph 5890A series II).
The ammonia concentration (mg per 100 ml rumen fluid) was 5.7, 2.3 and 2.6 for
diet Tl, diet T2 and diet T3 respectively.
The total VFA concentrations (mm01 per liter of rumen fluid) were 6.4, 9.1 and 8.5
for diet Tl, diet T2 and diet T3 respectively.
The acetic acid concentrations were 3.6, 5.1 and 4.8 and represented 57, 56 and
56% of the total VFA for diet Tl, diet T2 and diet T3 respectively.
The propionic acid concentrations were 1.7, 2.6 and 1.9 and represented 26, 28
and 22% of the total VFA for diet Tl, diet T2 and diet T3 respectively.
The butyric acid concentrations were 1 .O, 1.4 and 1.8 and represented 16, 15 and
21% of the total VFA for diet Tl, diet T2 and diet T3 respectively.
The ammonia concentration was lower (p < 0.05) for the diets containing
cardboard which show higher (p < 0.05) concentration of total VFA.
Although the acetic acid concentration was higher (p < 0.05) for the diet
containing cardboard, there was no significant difference (p < 0.05) between diet by
looking at the acetic acid concentration as percentage of the total VFA. The propionic
acid concentration as a percentage of total VFA was higher (p < 0.05) for diet containing
rice straw. the butyric acid was higher (p < 0.05) for diet containing cardboard but was
higher (p < 0.05) as a percentage of total VFA only for the diet without rice straw.
Al1 diets in the experiment show lower (p < 0.05) acetic acid concentration
expressed as percentage of total VFA than usual (63). Diets with rice straw show higher
(p < 0.05) propionic acid concentration expressed as percentage of total VFA than usual
(21). Diet with cardboard as sole source of roughage (without rice straw) shows normal
9
propionic acid concentration and higher (p < 0.05) butyric acid concentration expressed as
percentage of total VFA than usual(16).
It seems that there is a shifl in WA production from acetic acid to propionic acid
for the diet containing rice straw and from acetic acid to butyric acid for diet with
cardboard as sole source of roughage (without rice straw). The higher level of total VFA
for diet containing cardboard may be due to the fact that cardboard is more easily and
rapidly degraded than rice straw, and the same fact may explain the low level of ammonia
by a rapid incorporation of peptides by microbes because of the already available VFA
from cardboard degradation or by the sparing effect on protein degradation because of the
readily available carbon skeleton fi-om cardboard degradation.
The overall findings of theses triais suggests that cardboard is suitable to be a
ruminant feed and that it cari be a good substitute for low quality forage as source of
energy in ruminant feeding.
A growth tria1 involving the evaluation of weigh gain, body composition and weigh
gain composition was on schedule but could not be done for lack of fùnd to buy the
number of animals necessary for the experiment.
The proposa1 on: ‘Yest on potential for native chicken to use high fiber ration”
consisted of two trials: a digestibility one and another on growth which would have
evaluate three levels of fiber content of the diet (3, 5 and 7) and would have look at the
level of intake, digestibility, weigh gain, composition and nature of gain and the microbial
composition of digestive tract.
Although we had all the help needed for the feed from Dr. 1. K. Han, the animals
we had at our disposa1 were from a breeding stock and part of the experiment could not be
performed. The alternative we had to but the native chicken tiom outside and
manufacturing a new set of digestibility cages could not be made for lack of Lund.
10
On May 1995, 1 attended the symposium on c‘supply of Iivestock products to
rapidly expanding urban population”.
On September 1 made a presentation for the graduate students of the Department of
Animal Science and Technology on “Senegal: an overview” in which I underline Senegal
main characteristics: type of government, constitution, culture, politic, economy,
education system, population and geography.
1 also have the privilege to be present at two presentations by:
- Dr. Cheng (Livestock Sciences Section: Research Station, Lethbridge, Alberta,
Canada.) on :
a) the utilization of rumen fungi enzymes in biotechnology: exploitation of rumen
microbial enzymes to the benefit of the feed industry,
b) microbial attachment to feed and mode of action.
- Dr. Ushida (Kyoto Prefectural University Japan) on:
a) understanding of microbiological physiology of rumen and hind gut anaerobic bacteria,
fungi and protozoa,
b) inter-species hydrogen transfer in anaerobic microbial ecosystems.
My host scientist laboratory being mainly a rumen microbiology one, I did learn a
great deal about rumen microbes studies techniques (isolation and characterization,
enzyme activities determination and evaluation). The ruminant nutrition being the
understanding of the metabolism of the microbes of the rumen and finding way to açhieve
a more efficient way to improve the production by the microbes of the end products
needed by the host animais for its own production, one cari understand the importance of
rumen microbiology studies and its impact on the development of future strategies in
feeding ruminants. The metabolism of the microbes being the end result of the enzyme
activities, knowing and characterizing the different enzymes (and their mode of action)
involved in the process of degradation of the different constituents of the feed
(carbohydrates, protein, lipids and minerals) are essential in the improvement of the end
products production the host animal needs for its production (meat and milk).
11
What 1 have learn in these areas Will be of great importance and help in
implementing new topics of research in our laboratory and Will surely improve the use of
low quality forage and non conventional foodstuff.
ACKOWNLEDGMENTS
1 wish to thanks the Korea Science and Engineering Foundation (KOSEF) by
creating this new program of post doctoral fellowship for a better exchange of information
and cooperation between Korean scientists and foreigners which have allowed me to corne
to Korea and work with some of my colleagues of my field, and giving me the opportunity
to increase my knowledge in ruminant nutrition.
My thanks to Dr. J. K. Ha for allowing me to work with him in his laboratory, for
ali the support and help he gave and for facilitating the execution of all the experiments.
My thanks to dr. L K. Han for a11 the support and advise he gave me.
My thanks to Dr. S. S. Lee, Dr. W. Y. Kim, Mrs J. B. Lee, W. D. Kim and S. H.
Kim for their understanding, help and support.
RECOMMENDATIONS
The language barrier is a great handicap in the communication process and more
efficient work by the foreigners con-ring to Korea, it Will be therefore of great interest for
the future post doctoral fellowship participants of this program to have a two to three
months intensive language course. 1 did have a lot of problem communicating ( understand
and being understood) and think that 1 would have gain more in term of know-how f?om
my host scientist if 1 was able to speak, write and read the Korean language and also it is
the best way to understand the Korean culture which also is part of the aim of this
program.
Although we as participants of this program have an allowance sufficient for our
expenses, the host scientist needs more financial incentives to support the experiments the
participants are undertaking but also it may be a way to help upgrade the laboratory or
new apparatus needed for the work they are doing
ON
POST DOCTORAL F'ELLOWSHIP
YEARLY ACTIVITIES
EXBRUARY 1996
Dr. CHEIK23 MBAYE BOYE
2
INTRODUCTION
In mid-June 199@ the Senegalese government received an application form for
KOSEF (Korea Science and Engineering Foundation) post doctoral fellowship for foreign
researchers fiom the government of the Republic of Korea, and transmitted it to ail
research institutes and universities for applicants. Our institute (the Senegalese
Agricultural Research Institute) selected candidate for the fellowship and 1 was chosen. 1
filled out the application form and put together a research plan which outlined the area 1
wanted to be involved in and have research undertaken on . The plan stated:
“ a _ undertake experiments and courses on nutritional physiology for small
ruminants to better understand how to analyze and make inference on feeding behavior of
short cycle reproductive animals (small ruminants and poultry) and on response under
feeding with agricultural by-products under extensive or intensive feeding”;
” b -finding ways to optimize the value of those by-products in the feeding strategy
to be recommended”.
In December 1994, we received confirmation that the application sent was
accepted and that 1 Will be working with Dr. J. K. Ha (my host scientist) from the Seoul
National University College of Agriculture and Life Sciences. 1 made contact with him and
proposed to put together a program and schedule of activities upon my arriva1 in Korea.
Upon my arriva1 in Korea on the 24th of February 1995 and alter a first meeting
with my host scientist and a brief visit to the members (graduate students and post
doctorate assistant) of his laboratory, we decided that 1 Will take some times to hand out
the proposal on the experiments 1 intended to work on for the duration of my stay. A
month later 1 came up with two topics:
“study of the nutritive value of a non conventional foodstuffs: cardboard” and
“test on potential for native chicken to use high fiber ration”.
ACTIVITIES UNDERTAKEN
Upon my arrival, 1 was sheltered during the first month at the guest house of the
College of Agriculture and Life Sciences then moved to a room at the farm station.
The day of my arrival, 1 had a meeting with my host scientist and the graduate
students and post doctorate assistant of his laboratoty during which 1 was given a
summary on their works; afier the meeting 1 was introduced to the head of the Animal
Science and Technology Department dr. 1. K. Han with whom 1 took about my work and
my expectations then to the Dean of the College and his staff.
Mer settling down, 1 soon was faced with the fact that ail activities were
undertaken in Korean language which 1 could not read, Write or speak; this was and still is
an handicap in the pursuit of my activities because 1 could not use my files brought with
me and communicate or search for references on research works done by my fellows
Korean researchers in my field. 1 did overcome some of it by buying a computer and some
software in English which did allow me to Write my proposa1 and be able to perform the
analysis needed on the data 1 gather in the course of my experiments here.
The proposal on “study of the nutritive value of a non conventional foodstuff:
cardboard” was carried out on five experiments:
1) comparative digestibility of treated cardboard (sodium hydroxide: NaOH) and
rice straw using ‘Yumen collection” and “KNGF-SNU” a fùngi isolated by the research
team of the ruminant nutrition laboratory from the rumen of Korean native goat;
2) effect of chemical treatment i.e. sodium hydroxide, ammonium hydroxide,
hydrogen peroxide and soaked with running water) on in vitro dry matter digestibility
(IVDMD) of cardboard;
3) effect of protein supplement (cottonseed meal) on in vitro dry matter
digestibility (IVDMD) of cardboard;
4
4) effect of chemical treatment (i.e. NaOH or NI&OH) on in situ dry matter
digestibility (ISDMD) of cardboard;
5) biochemical rumen characteristics (volatile fatty acids and ammonia
concentration of sheep fed diets with different levels of substitution of rice straw by
cardboard.
Recycling waste products has received attention in recent years due to shortages of
food (roughage, cereal and cereal by-products) for feeding of animal especially in
developing countries where there is competition between humans and animals in the use of
some foodstuffs. This lead to the tria1 of non conventional foodstuffs. Wood products and
residues have been receiving consideration as possible energy sources for ruminants. Their
use could tiee more additional foodstuffs for man and allow recycling of wood products
such as waste paper into productive use (meat and milk) in ruminants, Feeding waste
paper to ruminants has created interest because it utilizes a waste product which has the
potential to become an economically feasible roughage substitute in ruminants diets.
Early works have shown that varieties of waste papers cari be consumed and
digested by ruminants, that dry matter disappearance (DMD) rate varies depending on the
nature of waste papers(i.e. brown cardboard and brown wrappings paper have higher
DMD than glossy or silk magazine which have higher DMD than newsprint paper). The
variation could be the effect of difference in manufacturing process. Chen&al treatment
(mainly NaOH) of cardboard have shown to improve IVDMD and the same is true for
nitrogen supplement. Complete diets incorporating cardboard have been well digested by
ruminants.
TO be successfùl in the promotional use of cardboard, one may show how well it
cari be a substitute to low quality forage and roughage. Our objective in the different trials
done was to evaluate the digestibility value of cardboard and its ability to be a good
substitute to low quality forage as basa1 diet in a feeding strategy of areas where there is
shortage of conventional foodstuffs for animals.
5
Experiment 1
200 g of cardboard were treated with a 2000 ml solution of 4% sodium hydroxide
(NaOH) into a becher, sealed for 96 hours at room temperature, then air dried for 48
hours. The treated cardboard and a same amount of rice straw and non treated cardboard
were grinned (1 mm) separately. 2 g of triplicates samples of each treatments were put
into test tubes and 10 ml of Lowe’s medium were added under CO1 and autoclaved for 45
mn. Rumen content fiom a fistulated sheep fed rice straw and concentrate (ratio 30:70)
was collected by aspiration through a rubber tube and under anaerobic conditions
(Hungate anaerobic system COz) was filtered using a four layer cheesecloth, the rumen
fluid was them centrifuged at 10000 rpm for 15 mn at 10°C, the supernatant and the Upper
white layer were collected and the ‘“rumen collection” which was homogenized using a
vortex and then diluted at 10% with a Bryant’s solution under COZ. Culture of “KNGF-
SNU” fungi was also homogenized using a vortex and then diiuted at 10% with a Bryant’s
solution under CO2. Samples were then inoculated with 1 ml of one of the treatments
(“rumen collection” or “KNGF-SNU”) and incubated for 7 days at 39’C. Rephcates were
taken out at day 4 and 7, dried for 48 hours at 7O*C then weighed for dry matter
disappearance (DMD).
The results show at 4 days of incubation a DMD rate of 8.8, 16.5 and 30.0 by
“rumen collection” for treated cardboard, non treated cardboard and rice straw
respectively 10.0, 20.5 and 29.2 by “KNGF-SNU” for treated cardboard, non treated
cardboard and rice straw respectively. At 7 day incubation the DMD rates were 13.2, 17.0
and 32.5 by “rumen collection” for treated cardboard, non treated cardboard and rice
straw respectively and 8.9, 21.9 and 31.8 by “KNGF-SNU” for treated cardboard, non
treated cardboard and rice straw respectively.
These data suggest that rice straw is more digested than cardboard and that
chemical treatment did not improve the digestibility of cardboard. The ‘KNGF-SNU”
shows higher (p < 0.05) potential for digesting cardboard than ‘%umen collection” but no
difference in digestibility potential between “‘KNGF-SNU” and ‘Yumen collection” was
found for rice straw. This may be due to the fact that ‘KNGF-SNU’” is cultured and
6
conserved under filter paper which may increase its potential for wood by-product
degradation.
Experiment 2
200 g of cardboard and 2000 g of a solution of one of the chemical treatments
(4% NaOH, 3% mOH, 1% Hz02 and running water) were put into a becher which was
then sealed and allowed the chemical treatments to react for 96 hours, then air dried for 48
hours, then grinned (1 mm). The rumen fluid was obtained in the same way than in
experiment 1 without the centrifugation. The first phase of the Tilley and Terry in vitro
digestibility method was then undertaken which consists of a 48 hours incubation of 2 g
sample with 20 ml rumen fluid at 39’C.
The in vitro dry matter disappearance (IVDMD) rates were 65.5, 59.3, 40.7, 52.2
and 54.4 for non treated cardboard, NILOH treated cardboard, NaOH treated cardboard,
Hz02 treated cardboard and soaked cardboard (running water treatment) respectively.
Non treated cardboard has higher (p < 0.05) IVDMD rate than NaOH treated
cardboard, but no Sign&ant difference in IVDMD rate was found between non treated
cardboard and the other chemical treatments. The overall finding is that chemical
treatment does not improve the IVDMD rate of cardboard.
Experiment 3
Cottonseed meal (CSM) was use as protein source in a trial to evaluate the effect
of protein supplement level in the digestibility improvement of cardboard. Three levels
were used: 10, 15 and 20%. The rumen fluid was obtained in the same way than in
experiment 2 and the Tilley and Terry in vitro digestibility method done also in the same
way than in experiment 2.
The IVDMD rates at 24 hour incubation were 25.7, 25.2 and 32.7 for non
supplemented cardboard, lO%, 15% and 20% CSM supplemented cardboard respectively,
and 45.8, 48.3, 46.4 and 44.5 at 48 hour incubation for non supplemented cardboard,
1 O%, 15% and 20% CSM supplemented cardboard respectively.
7
The results suggest that supplernented CSM at 15 and 20% levels improves
IVDMD rate of cardboard at 24 hour incubation but not at 48 hour incubation.
Experiment 4
The treated cardboard (NaOH and Nl&OH) tiom experiment 2 were used in the in
situ tria1 conducted using the facilities of the National Livestock Research Institute.
Triplicates of nylon bags containing 2 g of samples of one of the treatments (non treated
cardboard, NaOH treated cardboard and NI&OH treated cardboard) were incubated into
the rumen of a four years old fistulated Holstein cow fed concentrate and alfalfa hay.
Samples were removed at 0, 3, 6, 9, 12, 16, 24, 48, 72 and 96 hour; alter removal nylon
bags are washed gently under warm running water then agitated for more washing into a
bucket full with running water for 30 to 35 mn until the water is clear. the bags are then
dried for 48 hours at 70°C and weighed for dry matter disappearance rate. a11 replicates of
a given removal time and treatment are then mixed and sent for ADF and NDF analysis.
The in situ dry matter disappearance (ISDMD) rate were 29.7, 38.1 and 41.5 for
non treated cardboard, NaOH treated cardboard and WOH treated cardboard
respectively at 24 hour incubation time and 48.7, 47.9 and 44.4 for non treated cardboard,
NaOH treated cardboard and m0H treated cardboard respectively at 48 hour incubation
time.
The results suggest that chemical treatments (mainly NaOH or mOH) improves
(p < 0.05) ISDMD rate at 24 incubation but not at 48 hour incubation.
Experiment 5
Three fistulated adult sheep were used in a Latin square design 3 x 3 with 3 diets:
rice straw and concentrate (Tl)(ratio 40:60), cardboard, rice straw and concentrate (T2)
(ratio 20:20:60) and cardboard and concentrate (T3)(ratio 40:60). The adjustment period
was 4 days and the collection period 3 days. Every 7 days each sheep was fed a new diet
different fkom the one for the last week. Rumen content samples were taken using a
rubber tube 4 hours alter the morning feeding of every day of the collection period. Upon
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arriva1 at the laboratory, the samples are filtered using a four layer cheesecloth and 10 ml
of the rumen fluid are collected into test tubes where are added 1 ml of a 2% HgC12
solution and 2 ml of a 25% HP03 solution, then the mixture is centrifùged at 3000 rpm for
15 mn at 10°C. 2 ml of the supernatant were collected for fùrther ammonia analysis using
the Chaney and Marbach method with a spectophotometer at 630 mn. Duplicates of 1 ml
of the supernatant are then centrifùged again at 14000 rpm for 15 mn at 1OoC and the new
supernatant collected for VFA analysis at Kon Kuk university using a Gas Chromatograph
( Hewlett Packard Gas Chromatograph 5890A series II).
The ammonia concentration (mg per 100 ml rumen fluid) was 5.7, 2.3 and 2.6 for
diet Tl, diet T2 and diet T3 respectively.
The total VFA concentrations (mm01 per liter of rumen fluid) were 6.4, 9.1 and 8.5
for diet Tl, diet T2 and diet T3 respectively.
The acetic acid concentrations were 3.6, 5.1 and 4.8 and represented 57, 56 and
56% of the total VFA for diet Tl, diet T2 and diet T3 respectively.
The propionic acid concentrations were 1.7, 2.6 and 1.9 and represented 26, 28
and 22% of the total VFA for diet Tl, diet T2 and diet T3 respectively.
The butyric acid concentrations were 1 .O, 1.4 and 1.8 and represented 16, 15 and
21% of the total VFA for diet Tl, diet T2 and diet T3 respectively.
The ammonia concentration was lower (p < 0.05) for the diets containing
cardboard which show higher (p < 0.05) concentration of total VFA.
Although the acetic acid concentration was higher (p < 0.05) for the diet
containing cardboard, there was no significant difference (p < 0.05) between diet by
looking at the acetic acid concentration as percentage of the total VFA. The propionic
acid concentration as a percentage of total VFA was higher (p < 0.05) for diet containing
rice straw. the butyric acid was higher (p < 0.05) for diet containing cardboard but was
higher (p < 0.05) as a percentage of total VFA only for the diet without rice straw.
Al1 diets in the experiment show lower (p < 0.05) acetic acid concentration
expressed as percentage of total VFA than usual (63). Diets with rice straw show higher
(p < 0.05) propionic acid concentration expressed as percentage of total VFA than usual
(21). Diet with cardboard as sole source of roughage (without rice straw) shows normal
9
propionic acid concentration and higher (p < 0.05) butyric acid concentration expressed as
percentage of total VFA than usual(16).
It seems that there is a shifl in WA production from acetic acid to propionic acid
for the diet containing rice straw and from acetic acid to butyric acid for diet with
cardboard as sole source of roughage (without rice straw). The higher level of total VFA
for diet containing cardboard may be due to the fact that cardboard is more easily and
rapidly degraded than rice straw, and the same fact may explain the low level of ammonia
by a rapid incorporation of peptides by microbes because of the already available VFA
from cardboard degradation or by the sparing effect on protein degradation because of the
readily available carbon skeleton fi-om cardboard degradation.
The overall findings of theses triais suggests that cardboard is suitable to be a
ruminant feed and that it cari be a good substitute for low quality forage as source of
energy in ruminant feeding.
A growth tria1 involving the evaluation of weigh gain, body composition and weigh
gain composition was on schedule but could not be done for lack of fùnd to buy the
number of animals necessary for the experiment.
The proposa1 on: ‘Yest on potential for native chicken to use high fiber ration”
consisted of two trials: a digestibility one and another on growth which would have
evaluate three levels of fiber content of the diet (3, 5 and 7) and would have look at the
level of intake, digestibility, weigh gain, composition and nature of gain and the microbial
composition of digestive tract.
Although we had all the help needed for the feed from Dr. 1. K. Han, the animals
we had at our disposa1 were from a breeding stock and part of the experiment could not be
performed. The alternative we had to but the native chicken tiom outside and
manufacturing a new set of digestibility cages could not be made for lack of Lund.
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On May 1995, 1 attended the symposium on c‘supply of Iivestock products to
rapidly expanding urban population”.
On September 1 made a presentation for the graduate students of the Department of
Animal Science and Technology on “Senegal: an overview” in which I underline Senegal
main characteristics: type of government, constitution, culture, politic, economy,
education system, population and geography.
1 also have the privilege to be present at two presentations by:
- Dr. Cheng (Livestock Sciences Section: Research Station, Lethbridge, Alberta,
Canada.) on :
a) the utilization of rumen fungi enzymes in biotechnology: exploitation of rumen
microbial enzymes to the benefit of the feed industry,
b) microbial attachment to feed and mode of action.
- Dr. Ushida (Kyoto Prefectural University Japan) on:
a) understanding of microbiological physiology of rumen and hind gut anaerobic bacteria,
fungi and protozoa,
b) inter-species hydrogen transfer in anaerobic microbial ecosystems.
My host scientist laboratory being mainly a rumen microbiology one, I did learn a
great deal about rumen microbes studies techniques (isolation and characterization,
enzyme activities determination and evaluation). The ruminant nutrition being the
understanding of the metabolism of the microbes of the rumen and finding way to açhieve
a more efficient way to improve the production by the microbes of the end products
needed by the host animais for its own production, one cari understand the importance of
rumen microbiology studies and its impact on the development of future strategies in
feeding ruminants. The metabolism of the microbes being the end result of the enzyme
activities, knowing and characterizing the different enzymes (and their mode of action)
involved in the process of degradation of the different constituents of the feed
(carbohydrates, protein, lipids and minerals) are essential in the improvement of the end
products production the host animal needs for its production (meat and milk).
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What 1 have learn in these areas Will be of great importance and help in
implementing new topics of research in our laboratory and Will surely improve the use of
low quality forage and non conventional foodstuff.
ACKOWNLEDGMENTS
1 wish to thanks the Korea Science and Engineering Foundation (KOSEF) by
creating this new program of post doctoral fellowship for a better exchange of information
and cooperation between Korean scientists and foreigners which have allowed me to corne
to Korea and work with some of my colleagues of my field, and giving me the opportunity
to increase my knowledge in ruminant nutrition.
My thanks to Dr. J. K. Ha for allowing me to work with him in his laboratory, for
ali the support and help he gave and for facilitating the execution of all the experiments.
My thanks to dr. L K. Han for a11 the support and advise he gave me.
My thanks to Dr. S. S. Lee, Dr. W. Y. Kim, Mrs J. B. Lee, W. D. Kim and S. H.
Kim for their understanding, help and support.
RECOMMENDATIONS
The language barrier is a great handicap in the communication process and more
efficient work by the foreigners con-ring to Korea, it Will be therefore of great interest for
the future post doctoral fellowship participants of this program to have a two to three
months intensive language course. 1 did have a lot of problem communicating ( understand
and being understood) and think that 1 would have gain more in term of know-how f?om
my host scientist if 1 was able to speak, write and read the Korean language and also it is
the best way to understand the Korean culture which also is part of the aim of this
program.
Although we as participants of this program have an allowance sufficient for our
expenses, the host scientist needs more financial incentives to support the experiments the
participants are undertaking but also it may be a way to help upgrade the laboratory or
new apparatus needed for the work they are doing