Luận văn
Trang 1Ministry of Education and TrainingNational Institute of Animal Science -
Use of several agro-industrial by-products
in cattle finishing rations in Eakar district,
Daklak province
By Truong La
The first supervisor: Vu Van Noi, PhD.
The second supervisor: Trinh Xuan Cu, PhD.
Trang 2A summarized thesis submitted in fulfillment for the Degree of Doctor of Philosophy in Agriculture
of the National Institute of Animal Sciences
Daklak province has a plentiful and diversified agro-industrial by-product resource, in thisprovince; Eakar district has a big source of agro-industrial by-products such as corn cob, corn stoverand cocoa pods The utilization of these by-product as cattle feeds is necessary to overcome a feeddeficiency If these by-products are included in finishing cattle with other locally available, cheapfeed ingredients, the economic efficiency of cattle production will be higher For a sustainable cattleproduction system, better utilization of agro-industrial by-products for feeding cattle is an appropriatestrategy For the above reasons, this study: “Use of several agro-industrial by-products in cattlefinishing rations in Eakar district, Daklak province” was undertaken
3 Scientific and practical values
The study was successful to evaluate the potential (the yield, chemical composition and nutritivevalues) of agro-industrial by-product resources, which can be used for profitable cattle feeding andcan contribute to a sustainable cattle production system
The study was also successful to determine suitable agricultural by-product levels in fattening
rations by using the in vitro-gas production technique and cattle feeding trials
The study recommended some cattle fattening rations that can be applicable in the region
4 Innovations of the thesis
The study was successful to evaluate the potential (the yield, chemical composition and nutritivevalues) of agro-industrial by-product resources, which can be used as a basis for cattle developmentstrategy in the district
Trang 3The study was successful to formulate some cattle finishing rations containing different levels ofagro-industrial by-products such as corn cob, corn stover, cocoa pod and evaluate the efficiency ofthese rations on performance of cattle.
The author was the first person in Vietnam formulating some cattle finishing rations containingcocoa pod- a new source of industrial by-products and evaluating the efficiency of these rations onperformance of cattle
5 Thesis structure
Thesis contained 4 chapters, 43 tables, 3 diagrams and 14 figures, references, 3 published papers and
an appendix
Chapter 1: Literature review
Agro-industrial by-products are products with a high biomass from crops and processing industry.Normally, these by-products have a low quality, low protein content, high fiber content (20-35% DM),low digestibility (Nguyen Huu Tao and Le Van Lien (2005)
Several ways of treatment such as physical, chemical, biological treatments have been studied toenhance the quality of rich fiber agro-industrial by-products as cattle feed (Leng, 2003; Preston, 1995)
In addition, supplementation of protein and starch to based diets of cattle containing rich fiber industrial by-products has been studied
agro-In Vietnam, in an attempt to increase meat production and quality and optimize genetic potentials
of cattle breeds, many studies on better utilization of locally available feed resources such as ricestraw, corn stover, molasses, cotton seed…as feeds for finishing cattle have been done so far (Le Viet
Ly, 1995) The results from the mentioned works have shown that with rations containing locallyavailable feed resources, cattle can have the ADG of 0.5 to 1.1kg/cattle/day) By using locallyavailable feed resources we can increase the performance of cattle, the economic efficiency of cattleproduction and contribute to a friendly environment
However, most of studies mentioned early focused on treated agro-industrial by-products It appearedthat use of treated agro-industrial by-products as cattle feeds is only applicable for large scale farms Forhouse hold farms, it is necessary to find another solution For this reason, in our study, supplementation ofprotein and energy feeds to the based rations of finishing cattle containing different levels of agro-industrial by-products was chosen In addition, a new source of industrial by-product: cocoa pod wasincluded in the based rations of finishing cattle
Chapter 2: Materials and methods2.1 Materials
Agro-industrial byproducts used in the experiments included three kinds: corn cobs, corn stoverand cocoa pods
Two mature Lai Sind fistulated males were used for the in vitro gas production experiments
Sixty three Lai Sind males at 18-20 months of age were used for fattening experiments
2.2 Experiments of the study
The study included one survey and three experiments They were:
2.2.1 Survey on the potential of agro-industrial by-product resource, which can be used for cattlefeeding in Eakar district, Daklak province
2.2.2 Experiment No 1: Utilization of corn cob in finishing rations
2.2.3 Experiment No 2: Utilization of corn stover in finishing rations
2.2.4 Experiment No 3: Utilization of cocoa pods in finishing rations
Trang 42.3 Location of the study
Survey on the potential of agro-industrial by-product resource, which can be used for cattlefeeding in Eakar district, was undertaken in the district of Eakar, Daklak province The chemical
analysis of feeds, in vitro - gas production tests were performed at the Department of Feed Analysis
and Livestock Products, and Department of Animal Feeds, Nutrition and Pasture, National Institute ofAnimal Sciences Finishing trials were conducted in the district of Eakar, Daklak province
2.4.1.2 Feeding standard for ration formulation
The nutritive requirements for cattle in tropics of Kearl (1982), Utah University (USA) were usedfor ration formulation
2.4.1.3 Chemical analysis of animal feeds
All animal feeds and by-products are sampled and analyzed according to the Vietnamesestandards (TCVN) NDF, ADF were determined by the method of Goering and Van Soest (1970)
2.4.2 Methods for specific experiments
2.4.2.1 Survey on the potential of agro-industrial by-product resource, which can be used for cattle feeding in Eakar district, Daklak province
a Survey on cattle development situation and agro-industrial by- product output
The survey on cattle population, yield and seasonal utilization of agro-industrial by-products such
as rice straw, molasses, cottonseeds, corn stover, corn cobs, cocoa pods was conducted by usingquestionnaires During the survey, samples of agro-industrial by-products were taken for the chemicalanalysis
b Chemical composition, nutritional value and characteristics of in vitro gas production of some agro-industrial by- products and other feeds
The chemical composition of agro-industrial by-products and other feeds as dry matter (DM),crude protein (CP), crude fiber (CF), lipid, total ash (Ash), NDF and ADF were analyzed using theabove mentioned methods ME (Metabolisable Energy) of agro-industrial by- products and otherfeeds was estimated using DE (Digestible Energy) and TDN (Total Digestible Nutrients) Theequations for estimations as recommended by National Institute of Animal Sciences ( 2003) were :
ME (Kcal/kg CK) = 0,82 * DE
DE (Kcal/kg CK) = 0,04409 * TDN
The characteristics of by-product (corn cobs, corn stover and cocoa pods) digestion wereestimated using in vitro gas production technique recommended by Steingass of Menke (1988) Theamount of gas produced was recorded at different time of incubation: 3, 6, 12, 24, 48, 72 and 96hours A specialized software-NEWAY developed by Chen (1997) with the exponential equation ofOrskov and Mc Donald (1979): P = a + b (1 - e-ct) was used to characterize the gas production fromagro-industrial by-products
Where:
a = the gas produced from the readily fermented organic matter (OM) fraction (ml);
Trang 5b = the gas produced from the slowly fermented OM fraction (ml),
c = the rate of fermentation of OM fraction (b);
t = incubation time (h)
P = gas produced at time't'
c Estimation of the potential of agro-industrial by-product resource, which can be used for cattle feeding in Eakar district, Daklak province
The output of protein and ME from agro-industrial by-products was estimated using the yield,chemical composition and energy value of these by-products
The estimation of how many percentage of DM and ME requirements for cattle in this district can
be covered by utilization of main agro-industrial by-products in the district was calculated on thenumber of the tropical livestock unit in district per year (one unit for cattle = 250kg or 63kg0.75) (FAO,2000) and DM and ME requirements for the number of the tropical livestock unit in district per year(Karl, 1982)
2.4.2.2 Experiment N o 1: Utilization of corn cob in finishing rations.
This experiment included 2 experiments
Experiment 1a: Effects of different levels of corn cob in the rations on gas volume and characteristics
of in vitro gas-production of rations
Three rations with three levels of corn cob: 10%, 20%, 30% were used to examine the effects ofdifferent levels of corn cob in the rations on gas volume and characteristics of in vitro gas-production(Table 2.1) The gas volume and characteristics of in vitro gas-production of each rations wereestimated using in vitro gas production technique recommended by Steingass of Menke (1988) (see:2.4.2.1 b)
Experiment 1b : Effects of different levels of corn cob in the rations on performance of finishing cattle and quality of beef.
Experimental animals
Twenty four Lai Sind young bulls aging of 18-20 months were used in this experiment.Deworming all cattle was undertaken at the beginning of adaptation period of 14 days During a 14-day adaptation period, feeds were offered individually to the animals in exactly the same routine aswas planned for use during the experimental period of 84 day At the end of the adaptation period, 24Lai Sind young bulls were randomly allocated in three treatments (three diets) (Table 2.1), each of 8animals
Table 2.1 Chemical composition, nutritive value of feed ingredient and diets used in the experiment
Ration treatment 1(10% corncob)
1-Ration treatment 2(20% corncob)
2-Ration treatment 3(30% corncob)
Trang 6* NSC = 100 - (%NDF + %Pr + %Li + %Ash) (Stiffen et al., 1992; Stokes, 1991).
Rations and feeding
Three rations used in the experiment 1.1 were used in this experiment (Table 2.1) Feeds in theform of TMR (Total mixed ration) were given individually to each animal at 8 am and 4 pm everyday All animal had a free access to water
Measurements
The average daily gain (ADG), feed conversion ratio (FCR), beef quality and economicefficiency were estimated using measurements such as body weight change, feed intake, feed cost,and slaughter data, which were recorded individually
2.4.2.3 Experiment N o 2: Utilization of corn stover in finishing rations
Experiment 2a: Effects of different levels of corn stover in rations on gas volume and characteristics of in vitro gas production of diets
Three rations with three levels of corn stover: 5%; 15%; 25% were used to examine the effects ofdifferent levels of corn cob in the rations on gas volume and characteristics of in vitro gas-production(Table 2.1) The gas volume and characteristics of in vitro gas-production of each rations wereestimated using in vitro gas production technique recommended by Steingass of Menke (1988) (see:2.4.2.1 b)
Experiment 2b : Effects of different levels of corn stover in the rations on performance of finishing cattle and quality of beef.
Experimental animals
Twenty four Lai Sind young bulls aging of 18-20 months were used in this experiment.Deworming all cattle was undertaken at the beginning of adaptation period of 14 days During a 14-day adaptation period, feeds were offered individually to the animals in exactly the same routine aswas planned for use during the experimental period of 84 day At the end of the adaptation period, 24Lai Sind young bulls were randomly allocated in three treatments (three diets) (Table 2.2), each of 8animals
Table 2.2 Chemical composition, nutritive value of feed ingredient and diets used in the experiment
Ration 1 –treatment 1(10% cornstover)
Ration treatment 2(20% cornstover)
2-Ration treatment 3(30% cornstover)
Trang 7Rations and feeding
Three rations used in the experiment 2.1 were used in this experiment (Table 2.1) Feed in theform of TMR (Total mixed ration) was given individually to each animal at 8 am and 4 pm everyday All animal had a free access to water
Measurements
The average daily gain (ADG), feed conversion ratio (FCR), and economic efficiency wereestimated using measurements such as body weight change, feed intake, and feed cost , which wererecorded individually
2.4.2.4 Experiment N o 3: Utilization of cocoa pods in finishing rations
Experiment 3a: Effects of different levels of cocoa pods in rations on gas volume and characteristics of in vitro gas production of diets.
Three rations with three levels of cocoa pods: 25%; 30%; 35% were used to examine the effects
of different levels of cocoa pods in the rations on gas volume and characteristics of in vitro production of the ration(Table 2.1) The gas volume and characteristics of in vitro gas-production ofeach rations were estimated using in vitro gas production technique recommended by Steingass ofMenke (1988) (see: 2.4.2.1 b)
gas-Experiment 3b : Effects of different levels of cocoa pods in the rations on performance of finishing cattle and quality of beef.
Experimental animals
Fifteen Lai Sind young bulls aging of 18-20 months were used in this experiment Deworming allcattle was undertaken at the beginning of adaptation period of 14 days During a 14-day adaptationperiod, feeds were offered individually to the animals in exactly the same routine as was planned foruse during the experimental period of 84 day At the end of the adaptation period, 15 Lai Sind youngbulls were randomly allocated in three treatments (three diets) (Table 2.3), each of 5 animals
Table 2.3 Chemical composition, nutritive value of feed ingredient and diets used in the experiment
Ration Treatment 1(25% cocoapods)
1-Ration Treatment 2(30% cocoapods)
2-Ration Treatment 3(35% cocoapods)
Trang 8Rations and feeding
Three rations used in experiment 3.1 were used in this experiment (Table 2.1) Feeds in the form
of TMR (Total mixed ration) were given individually to each animal at 8 am and 4 pm every day.All animal had a free access to water
Measurements
The average daily gain (ADG), feed conversion ratio (FCR), and economic efficiency wereestimated using measurements such as body weight change, feed intake, and feed cost , whichwere recorded individually
2.4.3 Statistical analysis
The following mathematical model of ANOVA was used to analyze the effects of differentlevels of agro-industrial by-products in the rations on gas volume, characteristics of in vitro gasproduction of diets, performance of finishing cattle and quality of beef:
Xijk = µ + αi + eik
Where: Xik is the observed value of replicate k in treatment i
µ is the grand mean
αi is the fixed effect of treatment i
eik is the random error
If ANOVA indicated a significant effect, then multiple t-tests were applied for comparison ofpaired means All statistical analysis were made using Excel and Minitab software, release 12.1(1997)
Chapter 3: Result and discussion3.1 The potential of agro-industrial by-product resource, which can be used for cattle feeding in Eakar district, Daklak province
3.1.1 Cattle development situation and agro-industrial by- product output
3.1.1.1 Cattle development
Changes of cattle population in Eakar district from 2004 to 2006 are presented in Table 3.1
Table 3.1 The number of cattle through the year in Eakar districtYears Population (head) Growth rate (%) As % of the province
Trang 9It seemed that cattle population in this district was changed over 3 years, on average, growth rate
was 112.6% per annum Because cattle population seemed to increase from one year to another, better
utilization of agro-industrial by-products as feeds for cattle needs to be taken into account and begiven the highest priority to overcome a shortage of feed supply
3.1.1.2 Utilization of agro-industrial by- products in cattle feeding
Results of a survey at 200 farming households farms on the use of by-products for cattle feeding are presented Table 3.2
Agro-industrial by-products were underutilized as feeds for cattle in Eakar On average, there wasonly 25.5% of households surveyed using agro-industrial by-products for cattle feeding There wasalso only 14.8% of households surveyed applying treatment solutions of agricultural by-productsbefore feeding cattle Sugar cane molasses was used as cattle in most household family (73.3%) Thepercentage of households surveyed using rice straw for cattle feeding was 43.3% However, only23.1% households applied urea treatment of rice straw before feeding cattle The percentage ofhouseholds surveyed using corn stover, corn husk, corn cob and cocoa pods for cattle feeding was 30,
15, 10 and 5 %, respectively These by-products were mainly used as cattle feeds in their originalforms, the percentage of households surveyed applying any treatments for corn stover, corn husk,before feeding cattle was 16.7 and 33.3%, respectively
The utilization of agro-industrial by-products as cattle feeds was mainly in the harvesting seasons.Rice straw was mainly used as cattle feeds from March to May and from October to December Cornstover and cob was mainly used as cattle feeds in July, August, November and December Cocoa podswas mainly used as cattle feeds in two harvesting seasons: March, May and October, Decemberevery year Only sugar cane molasses was used as cattle feeds whole year round
Table 3.2 Utilization of agro-industrial by- products in cattle feeding
Agro-industrial
by-products
Number ofhouseholdssurveyed
Number ofhouseholdsusing by-products
Percentage(%)
Number ofhouseholdsprocessingby-products
Percentage(%)
Trang 103.1.2 Agricultural by-product output in Eakar
3.1.2.1 Area, production of main cash crops in Eakar
Area and production of main cash crops in Eakar from 2004 to 2006 are presented in Table 3.3.
Table 3.3 Area (ha) and production (MT*) of main cash crops in Eakar from 2004 to 2006
Plant Area2004Prod** Area 2005Prod Area2006Prod AreaAverageProdRice 6,576 37,905 4,942 22,300 7,408 48,850 6,309 36,352 Maize 21,474 74,244 21,929 61,699 20,030 85,643 21,144 73,862 Sweet potato 767 5,022 828 5,341 1,096 6,818 897 5,727 Cassava 2,290 54,125 2,719 54,554 3,330 66,590 2,780 58,423 Sugar cane 2,759 109,460 2,598 96,330 2,875 120,178 2,744 108,656
* MT: Metric tons; Prod: Production
Among rice, corn, sugarcane, cassava crops, which were main crops in term of area used forcultivation, cultivated areas for cassava, sugar cane increased over three years The cultivated area forsweet potato crops also increased over three years
The cultivated and production for cocoa, which was low but increased markedly over three years
In 2006, cultivated area and production for cocoa were only 160 ha and 187 MT, however, area forcocoa crops in Daklak is projected to be 5,000 ha and area for cocoa crops in Eakar will increase(Ministry of Agriculture and Rural Development, 2008) In the future, by-product from cocoa willalso increase
Although area and production of peanut, soybean, cotton crops were low, these crops provided agood source of rich protein feed for cattle feeding in the district
3.1.2.2 By product to main product ratios
By product to main product ratios of rice, maize (corn), cocoa crops are presented in Table 3.4.Table 3.4 By product to main product ratios of rice, maize, cocoa crops in Eakar
Crops Number of
samples
By productweight (kg)
Main productweight (kg)
By product tomain productratios
Corn + Stover+ Cob 2020 4.65 ± 0.412.10 ± 0.34 2.30 ± 0.387.70 ± 0.50 2,02 ± 0,290.27 ± 0,05
Trang 11It was found out that: by-product to main product ratios of rice, corn, cocoa crops (rice to ricestraw, corn seed to corn stover, corn seed to corn cob and cocoa main product to cocoa pod) were0.91; 2.02; 0.27 and 1.38, respectively This by-product to main product ratio of rice straw in ourstudy was similar to work of Pham The Hue (2007) in Daklak (0.92) However, our figure was
slightly higher than that of Pham Kim Cuong et al., (2002) in Red river delta (0.89) and that published
Table 3.5 Estimated agro-industrial by-products/year (MT) in the district
Crops Main product in
the district
By-product in thedistrict
Total by-product
in province
As % of total product inprovince
The amount of corn stover and corn cob in Eakar district was estimated to be 149,200 and 19,940MT/year in the district, accounting for 15% of corn stover and corn cob in the province
The amount of cocoa pods in Eakar district was low and estimated to be only 258 MT Thisamount occupied by 38.4% of total cocoa pods in the province
3.1.3 Chemical composition, nutritional value and characteristics of in vitro gas production of some
agro-industrial by- products
3.1.3.1 Chemical composition and nutritional value of some agro-industrial by- products
* Chemical composition
Table 3.6 Chemical composition of some agro-industrial by- products (%)
By- product DM Crude
Corn stover 90.13 4.10 0.70 34.41 3.35 72.21 38.91
Cocoa pods 89.45 6.82 1.43 28.62 8.32 56.50 43.63
Trang 12Among three by-products tested, crude protein (CP) content of corn cocoa pods was the highest(6.82%), followed by CP content of corn stover (4.10%) The CP content of corn cob was the lowest(2.86%) Among them, fiber and NDF content of corn cob was the highest, followed by fiber contentcorn stover The fiber, NDF contents of cocoa pods was the lowest Compared to the rest, cocoa podswere rich in he ash content.
All of these by-product was characterized by a low CP and high fiber contents When using themfor feeding beef cattle, it is necessary to supplement rations with other ingredients, which are rich in
CP and non structural carbohydrate (NSC)
Nutritional value of several by-products
Nutritional value of some agro-industrial by- products is presented in table 3.7
Table 3.7 Nutritional value of some agro-industrial by- products
The ME content of corn stover in our study (1,551 Kcal/kgDM), however, was lower than thatpublished by the National Institute of Animal Husbandry (2003) (1,711-1,962 kcal ME/kgDM)
3.1.3.2 Characteristics of in vitro gas production of some agro-industrial by- products
The cumulative in vitro gas production from some agro-industrial by- products is presented in
table 3.8
Table 3.8 Cumulative in vitro gas production from some agro-industrial by- products
By-product Cumulative in vitro gas production at different time of incubation (ml/200mg DM)
Trang 13Values bearing different superscripts a, b, c in columns differ significantly (P <0.05).
After 3 to 12 hour incubation, the cumulative in vitro gas production of corn stover and cocoa
pods was similar (P> 0.05) and higher than that of corn cob After 24 hours of incubation, the
cumulative in vitro gas production from three agro-industrial by-products was different (P> 0.05) The cumulative in vitro gas production from corn stover was the highest (22.64 ml), followed by that from cocoa pods (18.39 ml) The cumulative in vitro gas production from corn cob was the
lowest (10.45 ml) After 96 hours of incubation, the cumulative gas volume from cocoa pods andfrom corn cob was similar (P >0.05) and lower than that from corn stover (P <0.05)
It appeared that cocoa pods was fermented rapidly in the first phage and then they were fermentedslowly in the second and third phage of incubation
The characteristics of in vitro gas production of the above agro-industrial by- products are
presented in table 3.9
Table 3.9 Characteristics of in vitro gas production of three agro-industrial by- products
By product a (ml) b (ml) a + b (ml) c (%/h) Lag phase (h) Corn stover 2.36 a 43.38 a 45.73 a 0.003 4.03 b
Corn cob 0.41 b 37.52 b 37.93 b 0.001 5.70 a
Cocoa pod 2.43 a 39.33 b 41.76 a 0.002 1.13 c