ABSTRACT
This study investigates
the potential of biodegraded cassava root sievate (CRS) as a sustainable feed
ingredient for the production of West African Dwarf (WAD) goats in the
rainforest zone. The research aims to enhance the biological value of cassava
root sievate, an agricultural by-product, through biodegradation while
addressing its environmental impact. By leveraging biodegradation techniques,
specifically using Pleurotus tuber regium (PTR), the study focuses on
improving the nutritional profile and digestibility of cassava root sievate,
making it a viable alternative in goat diets.
The research objectives
include evaluating the proximate composition, fibre fractions, anti-nutritional
factors, and mineral content of biodegraded and non-biodegraded cassava root
sievate, as well as their impact on experimental diets. In vitro assessments of
gas production, metabolizable energy, organic matter digestibility (OMD), and
short-chain fatty acid (SCFA) production are conducted to estimate the
nutritional and digestive benefits of the biodegraded material. Furthermore,
the study examines the growth performance, blood profile, nutrient
digestibility, and nitrogen balance of WAD goats fed diets containing varying
levels of PTR-degraded cassava root sievate. Additional evaluations include
carcass characteristics, meat quality, and the economic viability of using
biodegraded cassava root sievate in goat production.
The cassava root sievate
used in this study was sourced from Nneato, Umunneochi L.G.A., Abia State,
Nigeria, and processed through traditional fermentation to reduce hydrogen
cyanide levels. The sievate was then sun-dried and coarsely milled to
facilitate microbial activity during biodegradation. PTR was identified as the
most effective agent for degrading cassava root sievate, significantly
enhancing its crude protein content and mineral profile while reducing fibre
fractions and anti-nutritional factors.
Experimental diets
formulated with PTR-degraded CRS demonstrated improved nutritional quality,
leading to higher dry matter intake (DMI), average daily weight gain, feed
conversion ratio (FCR), and dressing percentages in WAD goats compared to
control diets. In vitro gas production and digestibility assessments revealed
enhanced OMD, SCFA production, and reduced methane emissions in diets
containing biodegraded CRS. The optimal economic outcome was observed with
diets containing 60% PTR-degraded CRS, resulting in the lowest production costs
and the most cost-effective meat production.
Blood profiles of goats
across all treatment groups remained within the normal range, indicating the
safety and nutritional adequacy of the test diets. The study concludes that PTR
biodegradation effectively transforms cassava root sievate into a high-quality
feed ingredient, supporting goat growth and health while reducing environmental
pollution.
The findings recommend
the broader application of PTR for biodegrading low-quality agro-waste to
enhance livestock nutrition in Nigeria. Incorporating PTR-degraded cassava root
sievate into goat diets offers a sustainable solution for year-round feed
supplementation, potentially increasing meat production, improving farmers'
livelihoods, and contributing to the affordability and availability of animal
protein in the region.
TABLE OF CONTENTS
CHAPTER
1
INTRODUCTION
1.1 Background
to the Study
1.2 Objectives of the study
1.3 Statement of problem
1.4 Justification
CHAPTER
2
LITERATURE
REVIEW
2.1 Origin,
Domestication and Distribution of Goats
2.2 Goat
Population
2.
3 Socio-Economic Roles of Goat Production in Nigeria
2.4 Constraints to Goat Production in Nigeria
2.5 Nutrition of Goats
2.5.1 Feeding
behaviour
2.5.2 Nutrient
requirements
2.5.3 Digestion
in goats
2.5.4 Dry matter intake of goats fed forage with concentrate
supplementation
2.5.5 Substitution effects of concentrate supplemental diets fed to
ruminants.
2.5.6 Factors affecting voluntary feed intake in goats
2.6 Indigenous
Goat Breeds
2.6.1 Sahel / Bornu white goat
2.6.2
Red Sokoto /Maradi goats
2.6.3 West African Dwarf (WAD) goats
2.7 Cassava
2.7.1 Origin and adaptation of cassava
2.7.2 Recent trends in production and utilization of
cassava
2.7.3 Nutrient
profile
2.7.4 Anti-nutritional factors
2.7.4 Some cassava by products commonlyused in ruminant
feeding
2.8 Processing
and Improvement Methoths of Cassava Products Commonly Use In Ruminant Feeding
2.9 Rot Fungi
2.9.1. Use of solid-state
fermentation (SSF) in ruminant nutrition
2.9.2 Fungal ligninolytic enzymes
2.9.3 Enzymatic bioprocessing
2.9.4 Enzymatic improvement of lignocellulosic biomass for
animal feed
CHAPTER
3
3.0 MATERIALS AND METHODS
3.1 Experiment
1: Nutritional Evaluation of Biodegraded and Non-Biodegraded Cassava Root
Sievate
3.1.1 Location of the Experimental Site
3.1.2 Sourcing
and Processing of Cassava Root Sievate
3.1.3 Inoculation of Cassava Root Sievate with White
Rot Fungi
3.1.4 Proximate
and Fibre composition
3.1.5 Experimental
design and Statistical analysis
3.2 Experiment
2: In Vitro Gas Production and
Fermentation Characteristics of White Rot Fungi Biodegraded and Non-Biodegraded
Cassava Root Sievate
3.2.1 Location of the Experimental Site
3.2.2. Sourcing
and Processing of Cassava Root Sievate
3.2.3 Inoculation
of Cassava Root Sievate with White Rot Fungi
3.2.4 Collection
and preparation of rumen fluid
3.2.5 Preparation
of the buffer solution
3.2.6 Preparation
of the rumen liquor-buffer solution
3.2.7 Preparation
of the syringes for incubation
3.2.8 Methane determination
3.2.9. Calculations
3.2.10 Chemical
analysis
3.2.11 Experimental
Design and Statistical analysis
3.3 Experiment
3: Formulation of Experimental Diets with Graded Level of the Best Biodegraded
Cassava Root Sievate
3.3.1 Experimental
Site
3.3.2 Formulation
of experimental diets
3.3.3 Proximate
and Fibre composition
3.3.4 Experimental
Design and Statistical analysis
3.4 Experiment
4: In
Vitro Gas Production And Fermentation Characteristics Of The Experimental
Diets
3.4.1 Location of the Experimental Site
3.4.2 Formulation
of experimental diet
3.4.3 Collection
and preparation of rumen fluid
3.4.4 Preparation
of the buffer solution
3.4.5 Preparation
of the rumen liquor-buffer solution
3.4.6 Preparation
of the syringes for incubation
3.4.7 Methane determination
3.4.8 Calculations
3.4.9 Chemical
analysis
3.4.10 Experimental
Design and Statistical analysis
3.5 Experiment
5: Anti Nutrients and Macro/Micro Minerals of the Experimental Diets
3.5.1 Location of the Experimental Site
3.5.2 Formulation
of experimental diets
3.5.3 Determination
of anti-nutrients
3.5.4 Mineral
determination
3.5.5 pH
determination
3.5.6 Experimental
Design and Statistical analysis
3.6 Experiment
6: Feeding Trial
3.6.1 Location of the experiment
3.6.2 Sourcing
and Processing of Cassava Root Sievate
3.6.3 Inoculation of Cassava Root Sievate with White
Rot Fungi
3.6.4 Formulation
of experimental diet
3.6.5 Procurement
and adaptation of West African dwarf (WAD) goats
3.6.6 Feed
intake and body weight changes
3.6.7 Biochemical
and haematological studies
3.6.8 Carcass,
organ and meat quality evaluation
3.6.6 Economics of
production
3.6.7 Experimental
Design and Statistical analysis
3.7 Experiment
7: Nutrient Digestibility and Nitrogen Balance
3.7.1 Location of the experiment
3.7.2 Sourcing
and Processing of Cassava Root Sievate
3.7.3 Inoculation of Cassava Root Sievate with White
Rot Fungi
3.7.4 Formulation
of experimental diet
3.7.5 Procurement
and adaptation of West African dwarf (WAD) goats
3.7.6 Experimental
Animal and design
3.7.7 Analytical
procedure
3.5.6 Experimental
Design and Statistical analysis
CHAPTER
4
RESULTS
AND DISCUSSION
CHAPTER
5
CONCLUSION
AND RECOMMENDATIONS
5.1 Conclusion
5.2 Recommendations
References
LIST
OF TABLES
Table
2.1: Numbers of goats in the top ten countries, the ratio of goats to sheep
and their percentages from the total number in the world
Table 2. 2. Goat
meat nutrition comparative chart
Table 2.3: Some production trait and characteristics
of West African Dwarf and Red Sokoto goats in Nigeria
Table 3.1: Gross
composition of experimental diets
Table
4.1: Chemical compositions of non-biodegraded
and fungi degraded cassava root sievate
Table
4.2: Mineral compositions of non-biodegraded
and fungi degraded cassava root sievate
Table
4.3: Anti-nutritional factors of
non-biodegraded and fungi degraded cassava root sievate
Table 4.4: Volume of in-vitro gas produced at different
incubation time by non-biodegraded and fungi degraded cassava root sievate
Table
4.5: In vitro digestibility
characteristics of non-biodegraded and biodegraded cassava root sievate
Table 4.6: Chemical
composition of the experimental diets
Table 4.7: Mineral
composition of the experimental diets
Table 4.8: Anti-nutritional
compositions of the experimental diets
Table
4.9: Volume of in-vitro gas produced
at different incubation time by the experimental diets
Table
4.10: In vitro digestibility of the
experimental diets
Table 4.11: Nutrient
intake of West African dwarf goats fed Pleurotus tuber regium degraded cassava
root sievate in their diets
Table 4.12: Body
weight changes of West African dwarf goats fed Pleurotus tuber regium degraded
cassava root sievate in their diets
Table 4.13: Haematological parameters of West African Dwarf goats fed Pleurotus
tuber regium degraded cassava root sievate in their diets
Table 4.14: Serum
biochemical parameters of West
African Dwarf goats fed graded levels of Pleurotus tuber regium
degraded cassava root
sievate
Table 4.15: Carcass
characteristics of West
African Dwarf goats fed graded levels of Pleurotus tuber regiumdegraded cassava root sievate in their diets
Table 4.16: Offal
and organ weights of West
African Dwarf goats fed graded levels of Pleurotus tuber regiumdegraded cassava root sievate in their diets
Table 4.17: Proximate composition of meat of West
African dwarf goats fed Pleurotus tuber regium degraded cassava root sievate in
their diets
Table 4.18: Sensory evaluation of West African dwarf
goats fed Pleurotus tuber regium degraded cassava root sievate in their diets
Table 4.19: Economics
of production of West African dwarf goats fed Pleurotus tuber regium degraded
cassava root sievate in their diets
Table 4.20: Apparent
nutrient digestibility of West African dwarf goats fed Pleurotus tuber regium
degraded cassava root sievate in their diets
Table 4.21: Nitrogen
utilization of West African
Dwarf goats fed graded levels of Pleurotus tuber regiumdegraded cassava root sievate in their diets
LIST OF FIGURES
Fig 2. 1: Top
ten cassava producing countries in 2014
Fig
2. 2: Annual
Cassava production (tons) for the top five producing countries over period
1970
- 2014
Fig
2. 3: Area
cultivated with cassava (ha) for the top five producing countries over period
1970
- 2014
Fig 2. 4: Average
cassava yielding (t/ha) in selected countries in the world
CHAPTER 1
INTRODUCTION
1.0
1.1
BACKGROUND TO THE STUDY
Goat (Capra
hircus) is one of the oldest domesticated livestock, which belongs to the
order artiodactyla, suborder ruminanta and family Bovidae;
they are considered to have existed in the mountain area of Western Asia in the
seventh and ninth millennium BC (Jiwuba et
al., 2018a). Since history, goat production has fulfilled important
economic and social function in Nigeria due to their position as source of
income and protein for the teeming countries’ population (Jiwuba et al., 2017). The number of goats has increased by almost 50% at
world level, cattle increased by 9% whereas sheep decreased by 4% (Morand- Fehr
and Boyazogly, 1999; Devendra, 2001); thus confirming goats as an inestimable
livestock of importance. The demand for
goat meat is very high (Odeyinka, 2000) and often command higher market price
than beef, pork and chicken. Idiong and Orok (2008) attributed the preferable
of goat meat to those from other animal species because of its flavour,
tenderness and palatability. In
the rainforest ecological zone of Nigeria, West African Dwarf (WAD) goat
predominates.
The WAD goat is the dominant breed of small ruminants found
in the West Africa where they are raised under smallholder management system.
Chiejina and Behnke (2011) ranked WAD goat first with population approximately
eleven million in the humid zone of eastern Nigeria, and this population may be
higher today. In general WAD goat population is considered large in Nigeria,
but still far below its demand. It is a trypano-tolerant breed reared
extensively for meat (Ahamefule et al.,
2005) and weigh between 20 and 30 kg at maturity. It
is raised extensively by subsistent farmers mostly in the rainforest and
derived savanna ecological zone of Nigeria (Ahamefule et al., 2005) with average stock number of 3 to 20 goats per
household. WAD goat is vital in
marriages, religious rites, a good medium of establishing friendship, a common
stake used as an object of fine for restoration of peace in communities and a
ready source of family income. They are multipurpose animal,
contributing greatly to the nation’s animal protein supply. However, the production of this goat has been
hampered by poor quality diets which arise from nutritional imbalance as a
result of seasonal fluctuations in feed quality and quantity. This has led to
the formulation of dry season supplement with readily available agricultural
waste.
Cassava (Manihot esculenta Crantz)
is a non-seasonal crop grown in the tropics and subtropics mainly for its
underground starchy tuberous roots (Jiwuba et
al., 2018b). Recently cassava annual production has increased by
approximately 100 million tonnes since 2000 (Morgan and Choct, 2016), this may
be partly due to high demand for cassava food products and for dried cassava
by-products for use in livestock and poultry feeds. Cassava production is vital
as it is seen as the future of food security in Nigeria (Jiwuba et al., 2018b); with approximately one
billion people currently depending on it as a major carbohydrate source
(Ezenwaka et al., 2018). Cassava is a
drought and disease tolerant crop, with high underground storage ability and
can be planted in a poor soil with flexible harvesting dates. FAO (2014)
reported 4.6% cassava output growth in 2013 and 2014, with Nigeria being the
world largest producer. Under tropical conditions it is the most productive
crop in terms of energy yield per unit land area, with a yield of between 25
and 60 tonnes/ha (1 ha ¼ 10,000 m2) (Garcia and Dale, 1999). These have
enhanced the availability of cassava by-products for livestock feeds. One of
such by products from cassava processing, that has no human or industrial use
at the moment and that can be incorporated into goat feeding due to its high
energy and fibre density, local availability and not affected by seasonality is
cassava root sievate.
Cassava root sievate (CRS) is the residue (waste) that
results from processing the root of cassava into fufu, a popular West African
food. The sievate is the solid waste produced as a consequence of cassava root
production and made up of 88.60, 2.57 and 13.38% dry matter, crude protein and crude fibre
respectively (Jiwuba et al., 2018b);
it constitutes about 25% of the whole plant (Aderemi and Nworgu, 2007). The metabolizable energy value of
cassava root meal which is about 3,870 kcal/kg, is higher than that of maize
(3,430 kcal/kg) (Tion and Adeka 2000). However, Jiwuba et al. (2018c) reported 3.79 Kcal/g gross energy value for cassava root sievate meal.They are usually discarded poorly as waste heaps
near streams or homes where they are soaked, fermented and processed thereby
producing a strong offensive smell and contaminations; hence the need to add
value to this agro-waste. However, the low protein content (Jiwuba et al., 2016a), high cyanide content
(Ubalua and Ezeronye 2008; Morgan and Choct 2016) and high fibre contents are
the limiting factor in the utilization of cassava root sievate by goats.
However, due to high lignin content of cassava root sievate, its utilization is
impaired in goat feeding. These thus have affected the general performance of
animals fed such diet; hence the needs to improve the nutritive value of
cassava root sievate through biodegradation (use of white rot fungi).
The
biodegradation of agricultural waste by enzyme from microorganisms especially
white rot fungi (Pleurotusspp) has
been promising in degrading structural carbohydrates or structurally modifying
proteins and their anti-nutritional properties with the aim of producing high
quality product. White rot
fungi, belonging to the wood-decaying basidiomycetes, as
lignocellulolytic microorganisms are able to decompose and metabolize all plant
cell constituents (cellulose, hemicellulose and lignin) by their enzymes
(Eriksson et al., 1990). Many species of white rot fungi are effective
lignin degraders have been used to assess their ability to improve the
nutritive value of fodder for ruminant nutrition (Howard et al., 2003).
Their extracellular lignin-modifying enzymes consist of lignin-peroxidase
(LiP), manganese-dependent peroxidase (MnP), laccase (phenol oxidase) and H2O2producing
oxidase (aryl-alcohol oxidase; AAO and glyoxaloxidase) (Arora et al.,
2002; Novotny et al., 2004; Arora and Gill, 2005; Lechner and Papinutti,
2006). Some white-rot fungi are able to decompose free phenolic monomers and to
break the bonds with which lignin is cross linked to the polysaccharides in
straw thereby enhancing the digestibility (Fazaeli et al., 2006). The Pleurotus
species have been shown to be more efficient (Taniguchi et al., 2005). The Pleurotus fungi have
different ability to grow on agro waste and decompose its structural
carbohydrate because of the variation in culture behaviour and culturing
conditions (Fazaeli et al.,
2002). Information on cassava root sievate biodegradationon goat is virtually
non-existing.
1.2 Objectives
of the study
This
research is aimed at improving the biological value of cassava root sievate
through biodegradation and reducing the aesthetic nuisance (environmental
pollution) caused by this agricultural waste.
The
specific objectives are:
To
evaluate the proximate composition and fibre fraction of biodegraded cassava
root sievate and non-biodegraded cassava root sievate meals.
1.
To evaluate the in vitro gas production and estimate metabolizable energy, organic
matter digestibility and short chain fatty acids of biodegraded cassava sievate
and non-biodegraded cassava root sievate meals.
2.
To evaluate the proximate composition and
fibre fraction of diets containing biodegraded cassava
root sievate.
3.
To evaluate the in vitro gas production and estimate metabolizable energy, organic
matter digestibility and short chain fatty acids of diets containing biodegraded
cassava root sievate.
4.
To evaluate the anti-nutritional factors,
macro and micro minerals of diets containing biodegraded
cassava root sievate.
5.
To determine the growth
performance of WAD goats fed diets containing biodegraded
cassava root sievate.
6.
To determine the
blood profile of WAD goats fed diets containing biodegraded
cassava root sievate.
7.
To evaluate the carcass, organ
characteristics and meat quality of WAD goats fed diets containing biodegraded
cassava root sievate.
8.
To determine the economics of production
of feeding WAD goats with diets containing biodegraded
cassava root sievate.
9.
To determine the nutrient digestibility
and nitrogen balance of WAD goats fed diets containing biodegraded
cassava root sievate.
1.3 Statement
of problem
The poor quality and aesthetic nuisancse of
agricultural by products have attracted attention of many researchers into
finding gainful use for the farm waste. Huge amounts of lignocellulosic wastes
and residues of agricultural and domestic origin are generated annually (Yilkal, 2015). One such waste accruing
from the processing of cassava tuber to fufu is cassava root sievate. Its production is enormous and usually
discarded poorly as waste heaps near streams, homes or streets thereby
producing a strong offensive smell and aesthetic contaminant. Disposal problem
may arise in the future with fufu constituting the major stable food in the
rainforest zone and with no industrial use meanwhile. CRS is comprised most part of cellulose, hemicellulose
and lignin. Lignin major constituent of ADF is non digestible by goats and
resistant to most of the microbial and enzymatic metabolism of the rumen
ecosystem. The presence of lignin and its hemicellulose binding matrix
increases the unavailability of other energy-containing constituents present in
CRS and indeed other agricultural residues for the ruminants (Arora and Sharma,
2009).
The primary factors that limit the utilization of crop
residues are low digestibility, low protein content, high crude fibre and low
palatability. Thus, to increase the digestibility, it is important to release
the linkage between cellulose, hemicellulose and lignin or to modify the
compact nature of these tissues, so that lignified tissue might be separated
from non-lignified one. There have been attempts to do that by mechanical,
chemical or biological treatments (Shrestha et al., 2004; Mahmood
and Rahman, 2008; Abedo et. al. 2009). For various reasons, including
environmental considerations, biological rather than chemical approach is the
preferred route (Coughlan and Collaço,
1990). In recent years, much interest has been forwarded to develop new
bio-techniques for improving the nutritive value of lignocellulosic fibrous
using white rot fungi. This however is the major focus of this study.
1.4 Justification
White rot fungi are known to degrade lignin to a great
extent and at a faster pace when compared to any other group of organisms (de
Koker et al., 2000). They are the only fungi that can take the complete
lignin mineralization (Moore-Landecker, 1996). These organisms are also capable
of delignifying lingocellulosic substrate selectively, modifying or degrading
the lignin and transforming the lignocellulose substrate of the decomposition
to high quality feed for ruminants (Chaudhary, 1998), or better still utilizing
the polysaccharides liberated by hydrolysis and fermentation, in order to
produce fuels and other chemicals (Puniya and Singh, 1998). The fungi, whose
life depends on lignocellulosic materials, are able to produce laccase,
cellulase, xylanase and glucosidase enzymes to degrade lignocellulosic
compounds and utilize the releasing sugars (Taniguchi et al., 2005). Hence, by improving the
nutritional value of CRS and feeding them to WAD goats, it will enhance
their productivity, and make animal protein available and affordable.
Login To Comment