The study report here was undertaken to evaluate the nutritive value of leaves from tannin rich tropical multipurpose tree species with or without various tannin binding agents (TBAs). The studied species included Albizia gummifera, Carissa edulis, Draceana steudneri, Ficus sycomorus, Grewia ferruginea, Millettia ferruginea, Prunus africana, Rhus glutinosa, Syzygium guineense and Ekebergia capensis.
Six independent samples per species were collected separately. The species were subjected to proximate, detergent and polyphenolic analysis. Dry matter and organic matter digestibility (DMD & OMD) of the plant leaves were determined following two stage in vitro enzymatic analysis. Dried plant species were incubated in two runs with three replications per run with rumen liquid collected from three Boran Holstein-Friesian crossbred steers and gas production measured at 2, 4, 6, 8, 12, 24, 32, 48, 58, 72 and 96 h of incubation.
Table of Contents
1. Introduction
2. Materials and methods
2.1 Study site
2.2 Leaves of the plant species
2.3 Chemical analyses and nutritive value
2.4 In vitro gas production measurement
2.5 Statistical analyses
3. Results
3.1 Chemical composition, polyphenolic components and in vitro digestibility of the tannin rich plant leaves
3.2 In vitro gas production potentials of the plant leaves
3.3 Effects of tannin binding agents on in vitro gas production and kinetics of the leaves
3.4 Fermentation characteristics of tannin rich tree leaves
3.5 Effect of tannin binding agents on in vitro fermentation characteristics of tannin rich tree leaves
3.6 Correlation between some chemical composition and in vitro gas production
4. Discussion
4.1 Plant leaf effects on relative nutritive value
4.2 In vitro gas production potentials of tannin rich tree leaves
4.3 Effects of tannin binding agents on in vitro fermentation of leaves of tannin rich trees
4.4 Effect of plant species variation on in vitro fermentation kinetics
4.5 Effect of tannin binding agents on in vitro fermentation kinetics of tannin rich tree leaves
4.6 Correlation coefficient between some nutritive value and in vitro gas production parameters
5. Conclusion
Research Objectives and Focus Areas
This study aims to evaluate the nutritive value of leaves from ten tropical tannin-rich multipurpose tree species and assess the efficacy of various tannin-binding agents (TBAs) in improving their fermentation characteristics and nutrient availability for livestock.
- Nutritional and chemical characterization of ten specific tannin-rich fodder tree species.
- Assessment of in vitro fermentation kinetics and gas production potential.
- Comparison of the efficacy of four different tannin-deactivating agents (PEG4000, PEG6000, PVP, and PVPP).
- Statistical correlation between chemical composition and fermentation parameters.
Excerpt from the Book
Introduction
The major constraint to increase livestock productivity in Sub-Saharan African countries and many other developing nations is the scarcity and fluctuating quantity and quality of the year-round supply of feed resources (Besharati and Taghizadeh, 2009; Arigbede et al., 2011). The native pastures and crop residues are the major feed resources available in these areas for livestock (Salem et al., 2006). However, tropical graminaceous fodder and crop by-products have a low nutritive value due to their low protein and fermentable energy content (El Hassan et al., 2000). Addition of foliages of multipurpose tree species (MPTS) are of importance in animal production because they can provide a significant amount of protein, especially in the dry season and can improve the utilization of low quality roughages mainly through the supply of protein to rumen microbes (Makkar, 2003; Ozturk et al., 2006).
Although MPTS have important nutritional merits (Kaitho et al., 1998; Norton, 2000), there are also reports which indicate that secondary plant metabolites are found in many fodder trees and shrubs such as condensed tannins (CTs) (Makkar and Becker, 1998; Frutos et al., 2004) that can affect feed intake, digestibility, growth, onset of puberty and reproductive functions via interference in the nutrient availability.
In vitro gas production has been used to assess the nutritive value of browse species. It basically results from fermentation of carbohydrates, proteins and other organic compounds (Blümmel and Ørskov, 1993). Hence, the extent and rate of gas production reflects the efficiency and/or extent of degradability of feedstuffs.
Summary of Chapters
Introduction: Outlines the challenges of livestock feeding in developing nations and the potential role of tannin-rich multipurpose trees as protein sources, despite the anti-nutritional effects of tannins.
Materials and methods: Describes the study site in Ethiopia, the sampling of ten specific browse species, and the detailed chemical and in vitro gas production laboratory protocols.
Results: Presents experimental findings on chemical composition, gas production volumes, and the effectiveness of different tannin-binding agents across various tree species.
Discussion: Analyzes the nutritional implications of the findings, the variable effects of tannins, and the potential of specific binding agents like PEG to enhance feed utilization.
Conclusion: Summarizes that while tannin-rich trees show variation in nutritive value, the application of TBAs significantly improves fermentation characteristics and supports their potential as sustainable feed resources.
Keywords
Browse species, in vitro gas production, tannin, tannin binding agent, short chain fatty acid, metabolisable energy, chemical composition, nutritive value, ruminant nutrition, fermentation kinetics, feed resources, polyethylene glycol, condensed tannins.
Frequently Asked Questions
What is the primary objective of this research?
The study evaluates the nutritional potential of ten tropical tannin-rich tree species and investigates whether tannin-binding agents can neutralize anti-nutritional effects to improve livestock feed efficiency.
What are the central topics addressed in the paper?
The focus lies on the chemical composition of browse leaves, the impact of condensed tannins on digestibility, and the experimental application of deactivating agents to optimize rumen fermentation.
What scientific methodology is utilized?
The researchers employed proximate and polyphenolic chemical analyses combined with a two-stage in vitro enzymatic gas production technique to determine digestibility and fermentation kinetics.
Which tannin-binding agents were compared?
The study compared the efficacy of Polyethylene glycol (PEG4000 and PEG6000), Polyvinylpyrrolidone (PVP), and Polyvinylpolypyrrolidone (PVPP).
What does the main body of the work cover?
It covers detailed experimental data on gas production rates, interspecies variations in chemical profiles, and the statistical correlations between specific plant nutrients and fermentation outcomes.
What characterizes this study?
It is characterized by its comparative focus on ten specific fodder species and the determination of how dosage and type of binding agents influence gas production parameters.
Why are tannin-rich trees considered a challenge for ruminants?
Tannins can interfere with nutrient availability by binding to proteins and inhibiting digestive enzymes, which reduces fiber digestibility and can lead to lower intake and weight loss in livestock.
What was a key finding regarding PEG6000 and PEG4000?
The study found that both types of PEG were superior to PVP and PVPP in improving the extent and rate of gas production in most plant species studied.
Does the effectiveness of TBAs depend on the tannin concentration?
The study concluded that while TBAs help improve nutritive value, the effect size of the binding agents is not strictly related to the specific tannin content of the plant leaves.
- Quote paper
- Yisehak Kechero (Author), Afework Bedewi (Author), Assefa Getnet (Author), 2012, Tannin binding agents. Comparison of the effects of various tannin binding agents on nutritive value of leaves of tropical tannin rich fodder trees, Munich, GRIN Verlag, https://www.grin.com/document/352028
