finding a consensus on the effects of tropical legume ...€¦ · animal nutrition and rangeland...
TRANSCRIPT
Dr. agr. Joaquín Castro-Montoya
Animal Nutrition and Rangeland Management
in the Tropics and Subtropics
Finding a consensus on the effects of tropicallegume silages on intake, digestibility andperformance in ruminants:
A meta-analysis
XVIII International Silage Conference
26th July, 2018
2
Feeding ruminants with
forage legumes
The temperate experience
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
Medicago sativa
Trifolium pratense
Compared with grasses:
• Higher crude protein content
• Lower fiber content
• Higher digestibility
• High voluntary intake
3
Feeding ruminants with
forage legumes
Lablab purpureus Stylosanthes guianensis
Compared with grasses and whole
crop cereals:
• Higher crude protein content
• Lower fiber content
• Higher digestibility
• High voluntary intake
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
The tropical experience
4
The classical legume feeding experiment
Is it the legume... Or the protein?
Feeding ruminants with
forage legumes
The tropical experience
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
5
Finding a consensus
Literature search
• Legumes fed as silage
• In vivo studies with ruminants
• In tropical/subtropical regions
• Proportion of legume in the diet, anddiet composition
• Measure of dispersion and/ornumber of observations
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RE
Conditions
6
Database summary
Overview
29 trials with small ruminants
33 trials with cattle
51 publications
• 62 trials
• 218 treatments
• (56 controls, 162 legumes)
0
5
10
15
20
25
30
10-20 30-40 50-60 70-80 90-100Axis Title
20 30 40 50 60 70 80 90 100
Legume proportion in the diet (g/100 g DM)
%
INTRODUCTION │ METHODOLOGY │
Studies and treatments
Distribution of treatments by level of legume inclusion
7
Database summary
Legume species
119
4 43
4
4
8
5
4
0
2
4
6
8
10
12
14
16
Stylosanthes Soybean Lablab Leucaena Gliricidia
Nu
mb
er
of tr
ials
Legume species
■ Cattle
■ Small ruminants
• 23 species found
• Herbs, shrubs and trees
INTRODUCTION │ METHODOLOGY │
Most common species
29 trials with small ruminants
33 trials with cattle
8
Effects of the proportion of
legume in the diet
• Regression of diets
containing legumes
Comparison of diets without
legumes and with legumes
at varying levels:
• Control
• 100 to 400 g/kg DM
• 401 to 800 g/kg DM
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
Two statistical approaches
Finding a consensus
Data analyses
Results
10
70
80
90
100
110
120
Bajo Alto
Legume proportion in the diet
(g/kg BW0.75)
≈
Low High
High crude protein
Low crude protein
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
Tropical legume silage feedingEffects on intake
Dry matter intake per kg metabolic bodyweight
11
70
80
90
100
110
120
Bajo Alto
Legume proportion in the diet
(g/kg BW0.75)
≈
Low High
High crude protein
Low crude protein
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
Secondary plant
compounds
Silage fermentation
products
Digestibility
Fiber content and
characteristics
Tropical legume silage feedingEffects on intake
Dry matter intake per kg metabolic bodyweight
12
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
Fiber content and
characteristics
Passage rate,
buoyance
0
150
300
450
600
750
0 100-400 >400
Legume proportion in the diet (g/kg DM)
(g/kg)
aab
b
Tropical legume silage feedingEffects on apparent total tract digestibility
Organic matter
13
0
150
300
450
600
750
0 100-400 >400
Legume proportion in the diet (g/kg DM)
(g /kg)
ab
c
Fiber bound nitrogen
Excesive heating during storage in silo
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
Tropical legume silage feedingEffects on apparent total tract digestibility
Crude protein
Secondary plant
compounds
14
g/d
Legume proportion in the diet (g/kg DM)
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
Tropical legume silage feedingEffects on performance
Average daily gain
15
0
4
8
12
16
0 100-400 >400
Legume proportion in the diet (g/kg DM)
Milk yieldkg/d
0
0.3
0.6
0.9
1.2
1.5
0 100-400 >400
Legume proportion in the diet (g/kg DM)
FCE
kg milk/kg DMI
b
a
c
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
Tropical legume silage feedingEffects on performance
Milk yield and feed conversion efficiency (FCE)
16
Enhancement of
microbial protein
synthesis
Supply of dietary
nutrients
Urea recycling
Changes in
fermentation pattern
INTRODUCTION │ METHODOLOGY │ RESULTS INTAKE│ RESULTS DIGESTIBILITY │ RESULTS PERFORMANCE
ResultsTropical legume silage feeding
Rumen ammonia
-N
N-Energysnchroni-
zation
17
• Tropical legumes fed as silage
• Lower intake and digestibility
• Maintain or increase the performance
• Inclusion rates up to 400 g/kg DM
• Mechanisms of action are still to be understood
• Further research
• Focus on promising legumes
Final remarksThe consensus
18
Enterolobium cyclocarpum
The (other) classical legume feeding experiment
Final remarksThe consensus
Low biomass
Not mechanizable
19
• Tropical legumes fed as silage
• Lower intake and digestibility
• Maintain or increase the performance
• Inclusion rates up to 400 g/kg DM
• Mechanisms of action are still to be understood
• Further research
• Focus on promising legumes
• Quality, quantity, mechanization
• Lablab, stylosanthes, soybean, cannavalia
Final remarksThe consensus
Thank you very much!
Finding a consensus on the effects of tropicallegume silages on intake, digestibility andperformance in ruminants:
A meta-analysis
XVIII International Silage Conference
26th July, 2018
Contact: [email protected]