Download - Dr. Pedro Urriola - Overview Of Enzymes
Overview of utilization of enzymes in diets for growing pigs
Pedro. E. UrriolaDepartment of Animal Science
University of Minnesota, St. Paul
Digestion and breakdown nutrients for absorption
What are enzymes, how they work?
Enzymes modify activation energy to accelerate chemical reactions
Key-lock specific activity of enzymes
Types on digestive and exogenous enzymes
• Proteases: pepsin, trypsin, chymotrypsin, carboxypeptidases, keratinase
• Carbohydrases: amylase, maltase, xylanases or β-glucanase
• Lipases: pancreatic lipase• Esterases: ferulic acid esterase, acetyl-xylan esterase• Phosphatases: alkaline phosphatase, phytase-3 or
phytase-6
Pigs can’t digest all nutrients in feed
Corn
Whe
at
Barley
Soybea
n meal
Rapes
eed m
eal
Palm ke
rnel m
eal
Cottons
eed m
eal
Copra m
eal
DDGSc0
20
40
60
80
100
AT
TD
of D
M, %
ATTD of DM: apparent total tract digestibility of dry matter
Feed ingredients with high concentration of dietary fiber are less digestible
Rice Corn Peas Barley Soybean meal
Oats Corn DDGS
0
200
400
600
800837
680
432
585
60
466
3522108
192 221 233298 323
Starch Total dietary fiber
g/kg
DM
Bach Knudsen et al. (2013)
Even within the same ingredient (corn) digestibility of nutrients vary
ATTD of DM ATTD of N ATTD of P0.0000.1000.2000.3000.4000.5000.6000.7000.8000.9001.000
12345
Jeong et al. (2015)
Apparent total tract digestibility of DM decreases with dietary fiber
78.0 80.0 82.0 84.0 86.0 88.0 90.0 92.00.9050.9100.9150.9200.9250.9300.935
f(x) = − 0.00122790522752915 x + 1.024754268522R² = 0.306976306882285
ATTD of DMLinear (ATTD of DM)
Neutral detergent fiber, g/kg
Dig
estib
ility
coef
ficie
nt
Jeong et al. (2015)
Exogenous enzymes enhance digestibility of nutrients• The global feed enzyme market is today worth in excess of
$550 million • Saves the global feed producers an estimated $3 to 5 billion
per year– Phytase (60%) – Non-phytase (40%) mainly carbohydrases
Adeola and Cowieson (2011)
Phytase increases digestibility of phosphorus
• Approx. 60% of P in cereal grains is present as phytate
• Pigs cannot digest phytate• Phytase are enzymes added to feed to
help release P from phytate• Decrease of run off phosphorus
Phytase releases P, but also other nutrients
Plant carbohydratesClassification based on location in the plant cell:Intracellular carbohydrates: Cell wall carbohydrates:
Classification based nutritional or physiological impact:Organic acids Sugars Starch Oligo
Poly-fructans Β-glucan Cellulose Lignin
PhenolsPectins & gums Hemicellulose
Classification of plant carbohydrates
Corn fiber:-Arabinoxylans-Cellulose-Ferulic and coumaric acid
Classification of plant carbohydrates
Corn fiber:-ArabinoxylansL-arabino-D-xylane-Cellulose-Ferulic and coumaric acid
D-xyloseL-arabinose
Corn fiber vs. wheat fiber:-Wheat fiber contains greater amount of soluble arabinoxylans
Corn cDDGS Wheat Barley0
50
100
150
200
250
300
350
Tota
l die
tary
fibe
r, g/
kg
DM
Cereal grains and co-products contain different fibers-Soluble arabinoxylans
Corn cDDGS Wheat Barley0.000
0.100
0.200
0.300
0.400
0.500
0.600
0.700
SDF:
IDF
SDF:IDF = soluble vs. insoluble dietary fiber ratios
Xylanases are a group of enzymes that degrade hemicellulose
McKee et al. (2012)
GH = glycoside hydrolase
Type of DDGS Enzyme type Change in production of physiological parameter
Wheat DDGS1 xylanase + glucanase + cellulose ↑ 6.5% AID of CP;↑ 12.3% ATTD of GE; ↑ 6.6% ADG; ↓ 1.3% ADFI
xylanase + glucanase + cellulase (dose 2X) ↑ 9.6% AID of CP;↑ 12.6% ATTD of GE; ↑14.4% ADG; ↓1.6% ADFI
Corn DDGS4 xylanase and phytase ↑ 4% AID of CP; ↑6% ATTD of GE
Corn DDGS5 α-Galactosidase + galactomannanase + β-glucanase + xylanasegalactomannanase + XylanaseXylanase
↓ 2.4% ADG; ↓5.6 ADFI ↓ 7.2% ADG; ↓9.1% ADFI↑ 1.8% ADG; ↑1.6% ADFI
Wheat and Corn DDGS6
phytase and xylanase ↑ 13% of ATTD of phosphorus
Corn DDGS7 xylanase and phytase ↑ 9.5% diet ME
Corn DDGS8 xylanase and phytase No effect on growth performance
Corn DDGS9 xylanase, β-glucanase, pentosanase, hemicellulose, and pectinase.
↑2.4% ADG
Factors that affect the activity of exo-enzymes in swine feed Availability of substrate
StructureSolubility
Interaction among nutrients Thermal stability
Pellet diets Interaction among enzymes
Arabinoxylans
Carbohydrase enzymes improve energy digestibility in low energy diets
2750 2800 2850 2900 2950 3000 3050 3100 31500123456
f(x) = − 0.00929147595885498 x + 29.5127900486405R² = 0.708171091948177
Diet Metabolizable Energy, kcal/kg
% im
prov
emen
t in
diet
M
E
Adapted from Zhou et al (2009)
TDF ATTD of TDF0
20
40
60
80
100
31.223.4
42.1 43.746.355.0
%
Min.Mean Max.
Min.
MeanMax.
Content and digestibility of fiber varies among sources of DDGS
Urriola et al. (2010)
Digestible TDF, g/kg 0
50100150200250300
73
184
255
% .
Substrate availability varies among sources of corn distillers dried grains with solubles
Urriola et al. (2010)
1. Enzymes may have greater activity on low digestible fiber
2. Enzymes may have greater activity in highly digestible fiber
Factors that affect the activity of exo-enzymes in swine feed
In vitro
Enzyme• Nutrient
release• Increment in
fermentation
Substrate• Trapped
nutrients• Extent of
fermentation
Stomach and small intestine 2-6 h
Enzyme• Nutrient release• Degrade anti-nutr
Substrate• Entrapped nutrients• Anti-nutr
Large intestine 18-28 h
Enzyme• Beneficial fermentation products (VFA)• Harmful fermentation products
Substrate• Resist fermentation
Arabinoxylans
Dietary fiber increases secretion of mucins and number of goblet cells
Huang et al. (2015)
Goblet cell area (% of mucosa) of growing pigs fed:- Corn and soybean meal,- Wheat straw (WS)- Corn distillers dried
grains with solubles (DDGS)
- Soybean hulls (SBH)- All diets contained 17%
total dietary fiber
In summary• Efficiency of feed utilization can be increased with addition
of exogenous enzymes to diets of pigs– Carbohydrases degrade non-starch polysaccharides– Phytase degrades phytic acid, increases digestibility of
phosphorus• Effects vary according to dietary and pig digestive conditions
as well as availability of substrate