Protease catalyzes peptide bond and hydrolyzes protein into peptone, hydrazone, polypeptide and amino acid. As a kind of alkaline serine protease, keratinase enzyme not only has the function of normal alkaline protease, but also can break down disulfide bond and disintegrate keratin.
Specification of keratinase products
Name
Product Series Name
NutriGen Keratinase
Activity
100000–200000 U/g
Strain
Parengyodontium album
EC code
EC 3.4.99.11
Form
Powder,Liquid
Carrier
Starch
Color
White, Light yellow
Loss on drying
≤ 10%
Working pH
6.0–12.5
Optimum pH
11
Working T
30℃-70℃
Optimum T
60℃
Particle size
80% pass 40 mesh
Package
25kg /bag
Storage
Stored 6 months in dark, cool and dry conditions
Caution
Avoid direct sunlight, high temperature
Definition and Dosage of Activity Keratinase
One unit (U) of protease activity is defined as the amount of enzyme china which liberates 1 μg tyrosine per minute from substrate casein at 40℃ and pH 10.5 under the conditions of the test.
Recommended dosage is 50–100g/t with 50000 U/g in complete feed.
Functions of Keratinase
1. Supplement the deficiency of endogenous protease for animal.
2. Increase the digestibility of protein and amino acid in poultry and swine feed ingredients.
3. Degrade the trysin inhibitor and lectin, this is what endogenous protease can’t do.
4. Optimized the use of lower digestibility feed ingredient e.g corn, sorghum, feather meal,soybean meal and blood plasma powder.
5. Creat a better environment for animal and decrease pollution from nitrogen for human.
Application of Keratinase
1. The matrix value of keratinase (100g/t)
Nutrient
Poultry
Value
Amount provided in the diet
Metabolizable energy（Mcal/kg）
600
0.060
Crude protein, %
5400
0.540
Lysine, %
150
0.015
Methionine, %
180
0.018
Cystine, %
150
0.015
Threonine, %
210
0.021
Tryptophane, %
90
0.009
Isoleucine , %
150
0.015
Arginine, %
285
0.0285
Valine, %
255
0.0255
2. Application case: Improve the performance and digestibility of nutrients.
Experimental animal: 840 one-day-old AA broilers, 6×35 broilers/treatment.
Experimental design:
Table1. Experimental design
Item
Diet
PC
Basal diet
NC
Basal diet-0.5% crude protein
Group I
NC+125g/t competitor
Group II
NC+100g/t Keratinase(30000U/g)
Experimental cycle: 42 days
Results:
Table2 Effect of each treatment on the growth performance of AA broilers (g, %)
Items
PC
NC
Group I
Group II
Initial weight,g
62.79±0.31
62.58±0.29
62.56±0.33
62.33±0.27
1–21days
21stAG,g
986.16ab±10.08
977.41b±8.22
1013.59ab±25.72
997.17ab±10.53
ADFI,g
62.08± 1.43
60.93±1.10
62.09±2.04
58.71±2.12
ADG,g
43.94±0.47
43.45±0.39
45.12±1.29
44.33±0.53
F/G
1.41±0.03
1.40±0.03
1.38±0.05
1.33±0.04
Death rate,%
1.43±1.57
3.45±2.21
5.38±6.24
3.33±5.24
22–42days
22ndAG,g
1140.08±1.30
1135.33±5.97
1136.73±7.06
1138.33±5.41
42ndAG,g
2985.77±41.56
2971.06±47.61
3058.21±58.29
3010.25±44.17
ADFI,g
179.00±3.12
178.64±2.86
175.81±3.64
174.22±2.64
ADG,g
87.88±2.01
87.42±2.43
91.50±2.85
89.14±2.20
F/G
2.04±0.07
2.05±0.03
1.93±0.05
1.96±0.06
Death rate,%
2.00±2.19
1.33±2.07
0.67±1.63
1.33±2.07
1–42days
ADFI,g
120.51±2.39
119.78±1.63
118.94±2.01
116.47±1.60
ADG,g
69.59±0.98
69.25±1.13
71.32±1.39
70.18±1.05
F/G
1.73±0.02
1.73±0.02
1.67±0.02
1.66±0.03
Death rate,%
3.43±3.76
4.78±1.73
6.05±5.74
4.67±4.59
Note: In the same row, values with different small letter superscripts mean significant difference(P<0.05).
Diagram1 Effect of keratinase on the nutrient digestibility of broilers
Table3 Effect of keratinase on the amino acid digestibility of broilers （%）
Items
PC
NC
Group I
Group II
Asp
55.87±4.44
52.59±2.57
54.52±8.03
57.52±5.76
Thr
63.09±7.47
61.47±5.32
62.17±5.74
63.69±5.19
Ser
69.11±5.51
65.44±4.61
65.80±7.04
68.04±4.10
Glu
69.31±3.41ab
64.68±1.35b
67.12±5.82
74.82±3.39a
Gly
55.36±15.14ab
42.03±4.21b
49.11±11.59b
67.00±1.89a
Ala
31.82±2.11b
34.51±4.37b
35.35±5.19
35.92±4.82b
Val
46.32±0.75
45.59±1.66
44.68±4.68
50.18±3.73
Met
72.53±1.35
70.69±2.65
75.17±3.79
74.29±3.31
Ile
46.45±0.53b
47.40±2.87ab
47.47±5.60
51.65±4.65ab
Leu
56.28±1.57
52.87±7.19
55.44±8.01
53.05±4.90
Tyr
50.93±3.67
47.91±4.34
50.94±10.97
56.55±8.06
Phe
66.11±2.37
61.58±1.25
62.81±7.79
68.80±6.93
His
31.90±4.72ab
25.09±7.33b
28.06±14.13
40.79±5.43ab
Lys
78.58±4.31ab
71.44±2.54b
74.47±8.35
82.45±1.20a
Arg
79.15±2.86ab
75.18±3.10b
75.80±5.99
80.68±3.36ab
Pro
67.76±0.73b
70.57±1.32ab
69.36±7.39
68.06±2.90b
TAA
62.69±0.43ab
59.17±1.39b
60.83±5.69
66.45±3.73a
Conclusion of Keratinase
On the basis of these results, it is concluded that the supplement of keratinase into a low CP diet was as effective as normal level in broiler. As shown in diagram 1, keratinase improve the digestibility of dry matter, crude protein, crude fat, general energy and apparent metabolic energy. And in table 4, keratinase has a positive effect on the amino acids digestibility. In this experiment, it is appeared that keratinase improve the growth performance of broiler by increase average diary gain and feed conversion rate.
