Keratinase

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 Keratinase 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.