Protease catalyzes peptide bond and hydrolyzes protein into peptone, keratinase enzyme, polypeptide and amino acid. As a kind of alkaline serine protease, keratinase not only has the function of normal alkaline protease, but also can break down disulfide bond and disintegrate keratin.

Definition and Dosage of Activity Keratinase

One unit (U) of protease activity is defined as the amount of enzyme 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 Products

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)

Crude protein, % 5400 0.54

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

Alkaline Protease Alkaline protease works on most of the peptide bonds therefore can hydrolyze diversified proteins and save the protein resource.

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