**4. Feathers as source of proteins and amino acids**

An appealing alternating method to obtain amino acids and proteins is to use feathers that are relatively stable under natural conditions. Keratinophilic fungi used to hydrolyse keratin protein to obtain protein [33] and found maximum producer as *C. indicum*, *C. tropicum*, and *Malbranchea pulchella*. Parihar and Kushwaha [45] used *Verticillium tenuipes, Microsporum gypseum, Aphanoasus fulvescens*, *Chrysosporium keratinophilum* for study of protein release in hen feather degradation without rachis. *C. indicum* was used for degradation of human hair and estimated protein release 47.66 μg/ml and 112.66 μg/ml in 5 and 10 days respectively [46]. *Chrysosporium tropicum*, *Penicillium griseofulvum* and *Aphanoascus terreus* was analyzed for release of considerable amount of protein [47]. [48] observed protein release 409.6 μg/ml in case of *C. tropicum* in 12 days while *Malbranchea* sp. released 298.21 μg/ml in 4 days. [46] recorded 238 μg/ml in 25 days by *Alternaria tenuissima*.

Conversion of feathers into feather meals by applying physical and chemical methods results in the loss of nutritionally essential amino acids such as methionine, lysine and tryptophan. Therefore, currently the poultry feathers are converted into feather meal, a digestible dietary protein, for animal feed using keratinases. The microbial production of L-lysine is an expanding branch of manufacturing biotechnology. There are many reports are available worldwide. Indian researcher [37] studied the discharge of cysteine in the culture medium.

**37**

*Microbial Hydrolysed Feather Protein as a Source of Amino Acids and Protein in the Diets…*

The upgradation of feather meal through microbial or catalyst treatment has been defined earlier. Feather meal fermented with *Streptomyces fradiae* and supplemented with essential amino acid methionine bring about in the broilers growth rate comparable with those fed isolated soybean protein [49]. The application of feather-lysate from *B. licheniformis* with amino acid supplementation formed alike development rate in chickens when compared to chickens fed with a diet included with soybean meal [50]. Feather hydrolysates produced by microbial keratinases have been used as additives for animal feed [51]. The application of biotechnological approach using microbes for feather processing has nutritional significance. Culturing of the microorganisms and keratinase activity may result in modification of structure of feather keratin [4, 52–54]. This may alter its resistance to digestive enzymes of the consuming animals [55]. Fermentation of feathers involving microorganisms and microbial enzymes, not only it would retain the existing valuable amino acid content of keratin, but it would also add to it. Thus, the feather meal obtained after such microbial treatment would have enough nutritional value. Keratinase could play a significant role in enzymatic improvement of feather meal and amino acid production from high molecular weight substrate [56]. The microbial technology would significantly bring down the cost since it would not require hydrothermal treatment, however feather waste would be a cheap raw

Meat and feather meal protein gave equally as good results as soybean meal protein when supplied 3% protein in practical-type corn-soybean meal rations [58]. [59] observed growth of feather and composition in broiler chicken and found that that of threonine, isoleucine and valine increased with age while methionine content of feathers decreased with age. *B. licheniformis* produced crude keratinase enzyme augmented the total amino acid digestibility of raw feathers and commercial feather meal, could replace as much as 7% of the dietary protein for growing chicks [19]. [60] Studied dietary crude protein and lysine amino acid effect on growth of feather in chicks and found that crude protein has more influence on feather development than by levels of lysine. [61] Observed antioxidant potential property of protein hydrolysate developed by *Bacillus* sp. [62] observed replacement of fish meal with feather meal in broiler and found economic without any negative effect. Treated chicken feather meal used as a source of protein ton animal feed broiler chickens [63]. [64] Observed processed feather meal for their chemical composition and amino acid profile and found feather meal pre-soaked with wood ash for twentyfour hour boiled at 150°C for 1 hr. gave the best crude protein content. Using feather waste as a valuable resource can help the poultry industry to dispose of the waste feathers in an environmentally sustainable manner that also generates extra income for the industry [65]. [66] Improved digestibility of protein into feather meal by

[47] recorded cysteine produced by *Acremonium strictum* 32.00 μg/mL, *Chrysosporium tropicum* 25.00 μg/mL, *Chrysosporium indicum* 22.00 μg/mL, *Malbranchea aurantiaca* 21.00 μg/mL. [48] Studied the discharge of amino acids lysine, cysteine, methionine, valine by *C. tropicum* and *Malbranchea* sp. due to feather degradation. [6] Found *A. tenuissima* a potent feather degrading fungus and increased the nourishing value of the soil by adding proteins (238 μg/ml), cysteine (20.2 μg/ml), lysine (15.8 μg/ml), methionine (6.8 μg/ml) and valine

*DOI: http://dx.doi.org/10.5772/intechopen.96925*

(7.5 μg/ml) in 25 days.

**4.1 Animal feed**

material [57].

**4.2 Feather meal as Chick feed**

*Microbial Hydrolysed Feather Protein as a Source of Amino Acids and Protein in the Diets… DOI: http://dx.doi.org/10.5772/intechopen.96925*

[47] recorded cysteine produced by *Acremonium strictum* 32.00 μg/mL, *Chrysosporium tropicum* 25.00 μg/mL, *Chrysosporium indicum* 22.00 μg/mL, *Malbranchea aurantiaca* 21.00 μg/mL. [48] Studied the discharge of amino acids lysine, cysteine, methionine, valine by *C. tropicum* and *Malbranchea* sp. due to feather degradation. [6] Found *A. tenuissima* a potent feather degrading fungus and increased the nourishing value of the soil by adding proteins (238 μg/ml), cysteine (20.2 μg/ml), lysine (15.8 μg/ml), methionine (6.8 μg/ml) and valine (7.5 μg/ml) in 25 days.
