Use of chicken feather meal fermented with Bacillus subtilis in diets to increase the digestive enzymes activity and nutrient digestibility of silver pompano Trachinotus blochii (Lacepede, 1801)

Background: Feather has the potential to be used as a fish feed ingredient because it has high protein content (80-85%), and is rich in amino acids arginine, leucine, isoleucine and valine. However, the protein consists mainly of keratin, which is classified as fiber that is difficult to digest. Therefore, to improve digestibility, the keratin protein is degraded using microbial Bacillus subtilis. This study aimed to determine the digestibility of fermented feather meal (FFM) in silver pompano (Trachinotus blochii) diets and to observe the histological structure of their intestines after digestion. Methods: The method used was a one factor experiment with five treatments and three replications each, which were: diet without FFM, diet containing 10% FFM, 20%, 30% and 40%. The diets were given to juvenile silver pompano (with average body weight of 8.56 ± 0.18 g) and stocked in 15 similar 20-L plastic jars with 10 fish per jar in a density of 100 L capacity container. The experimental diets were given three times daily at approximately 8.00 AM, 12.00 PM and 5.00 PM to apparent satiation for 60 days. Results: The results showed that the use of FFM increased the activity of digestive enzymes (protease and lipase), but reduced the amylase activity of silver pompano, which was significantly different between treatments (P <0.05). Meanwhile, the diet containing 20% FFM produced the highest feed and protein, which are 37.05% and 67.24%, respectively. This was significantly different from other treatments (P <0.05), and was effectively absorbed by fish intestines. Conclusion: The addition of chicken feather meal fermented with Bacillus subtilis could increase the activity of protease and lipase enzymes and nutrient digestibility of silver pompano but not amylase activity.

Use of chicken feather meal fermented with Bacillus subtilis in diets to increase the digestive enzymes activity and nutrient digestibility of silver pompano Trachinotus blochii (Lacepede, 1801)

Background: Feather has the potential to be used as a fish feed ingredient because it has high protein content (80-85%), and is rich in amino acids arginine, leucine, isoleucine and valine. However, the protein consists mainly of keratin, which is classified as fiber that is difficult to digest. Therefore, to improve digestibility, the keratin protein is degraded using microbial Bacillus subtilis. This study aimed to determine the digestibility of fermented feather meal (FFM) in silver pompano diets and to observe the histological structure of their intestines after digestion. Methods: The method used was a one factor experiment with five treatments and three replications each, which were: diet without FFM (P0), diet containing 10% FFM (P1), 20% (P2), 30% (P3) and 40% (P4). The diets were given to juvenile silver pompano (with average body weight of 8.56 ± 0.18 g) and stocked with 10 fish in a 100 L capacity container. The experimental diets were given three times daily at approximately 8.00 AM, 12.00 PM and 5.00 PM to apparent satiation for 60 days. Results: The results showed that the use of FFM increased the activity of digestive enzymes (protease and lipase), but reduced the amylase activity of silver pompano, which was significantly different between treatments (P <0.05). Meanwhile, the diet containing 20% FFM produced the highest feed and protein, which are 37.05% and 67.24%, respectively. This was significantly different from other treatments (P <0.05), and was effectively absorbed by fish intestines. Conclusion: The addition of chicken feather meal fermented with Bacillus subtilis could increase the activity of digestive enzymes and nutrient digestibility of silver pompano.

Nitric Oxide Synthesis Inhibition and Anti-Inflammatory Effect of Polypeptide Isolated from Chicken Feather Meal in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

Nitric oxide (NO) plays a key role in the pathogenesis of inflammation and has been implicated in endotoxin-induced tissue injury. Chicken feather meal is a rich source of amino acids that may serve as a peptide hydrolysate to inhibit NO activity. Anti-inflammatory hydrolysates of chicken feather meal were prepared and fractionated into five samples based on molecular mass. The smallest fraction (<0.65 kDa) exhibited the highest NO inhibitory activity without cytotoxicity towards macrophage RAW 264.7 cells. Further subfractions were sufficient to obtain amino acid sequences by Q-TOF LC-MS/MS ESI analysis. Of these, the SNPSVAGVR (885.97 Da) peptide and its corresponding pure synthetic peptide have inhibitory activity against NO production by RAW 264.7 cells (IC50=(55.2±0.2) mM) without cytotoxicity. Reverse transcriptase polymerase chain reaction (RT-PCR) and quantitative real-time RT-PCR results revealed that the peptide of the obtained fraction reduced transcript expression levels of the pro-inflammatory cytokines iNOS, TNF-α, COX-2 and IL-6 in lipopolysaccharide-stimulated RAW 264.7 cells. These results suggest that the peptides derived from the chicken feather meal protein could potentially be used as a promising ingredient in functional foods or nutraceuticals against inflammatory diseases.

Substitution of Fish Meal with Chicken Feather Silage Meal on Feed Can Improve Growth Performance of Striped Catfish (Pangasius hypopthalmus)

The purpose of this research is to study the effect of substitution of fish meal with silage meal of chicken feathers on feed to protein digestibility, growth and survival rate of striped catfish (Pangasius hypopthalmus). The test fish used is catfish with an average weight of 2.31 ± 0.04 grams /fish. This research used experimental method with Completely Randomized Design, 5 treatments in triplicate. The treatments in this study were substitution of fish meal meal with different dose of chicken feather meal, namely A, B, C, D and E (0%; 25%; 50%; 75% and 100% silage meal of chicken feathers, respectively). Parameters observed included relative growth rate (RGR), feed conversion ratio (FCR), protein efficiency ratio (PER), Apparent Digestibility Coefficient of Protein (ADCP), and survival rate (SR) of catfish. The results showed that the substitution of fish meal with chicken feather silage meal was very significant (P <0.01) to RGR, FCR, PER, and ADCP, but no significant effect (P> 0.05) on SR of catfish. Dose 25% silage chicken feather meal in the feed is the best dose to improve the RGR and ADCP of catfish. Water quality during the study is still within a reasonable range for catfish culture.