Effect of processing systems on protein quality of feather meals and hog hair meals

Abstract

Experiments were conducted to evaluate the effects of five commercial processing systems and to a lesser extent, processing temperature within system, on protein quality of feather meals (FM). Two hog hair meals (HH) were also evaluated. True digestibilities of AA were determined with a 48-h excreta collection assay using cecectomized cockerels. Protein efficiency ratio (PER; grams of gain:grams of CP consumed) was determined with chicks by feeding Met-fortified 15% CP diets containing a FM or HH as the sole source of dietary protein. The six FM samples averaged 88.7% CP, 1.99% Lys, 4.83% Cys, and 0.71% Met on a DM basis. For HH, these values were 92.6, 2.78, 3.76, and 0.85%, respectively. True digestibilities of amino acids and PER of the FM varied among processing systems (e.g., lysine digestibility range was 58 to 72%, PER range was 0.71 to 1.13). Increasing the temperature during processing had no significant effect on protein quality of one FM and one HH. Digestibilities of AA in the FM water-soluble fraction collected after cooking were higher than those in the insoluble fraction. True amino acid digestibility coefficients for FM were higher than those for HH, whereas the PER of several FM were lower than those of HH. The latter response was probably due to the higher Lys content in the HH. The results of this study suggested that type of commercial processing system or conditions can affect the protein quality of FM.

Optimization of Bio-Mosquitocidal Production using Local Bacterial Strains of Bacillus Sphaericus

“…The obtained low productivity in feather extract medium comparing to that obtained in the poly medium may be reflected the deficiency of the former fermentation medium in required nutrients. Wang and Parsons 1997 reported that the hydrothermal treatment resulted in yielding a product with poor digestibility and variable nutrient quality [29]. Our results are not in accordance with the findings of Poopathi and Abidha [10] perhaps due to the differences in reference media that used as a control.…”

Identification and characterisation of a Bacillus licheniformis strain with profound keratinase activity for degradation of melanised feather

“…In addition, feather wastes are potentially valuable raw materials for the production of nutrient-rich animal feed supplements and amino acids (Shih 1993;Onifade et al 1998). Feather waste processing methods such as steam pressure, chemical treatment and feather milling are cost and labour intensive and may reduce the product's nutritional value by destroying important amino acids (Shih 1993;Wang and Parsons 1997).…”

Enzymatic Degradation of Pretreated Pig Bristles with Crude Keratinase of Bacillus cereus PCM 2849

“…Elevated levels of leucine, tyrosine and methionine could result from chymotrypsin-like specificity, but not trypsin or elastase specificity [18]. However, thermal treatment might also affect the composition of bristle substrate, since Wang and Parsons [45] presented slightly elevated concentration of leucine and valine in steam-cooked hog hair meals. High amounts of BCAAs could be obtained as well by alkaline hydrolysis of animal hair [7,46,47].…”