دراسات عن تأثير عمليات الأعداد المختلفة على الاستفادة من مسحوق الريش بواسطة كتاكيت اللحم.

Feather waste at poultry processing plants has been of interest in nutritional studies because of its high protein content. This material must be hydrolyzed in order to be digested by the animal, because in its natural state, it is virtually indigestible and of low nutritive value. Chemical and biological assays were carried out to investigate the effect of different processing conditions on the nutritional quality of feather meal and its utilization by broiler chicks. The raw feather was treated with five different processes (cooking, NaOH, autoclaving, NaOH + autoclaving and commercial), and the resulted materials were incorporated in the experimental diets at 5% level. Accordingly, in addition to the control diet (without feather meal), a 6 x 2 factorial design with and without enzyme supplementation was achieved. The results obtained could be summarized in the following. 1- Feather meal treated with different processing methods contains markedly high percentage of crude protein ranging between 81.30 to 84.55% indicating its potential value as a source of protein for livestock. 2- Methionine is the first limiting AA among all tested feather meal samples, while lysine and histidine are the second and third Limiting AA. Moreover, cystine content could be used as reasonable indicator for the processing adequacy, of hydrolyzed feather meal. 3- Processing conditions did affect the nutrient digestibility coefficients and feeding value of the experimental diets. The commercial feather mea1 and that treated with autoclaving recorded the highest values, while the lowest were obtained for feather meal treated with either cooking or NaOH. However, enzyme supplementation tends to improve these values. 4- In general, feather meal treated with autoclaving recorded the best performance of chicks and similar to that obtained either by chicks fed the control diet or those offered the commercial feather meal. 5- concerning the economic study, the chicks fed on different sources of tested feather meals gave a satisfactory growth response during the experimental period. All these findings indicate that processed feather could be used economically in poultry diets to replace part of the highly expensive other protein concentrates. This would result in saving appreciable amount of money that can be invested in other feed security projects