A new method is proposed, validated in the industrial practice, to determine possible bacterial and microbial degradation in textile wools and hairs. It is applied to wools of variable fineness between 18 and 34 microns and to alpaca fibers between 20 and 36 microns. It is based on a dynamometer test to determine tribocharge excision the slivers combed. The rheological behavior of degraded fiber slivers is quite different in the spinning process in addition to the major problems that appear in dyeing textiles made thereof. We propose two new indices to determine the extent of degradation that are well correlated to the results of the test the pH of the aqueous extract. The proposed new method for determining microbial and bacterial degradation is very sensitive for this type of degradation and keep a very good relationship with the results obtained by measuring the pH of the aqueous extract. The variation of the slope of the ascending curve of the excision tribocharge-elongation is a good indicator of degradation. The conventional parameters are complemented with isocharging elongation of the tape in addition to indicate the degree of degradation of the fibers, orients the spinner to the behavior of these materials in successive stretched degraded in the process of spinning machines. The results of industrial application of the new method in industry environment conditions, have been very successful in the full range of wool and alpaca fibers studied