Defleecing effects of mimosine on cashmere of Spanish goats

J. Luo, A. J. Litherland, T. Sahlu, R. Puchala, M. Lachica, and A. L Goetsch

E (Kika) de la Garza Institute for Goat Research, Langston University, Langston, OK

Ten 2-yr-old Spanish wethers (59.2 ± 2.01 kg BW), with primary follicle activity less than 50% and secondary follicle activity greater than 90% on December 19, 1997, were used to determine effects of 2-d intravenous infusion of mimosine on follicle activity (FA) and blood mimosine concentration. Goats were divided into two groups based on primary FA and BW; primary and secondary FA on d 0 were 43 ± 7.8% and 83 ± 7.6%, respectively. Jugular infusion began on January 8, 1998; one group was infused with mimosine at 120 mg kg BW^-1 d^-1 and the other received saline (0.9%; wt/vol). Blood mimosine concentration in goats infused with mimosine was 84 ± 9.3, 101 ± 20.8, 122 ± 9.1, 143 ± 21.2, and 173 ± 20.1 mol/L at 5, 20, 25, 30, and 48 h after infusion started and 60 ± 22.1 mol/L 6 h after infusion ceased. On d 4, all five goats infused with mimosine exhibited shedding; whereas, controls were not observed to shed at any sampling day (i.e., 0, 4, 12, and 20 d after the start of infusion). Cashmere shedding score (5-point scale determined by ease of hand-plucking: 1 = no shedding, 5 = high degree of shedding) on d 4 was greater for mimosine goats than for controls (2.0 vs 1.2; P < 0.001), and shedding score for goats receiving mimosine differed with time (i.e., 2.0 on d 4 vs 4.2 on d 12; P < 0.01). Primary and secondary FA on d 4 were similar between treatments (P > 0.10); however, secondary FA on d 12 was lower (P < 0.01) for mimosine than for control goats (6.8 vs 67.7%). Also, secondary FA for mimosine goats on d 12 was lower (P < 0.01) than on d 0 (99.0%), 4 (98.3%), and 20 (99.5%). In conclusion, 2-d intravenous infusion of mimosine at 120 mg kg BW^-1 d^-1 in the winter induced cashmere shedding in Spanish goats, with only a short-term decrease in secondary FA, indicating potential use of mimosine for cashmere harvest.