Excellent choice — #3 of 31 Alpaca ranks #3 of 31 fabrics for odour resistance. It is one of the best fabrics for this. Ranked with a wool-family bonus plus breathability and moisture management. The top pick is Merino.
Alpaca measures 58/100 for breathability, 14% moisture regain, 88/100 warmth, at 220 gsm. Wool fibres lead here: Alpaca is a wool fibre and resists odour naturally.