Speed of air drying and drying on silica gel

From the samples of the six horses collected in 2016, we evaluated how fast 1.5 g of feces lost humidity under the following conditions: (i) when spread out in a petri dish and air dried at room temperature (20°C) in a lab without air conditioner or controlled air flux (air drying = AD) and (ii) when given in a paper tea bag and dried in an air tight tube on 20 mL of colorless silica gel granules (silica gel drying = SD; Fig. 1). For each horse, we measured the weight loss (i.e. humidity loss) of the samples after 12, 24, 48, and 72 hours of drying.

Drying fecal samples on silica gel. 1a, From the fecal pool samples, an aliquot of 1.5 g was taken and formed to an approximate 2-cm-long roll to increase surface for faster drying. 1b, One way gloves, 20 mL of colorless silica gel granules, a small paper tea bag, and a 50-mL tube were used. 2a, The samples were placed in a tea bag, and the tea bag coiled, its ends folded, and placed in a tube with 20 mL of silica gel. 2b, The lid was screwed on the tube with the sample and tilted a couple times until silica gel was all around the tea bag with the sample.