Chemical Composition and <i>In Sacco</i> Degradation Kinetics of Four Common Biowastes in Canterbury

This research aimed to quantify the chemical composition and rumen degradation kinetics of three local and one imported biowaste using the in sacco nylon bag technique. Triplicate samples of oven‐dried biowastes ground to 4 mm were incubated in the rumens of four cows for 0 h, 2 h, 4 h, 6 h, 12 h, 24 h and 72 h. Bags attached to chains in descending order were placed in the ventral sac of the rumens. The soluble fractions (0 h) of dry matter were lowest for brewer's grains (BG) with 8.4% ± 0.88%, followed by palm kernel expeller (PKE) and potato waste (PW) with 25.4% ± 0.27% and 29.9% ± 1.08%, respectively. Apple pomace (AP) had the highest soluble fraction (54.7% ± 1.11%). For crude protein (CP), the rate of degradation was 9.5% ± 1.0%/h for BG, 5.0% ± 1.1%/h for AP, 0.1% ± 0.0%/h for PKE and 21.1% ± 2.0%/h for PW. These findings demonstrate the variability of local and imported biowastes and provide useful information on degradation kinetics which can be used for formulating diets.