Collection method affects hay waste estimates

Abstract Text:

Two waste collection methods, cumulative (CUML) and daily (Daily), were used to evaluate differences in hay waste estimates. Small (128.3 ± 3.19 cm), Medium (160.7 ± 6.38 cm), or Large (187.7 ± 3.52 cm) tall-fescue round hay bales (85.5% DM, 8.2% CP, 66% NDF, 152 cm wide) were placed in hay feeders equipped with cradle chain (CONE) or without (RING) in a 3 X 2 factorial design randomly assigned to a 6 x 6 Latin square. Bale replacement intervals (Small = 2d, Medium = 3d, Large = 5d) ensured ad libitum hay access. Waste was collected daily or at bale replacement as the Latin Square sub-plot. Bales were placed on flat end in round bale feeders (230 cm diameter, 170 cm height) with 16 feeding stations and metal sheeting on top (50 cm) and bottom (60 cm). We hypothesized hay waste estimates would not differ due to collection method. CUML increased waste compared to DAILY as percent of initial bale (20.8% vs 17.3%, P = 0.005), percent of disappearance (37.6% vs 30.0%, P = 0.01), and average kg·hd^-1·d^-1 (3.46 vs 2.93, P = 0.005). Collection method x feeder (P < 0.01) and collection method x bale size (P < 0.02) interactions were observed for dry waste as percent of total waste and average kg·hd^-1·d^-1. Interactions resulted from a greater magnitude of difference between CUML and DAILY as total waste amount increased  for percent  dry waste and average dry waste kg·hd^-1·d^-1 estimates. Clean, contaminated and total waste ash content was greater for CUML than DAILY (P < 0.05). CUML waste having greater ash content than initial bale suggests increased contamination could increase waste estimate. Different conclusions were reached when analyzing CUML compared to DAILY due to greater variance in CUML estimate. In conclusion, CUML is a more variable estimate and increased contamination increases waste estimation.

Keywords: Bale feeder, Collection method, Hay waste