A survey was conducted to assess factors associated with the dry matter digestibility (DMD) of silages on Manitoba dairy farms. A total of 20 farms were visited during the summer of 2018 to collect samples of silages (1 to 5 per farm) and to record herd size, silage cut, and storage method. Information on the silage production and feeding methods, including use of fertilizer and manure, seed variety, stage at harvest, wilting time, days between cuts, fill method, amount of wet mass ensiled per day, inoculants and enzymes, cover material, feed out rate, and age of stands were collected. The DMD of silage samples were determined in duplicate using the ANKOM Daisy II incubator with a NDF ending. Regression models were developed using the MIXED procedure of SAS 9.4 to test the relationships between the DMD and herd size (55–120 cows = small, 7 farms; 130–312 cows = average, 6 farms; 312–1100 cows = large, 7 farms), type of forage (corn or alfalfa), silage cut (direct for corn, first or later for alfalfa and alfalfa/grass mixes) and storage method (bunker, tower, pile or bale). The R-square, CV, and root MSE of the final model were 0.22, 3.70, and 3.02, respectively. Summary statistics of the DMD are given in Table 1. The effect of herd size on DMD was significant (P < 0.01) and the effect of cut of alfalfa on DMD tended to be significant (P = 0.09). The effects of type of forage, storage method, and the interactions between type of forage, herd size, and storage method were not significant. Farms with average and large herd sizes had higher silage DMD compared with farms with small herd sizes (83.9 vs 81.4%, P < 0.05). First cut alfalfa silages tended to have higher DMD than later cuts (83.8 vs. 81.9%, P = 0.10). Results show that farmers produced alfalfa and corn silages with a high DMD, but that the variation in silage DMD among farms was substantial. On average, the small size farms with the relatively low silage DMD used less synthetic fertilizer, had younger stands of alfalfa, were less aware of the alfalfa seed variety, ensiled less wet mass per day and had lower feed out rates compared with the average and large farms. Table 1 (Abstr. 496). Summary statistics of DMD (%) of forages

Forage	Average	SD	Maximum	Minimum	N
Alfalfa	82.2	3.28	74.4	87.8	28
Corn	81.1	3.06	72.9	84.9	17