Abstract #M158

# M158
Nutrient composition and management characteristics of California sorghum silage.
J. Heguy*1, J. Dahlberg2, P. Price4, J. Martins3, N. Clark3, N. Silva-del-Rio5, D. Meyer4, 1University of California, Ag & Natural Resources, Modesto, CA, 2University of California, Ag & Natural Resources, Parlier, CA, 3University of California, Ag & Natural Resources, Tulare, CA, 4University of California, Davis, Davis, CA, 5University of California, Veterinary Medicine Teaching & Research Center, Tulare, CA.

The aim of this study was to obtain information on current sorghum management practices and sorghum silage quality from dairy farms (n = 16) located in California’s San Joaquin Valley. Herd size ranged from 320 to 5,500 lactating dairy cows (median = 2,013). Dairy producers answered short agronomic and harvest management surveys. At harvest, during summer and fall of 2016, 10 consecutive truckloads of chopped sorghum were sampled and composited for wet chemistry nutrient analysis (Table 1). Hectares of farmed sorghum ranged from 16.9 to 232.3 ha (median = 76.1); sorghum types were grain (n = 5), brown midrib (n = 10) and unknown (n = 1). Sorghum was stored in piles (n = 12) and bags (n = 4). Dairies with piles built one (n = 7), 2 (n = 3) or 3 (n = 2) sorghum silage piles, while bagged silage was stored in 5 or more bags on all dairies. Half of the dairies stored their sorghum silage on dirt surfaces. Delivery rate of the 10 truckloads of sorghum ranged from 12 to 78 min (median = 40). All dairies utilized custom harvesting services. Quality of sorghum harvested for silage was variable, with lower starch and NFC content and higher ash content than the traditional summer corn crop grown in California. Table 1. Nutrient composition of chopped sorghum sampled at harvest from dairy farms (n = 16) in California’s San Joaquin Valley
DM% of DMNDFD 30, % of NDF
CPADFNDFStarchNFCAsh
Mean28.79.534.649.710.926.312.248.6
Median28.49.734.950.49.627.411.850.5
Minimum23.25.730.444.91.914.49.235.1
Maximum34.611.740.255.322.535.621.560.3
SD3.31.83.13.86.76.02.97.8

Key Words: California, sorghum silage, silage management