Brassica Reference Manual - Agricom

5. GRAZING MANAGEMENT
AND ANIMAL WELFARE
5. Grazing Management and Animal Welfare
5.1 Best practice brassica grazing
The successful grazing of livestock on brassicas requires farmers to be aware of a number of factors that may impact on the productivity and
health of animals; feed quality, crop utilisation, crop access, feeding fibre, animal health issues eg rape scald, photosensitivity, SMCOs, Goitre
nitrates.
5.2 Feed quality comparisons
The quality parameters of a feed influence stock performance. Adequate energy, protein and mineral supplies are especially important for high
producing stock. A general guide to crude protein (CP) requirements for ruminants is (as percentage of DM): 10-14% CP – minimum required
for adequate growth, 15-18% CP – minimum required for adequate lactation.
Table 16. Approximate nutritive values for a range of feeds
Crop
Dairy cow research
Research into the use of brassicas for subtropical dairy farms by the Wollongbar Agricultural Institute concluded that brassicas provide an
excellent source of energy and protein for lactating dairy cows in the autumn/winter period when grazed at the 6 leaf stage of regrowth (equivalent
to a 30 day grazing interval on the north coast of NSW), in conjunction with the use of a high fibre supplement (Slack & Fulkerson, 2002).
29
Crude Protein (%)
Digestibility (%)
Metabolisable Energy
(MJME/kgDM)
Green pasture 22 82 12
Dry pasture 10 53 7
Hunter forage brassica* 17 86 12
Winfred forage brassica* 22 78 11
Turnips 12 88 13
Corn 8 71 10
Millet 10 65 9
Sorghum 11 65 9
Tonic plantain* 22 78 11.3
Chicory* 23 79 11.7
*Hunter, Winfred, Tonic and chicory values collated from historical feed tests collected by PGG Seeds research staff.