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Herbage growth and utilized output from grassland on dairy farms in southwest England: case studies of five farms, 1982 and 1983. II. Herbage utilization
Author(s) -
PEEL S.,
MATKIN ELIZABETH A.,
HUCKLE C. A.
Publication year - 1988
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/j.1365-2494.1988.tb02142.x
Subject(s) - grazing , environmental science , grassland , agronomy , silage , dry matter , hay , forage , range (aeronautics) , irrigation , nutrient , fodder , zoology , mathematics , biology , ecology , materials science , composite material
Utilized Metabolizable Energy output was calculated and herbage utilization evaluated in two contrasting years on five profitable farms representing a range of soil types. Annual UME output was 72 GJ ha ‐1 on average, with a range from 47 to 91 GJ ha ‐1 . Grazed grass provided 66% of the utilized metabolizable energy, and conserved grass 34%. Higher utilized metabolizable energy output was not always obtained at higher fertilizer N inputs, even when soil moisture conditions favoured herbage growth. The efficiency of utilization of herbage conserved (almost always as silage rather than hay) was calculated by expressing utilized metabolizable energy output as a proportion of the quantity of herbage cut, measured by swath weighings; the mean value was 64%, with a range from 55 to 73%. Cellulose analyses indicated that mean dry matter losses via CO 2 and effluent were 10%; the remaining 26% loss appeared to be due to physical losses in the field, surface waste and wastage at feedout. For grazed herbage the utilized metabolizable energy output was expressed as a proportion of herbage accumulation measured over 28‐day periods. The resultant apparent efficiency of utilization averaged 67%, with a wide range from 51 to 83%. The lowest values were on badly drained farms. It is suggested that: (i) there is considerable potential for increasing output from grazing on dairy farms; higher grazing pressure and more flexible management would be needed. Targets should probably be set lower on badly drained soils; (ii) there is great potential for increasing the efficiency of utilization of conserved forage, by careful application of existing technology; (iii) on the farms studied the utilized metabolizable energy output from grazed and conserved fields appeared to be similar.