The energy requirements of sheep

I.E. Coop

Lincoln, College, Christchurch

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Proceedings of the New Zealand Society of Animal Production. 1961, 21: 79-91

The maintenance requirements of sheep fed in pens and under grazing conditions have been estimated in a series of trials. Four trials with pen-fed sheep gave a mean estimate for 100 lb sheep of 0.92lb D.O.M. (digestible organic matter) per day. The intake of grazing sheep was measured by the chromium oxide- faecal nitrogen method. A grazing trial in 1958 with 38 sheep of widely varying liveweight grazed on pasture which permitted only slight weight changes for a period of 17 weeks gave an estimate of maintenance D.O.M. (maintenance) = 0.061(±0.005) W_lb^{0,69(+ or - 0.04)} per day, equivalent to 1.48 lb D.O.M. per day for a 100 lb sheep. A second similar trial with 41 ewes extending over 12 weeks gave D.O.M. (maintenance) = 0.062(±0.003) W_lb^{0.73 (+ or -
0.07) or 1.63 lb D.O.M. per day for a 100 lb sheep. A third trial with
15 ewes in which gain was permitted gave an estimate of 1.36 lb D.O.M.
per day for maintenance for a 100 lb sheep. Estimates of the cost of
gain gave higher figures for pen-fed sheep than grazing sheep.

The environmental conditions causing the large difference in maintenance
requirement between pen-fed and grazing sheep are discussed and it is
suggested that the energy of harvesting the pasture is the most
important cause, together with wind and rain. It is also suggested that
maintenance of grazing sheep is not a constant but decreases as the ease
of harvesting the pasture increases.

Keywords: NZSAPAB;

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