Analysis of the data, for each seasonal period combined over the 2 years, showed large differences in the relationships between daily live- weight gain and herbage allowance between the 2 seasons. At the same allowance, beef cattle grew faster in spring than in autumn/winter. Relationships between allowance and daily live-weight gain were:
Autumn/winter: LWG = 0.48-1.37* 0.65 allowance Spring: LWG = 1.09-2.82* 0.45 allowance
These differences were not associated with differences in in vitro digestibility (70 to 78% in all trials) or N concentrations. Allowances required for maintenance were lower in spring than in autumn/winter and potential growth rates in spring approximately double those in autumn.
Keywords: NZSAPAB; Cattle; live-weight gain; herbage allowance; winter; spring