Abstract

Feed requirements of flocks of ewes from Romney dams mated to either Romney , Border x Dorset, Finn x Texel, or Texel x Dorset sires (R, BD, FT, TD), were estimated from assumed profiles of live weight and reproductive performance. These were constructed by extrapolating data collected from four flocks of 500 ewes each, born in 1994 and run under a common management system at Limestone Downs (a large Waikato sheep/beef property). Annual feed requirements for R, BD, FT and TD ewes (plus 25% replacements) were estimated to be : 670, 809, 766 and 740 kg DM/ewe; equivalent ewe numbers for the same annual intake: 1000, 829, 875 and 906 ewes; g lamb weaned/kg DM consumed: 37, 43, 47 and 40 g/kg DM. Live weight and reproductive profiles for ewes sired by East Friesian rams were also constructed by extrapolating data from East Friesian-cross ewes born at Limestone Downs in 1996 and mated as hoggets in 1997. Estimates of annual feed intakes, equivalent ewe numbers and g lamb weaned/kg DM consumed for East Friesian-cross ewes (plus 25% replacements), mated first as hoggets (EFH) were: 925 kg DM/ewe, 725 ewes and 56g/kg DM; or mated first as two-tooths (EF): 907 kg DM/ewe, 739 ewes, and 50g/kg DM. The increased feed demand for high producing ewes occurred mainly from late pregnancy until weaning.

IM, Brookes, KI Lowe, and DJ Garrick

Proceedings of the New Zealand Society of Animal Production, Volume 58, , 161-164, 1998