Effects of pasture allowance in winter on liveweight, wool growth, and wool characteristics of Romney ewes

Abstract

In each of two years, pasture allowances of 0.7, 1.2, 1.7, or 2.2 kg dry matter (DM)/ewe per day were offered to groups of Romney ewes for 6 weeks in June -July. The ewes were then run together until weaning in December. In Year I there were 70 2-year-old ewes per group; mean initialliveweight was 47 (SE 0.25) kg. In Year 2 each group comprised 25 2-year-old ewes with a mean initialliveweight of 48 (SE 0.49) kg and 25 6-year-old ewes with a mean initial liveweight of 57 kg. For liveweight change (g/day), the inverse linear relationship with pasture allowance (kg DM/ewe per day) for ewes with one lamb in utero was: [liveweight change = 136 (SE 4.4) -(132 (SE 5.0) allowance)]. On average, the pasture allowance that resulted in zero liveweight change was predicted to be 1.0 kg DM/ewe per day. With a pregrazing pasture mass of c. 2000 kg DM/ha, zero liveweight change was associated with a residual pasture mass of 760 kg DM/ha, a utilisation of 660/0, and an apparent intake of 0.59 kg DM/ewe per day. For ewes with zero, one and two lambs in utero, zero liveweight change was predicted to occur on pasture allowances of 1.3, 1.0, and 0.8 kg DM/ewe per day, respectively. However, a similar allowance (c. 1.3 kg DM/ewe per day) would maintain body weight (conceptus free) for ewes in all three categories. Pasture allowance in June -July affected liveweight in August by up to 3.4 kg but this effect had largely disappeared by

The effects of allowance of deferred herbage and concentrate supplementation when offered to ewe lambs, and system of allocation when offered to ewes in late gestation, on animal performance

“…Herbage utilization rate in this study was higher than that reported by Hawker and Thompson (1987), Carson et al. (2003) and Keady and Hanrahan (2009a,b,c).…”

“…Hawker and Thompson (1987) also reported a linear increase in herbage intake of pregnant ewes when daily herbage dry‐matter allowance per ewe was increased from 0·7 to 2·2 kg. The absence of a curvilinear relationship in this study is probably associated with the highest herbage allowance offered being only 57% greater than the intake, whereas in the study of Peyraud et al.…”