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Breeding ewe lambs is a management tool that can be used to increase farm profit. However, there are potential negative impacts on the liveweight of progeny at weaning and the liveweight of the ewe lamb at the following breeding. A potential method of minimising these impacts is through the provision of quality herbages such as lucerne or a herb mix containing chicory, plantain, and red and white clover. The aim of this 2-year study was to examine the impact of offering ewe lambs either a traditional ryegrass and white clover pasture (Pasture), Herb-mix or Lucerne throughout the lambing period and in lactation. During lactation in both years of the study, ewe lambs offered the Herb-mix or Lucerne treatments were heavier (P < 0.05) than those offered Pasture. In addition, progeny of ewe lambs offered the Herb-mix or Lucerne treatment were also heavier (P < 0.05) in lactation than those born onto ryegrass white clover. Interestingly, in one of the 2 years, the ewes and their progeny on the Lucerne treatment were heavier (P < 0.05) in lactation than those in the Herb-mix treatment. Combined, these results indicated that offering either Herb-mix or Lucerne increases the performance of the young dam and her progeny above that found on a ryegrass and white clover sward.

In sheep, maternal nutrition can affect the offspring’s milk production at its first lactation and the grand-offspring’s liveweight to weaning. However, this apparent developmental programming effect on milk production and grand-offspring liveweight has not persisted. Therefore, the aim of the present study was to determine if nutrition of the programmed ewe in mid- to late pregnancy affected this response. Developmentally programmed ewes (G1) that had been born from dams (G0) offered submaintenance, maintenance or ad libitum feeding levels from Day 21 to Day 50 of pregnancy and then either pregnancy maintenance or ad libitum to Day 140 were used for this study. These ewes were offered one of two pastoral-based pregnancy nutritional treatments (controlled vs unrestricted) from Day 76 of pregnancy until lambing. Pre- and post-herbage masses of the unrestricted treatment (2181 ± 47.6 and 1431 ± 24.6 kg DM/ha, respectively), were greater (P < 0.05) than the controlled treatment (1164 ± 31.6 and 819 ± 16.0 kg DM/ha, respectively). At Day 71 of pregnancy, there were no differences (P > 0.05) in G1 liveweight (70.2 ± 0.8 vs 70.3 ± 0.8 kg for controlled and unrestricted feeding, respectively), or body condition scores (2.5 ± 0.06 vs 2.5 ± 0.05) between pregnancy nutritional treatments. In late pregnancy, unrestricted G1 ewes were heavier (P < 0.05, 97.4 ± 1.0 vs 86.8 ± 1.0 kg) and had greater (P < 0.05) body condition scores (3.4 ± 0.06 vs 2.5 ± 0.06) and back-fat depths (8.0 ± 0.3 vs 5.9 ± 0.03 mm) than controlled nutritional treatment ewes. There were no interactions (P > 0.05) between grand-dam feeding levels and ewe nutritional treatment on lamb (G2) liveweights at birth or in lactation. This indicates that under the conditions of the present study, nutrition of the G1 ewe did not affect the expression of the developmental programming effect. Further studies might be warranted to determine the causes of this inconsistency in grand-offspring liveweight. Nutrition of the G1 ewe had a minor effect (P < 0.05) on G2 lamb birthweight and liveweight in early lactation but not (P > 0.05) in late lactation or on lamb survival. These findings indicate there is no little to no benefit to the lamb until weaning from offering ewes pre- and post-grazing masses above ~1200 and 800 kg DM/ha, respectively, in mid- to late pregnancy.