Effects of grass and maize silage feed value, offering soybean meal with maize silage, and concentrate feed level in late pregnancy, on ewe and lamb performance

Effects of Age at First Joining and Ewe Genotype on the Performance of Two-Tooth Ewes and That of Their Progeny to Slaughter

“…Ewes grazed pastures vacated by lambs during the post-weaning period in order to reduce residual sward height and thus remove some of the less digestible forage. The BW gain of lambs between birth and weaning (258 g/day) was similar to that obtained under Irish conditions by Keady and Hanrahan [ 9 ] and Earle et al [ 29 ] using two-tooth ewes and predominantly multiparous ewes, respectively; but was less than that reported for other similar Irish studies [ 12 , 24 , 34 , 35 ] and by Keady et al [ 36 ] for data over 12 consecutive seasons for a rotational-grazing system of prime-lamb production. The latter difference is attributable, at least in part, to the fact that in the present study dams were only 2 years old and that the growth rate of lambs from 2-year-old ewes is typically approximately 93% of the average for a mixed age flock (Hanrahan JP –unpublished data).…”

“…All lambs were finished prior to the end of the grazing season without any concentrate supplementation (except prior to weaning for the few lambs that were reared as triplets), demonstrating what is achievable from good grassland-management practices, as reported previously [ 2 , 9 , 24 , 33 , 34 , 35 , 36 ].…”

“…Lamb weights were recorded at approximately 5, 10 and 14 weeks of age and BW gain calculated for the intervals described previously [ 2 ]. Procedures relating to slaughter and carcass measurements were as described in [ 24 ].…”

Developments in nutrition for pasture-based cattle and sheep systems in Ireland

“…Form a review of the literature, concluded that each 10 g/kg increase in digestibility increased lamb BW and ewe weight at lambing by 52.3 g and 1.3 kg, respectively. Keady & Hanrahan (2021) reported that the proportional increase in silage intake due to increasing silage FV was similar during mid and late pregnancy, thus increasing the intakes of ME and digestible undegradable protein (DUP) by 53% and 28%, respectively. During the final 6 wk of pregnancy, ewes offered high FV grass silage (DM digestibility [DMD] = 788 g/ kg, silage intake potential = 92 g/kg W0.75) gained 0.15 units BCS whilst those offered medium FV silage (DMD = 698 g/kg, silage intake potential = 82 g/kg W0.75) lost 0.35 units BCS (Keady & Hanrahan, 2021).…”

“…Keady & Hanrahan (2021) reported that the proportional increase in silage intake due to increasing silage FV was similar during mid and late pregnancy, thus increasing the intakes of ME and digestible undegradable protein (DUP) by 53% and 28%, respectively. During the final 6 wk of pregnancy, ewes offered high FV grass silage (DM digestibility [DMD] = 788 g/ kg, silage intake potential = 92 g/kg W0.75) gained 0.15 units BCS whilst those offered medium FV silage (DMD = 698 g/kg, silage intake potential = 82 g/kg W0.75) lost 0.35 units BCS (Keady & Hanrahan, 2021). Furthermore, increasing silage FV offered to ewes during mid and late pregnancy improved their progeny weaning weight by 1.9 kg, thus reducing age at slaughter by 16 d. Whilst chop length has no effect on silage intake, or on the performance of beef cattle (Steen, 1984) or dairy cows (Gordon, 1982), it affects the intake characteristics of silage when offered to pregnant ewes (Chestnutt, 1989) and finishing lambs (Fitzgerald, 1996).…”