Effects of joining at 7 months, and ewe genotype, on the performance of ewes to 19 months of age and that of their progeny to slaughter

• Published in: Animal (Cambridge, England) England), 2021-06, Vol.15 (6), p.100232-100232, Article 100232
• Main Authors: Keady, T.W.J., Hanrahan, J.P.
• Format: Article
• Language: English
• Subjects: Body size; Ewe lambs; Ewe productivity; Lamb growth; Ram effect
• ISSN: 1751-7311; 1751-732X
• DOI: 10.1016/j.animal.2021.100232

Two ways of reducing the cost of replacements are increasing litter size and number of litters produced; thus, the total weight of lamb carcass output per ewe lifetime. The effects of ewe genotype on the performance of ewes lambing at 1 year and of their progeny to slaughter, and the effect of age at first joining (7 or 19 months) on BW at ~19 months and survival to joining at 19 months were evaluated over two consecutive years, using 460 ewe lambs from three genotypes: Belclare (Bel), Suffolk × Belclare (Suf × Bel) and ≥ 75% Suffolk ancestry (Suf75). Lambs from the three genotypes were at a similar proportion of mature BW and half of the lambs, within genotype, were allocated to be joined for the first time at 7 or 19 months. The ewe lambs were managed in a grass-based rotational-grazing system, except when housed from December to March on a grass silage-based diet. Belclare ewes had larger litters (P