Single female offspring born to primiparous ewe-lambs are lighter than those born to adult multiparous ewes but their reproduction and milk production are unaffected.

摘要

Little is known about the long-term impacts of selecting progeny born to ewe-lambs (EL) as replacements. This study investigated whether being born to a ewe-lamb affected the liveweight, milk production and reproductive performance of the offspring to 3 years of age in comparison with those born to adult multiparous ewes. Twenty-seven and 28 single-born Romney ewe progeny (G1) were born to either EL or to adult ewes (AE), respectively. Offspring born to ewe-lambs (ELG₁) were lighter (P<0.001) at birth and up to 12 months of age compared with offspring born to adult ewes (AEG₁). Reproductive performance of AEG₁ and ELG₁ did not differ in regards to puberty attainment, pregnancy rate and number of fetuses. First lactation milk production, fat, crude protein, total protein, casein, lactose and total solids yield did not differ (P1 and AEG₁ did not differ in birthweight in the first parity, but it did differ in the second parity and those lambs born to ELG₁ were heavier from birth to weaning compared with those lambs born to AEG₁. Combined, these results indicate, in the animals used in our study that productive performance of ewes born to EL does not differ to 3 years of age to that of ewes born to AE.