Extensive use of embryo transfer (ET) to accelerate genetic progress in the Texel breed is an important tool in multiplying important and influential breeding lines.
Signet breeding consultant Sion Parry explains, properly accounting for ET when performance recording is essential.
Producers should record both the genetic dam and the recipient dam when notifying ET lambs, this means the analysis can recognise both the source of the lambs genes and the environment in which it is reared.
The analysis takes into account both and thus the lamb’s genetic mother is credited with growth and carcase traits influenced by her genes, but her maternal ability (milk) and litter size (prolificacy) EBVs are unaffected, as neither of these traits have been expressed during an ET programme.
The issues surrounding ET are similar to those influencing fostered lambs, where again the genetic dam is not credited with rearing the lamb.
Accurate recipient records are important as they indicate which ewe has reared the lamb, which lambs have been reared together (as twins) and whether the lamb was reared as a single, twin or triplet.
ET lambs should be managed in an identical manner to the rest of the lamb crop. When they are subject to superior/different management they can be allocated to a different management group at eight weeks of age.