title: Carrying the FecB (Booroola) mutation is associated with lower birth weight and slower post-weaning growth rate for lambs, as well as a lighter mature bodyweight for ewes.
abstract: The present study was conducted in an Assaf flock in which the FecB (Booroola) mutation was segregated to determine whether the FecB mutation affects birthweight and the pre- and post-weaning growth rate of ewe lambs, as well as the mature bodyweight of ewes. Significant differences (P = 0.01) in birthweight (mean +/- s.e.m.) were found between BB ewe lambs (4.03 +/- 0.08 kg) and B+ and ++ ewe lambs (4.16 +/- 0.04 and 4.32 +/- 0.07 kg, respectively), which themselves did not differ significantly (P > 0.05). An FecB-associated maternal effect on the birthweight of ewe lambs was also detected, with the birthweight of lambs born to BB mothers (3.93 +/- 0.08 kg) being significantly (P < 0.0001) different from the birthweight of lambs born to B+ and ++ mothers (4.26 +/- 0.04 and 4.33 +/- 0.07 kg, respectively), which did not differ significantly. The genotypes of the lambs did not affect their preweaning growth rate. However, the post-weaning growth rate of ewe BB lambs (274 +/- 5 g day(-1)) was significantly (P = 0.05) different from the similar (P > 0.05) post-weaning growth rates of B+ and ++ lambs (284 +/- 3 and 290 +/- 4 g day(-1), respectively). The genotype at the FecB locus also affected the mature bodyweight of ewes, with that of BB ewes (67.3 +/- 1.4 kg) being significantly (P < 0.001) different from the similar mature bodyweight of B+ and ++ ewes (70.8 +/- 1.1 and 70.1 +/- 1.7 kg, respectively).
authors.affiliation: Institute of Animal Science, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel. gootwine@agri.gov.il
authors.forename: E
authors.initials: E
authors.lastname: Gootwine
authors.forename: A
authors.initials: A
authors.lastname: Rozov
authors.forename: A
authors.initials: A
authors.lastname: Bor
authors.forename: S
authors.initials: S
authors.lastname: Reicher
mesh_terms: D000818:Animals; D001724:Birth Weight / Q000235:genetics*; D001835:Body Weight / Q000235:genetics; D003433:Crosses, Genetic; D005260:Female; D005838:Genotype; D009154:Mutation; D012756:Sheep / Q000235:genetics* / Q000254:growth & development*; D014886:Weaning; D015430:Weight Gain / Q000235:genetics