Effect of ewe and lamb genotype on gestation length, lambing ease and neonatal behaviour of lambs.

摘要

To examine the effects of maternal and lamb genotype on characters of the dam and progeny, an embryo transfer study was carried out using a hill breed (Scottish Blackface (SB); body weight 54.25+-1.03 kg) and a lowland breed (Suffolk; 80.33+-1.52 kg)to obtain the 4 possible combinations of ewe and lamb. Data on 38 SB ewes (18 with SB and 20 with Suffolk lambs) and 41 Suffolk ewes (20 with SB and 21 with Suffolk lambs) were analysed. All ewes were given single embryos. Regardless of ewe breed, gestation length was longer for Suffolk than for SB lambs (by 1.5 days; P<0.01). The length of labour, from the appearance of fluids to the birth of the lamb, was 20 min longer for Suffolk than SB lambs (P<0.05). Lambing assistance was required equally for SBand Suffolk ewes (overall assistance was given to 21 of 79 ewes), however, the need for assistance was greater for ewes carrying Suffolk lambs (17/21 births; P<0.001) and for male lambs (19/21; P<0.01). SB lambs stood twice as quickly as Suffolk lambs after birth (13 vs. 24 min; P<0.001) and were more likely to suck in the first 2 h after birth (92.1 vs. 65.9%; P = 0.02); ewe breed had no effect on lamb behaviour.