EFFECTS OF EWES LIVE WEIGHT AND BACKFAT THICKNESS AT MATING ON FERTILITY AND PRODUCTION PERFORMANCE IN SUFFOLK SHEE P AND THEIR CROSSES

L. Stolc, L. Stadnik, M. Ptacek, J. Beran, J. Duchacek

Abstract: The objective of work was to evaluate relationships among ewes’ live weight and backfat thickness at mating and level of their fertility and production performance. The monitoring was carried out in meat type Suffolk sheep (n = 286) and their Merinolandschaf and Kent crossbreeds (n = 124) bred on five extensive farms in the period of one year. The fertility traits (lambing rate in % and litter size in pcs.) and production traits (total litter weight at birth and at weaning in kg) were observed. Selected factors concerning to ewe live weight (LW) and backfat thickness (BT) at mating measured via ultrasound were observed
and evaluated. Ewes were assigned to three groups according to their LW (≤ 69.9 kg; 70.0 to 80.7 kg; ≥ 80.8 kg) and BT (≤ 7.69 mm; 7.70 to 10.65 mm; ≥ 10.66 mm). The statistical analysis was performed using the SAS 9.1. Ewes of the highest LW (≥ 80.8 kg) showed higher lambing rate (+2.49 to 11.0%; P > 0.05). The higher LW, the higher litter size were determined (P < 0.05 to 0.01), when ewes´ LW above 70 kg means increased litter size (+0.20 to 0.28 pcs.). The same tendencies were detected as well as in total litter weight at birth (+0.68 to 0.75 kg; P < 0.01) and at weaning (+4.13 to 4.81 kg; P < 0.01). Results of BT
evaluation showed non-significant effect on both fertility parameters. On the other hand significant effect (P < 0.05) of BT was found in relation to total litter weight at birth. The highest BT caused increasing the total litter weight at birth by 0.23 kg. Despite the similar trend, differences in total litter weight at weaning were insignificant (P > 0.05).

Keywords: lamb; lambing rate; litter size; live weight at birth; live weight at weaning; ultrasound measurement

Date published: 2017-10-12