Akademik Veri Yönetim Sistemi
SMALL RUMINANT RESEARCH, cilt.100, sa.1, ss.34-36, 2011 (SCI-Expanded)
The objective of this study was to evaluate the effect of crossbreeding Awassi and Morkaraman ewes with Romanov sires on litter size and total productivity as reflected by reproductive performance and milk production in the ewes. Twenty-three Romanov x Awassi (RA) and 19 Romanov x Morkaraman (RM) ewes were used. All of the ewes were pregnant at the start of the study, and litter size at birth and at weaning (60 days) were recorded. Milk production was recorded weekly and milk composition was estimated as dry matter and fat percentage. Litter size at birth (RM: 1.89 +/- 0.18: RA: 1.62 +/- 0.15) and weaning (RM: 1.67 +/- 0.20; RA: 1.46 +/- 0.17), dam weight at lambing (RM: 50.2 +/- 2.37; RA: 44.2 +/- 1.98) and total productivity (RM: 29.9 +/- 3.05; RA: 24.4 +/- 2.54) were not influenced by breed-type. Lactation length and milk yield was relatively but not significantly higher in RA than RM ewes. Dry matter and fat percentage of milk were found to be similar for both breed-types. Results of the present study indicate that crossbreeding of Awassi and Morkaraman ewes with Romanov rams yielded similar performance in F1 ewes. When F1 ewe performance is compared with their pure breed maternal ancestor, it is concluded that reproductive performance is improved by crossbreeding with Romanov. (C) 2011 Elsevier B.V. All rights reserved.