COMPARISON OF THE OVULATION RATE, FERTILITY AND BIRTH WEIGHT IN SHEEP OF TRAKIAN MERINO BREED AND THEIR CROSSES WITH BOOROOLA
Staika Laleva, Petia Slavova, Nikola Pacinovski, Georgi Bonev, Goce Cilev, Yovka Popova
Institute of Agricultural Sciences – Stara Zagora, Bulgaria
pkslavova@abv.bg
The aim of this study was to compare the Trakian Merino sheep and their crossbreeds with Booroola in terms of their ovulation rate, fertility and birth weight. The investigations were made with 3 groups of animals: The I one – 46 daughters of 4012 ram who is crossbreed with 50% Booroola, the II one – 132 daughters of 509 ram who is crossbreed with 62.5% Booroola, and III one – 158 Trakian Merino breed sheep. The highest ovulation rate showed daughters of ram 4012 that amounted 2.875 ± 0.314 number (aged 1.5 years), i.e – 2.833 ± 0.522 (aged 2.5 years). In daughters of ram 509, ovulation rate values for these ages were somewhat lower and amounted to 2.560 ± 0.057, or 2.400 ± 0.320. The lowest ovulation rate had daughters of III group (Trakian Merino), who averaged 1.526 ± 0.137 for the age of 1.5 years, i.e 1.575 ± 0.147 for those animals who were aged 2.5 years. The highest fertility displayed daughters of ram 4012: 1.375 ± 0.117, 1.500 ± 0.129 and 1.500 ± 0.244 number for ages of 2.5, 3.5 and 4.5 years, respectively, while the lowest fertility was recorded in daughters of Trakian Merino, the values constituted were 1.175 ± 0.063, 1.333 ± 0.065 and 1.391 ± 0.102 number, respectively for the ewes of the similar age. The highest and lowest value for the birth weight for male lambs were identified with those obtained from 509 ram daughters, aged 2.5 and 3.5 years, respectively. In terms of birth weight of female lambs, the highest value was determined in lambs born from Trakian Merino daughters, aged 4.5 years, and the lowest in those obtained from the daughters of ram 509, at the age of 3.5 years
Keywords: sheep; Trakian Merino breed; Booroola; ovulation rate; fertility; birth weight
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