Akkaraman koyunu yetiştiriciliğinde üreme özelliklerinin araştırılması
The purposes of this research were to investigate some reproductive traits and determine levels of reproductive hormones in blood (progesterone, oestrogen, FSH and LH) during oestrus cycle which were not detected naturally before in Akkaraman ewes. This study was conducted at Gözlü Agricultural Enterprise in Konya province, a subsidiary of the General Directorate of Agricultural Enterprises, in 2012 and 2013 years. The animal materials of the research, 31 Akkaraman ewes in heat in different ages, were selected from elite flocks with using teaser rams. The research ewes were detected in three days (7-8-9 September 2012) at the beginning of the mating season. The ewes were divided into 4 age (8 ewe with 2 years old, 7 ewe with 3 years old, 8 ewe with 4 years old and 8 ewe with 5 years old) groups. All ewes weren't mated in the first oestrus to make them show the second oestrus. The ewes were monitored by rams twice a day after 12 days from the first oestrus and mated when in heat. The daily blood samples collecting was started at the first oestrus and continued until 5 days after the second oestrus. Reproductive hormones levels investigated were determined by ELISA. Oestrus cycle period was calculated as the days between two oestrus. The periods of oestrus cycle were determined by the results of hormone analyses. Births of ewes were followed at the lambing season (from the beginning of February 2013) and type of birth and sex of lambs were recorded. The days between insemination and birth date were calculated as the gestation period. Lambing rate, lamb production, single and twin birth rates and litter size of ewes were determined. The blood samples were collected two times again from the ewes at the 4th month of lactation, that is, in anoestrus period and reproductive hormone levels were also detected. The obtained data were compared by ewe age group and type of birth. One-way ANOVA and t-test were used to analyse the data of hormone levels. The means were obtained as 90.32% for lambing rate, 53.57% for single birth rate, 46.42% for twinning rate, 132.25% for lamb production and 1.46 for litter size. The mean periods for oestrus cycle and gestation were detected as 15.29 ± 0.26 ad 150.24 ± 0.27 days, respectively. In the test days between the first and second oestrus, the mean hormone levels were 3.24 – 11.55 ng/ml for progesterone, 44.29 – 76.06 pg/ml for oestrogen, 4.10 – 4.58 mIU/ml for FSH and 4.05 – 4.42 mIU/ml for LH. The corresponding valuse at the anoestrus period (4th month of lactation) were 1.60 ng/ml for progesterone, 45.14 pg/ml for oestrogen; 4.76 mIU/ml for FSH and 6.33 mIU/ml for LH. The effects of age and birth type on the levels of oestrogen, FSH and LH were not significant while the effect of birth type on progesterone was important at the 2nd and 3th days before the second oestrus. On the other hands, the ewes bearing single lambs had higher progesterone levels than those bearing twin lambs although the differences were not significant. In conclusion, Akkaraman ewes had shorter (approximately 2 days) oestrus cycle period and similar pregnancy period compared to the other breeds. Mean levels of progesterone and the differences between maximum and minimum progesterone levels were similar to prolific breeds, however generally higher than the non-prolific breeds. Mean levels of oestrogen were lower than the prolific breeds, but generally were higher than the non-prolific breeds. On the other hands, the levels of FSH and LH were not evaluated in terms of comparing to the prolific or non-prolific breeds.