engleski

The stimulation of ovulation during high temperature, a technique of fertility increasing in cows

The high temperature over 35 C (heat stress) is one of the factors which influence in general reproduction processes and specially the ovulations process. In our country these temperatures are present from June to August month. Therefore the fertility rate during these months is lower than in other periods of the year. Because of this the authors have thought to experiment the use of hormonal substances (analogue synthetic of GnRH). This study was performed on 2007-2008 during summer's months. Two cows of Simmental and their crossbreed groups were made up. All the cows have the same breeding conditions. Their age is about 3-6 years old and they are 60 days after their parturition, they are also in normal healthy condition and with oestrus normal cycle. Each group was compound of 30 animals (cows) and they have been treated as below. The A experimental group (IA + GnRH), the cows of this group were inseminated and they have been treated with Fertagyl (Intervet, 0.1 ng/ml) 2.5 ml/animal, (IM). The B group of control (IA), the cows of this group have been inseminated without hormonal above. The artificial insemination of the cows was performed about 12 hours after the beginning of the oestrus. It resulted that (for two cows groups) the rate of fertilization for the experiment group is 80%against 60% of the control group (P>0.05). As conclusion the treatment of the cows by using synthetics analogue of GnRH and at the same time the artificial insemination influences positively on their fertility.

analogue; fertility; fertilization; estrus; artificial insemination

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