عنوان

اثرات برنامه هم‌زمان‌سازی PG-3-G و PG-HS بر میزان آبستنی در گاوهای شیری دچار مرگ دیررس رویانی عنوان انگليسي

متن يادداشت

The profitability of dairy farms depends greatly on the reproductive efficiency of dairy cows. Because the economy of the herd is affected by milk production and the number of calves. Despite increasing knowledge of bovine reproductive biology, reproductive efficiency is decreased in dairy herds. For example, pregnancy loss between 24 and 42 of gestation, which is called late embryonic death reduce reproductive efficiency. Therefore, the aim of this study was to evaluate the two hormonal programs PG-3-G and PG-HS and to compare effect of these programs on reproductive efficiency in cows with late embryonic death. The total of 208 dairy cows with late embryonic death and normal ovarian conditions and with corpus luteum will be selected and randomly divided into two treatment groups. First group received PG-3-G consisting of the following: PGF2α –3 d–GnRH–7 d–GnRH–7 d–PGF2α–24 h– PGF2α –24 h–Estradiol-24 h-AI. Second group received PG-HS consisting of the following: PGF2α –4 d–GnRH–7 d–PGF2α–24 h– PGF2α –24 h–Estradiol-24 h-AI. Pregnancy diagnosis was performed in all cows on the 30-35 day after artificial insemination using ultrasound. The pregnancy rate was analyzed using Chi-square test and SPSS software. In the PG-3-G and PG-HS treatment groups, the pregnancy rate of 1 test was 50 and 53.6%, respectively, the pregnancy rate of 2 test was 36 and 42.5%, respectively, the pregnancy loss was 26.5 and 20%, respectively. No differences were observed between treatments groups in pregnancy rate and pregnancy loss rate, although, pregnancy rate a tendency to be greater and pregnancy loss rate a tendency to be lesser for PG+G group. The results of the present study showed that according to the lack of statistically significant difference in the pregnancy rate between the two treatment groups, the duration of the program (13 days vs. 19 days) and hormone costs were lower in the PG-HS program compared to the PG-3-G program, it is preferable to use the PG-HS hormonal program