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1

Use of a decreased dose of cabergoline to treat secondary anoestrus in bitches

100%

Cirit U. , Bacinoglu S. , Tas M. , Alkan S.

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tom 51

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nr 1

EN

The aim of the study was to determine whether a dose (0.6 µg/kg/d) quite lower than the prolactin-lowering dose of cabergoline, prepared for humans, would be a safe and effective method for the stimulation of oestrus in bitches at secondary anoestrus or late anoestrus. Twenty-four pure blood bitches from various breeds were used in the study at their already determined periods of anoestrus. The treatment group included bitches at late and prolonged anoestrus. Eight bitches that had not shown any signs of oestrus for the preceding 370 to 485 d formed the secondary anoestrus group. Eight of the 16 bitches at late anoestrus (days 165-280) have accomplished the late anoestrus group and another 8 have been chosen randomly for the control group (untreated). Cabergoline was orally administrated until day 2 after the onset of pro-oestrus or for a maximum of 42 d. Blood samples were taken daily from each bitch during the first 5 d of behavioural oestrus to measure progesterone concentrations. In the secondary anoestrus and late anoestrus groups, oestrus was induced on days 4-14 and 12-45 at a ratio of 75.0% (6/8) and 87.5% (7/8), respectively. The mean pro-oestrus and behavioural oestrus durations, serum progesterone concentrations on day 5 of oestrus, ovulation rates, pregnancy rates, and the mean litter sizes in secondary anoestrus, late anoestrus, and control groups were found to be similar. None of the dogs had any adverse gastrointestinal effects associated with cabergoline administration. The results of the present study suggest that the administration of 0.6 µg/kg/d of cabergoline is a safe and effective treatment for secondary anoestrus in bitches.

2

New strategies to improve the efficiency of the ovsynch protocol in primiparous dairy cows

100%

Cirit U. , Ak K. , Ileri I. K.

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tom 51

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nr 1

EN

The aim of this study was to create new strategies to increase the pregnancy rate, in "ovsynch protocol" treatment. Two programs for synchronisation of ovulation and for synchronisation of ovulation and oestrus, similar to the ovsynch, were developed for the use in lactating primiparous dairy cows. Lactating Holstein-Friesian cows were randomly divided into five treatment groups: the GPG group (ovsynch) was treated with GnRH on day 0, PGF (PGF2α) on day 7, and received the second dose of GnRH 48 h later; the groups -7PGPG and - 2PGPG received the same treatment as the GPG group, but were given an additional injection of PGF 7 and 2 d before the start of the GPG treatment; respectively, the PG9PG group received the same treatment as the -2PGPG group, with the modification that the first GnRH injection was given simultaneously with the first PGF on the 2nd d; the GPEG group received the same treatment as the GPG group, but was injected an additional oestradiol propionate (EP) 24 h after the PGF. Plasma progesterone concentrations were determined at the days of the first hormone injection and the last PGF injection. Ovulation rates after the first GnRH and last PGF injections were calculated and presumptive sizes of the follicles on the last PGF injection day were determined in all the cows by rectal palpation. Cows detected to be at oestrus in 72 h after the last PGF injection was inseminated between the 8th and 12th h of their oestrus. Cows not detected to be in oestrus by 72 h after the last PGF received timed artificial insemination (TAI). While the ovulations mostly occurred in the GPG, GPEG, and -7PGPG groups at a period between the 48th and 96th h after the last PGF injection, the ovulations had shifted and occurred between 72 and 120 h, with 66.7% of all ovulations recorded between 72 and 96 h in the -2PGPG group. In the PG9PG group, ovulations took place dispersedly between the 0th and 120th h after the last PGF injection. The pre-synchronisation treatment (-7PGPG) by a PGF injection 7 d prior to the ovsynch protocol did not enhance the ovulation or pregnancy rates. The pre-synchronisation treatment by PGF injected 2 d before the ovsynch protocol, increased the number of cows that ovulated after the first GnRH injection (88.9% vs. 38.9%; P<0.05), produced smaller follicles at the time of the second PGF injection (1.1±0.13 vs. 1.6±0.16 cm; P<0.05) and increased pregnancy rates numerically (72.2% vs. 50.0%; P>0.05). Adding EP to GPG (GPEG), enhanced the expression of oestrus (P<0.05) and increased pregnancy rates slightly (60.0% vs. 50.0%; P>0.05). In conclusion, the -2PGPG and GPEG treatments are potentially new methods for routine synchronisation of ovulation and oestrus and/or ovulation, respectively, in primiparous Holstein-Friesian cows.

3

Short oestrus synchronization with PGF2alfa, estradiol and GnRH or hCG in lactating dairy cows

75%

Cirit U. , Tas M. , Bacinoglu S. , Ozdas O. , Ak K. , Ileri I.

Medycyna Weterynaryjna

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2008

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tom 64

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nr 02

EN

The objectives of this study were to develop short oestrus synchronization methods allowing timed artificial insemination (TAI) in lactating dairy cows and to compare the synchronizing effects of the use of human chorionic gonadotropin (hCG), instead of a gonadotropin releasing hormone (GnRH), on ovulation and pregnancy rates. An additional goal was to determine the effects of the presence or absence of an active corpus luteum (CL) on the treatment efficacy at the beginning of treatment. Sixty-three cows at random stages of the oestrus cycle on the 50th-95th postpartum day were randomly distributed into two groups. Cows of GnRH group (n = 33) received prostaglandin F-two alpha (PGF, 0.150 mg), estradiol propionate (EP, 2 mg) and GnRH (50 µg) in 24 hour intervals (PGF at hour 0; EP at hour 24 and GnRH at hour 48). Cows in the hCG group (n = 30) were treated in a similar manner to the GnRH group, but, alternately, these cows received hCG (500 IU, i.m.) instead of GnRH. All cows in the treatment group were inseminated timely 16-20 hours after GnRH or hCG injections regardless of oestrus signs. During the study, animals exhibiting natural oestrus were inseminated 10-12 hours later and served as controls (n = 44). Cows in the hCG group have significantly higher synchronized (P = 0.018) and total (P < 0.05) ovulation rates and shorter intervals between the last hormone injection and ovulation (P = 0.012) compared to cows in the GnRH group. In both GnRH and hCG groups, cows with an active CL at the beginning of the treatment have acceptable pregnancy rates (40.0% and 47.6% respectively, P > 0.05). The PGF/EP/GnRH and PGF/EP/hCG treatments resulted in comparable pregnancy rates after TAI of lactating dairy cows at random stages of the oestrus cycle relating to those inseminated at natural oestrus (33.3%, 40.0% and 40.9% respectively, P > 0.05).

4

Effect of different transport temperatures of cattle and sheep ovaries on in vitro maturation of oocytes

63%

Ozdas O. B. , Tas M. , Cirit U. , Evecen M. , Bacinoglu S. , Demir K. , Ak K. , Ileri I. K.

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tom 62

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nr 02

EN

The aim of study is to determine the effects of different transport temperatures (4°C, 32°C) of sheep and cattle ovaries on the in vitro maturation of oocytes. Two experimental groups were formed. Sheep and cattle ovaries were put into saline solution at 32°C. The ovaries were transported to the laboratory, at the same temperature (Group I) or at 4°C following 10 minutes of incubation at room temperature (Group II) (n=6). Oocytes were collected from ovaries using the dissection method. Oocytes matured in their own group in 700 ml TCM-199 (supplemented with pyruvate, LH, FCS) for 23 h at a gas atmosphere of 5% CO2, 5% O2, 90% N2 and at 38.8°C. After maturation, oocytes were fixed in acetic acid-ethyl alcohol (1:3) for 48 hours. The stages of development up to MII, of the oocytes stained with aceto-orsein were then examined. The Chi-Square test was used for statistical analysis. While in the 4°C group, sheep oocytes reached 30.6% (MI), 15.3% (MII) and cattle oocytes reached 17.3% (MI), 46.8% (MII), in the 32°C group these percentages were respectively 38.3%, 33.1% in sheep and 19.3%, 55.4% in cattle. While oocytes obtained from sheep ovaries transported at 32°C reached the MII stage at a higher rate compared to those at 4°C (P<0.001), no statistically significant difference was observed between maturation to the MII stage of oocytes obtained from cattle ovaries transported at 4°C and 32°C. As a result of this study, it was established that cattle ovaries could be transported both at +4 C, +32°C and that there was no difference in oocyte maturation.