Wyniki wyszukiwania - Biblioteka Nauki

1

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

100%

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

|

tom 51

|

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

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.

|

tom 64

|

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).

3

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.

|

tom 62

|

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.