The aim of this study was to compare the efficacy of estrus induction and fertility by using subcutaneous melatonin (MEL, T1) and short-term intravaginal medroxyprogesteronacetate plus pregnant mare serum gonadotropin treatments (sMAP+eCG, T2) in ewes on seasonaly anestrus. In this study, 105 mature clinically healthy Kivircik ewes in anestrus season and 4 rams were used. After synchronization applications, ewes exhibiting estrus signs were hand-mated with rams known to be fertile. Blood samples were collected at different times in order to determine progesterone (P4) concentrations. Results showed that estrus manipulation protocols induced significant improvement in pregnancy rate. All the fertility results obtained with the sMAP+eCG or MEL groups were similar, in seasonal anestrus. The efficacy duration of P4 in the MEL group was longer than that in short-term progestagen group. Plasma P4 concentrations was significantly different between the first (I) and last (III) measurement days (p<0.01). Increase in P4 concentration in T2 group was faster than that in T1 group, and blood P4 concentrations at higher levels could successfully be achieved by using any of the protocols in this study during the seasonal anestrus. In conclusion, according to the results obtained, the hormone application groups received very high estrus response. In addition, the twin ratio was found to be higher in T1 group compared to those determined in the other groups (T2 and Control group). Furthermore, plasma P4 concentrations and high birth rates were obtained in ewes in T1 and T2 groups. These procedures can be considered a good alternative to traditional procedures due to its flexibility under field conditions.
The article is a follow-up and an extension to previously published papers by HolzerŻelażewska & Holzer (1997) and Holzer-Żelażewska & Tymicki (2009). Fristly, we have added new cohorts to the cohort analysis based on the individual data from births registration for the years 2009–2015. Secondly, we have extended the scope of the study by taking into account the context of postponement and recuperation to analyses of cohort fertility of Polish women. The approach applied to the fertility postponement and recuperation on the cohort data refers to the method which was originally proposed by Frejka (2011) and Lesthaeghe (2001) and further developed by Sobotka et al. (Sobotka et al., 2011). This method allows for calculation of fertility postponement and recuperation measures with respect to a benchmark cohort chosen as the one that first experiences an onset of the increase in the mean age of motherhood at first birth. The results show the remarkable changes in the fertility patterns in Poland. The main driving forces behind the change in fertility patterns in Poland are related to the postponement of first births along with a relatively good recuperation. The magnitude of recuperation for Polish cohorts dropped significantly for second births and was almost non-existent for third and higher births. Therefore, the pattern of fertility in Poland observed till 2015 could be characterized by postponement and recuperation of first births along with a significant decrease in second births with perpetual postponement of third and higher births.
The objective of this study was to evaluate the effect of a second prostaglandin F2α (PGF2α) treatment during Ovsynch on luteal regression and fertility in dairy cows, compared with standard Ovsynch. The study was conducted on 111 Holstein Friesian multiparous cows on commercial dairy farm. The cows in the experimental group (n=48) received two treatments of PGF2α 24 hours apart during Ovsynch. The cows in the control group (n=63) were synchronized with standard Ovsynch. To assess the progesterone (P4) concentration blood samples were collected at the day of PGF2α treatment and at the 2nd GnRH treatment. Pregnancy was evaluated by ultrasound examination 37-40 days after timed artificial insemination (TAI) by ultrasound. Cows diagnosed pregnant were re-examined between days 70-80 after TAI. The percentage of cows with complete corpus luteum (CL) regression (P4<0.5 ng/ml at the time of the 2nd GnRH treatment) was 89.6 % after two PGF2α treatments and 88.9 % after one PGF2α treatment. There were no statistically significant differences (p>0.05) in the pregnancies per artificial insemination (P/AI) between the experimental and control group (P/AI). However, the pregnancy loss rate was lower in cows receiving two PGF2α treatments than in the control animals (0.0 % vs. 6.4 %; p<0.05). In conclusion, the second PGF2α treatment during Ovsynch protocol had no significant effect on CL regression and P/AI in dairy cows. The pregnancy losses until days 75-80 after TAI were significantly lower after two PGF2α treatments than after one PGF2α treatment.
The aim of the study was to investigate the effect of soybean lecithin as a substitute for egg yolk in milk and tris based extenders in ram semen cryopreservation. Twenty ejaculates were col- lected from four healthy, mature Wrzosówka rams (2-3 years of age). Each ejaculate was divided into four equal aliquots and diluted with four different extenders: 1) milk extender containing 5% egg yolk, 2) milk extender containing 1.5% soybean lecithin, 3) tris extender containing 20% egg yolk, 4) tris extender containing 1.5% soybean lecithin. Extended semen was loaded into 0.25 ml French straws, cooled and frozen in liquid nitrogen vapor. Total motility, curvilinear velocity, plasma membrane integrity and fertilizing ability of sperm were assessed after thawing. Total mo- tility was lower (p<0.05) in tris-soybean lecithin extender when compared to other extenders. Curvilinear velocity was higher (p<0.05) for spermatozoa cryopreserved in milk-soybean lecithin extender compared to other extenders tested. For the percentage of live sperm no significant difference was observed between extenders. The lambing rate were higher (not statistically signifi- cant) in ewes inseminated with semen doses frozen in milk-soybean lecithin extender (42.9%) than in the tris-egg yolk extender (16.7%). In conclusion, replacing the egg yolk with soybean lecithin was effective in milk but not in tris extender.
Previous studies identified large differences between countries in the extent to which childbearing intentions are realised. Failure to realise an intention to become a parent was found to be particularly common in the post-socialist countries. In this paper we examine whether similarly low rates of realisation of fertility intentions can be found in Poland. We use two waves of the Polish Generations and Gender Survey (GGS-PL), conducted in 2010/2011 and 2014/2015. We first describe fertility intentions of Polish women and men as declared at the survey’s first wave. Next, we examine whether the short-term childbearing intentions expressed at wave 1 were followed by an actual birth by the second round of the data collection. For the respondents who did not get a child between waves 1 and 2, we analyse the stability of their fertility plans. We find that approximately 35% of the respondents who at wave 1 intended to have a child in the next three years actually had one by wave 2. Both realisation and stability of fertility intentions varied markedly by gender and parity.
Being more sensitive to economic fluctuations, childbearing postponement increased during the second demographic transition and was accompanied by a moderate decline in the number of children per woman and the progressive rise of mother’s age at first birth. Under the hypothesis that recessions have a marked influence on population dynamics, the present study investigates spatial changes in mother’s age at birth in Greece with the aim to assess the differential impact of economic crisis along the urban-rural gradient. The percent composition of births by mother's age class – considered a gross indicator of fertility under a changing socioeconomic context – was studied at 4 spatial scales (the whole country, administrative regions, prefectures and metropolitan areas or specific economic districts) over an economic cycle from expansion to recession (1980–2016). While stimulating childbearing postponement observed since the early 1980s, empirical results of this study indicate that the 2007 recession was quite neutral on fertility trends in Greece, consolidating the traditional divide between urban and rural areas.
Previous studies have compared the effectiveness of dinoprost and cloprostenol in cows yielding conflicting results. The aim of our study was to evaluate the efficacy of single treatment with cloprostenol or dinoprost on estrus and reproductive performance in cows with unobserved estrus after service. The study was conducted over four years in two dairy herds of Polish Holstein Frisian cows under a herd health program with an average milk yield per cow over 9000 L. Cows (n=523) diagnosed ultrasonographically as non-pregnant and with a corpus luteum were randomly assigned to be treated with either cloprostenol (n=261) or dinoprost (n=262). The estrus detection rates after administration of cloprostenol or dinoprost were 59.4%, and 57.6%, respectively. The difference between both groups was not statistically significant (p>0.05). Distribution of observed estrus did not differ between cloprostenol and dinoprost. There were no differences (p>0.05) between cloprostenol and dinoprost in conception rate (65.2% vs. 66.2%, respectively) and pregnancy rate (57.5% vs. 54.9%, respectively). Mean days open were similar in cows of both treatments (177.5 ± 74.6 days vs. 175.8 ± 62.6 days, respectively; p>0.05). In conclusion, data from this study showed no significant differences in estrus detection rates and fertility between cows with unobserved estrus after service treated with cloprostenol or dinoprost. Both products are equally useful for the treatment of non-pregnant dairy cows with anestrus after service within a reproductive herd health program.