Fixed-time artificial insemination in beef cattle

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: The study was designed to test the effect of fixed-time artificial insemination (fixed-AI) after the slightly modified Ovsynch protocol on the pregnancy rate in beef cattle in Finnish field conditions. The modification was aimed to optimize the number of offsprings per AI dose. Methods: Ninety Charolais cows and heifers were entered into the program an average of 1.8 times. Thus, 164 animal cases were included. Animals were administered 10-12 μg of buserelin. Seven days later animals without a corpus luteum (CL) were rejected (20.7%) while the remaining 130 cases with a CL were administered prostaglandin F2α, followed 48 h later with a second injection of buserelin (8-10 μg). Fixed-AI was performed 16-20 hours after the last injection. Results: The pregnancy rate was 51.5 % (67/130). The pregnancy rate after a short interval (50-70 d) from calving to entering the program was significantly higher than that after a long interval (>70 d). Conclusion: This protocol seems to give acceptable pregnancy results in beef herds and its effect on saving labour is notable

Cisto ovariano em vacas de leite: incidência, resposta à aplicação de GnRH e desempenho reprodutivo Ovarian cysts in lactating dairy cows: incidence, response to GnRH, and reproductive performance

A incidência de cistos ovarianos, a resposta ao tratamento com GnRH e os efeitos da ocorrência de cisto no desempenho reprodutivo e na taxa de descarte foram determinados em vacas lactantes da raça Holandesa. Vacas lactantes (n=333) foram avaliadas semanalmente por ultrassonografia a partir da quarta semana pós-parto, visando à detecção de corpos lúteos (CL) e de folículos ovarianos maiores que 10mm. Na sétima semana pós-parto, as vacas foram classificadas: em ciclando (n=248; presença de CL em um dos exames ultrassonográficos); em anestro (n=54; ausência de CL e de folículos >25mm) e com cisto (n=31; ausência de CL e presença de estruturas >25mm), quando foram distribuídas em: grupo-controle (n=16; sem tratamento) e grupo-tratamento (n=15; vacas que receberam uma aplicação de GnRH). A taxa de cura foi de 60,0% no grupo das vacas tratadas e de 87,5% no grupo-controle. As vacas com cistos apresentaram maior intervalo parto-primeira inseminação artificial (P<0,05; 91,4±8,3 vs. 77,8±2,5), maior número de serviços por concepção (P<0,05; 4,4±1,2 vs. 3,6±1,5), maior intervalo parto-concepção (P<0,05; 214,8±25,9 vs. 174,9±7,7) e maior taxa de descarte (P<0,05; 41,2 vs. 21,8%) do que as vacas ciclando. Vacas diagnosticadas com cisto na sétima semana pós-parto apresentaram recuperação espontânea, embora o intervalo parto-concepção e a taxa de descarte tenham sido maiores para essas vacas.<br>The incidence of ovarian cysts, response to GnRH treatment, and effects on reproductive performance and culling rate of Holstein cows were determined. Ovaries of lactating cows (n=333), were weekly monitored by ultrasound, beginning at fourth week postpartum, to determine the presence of corpus luteum (CL) and follicles greater than 10mm. In the seventh week the cows were classified as cycling (n=248; presence of corpus luteum (CL) in one of the ultrasound evaluations); anovulatory (n=54; absence of CL and follicles less than 25mm), and cystic (n=31; absence of CL and presence of structures greater than 25mm). The cysts cows were distributed in two groups in the seventh week: control group (n=16; without treatment) and treatment group (n=15; cows received one GnRH injection). The recovery rate was 60.0% in treated cows and 87.5% in control cows. The cystic cows had longer average interval from parturition to first AI (P<0.05; 91.4±8.3 vs. 77.8±2.5), higher number of services per conception (P<0.05; 4.4±1.2 vs. 3.6±1.5), longer interval parturition to conception (P<0.05; 214.8± 25.9 vs. 174.9±7.7), and higher percentage of culled cows (P<0.05; 41.2% vs. 21.8%), than cycling cows. Cystic cows without treatment had the same recovery rate as cows treated with GnRH. Cystic cows had longer intervals from parturition to conception, and higher culling rate

Comparison of aspiration and hormonal therapy for the treatment of ovarian cysts in cows

Despite the variety of hormonal treating regimes used, a proportion of cows with cystic ovarian disease (COD) fail to be cured. The hypothesis of this study was that cyst aspiration would improve the curing rate and/or accelerate the resumption of ovarian activity in affected cows. In four groups of cows the following treatments were administered: Group A (n = 18) only cyst aspiration, Group AGP (n = 19) cyst aspiration and a combination of GnRH and PGF 2α , Group GP (n = 25) only GnRH and PGF 2α , and Group C (n = 15) untreated control. Cysts were aspirated without ultrasonographic guidance, using a new device. All cows from Group AGP responded to treatment, while 5.5% from Group A and 16% from Group GP remained anoestrous (P < 0.05). These refractory cases were re-treated with the AGP protocol and exhibited oestrus within 12.4 ± 1.1 days. The interval from PGF 2α injection to oestrus was significantly reduced in cows treated with cyst aspiration. Until day 80 post partum (pp), 11 of the 15 untreated cows (73.3%) retained the initial cyst and remained anoestrous. It is concluded that persisting cases of COD can be treated by combining aspiration with a hormonal regime. The technique presented here has no complication for the cow, is efficient, easy, safe for the operator, and requires low-cost equipment. © 2009 Akadémiai Kiadó

Differenz als Rechenaufgabe: über die Relevanz der Kategorien Race, Class und Gender

Dieser Aufsatz versucht, „die Relevanz der Kategorien (Race, Class und Gender) für die deutsche erziehungswissenschaftliche Debatte aufzuzeigen“. Während im ersten Teil „auf die bislang nur in Ansätzen rezipierte englischsprachige Debatte“ eingegangen und danach der „deutsche Sonderweg“ skizziert wird, wird im zweiten Teil „die Nützlichkeit einer Kategorienverknüpfung an einem Beispiel“ verdeutlicht. (DIPF/ ssch