Jan Miciński, Grzegorz Zwierzchowski, Wojciech Barański, Magdalena Gołębiowska and Miroslav Maršálek
Locomotor activity and daily milk yield of dairy cows during the perioestrous period in successive lactations
The experiment was conducted in a herd of high-producing Holstein-Friesian cows, using the AfiFarm Herd Management Software, to analyze their locomotor activity during 236 oestruses in relation to the daily milk yield determined during the periooestrous period in four successive production and reproductive cycles. Day "0" was the day of the observed oestrus. Locomotor activity and milk production levels were monitored five days before and five days after oestrus. A correlation was noted between high milk yield and the reproductive performance of cows. An increase in milk yield was accompanied by extended inter-pregnancy and inter-calving intervals and a drop in the insemination index which also tended to decrease in multiparous cows. Primiparous and the highest-yielding cows were characterized by the highest levels of locomotor activity. The physical activity of cows increased by around 67% during oestrus. However, daily milk yield declined at oestrus, compared with the average milk production levels determined five days before and five days after oestrus in each lactation. The installation of pedometers supported the detection of oestrus, including silent oestrus, in dairy cows, and the AfiFarm system was found to be an effective tool for dairy farming and herd management.
Małgorzata Rudowska, Wojciech Barański, Piotr Socha, Sławomir Zduńczyk and Tomasz Janowski
The aim of the study was to determine the therapeutic efficacy o f simultaneous administration of GnRH and PGF2α in dairy cows with ovarian cysts. Ovarian cyst-affected dairy cows were divided into two experimental groups: 54 cows treated with GnRH and PGF2α, and 42 cows treated with GnRH alone, whereas 22 untreated cows served as the control group. Clinical response and reproductive performance were evaluated. The cumulative disappearance was better in treated cows than in the control group; however, there were no differences between the treatment groups (92.6; 95.2% vs. 72.3%). The mean interval from calving to conception was not significantly shorter (being so by 29 d) in the GnRH/PGF2α group than in the cows treated with GnRH alone (P > 0.05). The intervals from treatment to conception were also similar in these groups. The pregnancy rate in both treated groups was similar (62%) and higher than in the control cows (53%). In the cows with luteal cysts, the total pregnancy rate was higher in all experimental groups; however, only in GnRH-treated cows was this difference statistically significant (77.8% vs. 50.0%, P < 0.05). With time after parturition, the pregnancy rate decreased in all groups. In general, the cows treated with GnRH and PGF2α simultaneously displayed a good clinical response and slight improvement in reproductive performance compared to the single-therapy GnRH group; however, this was not fully convincing.
Arkadiusz Nowicki, Wojciech Barański, Agnieszka Baryczka and Tomasz Janowski
Current knowledge about the function of the reproductive tract and appropriate use of hormonal drugs affords control of the oestrus cycle of cows. One of the hormonal protocols is OvSynch, which enables artificial insemination (AI) to be performed at the precise optimum time without control of the ovaries and uterus. Use of such protocols in reproductive management allows oestrus cycles to be synchronised and cows to be effectively inseminated without oestrous detection, which is time-consuming and difficult in farms with numerous cows. Therefore, OvSynch has become the first management tool for AI and is an alternative method to heat detection. Over the 20 years since its first implementation, OvSynch has been modified many times to improve its reproduction outcomes and widen its use. Besides its original use for heat synchronisation, it is also used in many ovarian disorders as a therapeutic method. This review article describes the possibilities which OvSynch provides, its current modifications, various applications, and the advantages and disadvantages of its use in practice.