This study examined the impact of cow body condition on the quality of bovine preimplantation embryos. The embryos (n = 107) were flushed from dairy cows and classified according to a five-point scale body condition score (BCS2 n = 17; BCS3 n = 31; BCS4 n = 11) on the 7th day after insemination and then analyzed for development, dead cell index (DCI), cell number and actin cytoskeleton quality. The highest embryo recovery rate (P < 0.05) was recorded in the BCS3 group and the lowest in the BCS4 group. More transferable (morula, blastocyst) embryos were obtained from the BCS4 cows (79%), compared with the BCS2 (64%) or BCS3 (63%) animals. However, cell numbers were higher in the BCS2 and BCS3 groups (P < 0.05) compared with the BCS4 embryos. Conversely, the DCI was lowest in the BCS2 (3.88%; P < 0.05) and highest in the BCS4 (6.56%) embryos. The proportion of embryos with the best actin quality (grade I) was higher in the BCS2 and BCS3 cows compared with the BCS4 group. Almost 25% of all embryos showed fragmented morphology and a higher DCI (5.65%) than normal morulas (1.76%). More fragmented embryos were revealed in the BCS2 (28.6%) and BCS4 (31.25%) groups, and less (19.15%) in the BCS3 group. The cell numbers in such embryos were lower in the BCS4 (22.57) than in the BCS2 (46.25) or BCS3 (42.4) groups. In conclusion, the body condition of dairy cows affects the quality of preimplantation embryos. A BCS over 3.0 resulted in a higher incidence of poor (fragmented) embryos.

DOLEŽALOVÁ MARTINA, STÁDNÍK LUDĚK, NEJDLOVÁ MICHAELA, NĚMEČKOVÁ DANA, BERAN JAN, DUCHÁČEK JAROMÍR: The relationship between energy balance a er calving and reproductive functions in Holstein dairy cows treated by the OVSYNCH system. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 2013, LXI, No. 3, pp. 601-610 The objective of this research was to evaluate the relationship between the course and the depth of negative energy balance (NEB) rated by changes of the body condition a er calving and subsequent recovery of reproductive abilities of Holstein dairy cows treated by OVSYNCH. The body condition was evaluated by the BCS system one week before calving and subsequently at 30-day intervals for the period of 6 months of lactation. Recovery of ovarian functions was evaluated by the results of ultrasound examination of all the dairy cows' ovaries in two controls a er calving. The fi rst one was performed on an average of 67 days a er calving, and the second at a 60-day interval. The occurrence of individual fi ndings -the presence of corpus luteum, ovarian cysts or ovaries without fi ndings was evaluated as an eff ect of NEB on the recovery of the ovarian cycle of dairy cows and their subsequent possibility of conception. The suitable cows were treated by the OVSYNCH system a er the 1 st and 2 nd ultrasound examination. Therefore, the insemination interval was calculated and in the case of dairy cows, pregnancy detection, also the number of services per conception and the length of open days. Twice performed hormonal treatment of 73.6% of the animals delayed the period by 50.2 days. In all, 202 dairy cows calved in the period from 29 th July 2011 to 7 th February 2012 were included in this observation. Signifi cant eff ects of the body condition change on the ovarian activity as documented by sonographic examination and reproductive indicators appeared primarily in the second month of lactation. The best reproductive indicators were found in cows with the lowest body condition change, thus with a small decline or even increase of body condition score (−0.0 to +0.75 points, P < 0.05). On the contrary, the worst level of indicators of recovery of the reproduction functions were documented in the dairy cows with the most marked decline of BCS (P < 0.05). dairy cattle, energy balance, body condition, ovarian functions, reproductionThe most common problem in dairy cows is health and fertility (Garnsworthy, 1988). Milk yield in dairy cows increased through intensive breeding (Říha et al., 2003) as a result of one-sided selection; however, fertility and reproductive parameters simultaneously declined in most herds (Motyčka et al., 2005). The rapid increase of energy requirements a er calving are related to the start of lactation and result in a negative energy balance (Říha et al., 2000). The result of the NEB eff ect at the beginning of lactation is reduction of conception ability, which causes prolongation of the calving interval (Collard et al., 2000) and is related to deterioration o...

The aim of this study was to evaluate the effect of inbreeding on the yield and quality of bovine embryos. The data were obtained from 125 Holstein cows superovulated on 3 farms in the Czech Republic. In total, 125 flushings of embryos were analyzed, from which 761 embryos were obtained. Of all donors, 36 cows were inbred (199 embryos) and 89 cows were noninbred (562 embryos). The inbred cows were divided into 2 groups according to their inbreeding coefficient (F X ) level. The low F X group (F X 1.26%-1.56%) had 23 cows and 147 embryos, and the high F X group (F X 3.1%-25%) was represented by 13 cows and 52 embryos. The average value of the F X coefficient in inbred cows was 6.552%. The data were subsequently analyzed using PROC GLM of SAS as descriptive statistics and t-tests (SAS/STAT ® 9. 1., 2009). All evaluated traits in inbred cows had worse results than noninbred cows. Although there were poorer results for inbred versus noninbred cows, the differences were not great at lower F X values and were not statistically significant. Important and significant differences (P ≤ 0.05) were found in the proportion of transferable embryos and unfertilized oocytes at higher rates of F X .

DUCHÁČEK, J., VACEK, M., STÁDNÍK, L., BERAN, J., VODKOVÁ, Z., ROHLÍKOVÁ, V. NEJDLOVÁ, M.: Relationship between energy status and fertility in Czech Fleckvieh cows. Acta univ. agric. et silvic. Mendel. Brun., 2012, LX, No. 6, pp. 67-74 The aim of this study was to confi rm that a negative energy balance expressed by declining body condition score (BCS) can lead to the deterioration of fertility results of Czech Fleckvieh cows. The BCS of cows was evaluated before calving and during the fi rst fi ve weeks of lactation. The evaluation was based on 338 Czech Fleckvieh cows calved between the October 13th, 2009 and April 27th, 2010 at one dairy farm. Analysis of relationships between the energy balance results and fertility score expressed by the reproduction results (pregnancy rate a er the fi rst and all inseminations, the insemination interval, service period, insemination index, calving period) of the observed group were performed. The higher body condition score of the Czech Fleckvieh cows before calving turned out advantageously regarding the energy source during the postpartal period. No negative eff ect of higher BCS in cows before calving was confi rmed. The best reproduction parameters were attained in the group of cows with no change or marked increase of body condition a er calving recorded. However, statistically signifi cant diff erences between the groups were detected only in the third week of lactation. Signifi cant diff erences in the level of body condition were detected in relation to the length and type of oestrus onset.reproduction, negative energy balance, body condition score, Czech Fleckvieh Negative energy balance (NEB) is the main cause of fertility decline in early lactating dairy cows. It results in an increasing in the calving interval length and a decrease in dairy herd profi tability (Wathes et al., 2007;Rossi et al., 2008). Energy defi ciency causes extension of the interval from parturition to recovery of ovarian cyclicity and activity of corpus luteum (Banos et al., 2004;Patton et al., 2007). A low pregnancy rate was observed in dairy cows with severe BCS loss (> 10 % of live weight) during early lactation, or in cows losing weight from calving to fertilization by more than 1% weekly (McClure, 1994). Anestrus occurrence a er parturition tends to be more expressive in high-yielding cows, which calve with a low BCS status and a loss of 0.75 -1 BCS points (Moreira et al., 2000, Vacek andStádník, 2007). BCS status decline in the fi rst month postpartum is associated with impaired conceiving (Pryce et al., 2001). However, other authors did not fi nd any signifi cant relationship between BCS losses and fertility performance (Waltner et al., 1993;Ruegg and Milton, 1995). Also, dependencies observed in dairy breeds were not conclusively confi rmed in dual purpose breeds (Jílek et al., 2008). Most of the investigations assessing the relationships between BCS status and BCS changes, recovery of ovarian cyclicity and fertility performances of dairy cows in detail, were related only...