Quality of preimplantation embryos recovered in vivo from dairy cows in relation to their body condition.

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.

Relationships between milk fatty acids composition in early lactation and subsequent reproductive performance in Czech Fleckvieh cows.

Increase of milk yield after calving causes changes in milk fatty acids (FA) composition and simultaneously corresponds with reproduction performance decrease. The objective of this study was to evaluate the relationships between milk FA group composition (SFA, saturated fatty acids; MUFA, monounsaturated fatty acids; and PUFA, polyunsaturated fatty acids) during the first 5 lactation weeks and subsequent reproductive results (INT, calving to first service interval; NUM, number of services per conception, and DO, days open) in Czech Fleckvieh cows. A total of 1231 individual milk samples from 382 cows were collected and subsequently analyzed. Simultaneously, body condition score (BCS) was weekly evaluated as well. Software SAS 9.1 was used for statistical analysis. Daily milk yields increased whereas BCS, milk fat and protein contents decreased during period observed. The reduction of basic milk components (% of fat, % of protein) was associated with increased SFA and decreased MUFA, respectively PUFA contents. Significant (P<0.01-0.05 days) increase in NUM (+0.15 to +0.29 AI dose) and DO (+8.16 to 15.44 days) were detected in cows with the lowest SFA content. On the contrary, cows with the highest content of MUFA presented significantly (P<0.01-0.05) higher values of NUM (+0.13 to +0.30) and DO (+7.26 to +15.35 days). Milk FA groups composition in early lactation potentially used as NEB indicators, especially SFA and MUFA proportion, affected subsequent reproductive results of Czech Fleckvieh cows. Therefore, its post-partum values could serve as predictors of potential fertility of dairy cows.

Effect of prepubertal and postpubertal growth and age at first calving on production and reproduction traits during the first 3 lactations in Holstein dairy cattle.

The objective of this study was to evaluate the effect of body condition score (BCS), body weight (BW), average daily weight gain (ADG), and age at first calving (AFC) of Holstein heifers on production and reproduction parameters in the 3 subsequent lactations. The data set consisted of 780 Holstein heifers calved at 2 dairy farms in the Czech Republic from 2007 to 2011. Their BW and BCS were measured at monthly intervals during the rearing period (5 to 18 mo of age), and the milk production and reproduction data of the first 3 lactations were collected over an 8-yr period (2005 to 2012). The highest milk yield in the first lactation was found in the group with medium ADG (5 to 14 mo of age; 0.949 to 0.850 kg of ADG). The highest average milk yield over lifetime performance was detected in heifers with the highest total ADG (≥ 0.950 kg/d). The difference in milk yield between the evaluated groups of highest ADG (in total and postpubertal growth ≥ 0.950 kg/d and in prepubertal growth ≥ 0.970 kg/d) and the lowest ADG (≤ 0.849 kg/d) was approximately 1,000 kg/305 d per cow. The highest milk yield in the first lactation was found in the group with the highest AFC ≥ 751 d, for which fat and protein content in the milk was not reduced. Postpubertal growth (11 to 14 mo of age) had the greatest effect on AFC. The group with lowest AFC ≤ 699 d showed a negative effect on milk yield but only in the first 100 d of the first parity. The highest ADG was detrimental to reproduction parameters in the first lactation. The highest BW at 14 mo (≥ 420 kg) led to lower AFC. Groups according to BCS at 14 mo showed no differences in AFC or milk yield in the first lactation or lifetime average production per lactation. We concluded that low AFC ≤ 699 d did not show a negative effect on subsequent production and reproduction parameters. Therefore, a shorter rearing period is recommended for dairy herds with suitable management.

Relationships among the cervical mucus urea and acetone, accuracy of insemination timing, and sperm survival in Holstein cows.

The objectives of this study were to evaluate the relationships among urea and acetone content in cows' cervical mucus (CM), its crystallization type (CT) and sperm survival (SS) after timed AI. Samples of CM were collected from 192 Holstein cows treated by Ovsynch(®) protocol. Analysis of the urea and acetone content for identification of the metabolic status, the arborization test for evaluation of insemination timing and the short-term heat test of SS for assessment of its suitability as a biological matrix were performed. The data set was analyzed by the GLM procedure using SAS(®). The results documented the existence of substantial differences in individual response to the Ovsynch(®) protocol causing insemination of 55.2% cows at an inappropriate time. The urea content was found as a possible indicator of a cow's metabolism and/or of insemination timing, concentrations of less than 500 mg/L corresponded (P<0.05-0.01) to the cows' expected response to timed AI. The greater the urea content, the greater the proportion of cows inseminated at an inappropriate time. Effects (P<0.05-0.01) of CT, urea and acetone content on SS were determined. The greatest values of SS were detected in cows with an expected response to precisely timed oestrus documented by the corresponding CT. Greater values of urea (>260 mg/L) and acetone (>5mg/L) negatively affected SS as well (P<0.05-0.01). The results confirmed that the accuracy of insemination timing can be affected by the metabolism intensity, just as CM quality directly influences sperm survival.

[Metrological and operating characteristics of thermoluminescent and photographic film dosimeters for the centralized individual dosimetric monitoring of medical personnel]. / Metrologicheskie i ékspluatatsionnye kharakteristiki termoliuminestsentnykh i fotoplenochnykh dozimetrov dlia tsentralizovannogo individual'nogo dozimetricheskogo kontrolia meditsinskogo personala.

Characteristics of a TLD thermoluminescent kit with LiF detectors of TLD and DTG-4 types (diameters 3.5 and 5 mm) and TLD-400 were compared with those of a kit of IFKU-1 individual photographic film badges. Individual thermoluminescent dosimeters record a total dose of occupational and background irradiation, and film badges--a dose of occupational irradiation only. It should be taken into account in radiation-hygienic interpretation of individual dosimetric control readings.