Novotný L., Frelich J., Beran J., Zavadilová L. (2017): Genetic relationship between type traits, number of lactations initiated, and lifetime milk performance in Czech Fleckvieh cattle. Czech J. Anim. Sci., 62, 501-510.Genetic relationship was analyzed between type traits and longevity measures in dual-purpose cattle. Data from 91 486 Czech Fleckvieh cows first calved between 2003 and 2009 were used. Longevity was defined as the actual number of lactations initiated per cow and also as functional longevity, which incorporated an adjustment to account for variation in voluntary culling based upon milk production. Lifetime performance was defined as cumulative milk production through the 6 th parity. All cows were scored for conformation traits during their first lactation. Genetic correlations between these traits and longevity measures were estimated by bivariate analysis using the DMU variance component program package. Type trait heritabilities ranged from 0.30 to 0.59, while heritabilities for longevity and functional longevity were 0.06 and 0.05, respectively. Heritability of lifetime performance was 0.08. Genetic correlations between type traits and longevity measures ranged from low to intermediate values. Genetic correlations of the measured body size traits to the real and functional longevity ranged from -0.06 to -0.29, for udder traits from -0.02 to 0.33, and for foot and leg traits from -0.03 to 0.17. Genetic correlations between the measured body size traits and lifetime performance ranged from -0.03 to -0.30, for udder traits from 0.05 to 0.47, for foot and leg traits from -0.07 to 0.15. Genetic correlations of composite trait scores for frame, muscularity, feet and legs, and udder with longevity traits ranged from -0.20 to 0.41 and for lifetime performance -0.14 to 0.51. The highest genetic correlations between a type trait and functional longevity were for composite udder score (0.25), feet and legs (0.26), and udder depth (0.33), suggesting that these traits could serve as indicators of functional longevity. We conclude that selection based upon easily and inexpensively measured type traits could improve functional longevity of cows as well as lifetime milk production.

The aim of this study is to call attention to the possibility of using ultrasonography as a useful tool for the evaluation of morphological characteristics of the udder and teats in dairy cows in relation to milking characteristics and udder health. A total of 26 dairy cows of the Holstein breed in the first (n = 13) and second lactation (n = 13) were investigated with a linear array ultrasound probe. Recovery of the teat internal parameters after milking was determined by ultrasonographic scanning. Teat canal length, teat canal diameter and teat wall thickness of 103 teats were evaluated from 622 measurements before and directly after milking and every 15 minutes until 1 hour after milking (6 measurements). The most significant differences in internal proportions were determined within those values measured before and immediately after milking. The dynamics of changes in the length of the teat canal demonstrated the extension by 27%. A sudden restoration of the initial length by 11% was detected one hour after milking. Differences in teat canal diameter were significant at P<0.01 between the 1st and 4th measurement. The initial extension was 17% immediately after milking and the restoration about 9% one hour after milking. The wall thickness was strengthened during the 2nd measurement immediately after milking in comparison with the 1st measurement before milking (P<0.01). Significant differences in the wall thickness were detected between the 1st and 2nd measurement (+26%; P<0.01) and between the 2nd and 3rd measurement. The ultrasonographic scanning of the teat parameters was a useful tool to study teat changes caused by milking.

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Body tissue development and proportion affect predisposition to optimum functioning of production attributes, health, and fertility of sheep. Therefore, the objective of this study was to determine relationships among indicators of mature ewes' nutritional status documented by the body condition score and live weight using ultrasonic evaluation of backfat thickness and depth of musculus longissimus lumborum et thoracis. The monitoring was carried out in Suffolk sheep (n = 942) for a period of 2 years. A significant increase (P < 0.05 to P < 0.01) of all the evaluated indicators was detected corresponding to an increase of the body condition score from 1 to 5 points. The differences in ewes' live weights depending on particular condition scores reached up to 31.04 kg with the lowest value (58.71 kg) in 1 point and the highest (89.75 kg) in 5 points. The variability of backfat thickness and muscle depth depending on individual condition scores was up to 352.08% (11.02 mm) in backfat thickness and up to 50.10% (12.83 mm) in muscle depth (P < 0.05 to 0.01) compared to the lowest condition score of 1 point. Strong positive linear relationships were also detected between the live weight and back tissues development in ewes (P < 0.001). This study innovatively determinates mutual relationships among growth indicators and body tissue development performed on intensive meat-purpose sheep in vivo. Results of the present study could serve in flock management as a tool for evaluation of the current nutritional status as well as a basic ground for further research focused on development of sheep fattiness and carcass traits evaluation. Suffolk, backfat thickness, musculus longissimus lumborum et thoracis depthThe total milk as well as meat efficiency of sheep is dependent on an adequate forage intake, its energy and microelement supply as well as microorganism activity and rumen function (Żarczyńska et al. 2012). The animal's growth ensured by nutrients of the feed ration is manifested by body development, including morphological and anatomical formation of the body, and changes in body tissue proportions or microstructure (Młynek et al. 2012). These traits determinate final commercial profitability; therefore, the animals are selected for these mentioned indicators. The basic indicators of growth and body development are the body condition score (BCS), live weight (LW), backfat thickness (BT), and the depth of musculus longissimus lumborum et thoracis (MLLT). These indicators influence (P < 0.05 to 0.01) reproduction and production performance of sheep (Kenyon et al. 2004;Ptáček et al. 2014). Relationship between LW and BCS, or rather, relationships among BCS, LW and body tissues indicators have been previously published by Sanson et al. (1993) or Caldeira andPortugal (2007). They performed their observation on local or rustic breeds of sheep or sheep carcasses. This study differs from others in detailed analysis of mutual relationships among selected indicators of growth and body development in live animals, concu...

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The objectives of this study were to determine the effects of sire, extender, and addition of Low Density Lipoprotein (LDL) to extenders used on the percentage rate of spermatozoa survival after cold shock. Two groups of extenders were compared: without LDL addition (control variants) and LDL enriched (experimental variants). Three extenders were used: AndroMed ® extenders, and 6-10% LDL addition into the Triladyl ® extender. In total, 12 samples of fresh semen were collected from 4 bulls during a period of 8 weeks. Bovine spermatozoa cold shock resistance (1 ± 1 °C, 10 min) was evaluated by the percentage rate of live sperm using eosin-nigrosine staining immediately and after heat incubation (37 ± 1 °C, 120 min). The results showed the effect of sire as important and individual differences between selected sires in their sperm resistance against cold shock were confirmed. AndroMed ® and Bioxcell ® were found to be providing better protection of bull semen to cold shock compared to Triladyl ® due to lower decline of live sperm proportion. Our results detected a positive effect of LDL addition on sperm resistance against cold shock, especially on lower decrease of live sperm percentage rate after 120 min of the heat test (P < 0.05). Further studies are needed to assess the optimal concentration of LDL in various kinds of extenders as well to state ideal time and temperature conditions for ensuring LDL reaction with sperm. , bull sperm, extender, LDL cholesterol, sperm survival, cold shock, eosin-nigrosine staining Reproduction

The objective of this work was to determine the effect of selected freezing curves on spermatozoa survivability after thawing, defined by its motility. The ejaculates of nine selected sires of the same age, breed, and frequency of collecting, bred under the same breeding conditions including handling, stabling, feeding system and feeding ratio composition, were repeatedly collected and evaluated. Sperm samples of each sire were diluted using only one extender and divided into four parts. Selected four freezing curves -the standard, commercially recommended threephase curve; a two-phase curve; a slow three-phase curve; and a fast three-phase curve, differing in the course of temperature vs time, were applied. The percentage rate of progressive motile spermatozoa above head was determined immediately after thawing, and after 30, 60, 90, and 120 min of the thermodynamic test (TDT). Moreover, average spermatozoa motility (AMOT) and spermatozoa motility decrease (MODE) throughout the entire TDT were evaluated. Insemination doses frozen using the simpler two-phase curve demonstrated the highest motility values (+2.97% to +10.37%; P < 0.05-0.01) immediately after thawing and during the entire TDT. Concurrently, the highest AMOT (+4.37% to +8.82%; P < 0.01) was determined. The highest spermatozoa motility values were detected after thawing doses frozen by the two-phase freezing curve in eight out of nine sires. Simultaneously, a significant effect of sire individuality was clearly confirmed. Inter-sire differences of spermatozoa motility during TDT as well as AMOT and MODE were significant (P < 0.01). The findings describing both factors of interaction indicate the necessity of individual cryopreservation of the ejaculate to increase its fertilization capability after thawing.

Currently, considering cryopreservation of bull semen, there is no clear consensus over the comparability of cryoprotective efficacy of extenders with soybean lecithin and those based on egg yolk. The objective of this study was to prove the use of Low Density Lipoprotein (LDL) extracted from hen-egg yolk as an enhancing factor for soybean lecithin-based extenders. In total, 35 ejaculates of (seven bulls x five ejaculates per bull) were collected and cryopreserved at a commercial insemination centre. The effect of the LDL addition to the extenders AndroMed ® and Bioxcell ® was tested in a 6% (v/v) concentration on spermatozoa after thawing. Modified extender composition effects were assessed on sperm functional parameters motility, plasma membrane, mitochondrial membrane potential and acrosomal integrity after thawing by CASA, flow cytometry and fluorescent microscopy, respectively. Based on kinematic parameters determined from CASA, k-means cluster analysis was used to classify individual spermatozoon into specific subpopulations (fast, medium fast and slow). A subpopulation of fast spermatozoa was increased in the presence of LDL in both selected extenders (P < 0.05). Moreover, the positive effect of LDL on sperm motility was confirmed by decreasing the percentage of sperm in slow subpopulation (P < 0.05). The effect of LDL addition on the incidence of spermatozoa with intact plasma membrane was not demonstrated in any case of extender used (P > 0.05). The percentage of sperm with intact acrosome was improved when LDL was added to Bioxcell ® extender (P < 0.05). On the other hand, addition of LDL to AndroMed ® extender improved mitochondrial intactness after thawing (P < 0.05). In conclusion, our results showed that adding LDL to selected soybean lecithinbased extenders considerably ameliorated the functional parameters of spermatozoa after thawing and thus this lipoprotein could represent an improving agent for soybean lecithin-based extender for bull semen cryopreservation.