Negative energy balance (NEB) is a serious problem in most dairy cows. It occurs most frequently after calving, when cows are unable to consume sufficient DM to meet their energy requirements during early lactation. During NEB, the breakdown of fat stores releases non-esterified fatty acids (NEFAs) into the bloodstream. High blood concentrations of NEFAs cause health problems such as ketosis, fatty liver syndrome, and enhanced susceptibility to infections. These issues may substantially increase premature culling from the herd. Serum NEFA concentrations are often used as a direct marker of energy metabolism. However, because the direct measurement of serum NEFAs is difficult under commercial conditions, alternative indicators, such as milk components, have been increasingly investigated for their use in estimating energy balance. The objectives of this study were to (1) evaluate the relationships between serum NEFA concentrations and selected milk components in cows from two farms during the first 5 weeks of lactation, and to (2) develop a model valid for both herds for predicting serum NEFA concentrations using milk components. A total of 121 lactating Holstein cows from two different farms were included in the experiment. Blood samples were collected for NEFA analysis on days 7 (+/- 3), 14 (+/- 3), 21 (+/- 3), and 35 (+/- 3) after calving. Composite milk samples were collected during afternoon milking on the same days as blood sampling. Concentrations of fat, protein, lactose, and milk fatty acids (FAs) were determined using Fourier-transform IR spectroscopy analysis. The strongest correlations (r > 0.43) were recorded between serum NEFAs and milk long-chain FAs, monounsaturated FAs, C18:0, and C18:1 within each farm and for both farms combined. Two prediction models for serum log(NEFA) using milk components as predictors were developed by stepwise regression. The prediction model with the best fit (R-2 = 0.52) included days in milk, fat-to-protein ratio, and C18:1, C18:1(2) and C14:0 expressed as g/100 g of milk fat. An essential finding is that, despite different concentrations of NEFAs, and of most milk components observed in the evaluated herds, there were no significant interactions between farm and any of the FAs, so the same regression coefficients could be used for the prediction models in both farms. Validation of these findings in a greater number of herds would allow for the use of milk FAs to identify energy-imbalanced cows in herds under different farm conditions. (c) 2024 The Authors. Published by Elsevier B.V. on behalf of The Animal Consortium. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

The nutritional quality of beef relates to the fatty acid (FA) composition of bovine adipose tissue. Those molecular mechanisms that induce the differing amounts and composition of fat in cattle breeds according to age at maturity and purpose of production remain unclear. Therefore, this study investigated the composition of total FAs, adipocyte size, and expression of some key genes involved in several adipogenesis and lipogenesis pathways measured in distinct adipose tissue depots from bulls of the genetically diverse cattle breeds Aberdeen Angus (n = 9), Gascon (n = 10), Holstein (n = 9), and Fleckvieh (n = 10). The animals were finished under identical housing and feeding conditions until slaughter at a similar age of 17 months. After slaughter, cod adipose tissue (CAT), subcutaneous adipose tissue (SAT), and M. longissimus lumborum (MLL) samples were collected. The saturated FA proportions were higher (P < .01) in CAT than in SAT across all breeds, whereas monounsaturated FA proportions were consistently higher (P < .001) in SAT compared to CAT and MLL. Aberdeen Angus bulls were distinguished from the other breeds in the proportions of mostly de novo synthesized C14:0, C16:0, C14:1n-5, C16:1n-7, and conjugated linoleic acid (P < .05). Adipocyte size decreased in the order CAT > SAT > MLL, and the largest adipocytes were observed in CAT of Holstein bulls (P < .05). Gene expression differences were more pronounced between adipose tissue depots than between breeds. The expression levels of ACACA, FASN, and SCD1 genes were related to tissue-specific, and to a lesser extent also breed-specific, differences in FA composition.

Allelic and genotypic distribution of polymorphisms in diacylglycerol acyltransferase 1 (DGAT1), fatty acid binding protein 4 (FABP4), fatty acid synthase (FASN), and peroxisome proliferator-activated receptor-γ coactivator-1α (PPARGC1A) genes were assessed in 679 Fleckvieh bulls. Single-locus genotype effects and the combined effect of the two polymorphisms within the FASN gene were evaluated for association with the intramuscular fat content and fatty acid profile determined in muscle and subcutaneous fat. The FASN (g.16024G>A) and FASN (g.17924A>G) polymorphisms were significantly associated mainly with C14:0, C16:0, and C18:1 n-9 concentrations as well as with the atherogenic index. The proportion of explained phenotypic variation markedly increased when the effect of a combination of the two polymorphisms within the FASN gene was tested, with the highest values of 8.6% and 14.8%, respectively, observed for C14:0 in muscle and subcutaneous fat. With a focus on improving the fatty acid composition of beef, the results of this study provide valuable information about the markers applicable in marker-assisted selection.

The objective of this study was to examine performance, carcass traits, muscle chemical composition, and blood and rumen metabolites of bulls fed diets with different levels of crude glycerine. A total of 48 Fleckvieh bulls (initial age and live weight 222±16d and 232±29kg, respectively) were divided into four dietary treatment groups with different levels of glycerine supplementation: C (without glycerine), G5 (4.7% of glycerine), G10 (9.3% of glycerine) for the entire experimental period (266±38 d), and CG10 (0% for 118 d and then 9.3% of glycerine until slaughter). The diets were similar in their energy and protein contents with glycerine proportionally substituting barley meal. Feed intakes were recorded daily and the bulls were weighed every two weeks until slaughter (592±29kg of live weight). In addition, blood samples were collected on day 0, 118, and 189 of the experiment. After slaughter, rumen fluid was collected, carcass characteristics were recorded, and m. longissimus lumborum composition was determined. No significant effect of glycerine inclusion was observed in any of the growth performance, carcass and meat quality traits studied. Also, no apparent effects on blood and rumen metabolites were detected. We conclude that crude glycerine can be used as a long-term substitution for barley meal up to the level of approximately 10% of dry matter in the diets of finishing bulls.

The objective of the present study was to examine if luteal blood flow (LBF) monitoring could be used as an additional prognostic tool for early pregnancy diagnosis, and we particularly focused on the differences in LBF between pregnant and nonpregnant mares.Furthermore, other possible developmental differences of corpus luteum (CL) between pregnant and nonpregnant mares were evaluated.The CL (n = 119) of 27 mares were monitored once daily in B-and Power-Doppler Mode on days 1, 2, 9, 12, and 16 after ovulation (day 0 = ovulation).The data were evaluated using the MIXED Linear Model with repeated measures, and parameters were estimated by the REML method.The course of LBF, area of CL, and pixel intensity differed in nonpregnant mares on a day-to-day basis in contrast to more stable values in pregnant mares.Further, the profiles of the courses were identical until day 9, but since day 12 the differences between pregnant and nonpregnant mares started to be prominent.The LBF, pixel intensity, and level of progesterone (P4) were similar in all mares until day 16, when smaller LBF, lower pixel intensity, and lower levels of P4 were found in nonpregnant mares (P = 0.04, P = 0.02, P < 0.05, respectively).In pregnant and nonpregnant mares the LBF was weakly (r = 0.29 in both) and pixel intensity strongly (r = 0.48 and 0.59, respectively) correlated to the levels of P4.LBF was strongly correlated to the area of CL in pregnant as well as nonpregnant mares (r = 0.72 and 0.64, respectively).In accordance with the results presented in our study we can state that LBF monitoring is not a suitable tool for early pregnancy diagnosis or prognosis as the differences between pregnant and nonpregnant mares are notable -similarly to other indicators of CL status -just after the onset of luteolysis (day 16) when embryo itself is detectable.

The indicators of follicle development with regard to the growth wave order, the first ovulation, animal parity, and also with regard to the simultaneous presence or absence of a follicular cyst were determined in cows in the course of 60 days postpartum. Follicular dynamics were monitored daily by ultrasonography. The animals were assigned to three groups based on the time of the 1st ovulation: G1 (n = 9) - the 1st dominant follicle (DF) ovulated, G2 (n = 10) - ovulation occurred on the 2nd or later follicular waves, and G3 (n = 5) - no ovulation occurred during the experimental period. G1 animals showed better fertility later (no cyst, less days open, P = 0.07, less hormonal treatment, P = 0.008). The rhythm of follicular wave development was generally similar in all the animals (based on emergence of the first follicular wave, the interval from emergence to deviation, and the number of all follicular waves). Nevertheless, emergence of follicular waves and deviation occurred by 0.5-0.9 day earlier in primiparous than in multiparous cows and in G1 vs. G2, or G3, respectively (in all P < 0.05). DF development was independent of parity as well as group effects, but the maximum size and growth rate (1.2 vs. 0.8 cm/day, P < 0.05) were higher in ovulatory follicles (OF) than in regressive ones (rDF). The presence of a growing cyst decreased the probability of rDF as well as OF development (P < 0.0001). The OF growth rate was faster in the milieu of a stagnating cyst than without any cyst (P < 0.04). Therefore, the development of follicles was dramatically suppressed beyond, but nor before, deviation in the milieu of a growing cyst. Cessation of the cyst growth accelerated the development of OFs. On the contrary, a cystic structure without any significant growth can persist for weeks with no effect on successful follicular development.

The objective of this study was to determine the dynamics and relative body weight (BW) changes after parturition and their relationships to milk yield in Holstein (H) and Czech Fleckvieh (F) cows, and also the relationships between their BW changes in the first 8 weeks of lactation and reproductive performance. A retrospective, observational study comprised analyses of individual cow records from a computerised herd management system. Production, body weight, and reproduction data were collected between December 2004 and February 2009 from F and H cows kept in a single experimental station. A total of 475 calving interval records (F: N = 132; H: N = 343) were included in the analysis. The data were evaluated using the mixed linear model with repeated measures, and parameters were estimated by the REML method. Whereas BW changes in F first-parity cows significantly (P < 0.01) differed from those detected in greater-parity cows during the major part of lactation, no such differences were manifested for H first-parity animals. The average BW change in weeks 1 to 8 was closely correlated with the BW change in the lactation week, with the lowest BW (NADIR) (r > 0.83, P < 0.0001) in both breeds. In H cows, the average BW change in weeks 1 to 8 and in NADIR significantly (P < 0.01) negatively correlated with the length of postpartum anoestrus, days between parturition and conception, days between first service and conception, and calving interval (P < 0.05 and P < 0.01, respectively). In F cows, the only significant correlations were those with days between parturition and first service (P < 0.05 and P < 0.01, respectively). It was concluded that BW changes postpartum might indicate reproduction problems particularly in H cows.

The objective of the study was to investigate the effects of sex and slaughter age on the fatty acid (FA) composition and stearoyl-CoA desaturase gene expression in muscle and adipose tissue. Twenty-four Charolais × Simmental crossbred bulls and heifers were raised under similar conditions and slaughtered at 14 or 18 months of age. The total amount of FA in muscle increased markedly in older animals with higher contents of monounsaturated FA (MUFA) in heifers than bulls. The proportions of MUFA and desaturation indices were higher in heifers, whereas polyunsaturated FA were higher in bulls in both muscle and subcutaneous adipose tissue. The results of this study demonstrated sex-dependent differences in the FA composition of muscle and subcutaneous adipose tissue from cattle slaughtered at different ages. The expression of the stearoyl-CoA desaturase gene was higher in the adipose tissue of heifers compared to bulls, and its variation partly contributed to sex- and age-differences in the FA composition of bovine adipose tissue.

The nitric oxide donor (+)-S-nitroso-N-acetylpenicillamine (SNAP) is capable of inducing parthenogenetic activation in pig oocytes matured in vitro. However, quite a long exposure to the nitric oxide donor, exceeding 10 h, is necessary for successful oocyte activation. Repeated short-term treatment with 2 mm SNAP significantly increased the activation rates despite the fact that the overall exposure time to the nitric oxide donor did not exceed 4 h. With regard to the activation rate, 12 repeated treatments lasting 10 min each were found to be the most efficient regimen (63.3%). The continuous exposure to the nitric oxide donor for the same overall time induced parthenogenetic activation in 12.5% oocytes (2-h continuous treatment with 2 mm SNAP). The development of parthenogenetic embryos increased after repeated short-term treatment with SNAP. After continuous treatment with 2 mm SNAP for 10 h, only 6.7% of the oocytes cleaved, and none developed beyond the 4-cell stage. Thirty-minute treatment repeated four times with 2 mm SNAP induced cleavage in 37.5% of the oocytes, 18.3% developed to the morula stage, and 6.7% reached the blastocyst stage. Based on the results, it is concluded that pulsatile treatment can significantly improve parthenogenetic activation rate when compared with the continuous treatment using nitric oxide donors.

Through data analysis of 7 571883 pig carcasses slaughtered from 2004 to 2007 the means of quality classes (QC) 2.32, lean meat percentage (LM) 55.83%, carcass weight (CW) 87.21 kg, muscle thickness (MT) 61.95 mm and fat thickness (FT) 15.95 mm were determined. The highest correlation coefficients are between QC and LM (r = -0.920), LM and FT (-0.900) as well as QC and FT (0.828), the lowest between FT and NIT (r = -0.084). Quality class as the dominant indicator is influenced mainly by LM, which explains from 77% to 89% of variability in the case of linear regression. Among the eight methods of pig carcass classification the FOM apparatus was used the most frequently (46.5% carcasses) followed by the ULTRA-FOM 300 apparatus (15.6%), another apparatus (13.2%) and by the IS-D-05 unit (9.8%). In the statistical models used all effects (differences) are statistically significant because of the large size of the data set. The results from the separate evaluation of each cross-classified effect are that EV has the largest influence and year-season and methods have a smaller influence. The time trend (42 months) documents stable CW and NIT, a slight increase in LM and improvement of QC. The estimated results indicate the successful introduction of pig carcass classification in the CR after accession to the EU.

The objective of this study was to determine how the concentration of milk urea (MU) and FPCM production affect reproduction in selected Holstein dairy herds in the Czech Republic. A retrospective, observational study comprising analyses of individual cow records from monthly dairy herd improvement (DHI) milk tests including milk urea (MU) concentration was conducted in six commercial Holstein dairy herds in cows that were bred from July 2000 to August 2003. A total of 1 333 cows with available breeding date, pregnancy status, and calving to first service interval from 31 to 150 days were selected. The data were evaluated using the mixed linear model and logistic analyses. The effect of MU concentration on the probability of conception at first service was not significant (P = 0.11). The results indicated a nonlinear relationship between MU concentration and the probability of conception. A significant effect of the length of calving to first service interval (P < 0.05) and FPCM (P < 0.05) was determined. The cows with the calving to first service interval longer than 2 months had higher probability of conception (10% higher). In the group with the highest FPCM a markedly lower level of successful pregnancy was determined (38.99%), which significantly differed from the group with average FPCM production (48.53%). The probability of conception at first service in the group with the lowest FPCM is at an average level (43.55%).

The previously reported genetic polymorphisms of the stearoyl-CoA desaturase (SCD1) and sterol regulatory element binding protein-1 (SREBP-1) genes were investigated in Fleckvieh bulls using the PCR-RFLP and AS-PCR methods, respectively. The genomic DNA was obtained from a total of 370 bulls. The frequencies of alleles A and V of the single nucleotide polymorphism in exon 5 of the SCD1 gene (SNP 878C>T) were 0.555 and 0.445, respectively. In the 84-bp Ins/Del polymorphism in intron 5 of the SREBP-1 gene, the frequency of the L allele (insertion) was markedly higher (0.920) than that of the S allele (deletion; 0.080). Fatty acid profile was determined in a total of 367 samples of muscle fat (MSF) and 150 samples of subcutaneous fat (SCF). The AA genotype of SCD1 polymorphism showed a lower content of C18:0 (P<0.01) and higher contents of C14:1 cis-9 (P<0.001) and C18:1 cis-9 (P<0.05) in MSF compared to the VV genotype. As a result, the bulls with genotypes AA or AV had lower SFA (P<0.01), higher MUFA (P<0.05) and higher MUFA/SFA (P<0.01) than VV animals. The results obtained for SCF were similar. The SREBP-1 polymorphism was associated with a higher content of C14:1 cis-9 (P<0.01) in the LS compared to LL genotype in SCF. The results of this study demonstrated the existence of the polymorphisms in the SCD1 and SREBP-1 genes in the population of Fleckvieh cattle and their associations with the concentrations of several MSF and SCF fatty acids.

The objective of this study was to analyze the effects of non-genetic factors affecting calving difficulty in the Holstein population of the Czech Republic for subsequent compilation of the model for genetic evaluation as well as for herd management practice. Calving difficulty recorded in 1997-2006 was assessed in three categories: 1 = normal, 2 = hard pull, 3 = complicated. The original observations were transformed to an underlying normal scale. A data set containing 409 255 records was analysed by a linear model with fixed effects of season, parity of dam, sex of calf and Holstein gene proportion. All these effects were significant, and their appropriate categorization was considered. Analyses of additional factors such as gestation length, age at first calving and preceding calving interval were performed. The results revealed that gestation length was in a non-linear relationship with calving difficulty. A higher risk of difficult calving was associated with short or long gestation and with a prolonged preceding calving interval in multiparous cows. Calving difficulty should be adjusted for these factors. A decreased risk of difficult calving could be achieved by an altering of calving interval and age at first calving as a management tool.

The objective of this study was to assess the effect of vitamin E and selenium (Se) supplementation on the plasma levels of F2-isoprostanes as a marker of oxidative stress in horses in their training period. Twelve healthy 3-year-old English thoroughbred horses were divided into two groups: control (n = 6) and experimental (n = 6). Feeding rations were adapted to a moderate workload. The horses of the experimental group received supplements of DL-α-tocopheryl acetate E (2 250 mg/day/horse) and of sodium selenite (0.5 mg/day/horse). The plasma concentrations of both antioxidants and F2-isoprostanes were monitored on days 0, 44 and 70. After 70 days of supplementation, the concentrations of selenium in the experimental group were significantly higher (P < 0.05) compared to the beginning of the experiment (mean ± SE: 135.81 ± 10.19 μg l -1 vs. 98.70 ± 10.88 μg l -1), as well as to the control group (day 0: 101.78 ± 11.06 μg l -1, day 70: 108.18 ± 7.77 μg l -1). In the horses of the experimental group, plasma α-tocopherol levels significantly increased from the 44th day of supplementation compared to the beginning of the study as well to the control group (5.23 ± 0.52 mg l -1 vs. 2.45 ± 0.25 mg l -1 or 3.46 ± 0.34 mg l -1, respectively). The plasma concentration of F2-isoprostanes tended to be lower in the experimental group at the end than at the beginning of monitoring (156.8 ± 12.89 pg l -1 vs. 170.3 ± 60.8 pg l -1), although the control group showed the opposite trend (181.2 ± 15.67 pg l -1 vs. 137.0 ± 47.05 pg l -1). Nevertheless, none of these differences were significant because of the large variability of the individual values. It can be stated that supplementation of the diet used with selenium and vitamin E caused a non-significant decrease of F2-isoprostane concentration in the blood plasma only, and a significant increase of plasma concentrations of these antioxidants. The variation of isoprostane levels probably reflected rather the individual responses of the horses' organisms to the training workload.

The objective of this study was to determine how non-nutritional factors such as herd, parity, days in milk, milk production, and milk components affect the concentration of milk urea. A retrospective, observational study comprising analyses of individual cow records from monthly dairy herd improvement milk tests including milk urea tests was conducted. Six commercial Holstein dairy herds were involved in the investigation from October 2000 to September 2003. The data were evaluated using the mixed linear model with repeated measures, and parameters were estimated by the REML method. Significant differences in milk urea concentrations were observed between herds (P < 0.0001), with a significant variability between test dates within herds. Significant effects of parity (P = 0.0003), days in milk (P < 0.0001). and their interaction were also found. Higher concentrations of milk urea were determined in the cows on the first and second parity (5.63 and 5.62 mmol/l, respectively) compared to the groups of cows on the third and fourth parity (5.47 mmol/l). It was found that milk urea concentration increased with the square of milk yield (P < 0.0001), while a negative quadratic relationship was found between milk urea concentration and milk fat % (P < 0.0001). It was concluded that milk urea concentration should be evaluated in association with days in milk, milk yield, milk fat %, and milk protein %.

Breed effects on live weight gain, slaughter characteristics and carcass composition were compared in Aberdeen Angus, Charolais, Hereford and Simmental bulls. The experiment extended over 2 years and involved totally 96 animals. The target slaughter live weights were determined 550 kg for earlier maturing breeds Aberdeen Angus and Hereford and 630 kg for later maturing breeds Charolais and Simmental. Charolais and Simmental gained more rapidly (P < 0.05) than Aberdeen Angus while Hereford were intermediate. Hereford had lower (P < 0.05) dressing percentage than the other breeds. Percentages of grade I meat were significantly higher (P < 0.05) in Charolais and Simmental. The highest percentage of separable fat was recorded in Hereford (P < 0.05). Charolais and Simmental had lower (P < 0.05) thickness of subcutaneous fat over MLLT than Aberdeen Angus and Hereford. The later maturing bulls generally tended to achieve higher live weight gains during the experiment, produced less fat and had higher percentage of meat from high priced joints in comparison with earlier maturing animals.