„breed“ 119 výsledků

Feed represents a substantial proportion of the variable costs of pig production. Feed efficiency is traditionally expressed as the feed conversion ratio (FCR) and more recently as residual feed intake (RFI). Although feed efficiency can be generally improved indirectly by selection for increased growth rate and decreased adipose tissue, a higher genetic response could be achieved through direct selection of feed intake traits. The aim of this study was to provide a pilot analysis of feed intake data of 281 Czech Large White boars. Data were recorded individually using the Feed Intake Recording Equipment in field performance testing from 2018 to 2020. The analysed feed intake traits were average daily feed intake (ADFI), FCR and RFI. RFI was calculated as the deviation of observed ADFI and average population ADFI predicted on the basis of the model, with mid-test metabolic weight and average daily gain as regressors. The heritability estimates were 0.35 and 0.34 for ADFI and FCR, respectively, and the estimate was slightly higher (0.43) for RFI. The genetic standard deviations ranged from 100 to 110 g of feed per day and 103 g of feed per kg of weight gain. The amounts of explained variability by environmental effects of jointly tested animals were from 0.20 to 0.46. The sufficient amount of genetic variability and moderate heritability estimates give the possibility for selection of feed intake traits, although a larger number of animals will be essential to estimate more precise breeding values.

Pregnancy assessment is a very important tool for the reproductive management in efficient and profitable dairy farms. Nowadays, mid-infrared (MIR) spectroscopy is the method of choice in the routine milk recording system for quality control and to determine standard milk components. Since it is well known that there are changes in milk yield and composition during pregnancy, the aim of this study was to develop a discriminant model to predict the pregnancy state from routinely recorded MIR spectral data. The data for this study was from the Austrian milk recording system. Test day records of Fleckvieh, Brown Swiss and Holstein Friesian cows between 3 and 305 days of lactation were included in the study. As predictor variables, the first derivative of 212 selected MIR spectral wavenumbers were used. The data set contained roughly 400,000 records from around 40,000 cows and was randomly split into calibration and validation set by farm. Prediction was done with Partial Least Square Discriminant Analysis. Indicators of model fit were sensitivity, specificity, balanced accuracy and Area Under Receiver Operating Characteristic Curve (AUC). In a first approach, one discriminant model for all cows across the whole lactation and gestation lengths was applied. The sensitivity and specificity of this model in validation were 0.856 and 0.836, respectively. Splitting up the results for different lactation stages showed that the model was not able to predict pregnant cases before the third month of lactation and vice versa not able to predict non-pregnancy after the third month of lactation. Consequently, in the second approach a prediction model for each different (expected) pregnancy stage and lactation stage was developed. Balanced accuracies ranged from 0.523 to 0.918. Whether prediction accuracies from this study are sufficient to provide farmers with an additional tool for fertility management, it needs to be explored in discussions with farmers and breeding organizations.

The aim of the study was to investigate the genetic differentiation of the Black Slavonian pig population. Two parallel analyses were performed using genealogical records and molecular data. Pedigree information of 6,099 pigs of the Black Slavonian breed was used to evaluate genetic variability and population structure. Additionally, 70 pigs were genotyped using 23 microsatellite markers. Genealogical data showed shrinkage in genetic diversity parameters with effective population size of 23.58 and inbreeding of 3.26%. Expected and observed heterozygosity were 0.685 and 0.625, respectively, and the average number of alleles per locus was 7.826. Bayesian clustering algorithm method and obtained dendrograms based on pedigree information and molecular data revealed the existence of four genetic clusters within the Black Slavonian pig. Wright’s FIS, FST and FIT from pedigree records were 0.017, 0.006, and 0.024, respectively, and did not prove significant population differentiation based on the geographical location of herds, despite the natural mating system. Obtained results indicate that despite the increased number of animals in the population, genetic diversity of Black Slavonian pig is low and conservation programme should focus on strategies aimed at avoiding further loss of genetic variability. Simultaneous use of genealogical and molecular data can be useful in conservation management of Black Slavonian pig breed.

This study aimed to evaluate the score for subclinical ketosis risk, which is routinely monitored in Czech Holstein cows. The score is based on milk recording indicator traits which include fat-to-protein ratio, fat-to-lactose ratio, citric acid, β-hydroxybutyrate, and acetone concentrations. The score was significantly (P <0.001) affected by the age of cow at calving, days in milk (DIM) and season of test-day recording. Variance components were estimated with a univariate linear animal model for the score on the first test-day and with a multivariate linear animal model for the score in 3 successive test-days (6-40, 30-70, 60-100 DIM). The heritability estimate was lower at the beginning of lactation (0.08) and increased gradually to 0.11 at the end of the recorded period. Genetic correlations between the score at the first and the other two test-days were lower than 1 indicating that they are genetically different traits. Estimated breeding values were normally distributed with mean 0.20 and reliabilities up to 0.66 in females and 0.98 in males. Breeding values were negatively correlated with most of other routinely evaluated traits, with the strongest correlations with milk fat percentage (0.39), body condition score (-0.26) and fertility of cows (-0.25). The score for subclinical ketosis risk showed sufficient genetic variability and had the potential to be used in genetic improvement of resistance to (sub)clinical ketosis of Czech Holstein cows.

The study was performed on 136 pig carcasses representing the Croatian pig population with regards to the breed structure. The carcasses were dissected according to the EU reference method and lean meat percentage was estimated using the Hennessy Grading Probe (HGP7) device and the “Two points” (ZP) method. Comparison of lean meat percentage obtained by dissection and two prediction methods showed significant differences in estimating the lean meat percentage of pig carcasses (P <0.05). The distribution of carcasses according to SEUROP system showed a difference in the classification depending on the applied method, indicating a need for adjustment of current formulae for lean meat percentage estimation in Croatia.

The objective of the present study was to investigate the effect of genotype and sex on growth and carcass traits of grazing lambs. A total of 32 lambs (16 Improved Jezersko-Solčava - JSR and 16 crossbreds with Texel - JSRT, 8 males and 8 females within each genotype) were included in the study. The lambs were grazed together with their dams from the beginning of the grazing period and had free access to commercial concentrate from the age of 10 days. Lambs were weaned at the average body weight of 22.9 kg. Feeding with a concentrate was finished when lambs achieved 35 kg of body weight and were slaughtered. Daily gains from birth to slaughter and from weaning to slaughter were calculated. Several carcass traits were determined. JSRT lambs had significantly higher daily gain from birth to slaughter, hot and cold carcass weights, and dressing percentages compared to JSR lambs. Carcass conformation was higher in JSRT than JSR carcasses. Also, carcasses of JSRT were shorter and wider than JSR carcasses. Rib eye muscle areas of JSRT lambs were significantly larger, and the colour was significantly lighter. Males had significantly higher average daily gain from birth to slaughter and from weaning to slaughter than females. Females had higher dressing percentages and subcutaneous and internal fatness scores than males. Females had significantly higher amount of kidney fat. The colour of males’ meat was significantly lighter than that of females. Crossbreeding with Texel rams improved growth and carcass traits of lambs, and males had better growth performance and several carcass traits than females.

A common practice to improve meat quality is aging under controlled conditions, which results in improved tenderness, a key factor in the consumer acceptance of beef meat. Among other traits, the tenderness and the effect of ageing are also genetically determined. Therefore, a trial was performed to assess the effect of ageing in the progeny of young bulls included in the routine breeding program for Simmental breed in Slovenia. In the trial, 127 young bulls were included, and the shear force of grilled Longissimus thoracis muscle was measured fresh and after three weeks of ageing. There was a significant difference between the fresh and aged muscle in shear force, but growth and other carcass traits did not affect it as it was expected. We assume that after enlarging the number of animals, the data will be usable to be included in the genetic evaluation of the breeding program for Simmental breed in Slovenia.

Yield performance and external and internal quality traits of eggs laid by two Italian purebreds, Ermellinata di Rovigo (ER) and Pepoi (PP) were studied at 36 and 50 weeks of age. Daily egg production and egg traits were evaluated by a factorial model (2 x 2) with genotype and age as main effects and their interaction. The daily laying rate was similar between the breeds and the hen-day egg mass was higher (p<0.01) for ER than for PP. The ER eggs differed (p<0.01) from PP eggs with higher egg weight, yolk and albumen weight, and a more coloured eggshell with lower L, higher a* and b*, and lower eggshell thickness. PP showed more (p<0.05) inclusion of albumen than yolk in comparison to ER. With increased hen age, egg weight, eggshell lenght, width, lightness and thickness increased (p<0.01), whereas shape index and a* and b* did not change. Throughout the laying period, the eggs were classified as small (PP) and medium size (ER). With increased hen age, PP eggs were more spherical, ER eggs were more ovoid; yolk and albumen weight increased (p<0.01) in ER, whereas yolk and eggshell weight increased (p<0.01) in PP. The yolk:albumen ratio increased (p<0.01) along with hen‘s age and the Haugh Units and egg inclusions decreased (p<0.01). The ER and PP eggs differed for many egg external traits, which allow to distinguish the eggs by weight, shape, and eggshell colour and for the eggshell thickness and the albumen traits.

The increase of milk production at the farm level requires an accurate balancing of the diet and the nitrogen supply also to minimise the possible environmental pollution deriving from dairy farming. The aim of this study was to evaluate dietary protein utilization at different crude protein (CP) levels and to predict nitrogen content in faeces on the basis of nutritional parameters and milk urea nitrogen content (MUN, mg dL-1). The study was conducted on three groups (A, B, C) of lactating dairy cows (8 cows per group, including Latvian Brown and Holstein Black and White breeds) from 10 to 30 days in milk. Total mixed rations containing different levels of CP (approximately 18.0%, 17.5% and 17.0% for A, B and C, respectively) were fed. The amount of feed consumed by each cow was measured and feed samples collected during the trial. Milk yield (kg d-1-1) and faeces amount were recorded, and samples were collected at day 21 of the study for further analysis. Feed samples were analysed for CP, net energy for lactation (NEL, MJ kg-1) and other parameters. Milk samples were analysed for fat (%), total protein (%), casein (%) and urea content (mg dL-1). The statistical investigation was conducted using ANOVA, and correlation and regression analyses. The results showed that milk yield, fat, total protein, casein, urea, and MUN were not significantly different among groups being not affected by the dietary CP levels. The correlation between faecal nitrogen content and CP content in feed was moderately positive and statistically significant (r=0.44, P=0.03), while the correlation between faecal nitrogen content and MUN was moderately negative and showed tendency towards significance (r=-0.39, P=0.06). The regression analysis showed that feed CP explained approximately 20% of faeces nitrogen content.

Feed efficiency has a major influence on farm profitability and environmental stewardship in the dairy industry. The aim of this study was to describe a new selection index adopted by the Italian Holstein and Jersey Association (ANAFIJ, Cremona, Italy) to improve feed efficiency using data recorded by the official dairy recording system. Predicted dry matter intake (pDMI) was derived from milk yield, fat content, and estimated cow body weight. Fat-protein corrected milk (FPCM) was derived from milk yield corrected for fat, protein, and a fixed coefficient for lactose content (4.80%). Therefore, the predicted feed efficiency (pFE) was estimated as ratio between FPCM and pDMI. Average pFE was 1.27±0.18 (kg.d-1) with heritability of 0.32. Predicted Feed Efficiency index (pFEi), traditional and genomic, has been implemented in the Italian Holstein Friesian evaluation system. Results suggest that pFEi may be a new breeding objective for Italian Friesians. The official selection index (PFT), in use since 2002, is positively correlated with pFEi. However, the introduction of pFEi will improve the positive feed efficiency trend. This approach will permit the Italian Holstein Friesian breeders to improve feed efficiency, without increasing costs of recording system. However, to avoid the risk of selecting animals with an excessive negative energy balance after calving, it would be useful to include in the pFE a correction for body condition score and reproductive performances. Meanwhile, in order to increase the accuracy of the predicted phenotype, an Italian consortium is creating a consistent phenotypic critical mass of individual data for dry matter intake in cows, heifers and young bulls.

In this study, 68 genotyped purebred cows and bulls of Charolais cattle were used to determine runs of homozygosity (ROH) for evaluation of selection effect on the genome structure. ROH analysis was performed for 41,153 SNPs, and homozygous segments considering a minimum of 15 consecutive SNPs. The aim was to identify if regions of the genome with a high frequency of SNPs in ROH include signatures of selection. The most significant outlier SNPs were found on BTA2, 5, 7 and 19 (11 regions), with a sum of ROH length of 15.85 Mb. These regions contained genes included in various biological processes associated with the functioning of the immune system, growth, reproduction and metabolism. Various quantitative traits loci (QTLs) which affected the characteristics of meat production and reproduction have been identified in these regions. Overall, obtained results suggest that the Charolais cattle genome includes selection signatures reflecting the improvement of meat production and reproduction in accordance to breeding objecives.

The aim of the study was to evaluate the effect of birth season, average maximum temperatures 6 weeks before and after birth of heifers on their first lactation milk yield. In chosen herd, the effect of birth weight, weight gain until weaning on first lactation milk yield was also investigated. Additionally, the effect of the average maximum temperatures before birth, effect of birth season on birth weight were evaluated. The data were collected from the herd “A” in Orava region consisting of Slovak spotted breed (127 records), the herd “B” in Lower Nitra (150 records) and herd “C” in Upper Nitra (116 records) both consisting of black Holstein Friesian cows. Birth season tended to influence the heifers first lactation milk yield in the herd “C” (P <0.06). The maximum average temperatures during the first 6 weeks after birth significantly affected heifers first lactation in the herd “A” (P <0.01). The maximum average temperatures affecting pregnant cows before birth of their heifers did not influence heifers’ milk yield during the first lactation in all herds (P >0.66, herd “A”; P >0.59, herd “B”; P >0.38, herd “C”). In the herd “B” there was insignificant effect of prenatal temperatures, birth season on birth weight of heifers (P >0.97; P >0.74). However, the heifers with the highest weight gains until weaning had numerically higher first lactation milk yield (P >0.20).

The aim was to review obtained results related to molecular-genetic analyses by high-density SNP chips and mtDNA in farm and wild populations within the project APVV-17-0060 Genomic Indicators of extranuclear DNA as a source of Diversity for Animal Breeding. Continuous human activity and subsequent socioeconomic and climatic changes of the environment significantly affect the genetic diversity of livestock on both intra- and inter-population levels. Concerning the conservation of local livestock populations and thus animal genetic resources (AnGR) for future generations is, therefore, necessary to monitor and look for new “more precise“ tools to measure the amount of genetic diversity. The expected result will be the identification of SNP markers and spot mutations with a significant effect on the process of development resp. variability of traits. In the case of the dog, identification of regions related to fitness, health, and trainability will be the primary objective.

The breeding studies targeted to develop high yielding varieties in maize have led to a decrease in genetic variation in secondary biochemical components. Local maize landraces are important genetic sources for these components. The objective of this study was to examine the genetic variation for phytic acid and total phenolic compounds within 192 Turkish maize landraces. The plant material was grown during the summer season of 2017 in Çanakkale, with the inclusion of 7 check hybrids. The field trial used an Augmented Experimental Design, with 6 blocks, each one containing 32 landraces and 7 check hybrids. Phytic acid and total phenolics were detected spectrophotometrically in the seeds of landraces propagated by bulk pollination. The data were subjected to analysis of variance and some genetic estimations (coefficients of variation, heritability, genetic advance) were calculated for the observed traits. Results of data analysis suggest that there is a considerable genetic variation among the investigated genetic materials. The phytic acid content was found between 0.82–4.87 mg g-1 and the total phenolic content was between 0.03–1.99%. For both traits, genetic variation in local maize landraces was observed to be wider than check varieties. The promising materials among landraces may have potential use in the future breeding programs for manipulating the levels of phytic acid and phenolic compounds. According to the calculations made for the inheritance of the traits, it was determined that the heritability in phytic acid content was higher (56.2%) than those for the total phenolics. Genetic gain calculations showed that genetic improvement can be achieved by selection for both investigated traits.

Our research aimed to analyse the current state of the sheep industry in Ukraine, to highlight the geographical location of genetic resources, to describe the state of the breeding work, and to form the proposals for the development of this branch in the future. The date from the State register of breeding farms for 2005-2019 and statistical reporting were used for analysis. It is shown that over the last 14 years, the sheep industry in Ukraine has undergone significant changes: the form of ownership has changed, the number of livestock has decreased and the breed composition of sheep has changed. Currently, there are 0.7 million sheep in Ukraine, of which 26.7 thousand are registered like breeding animals belonging to 10 breeds. The largest number of sheep is concentrated in the south and west of the country, where the climatic conditions are favourable for this branch in the past. The leaders in terms of numbers are Odesa and Transcarpathia, Chernivtsi and Zaporizhia regions. Breeding pedigree animals are concentrated in Odesa and Kherson oblasts. The most numerous breeds are the Askanian meat-wool breed with crossbred wool and the Askanian Karakul breed. Taking into consideration the big potential of the sheep breeding, it is proposed to perform some steps to stimulate its development in Ukraine.

DGAT1 gene polymorphism in exon 8 AA→GC which converts lysine to alanine at position 232 (K232A) was determined to have significant influence on bovine milk production characteristics like milk yield, protein content, fat content, and fatty acid composition. The aim of this study was to analyse the effect of DGAT1 gene polymorphism on dairy production traits [milk yield (kg), fat yield (kg), fat content (%), protein yield (kg) and protein content (%)]. Genotyping of 136 Holstein cows was performed using the ACRS-PCR method. The genotypes frequencies were as follows: homozygous genotype AA (80.88%), heterozygous genotype AK (16.91%) and homozygous genotype KK (2.21%). In the monitored population, allele A had a predominance with a frequency of 89.34% over allele K with a frequency of 10.66%. In the study was observed a statistically significant (P <0.0001) effect of DGAT1 K232A marker genotypes on breeding value variability for milk fat and protein content (%) as well as milk yield (kg) was observed.

The aim of this study was to compare two methods for determining the concentration of sperm in stallion ejaculate and to evaluate the influence of different levels of concentration on the determination of sperm motility using an objective method. The total number of evaluated samples was 123. For the experiment, 14 stallions of different breeds housed in the Tlumačov Provincial Stud Farm were used. Sperm concentration was assessed by the hemocytometric method using a Bürker chamber and the automatic method using the Sperm Class Analyzer®. The SCA system was used to evaluate sperm motility. The samples were divided into 6 groups with sperm concentrations of 50, 100, 150, 200, 250 and 300·106 sperm ml-1. The results were statistically evaluated by Tukey’s HSD test. There were statistically significant differences in the determination of sperm concentrations between the hemocytometric method and the SCA system in samples with concentration exceeding 100·106 sperm ml-1. Sperm motility increased in samples with higher concentration, however the effect of sperm concentration on motility parameters has not been statistically significant. The results of this study indicate that samples with sperm concentration higher than 100·106 sperm ml-1 reduce the accuracy of the SCA system evaluation and these samples need to be diluted to concentration ≤100·106 sperm ml-1 for more accurate evaluation.

Congenital malformations occur in numerous pig breeding programs. Clinical symptoms, etiopathogenesis and candidate genes of the most critical congenital malformations in pigs were briefly overviewed in the study. Based on the recent literature, identifying and evaluating the genomic regions associated with defects, such as splay legs syndrome, hernias, cryptorchidism, atresia ani, kyphosis, intersexuality, and malignant melanoma, can enhance the selection response. As promising genes were published e.g. NREP, FBXO32, and HOMER1 for splay leg syndrome, SRC, OSM, COL family, and CGRP for hernias, GNRHR, GATA2, and RLF for cryptorchidism, and GLI2 for atresia ani. Potential candidate genes associated with defects were mainly detected in literature by the genome-wide association approach. Reviewing the studies and following the suggestions in some of papers it is indicated the necessity for molecular and more comprehensive evaluation in terms of the sample standardisation and accurate phenotyping of a broad spectrum of populations and breeds. Moreover, knowledge transmission among all livestock species and humans is recommended in literature to better understand malformation biology.

Over the past decades natural substances are widely used in the maintaining of spermatozoa viability. The target of present study was to evaluate the effect of various taurine concentrations on stallion spermatozoa during 37°C cultivation. Fresh semen was collected from 10 breeding stallions. The experimental groups were supplemented with six different concentration of taurine (in mg/ml): A – 2.5, B – 5, C – 7.5, D – 10, E – 15, F – 20 and compared to control (CON – 0). Spermatozoa motility was assessed using the Computer Assisted Semen Analyzer (CASA) system in 6 time periods (0, 1, 2, 3, 4 and 5 hours). The MTT test was used for detection of viability. For measuring antioxidant activity FRAP and TOS methods were used. Significantly negative effect was observed in the samples with the highest concentration of taurine (20 mg/ml). Spermatozoa viability was not significantly affected in analysed concentrations of taurine. Significant higher antioxidant activity was detected in the sample with the highest taurine concentration. Data clearly showed negative effects of high taurine concentrations on stallion spermatozoa.

The aim of this research was to evaluate the effect of cow exterior on the weight of the calf at parturition and the size of the calf’s head. 453 purebred Holstein Friesian dairy cows at a selected farm were analysed within this research, and the measurements of the withers height, hip width, backside width and ischial width were taken from each specimen. Considering the calves, the measurements taken were the width and length of the head and weight at parturition. The research did not prove any significant (p>0.05) effect of the cow body conformation on any of the measured proportions of the calf. There was, however, a significant (p<0.05) difference in the head length and weight in calves in relation to the calving ease. As opposed to our expectations, the parturition weight of calves going through a more difficult parturition was lower (30.36 kg, as opposed to 36.57 kg in the less difficult parturition) and the length of the head was lower as well (23.47cm, as opposed to 23.98 cm in a less difficult parturition). At the same time, the weight and head length increased with each undergone lactation cycle of the mother – more specifically, this trend of increasing was observed from the first to the fifth lactation cycle. The parturition weight of calves was significantly affected by the gestation length itself. Another factors that had an effect on the weight and size of the calves were the season during which calving took place and the effect of the father bull. The results show a possibility of using the data collected in this research for breeding value estimation in difficult parturitions, since the effect of the father of the calf has to be taken into consideration as well as the effect of the the cow’s father.