Genetic parameters for first calving interval in beef cattle

The aim of this study was to estimate genetic parameters for first calving interval in beef cattle population of the Czech Republic. Database of performance testing of 64 thousand of cows with repeated records was used to analyse. There were significant effects (P<0,001) of age at first calving, herd-year-season, breed, calving difficulty and heterosis of cow (P=0.038). Genetic parameters were estimated by AIREML. Heritability of first calving interval (0.1) was estimated

Carcass Traits and Meat Quality of Prestice Black-Pied Pig Breed

The objective of the study was to evaluate fattening performance, carcass value and meat quality in pigs of Prestice Black-Pied breed in relation to slaughter weight (SW) and gender (barrows and gilts, resp.). Pigs were divided into weight categories: SW1 (75 to 99.9 kg), SW2 (100 to 109.9 kg) and SW3 (110 to 130 kg) and all individual traits were analyzed by the general linear model procedure (SAS 9.3). Average SW of each weight group was as follows: SW1 94.2 kg, SW2 105.8 kg, and SW3 115.2 kg. Differences among average backfat thickness of 36.07 mm in SW1, 40.16 mm in SW2, and 43.21 mm in SW3 were significant (p<0.01). Lean meat content was 48.94% (SW1), 48.78% (SW2), and 48.76% (SW3). Pigs were slaughtered at average weight of 105.7 kg for barrows and 104.4 kg for gilts. Average backfat thickness for barrows was 40.90 mm and 38.72 mm for gilts (significant difference p<0.05). Lean meat content was 48.75% in barrows and 48.91% in gilts. The values of pH45, characterizing the meat of very good quality. The loin in SW3 was darker than the muscles of SW1 and SW2. Drip loss was the lowest in SW1 (1.96%), compared to the highest drip loss in SW3 (2.59%). Content of intramuscular fat was 2.68% in SW3, 2.79% in SW2, and SW1 had the lowest content 2.47%. The values of pH45, colour lightness and drip loss were similar in both genders. However barrows had higher intramuscular fat content by 0.31% than gilts (p<0.05)

Optimization of methods for evaluation of antimicrobial activity of selected active matters against chosen spectrum of bacterial pathogens

The bachelor thesis deals with optimalization of selected methods (e.g. evaluation of bacterial suspension concentration, Resazurin antibacterial assay) needed for evaluation of active substances antibacterial activity against pathogens Pectobacterium carotovorum, Pseudomonas syringae and Clavibacter michiganensis subsp. michiganensis. Literature review contains information about potato tubers proteins, especially proteins with antibacterial activities, as well as a brief overview of mechanisms of action of plant defense system against pathogenic microorganisms and the effect of antimicrobial substances on bacterial pathogens. The experimental part deals with optimalization of methods needed for evaluation of antibacterial activities of selected substances. Optimized were methods of McFarland Turbidity Standards, Most-probable number method and Resazurin antibacterial assay. It was found that increase of optical density, measured by spectrometer at 620 nm, is in direct correlation with increase of bacterial suspension concentration (CFU/ml). It was identified proteins of patatin complex and protease inhibitors by using SDS-PAGE method to evaluated potato tuber proteins of variety Bella and Westamyl and also changes of molar mass of the patatin proteins in relation of their modification were evaluated. Antimicrobial activity of these proteins was verified by resazurin antibacterial assay and ability of modified proteins of cultivars Bella and Westamyl in higher concentration (10 mg/ml) to inhibit growth of bacteria Pseudomonas syringae

Association Between Polymorphism of FGF2 and Milk Yield in Cattle

The objective of this study is to investigate the effect of polymorphism of the FGF2 gene locus at the milk yield and fertility of Holstein cows. Review contains information about milk yield and reproductive performance of Holstein cows and point out the problem with decreasing fertility of high-producing dairy cows. The second part of review contains information about FGF family, its characterization and its effect of production traits and reproductive traits in Holstein cows. FGF2 was chosen for this study because it is a member of the placental lactogen pathway and interferon- and which means that, FGF2 is included in initiation and maintaining of pregnancy in ruminants and therefore is possible to expect an effect on FGF2 on the milk traits and reproductive traits of cattle. The experimental part of the work deals with the genotyping of 150 bulls of Holstein breed. Genotyping was performed by PCR-RFLP method. Data was obtained and statistically evaluated. No significant effect of SNP11464 FGF2 polymorphism was found with association to milk production of Holstein breed. However, a significant effect of SNP11464 was found in regards to fertility with association to fertility of cows and breeding cattle of the Holstein breed line NXA. This effect was not significant in heifers of both lines and fertility of cows and breading cows in line NEA. SNP11646 FGF2 gene might be useful as a criterion in gene-assisted selection to increase the fertility of Holstein dairy cows but prior to its introduction as a selection criteria in the breeding programme a further investigation of possible effect on fertility is necessary

Genetic Parameters for Limousine Interbeef Genetic Evaluation of Calving Traits

The aim of this study was to estimate across-country genetic correlations for calving traits (birth weight, calving ease) in the Limousine breed. Correlations were estimated for eight populations (Czech Republic, joint population of Denmark, Finland, and Sweden, France, Great Britain, Ireland, Slovenia, Switzerland, and Estonia). An animal model on raw performance accounting for across-country interactions (AMACI) was used. (Co)variance components were estimated for pairwise combinations of countries. Fixed and random effects were defined by each country according to its national genetic evaluation system. The average across-country genetic correlation for the direct genetic effect was 0.85 for birth weight (0.69–0.96) and 0.75 for calving ease (0.62–0.94). The average correlation for the maternal genetic effect was 0.57 for birth weight and 0.61 for calving ease. After the estimation of genetic parameters, the weighted bending procedure was used to compute the full Interbeef genetic correlation matrix. After bending, direct genetic correlations ranged from 0.62 to 0.84 (with an average of 0.73) for birth weight and from 0.58 to 0.82 (with an average of 0.68) for calving ease

Genetic Parameters for a Weighted Analysis of Survivability in Dairy Cattle

The genetic parameters for the survival of Holstein cows, analysed in nine consecutive time periods during the first three calving intervals, were estimated. The earlier the animals are culled, the more they are informationally underestimated. This undervaluing can be remedied by using a weighted analysis that balances the amount of information. If the method of estimating breeding values changes, the genetic parameters will also change. The Holstein cattle dataset from 2005 to 2017 used in this study included 1,813,636 survival records from 298,290 cows. The pedigree with three generations of ancestors included 660,476 individuals. Linear repeatability models estimated genetic parameters for overall and functional survivability. Due to weights, heritability increased from 0.013 to 0.057. Repeatability with weights was 0.505. The standard deviations of breeding values were 1.75 and 2.18 without weights and 6.04 and 6.20 with weights. Including weights in the calculation increased the additive variance proportion and the breeding values’ reliabilities. We conclude that the main contribution of the weighted method we have presented is to compensate for the lack of records in culled individuals with a positive impact on the reliability of the breeding value

Genome-Wide Association Study for Body Conformation Traits and Fitness in Czech Holsteins

The aim of this study was a genome-wide association study (GWAS) on conformation traits using 25,486 genotyped Czech Holsteins, with 35,227 common SNPs for each genotype. Linear trait records were collected between 1995 and 2020. The Interbull information from Multiple Across Country Evaluation (MACE) was included for bulls that mostly had daughter records in a foreign country. When using the Bonferroni correction, the number of SNPs that were either significant or approached the significance threshold was low—dairy capacity composite on BTA4, feet and legs composite BTA21, total score BTA10, stature BTA24, body depth BTA6, angularity BTA20, fore udder attachment BTA10. Without the Bonferroni correction, the total number of significant or near of significance SNPs was 32. The SNPs were localized on BTA1,2,4,5,6,7,8,18,22,25,26,28 for dairy capacity composite, BTA15,21 for feet and legs composite, BTA10 for total score, BTA24 stature, BTA6,23 body depth, BTA20 angularity, BTA2 rump angle, BTA9,10 rear legs rear view, BTA2,19 rear legs side view, BTA10 fore udder attachment, BTA2 udder depth, BTA10 rear udder height, BTA12 central alignment, BTA24 rear teat placement, BTA8,29 rear udder width. The results provide biological information for the improvement of body conformation and fitness in the Holstein population

Associations among Farm, Breed, Lactation Stage and Parity, Gene Polymorphisms and the Fatty Acid Profile of Milk from Holstein, Simmental and Their Crosses

This study aimed to analyze the factors affecting the fatty acid (FA) profile in cow’s milk. The effects of a farm, lactation parity and stage, breed and polymorphisms in the AGPAT6, DGAT1, LEP, FASN and SCD1 genes were evaluated. A total of 196 Holstein cows, 226 Simmental cows and seven crosses were sampled 751 times. The cows were kept at five farms and were in the first up to the sixth lactation, and 49 individual FAs and 11 groups were analyzed. The farm significantly affected the proportion of all FAs except for C16:1n-7c and isoC14:0. Additionally, the lactation stage was significant for most FAs, and the opposite was true for lactation parity. The effect of the breed was negligible. For the gene polymorphisms, the SCD1&nbsp;TT genotype exceeded the CC in C10:0, C12:0, C14:0, C16:1n-7c and C18:2, and the opposite was true for C10:1, C12:1, C14:1n-5c, isoC17:0, C16:1 and C18:1, i.e., the TT genotype was higher for saturated FAs, and the CT genotype was higher for monounsaturated FAs. The results hint at the intermediary heredity of the SCD1 gene. The FASN gene was strongly associated with four FAs and branched-chain FAs, and genotype AG was better than GG. LEP was significant for five individual FAs and branched-chain FAs. The differences in FA composition among genotypes were rather small, which could lead to overestimation of the effect and needs to be considered in the next research