Polish Holstein-Friesian Bulls Research Articles

Gene Expression Level and Immunohistochemical Localization of Cannabinoid and Cannabinoid-Related Receptors in The Small Intestine of Holstein Bulls (Bos Taurus Taurus)

Abstract The gastrointestinal tract plays a crucial role in nutrient absorption, secretion, and motility, ensuring proper digestion and overall homeostasis. Regulation of this complex system involves the coordination of various communication pathways, including neural and humoral mechanisms. One such mechanism is the endocannabinoid system (ECS), a signaling network comprising endogenous cannabinoids, receptors, and enzymes involved in the regulation of physiological processes in mammals and non-mammalian species. While extensive research has been conducted on the ECS in monogastric animals, limited information is available on its presence and distribution in cattle. This study aimed to investigate the distribution and localization patterns of cannabinoid receptors type 1 (CB1R) and type 2 (CB2R) and transient receptor potential vanilloid type 1 (TRPV1) in the bovine small intestine. The study included immunohistochemical analysis of intestinal tissue samples from Polish Holstein-Friesian breed bulls. Gene expression levels of CNR1, CNR2, and TRPV1 genes, encoding CB1R, CB2R, and TRPV1, respectively, were quantified using qPCR analysis. The results showed that all three receptors were expressed in the bovine small intestine, with TRPV1 exhibiting a significant upregulation in the jejunum compared to the duodenum and ileum. Immunoreactivity for CB1R and CB2R was predominantly observed in neurons of the enteric plexuses, while TRPV1 immunolabeling was detected in both enteric neurons and duodenal Brunner’s glands. These findings may establish an anatomical foundation for further investigations, lending support to the potential therapeutic efficacy of cannabinoid receptor agonists in alleviating gastrointestinal motility disorders associated with bovine enteropathies and optimizing milk production in dairy cattle.

Eradication of carriers of Complex Vertebral Malformation (CVM) and Brachyspina in Polish Holstein-Friesian bulls.

CVM ( Complex Vertebral Malformations) and Brachyspina (BY) are the most common autosomal recessive genetic defects occurring in the last two decades in Holstein dairy cattle around the world. Beginning from 2004 and 2014, 3035 and 338 Polish Holstein-Friesian bulls were tested to find carriers of CVM and BY, respectively. Among analyzed bulls 191 CVM carriers (6.29%) and 20 BY carriers (5.92%) were identified. No CVM carriers were observed beginning from 2016, whereas only single BY carriers was identified annually for the last 5 years. One bull turned to be double CVM/ BY carrier as a son of also double CVM/BY top Dutch sire (JABOT 90676-4-9). It is shown that CVM and BY defects are practically eradicated from Polish dairy cattle although incidental testing should be continued if new bulls with CVM or BY carriers in sire or dam pedigree will unexpectedly appear.

Correlation of Polymorphism of AQP7 Gene with the Sperm Cells Quality Traits of the Polish Holstein Friesian Bulls

Correlation of Polymorphism of AQP7 Gene with the Sperm Cells Quality Traits of the Polish Holstein Friesian Bulls

Fatty Acid Profile of Intramuscular Fat in the Longissimus Lumborum and Semimembranosus Muscles of Bulls Fed Diets Based on Virginia Fanpetals, Grass and Maize Silages

Abstract The aim of this study was to determine the effect of Virginia fanpetals (Sida hermaphrodita) silage on the fatty acid profile and the content of selected nutrients and vitamins in the Longissimus lumborum (LL) and Semimembranosus (SM) muscles of young bulls. Forty Polish Holstein-Friesian bulls aged 16 months were assigned to four dietary treatments (n=10) and were fed different types of silage during a 7-month fattening period. The proportion (g/kg dry matter) of silage in the diets was as follows: (1) grass silage (GS) (600); (2) Virginia fanpetals silage (VFS) (600); (3) VFS (300) and GS (300); and (4) VFS (300) and maize silage (MS) (300). Silage was supplemented with concentrate at 400 g/kg DM in each diet. The animals were slaughtered at the end of the fattening period. The intramuscular fat (IMF) of bulls fed GS had the highest (P<0.05) concentrations of n-3 polyunsaturated fatty acids (PUFAs) and linolenic acid (LNA), whereas the IMF of bulls receiving GS and VFS was characterized by the highest proportion of MUFAs, mostly oleic acid (C18:1 cis 9). In comparison with the LL muscle, the SM muscle contained less IMF (by 40%) with a more nutritionally desirable profile. The SM muscle was characterized by a more desirable mineral composition and a higher concentration of α-tocopherol.

The Quality, Intake, and Digestibility of Virginia Fanpetals (Sidahermaphrodita L. Rusby) Silage Produced under Different Technologies and Its Effect on the Performance of Young Cattle.

Simple SummaryCompetition for high-quality arable land has prompted a search for alternative forage crops. For example, Virginia fanpetals is a high-yielding perennial plant with low soil requirements. Due to its chemical composition, it can be a valuable component of ruminant diets. Previous research has shown that it cannot be used for hay production, and the natural moisture content of silage was unsatisfactory. Laboratory analyses suggest that the quality and feed value of Virginia fanpetals silage may be affected by harvesting and preservation methods. However, to date, most studies have focused on the nutritional value of Virginia fanpetals silage and its inclusion in animal diets. Therefore, the present study investigated different harvesting and preservation methods, such as direct-cut harvesting with a forage harvester, and harvesting after field wilting with a forage harvester or a round baler. The quality parameters, intake and digestibility of silage, and the performance of growing bulls, fed the experimental silage, as the sole forage was evaluated. It was discovered that the highest-quality silage was produced when herbage was harvested with a forage harvester after field wilting.Different harvesting and preservation methods of Virginia fanpetals herbage were evaluated, based on the chemical composition and digestible organic matter (OM) content (D-value) of silage fed to adult sheep, the intake and digestibility of silage, and the performance of young cattle. The following harvesting methods were compared: direct-cut harvesting with a precision-cut forage harvester (DC), harvesting after field wilting with a precision-cut forage harvester (WC) or a round baler (WRB). The silage was fed for 81 days to 24 Polish Holstein Friesian (HF) bulls, as the sole forage supplemented with 3.0 kg of concentrate/head/day. Harvesting methods affected the density (p < 0.001) and water-soluble carbohydrate (WSC) content (p = 0.047). Differences were found among the groups in the digestibility coefficients of OM (DC-73.7, WC-78.9, WRB-79.9%) (p = 0.007), and crude protein (CP) (69.8%, 77.1%, 78.5%, respectively) (p < 0.001). Dry matter intake (DMI) reached 8.38 kg (DC), 8.74 kg (WC) and 7.21 kg (WRB). Live weight gain (LWG) differed (p < 0.001) among groups (0.939, 1.033, 0.813 kg/day, respectively). The feed conversion ratio (FCR) tended to improve in WC (8.66 kg DMI/kg LWG) (p = 0.08). The highest-quality silage was produced in group WC, and it could be successfully fed to growing bulls as the sole forage.

Carcass and Meat Quality Traits in Young Bulls Fed Virginia Fanpetals Silage

Abstract The aim of this study was to determine the effect of Virginia fanpetals (Sida hermaphrodita) silage on carcass and beef quality characteristics. Forty Polish Holstein-Friesian bulls aged 16 months were assigned to 4 dietary treatments (n=10) and were fed different types of silage during a 7-month fattening period. The proportion (g/kg dry matter) of silage in the diets was as follows: (1) grass silage (GS) (600); (2) Sida silage (SS) (600); (3) SS (300) and GS (300); and (4) SS (300) and maize silage (MS) (300). Silage was supplemented with concentrate at 400 g/kg DM in each diet. The animals were slaughtered at the end of the fattening period. Silage type had no significant effect on BWG or feed to gain ratio. The carcasses of bulls fed Sida silage and maize silage received higher scores for conformation than the carcasses of bulls fed grass silage (P&lt;0.05). The meat of bulls fed Sida silage had the lowest value of Warner-Bratzler shear force. Meat from SS+MS group bulls had the highest intramuscular fat (IMF) content and was lightest in color, whereas meat from bulls fed Sida silage and grass silage received the highest scores for color uniformity, aroma, taste and overall acceptability.

Novel method for identification of the lethal mutation in bovine APAF1 gene and its preliminary prevalence in Polish Holstein-Friesian bulls.

The aim of the study was to develop a reliable and cost-effective method for detection of nonsense mutation in APAF1 gene causing lethal effect called HH1 (Holstein Haplotype1) and to evaluate its prevalence in a sample of Polish Holstein-Friesian bulls. One hundred seventy eight bulls born between 1996 and 2017 were included in the analysis. They were kept in four artificial insemination centers and have in the pedigree the known carrier of HH1. All bulls were diagnosed by novel PCR-SSCP technique. Specific amplicons of 261 bp APAF1 gene fragment were used to detect changes in single stranded conformation (SSCP) caused by nonsense mutation C/T responsible for HH1. Each new carrier was used to trace another potential carriers among their offspring available in Polish Holstein Bull Repository Database. Among 178 bulls, 85 HH1 carriers were found. Our results show that nonsense mutation in APAF1 gene is already transmitted and segregating in Polish Holstein-Friesian cattle and its frequency may increase if no action will be undertaken against actual carriers.

Inbreeding in a Population of Polish Holstein-Friesian Young Bulls Before and After Genomic Selection

Abstract Inbreeding was analysed in a population of 14,144 Polish Black-and-White Holstein-Friesian (PBWHF) young bulls born between 1994 and 2017 and bred under both conventional and genomic breeding programmes. The inbreeding coefficients were computed using a model with genetic groups, according to the algorithm given by VanRaden. It was found that in the analysed population all bulls are inbred (100% of the population), with the mean coefficient of inbreeding ranging from 0.09% to 26.95%. Pedigree analysis also showed a relationship between the changing number of bulls over the years and the dynamics of population inbreeding. These trends are connected with changes in the breeding scheme, related to the implementation of genomic selection in the breeding programme for PBWHF cattle in 2014. The increasing number of weaned young bulls in Poland was paralleled by a fairly consistent increase in the mean inbreeding, but the inbreeding dynamics were relatively small. A reverse trend was observed in the group of young bulls born after 2013. As the number of bulls very rapidly decreased in successive birth years, the mean inbreeding for successive birth-year groups very rapidly increased. As a result, the estimated linear trend was equal to 0.02% inbreeding per year of birth in the group of bulls raised before genomic selection (~20 birth-year) whereas in the group of bulls raised after genomic selection (~4 birth-year) the trend was much higher and amounted to 0.56% inbreeding per year of birth. The high mean inbreeding found in the group of the genomically selected young bulls may translate into higher inbreeding in the whole population of PBWHF cattle, because these bulls are now intensively used as sires. The results of our study also show that the implementation of genomic selection in the breeding programme caused a very rapid increase in the inbreeding rate per birth-year in young bulls.

Missense mutation in SDE2 gene - new lethal defect transmitted into Polish Holstein-Friesian cattle.

The aim of the study was to find out whether carriers of new lethal mutation in SDE2 gene occur in the population of Polish Holstein-Friesian bulls. Eighty seven bulls were included in the analysis. Bulls were selected as having in the pedigree known carrier of SDE2 mutation (bull Mountain USAM000002070579). All bulls were diagnosed by PCR amplification of 524 bp fragment of SDE2 gene followed by digestion of Bcc I restriction enzyme. Heterozygotes (carriers) were confirmed by sequencing. Each new carrier was used to trace another potential carriers among its offspring available in Polish Holstein Bull Repository Database. Among 87 bulls, 50 new SDE2 carriers were found. The study has shown that mutation in SDE2 gene causing early embryo mortality is already transmitted to Polish Holstein-Friesian cattle. The results are sufficient to initiate the screening program to reveal new carriers and to avoid further spreading of SDE2 lethal mutation.

An analysis of the influence of various tenderising treatments on the tenderness of meat from Polish Holstein-Friesian bulls and the course of changes in collagen

The aim of the study was to analyse the influence of tenderising treatments applied to the carcasses of Polish Holstein-Friesian (PHF) bulls of Black-and-White variety on the process of meat tenderisation and to assess the role of collagen in this process. The research was carried out on m. longissimus thoracis et lumborum. The carcasses were subjected to high-voltage electrical stimulation (ES), conditioning (CD), and both treatments together (ES + CD). The carcasses which were only refrigerated were the control group. The content of collagen in meat, its solubility, the share of the polypeptide subunits α1(I)CB7 and α1(I)CB8 of type I collagen and α1(III)CB5 of type III collagen were also analysed. ES with and without CD significantly accelerated the meat tenderisation and increased collagen solubility. CD always caused the degradation of type I collagen subunits, especially the α1(I)CB7 subunit. However, CD had significantly lesser influence on the rate of meat tenderisation than ES.

Influence of ageing on longissimus lumborum quality from Holstein-Friesian young bulls fed different diets

The aim of the study was to investigate the effect of ageing (9 and 14 days) on beef obtained from Polish Holstein-Friesian bulls (n = 24) fed different dietary treatments containing the addition of herbal preparations (treatments: control, one and two herbal preparations). Between the 9th and 14th day of ageing, moisture and expressible water contents, Warner–Bratzler Shear Force (WBSF) and intensity of untypical taste significantly decreased, whereas redness, yellowness, chroma, intensity of meat aroma and tenderness increased. Interactions between ageing and dietary treatment on pH, expressible water, cooking loss and WBSF were noted. Using two herbal preparations in a dietary treatment enabled to obtain 9-days aged beef with similar tenderness as compared with 14-days aged beef from the control treatment. Therefore, it is possible to decrease the ageing time of beef by using a well-designed dietary treatment.

High-frequency marker haplotypes in the genomic selection of dairy cattle

The aim of this study was to predict the genomic breeding value (DGV) of production, selected conformation and reproductive traits, and somatic cell score of dairy cattle in Poland using high-frequency marker haplotypes. The dataset consisted of phenotypic, genotypic, and pedigree data of 1216 Polish Holstein-Friesian bulls. The genotypic data consisted of 54,000 single-nucleotide polymorphisms (SNPs). The data were divided into two subsets: a test dataset (n = 1064) and a validation dataset (n = 152). Genotypic data were selected using three criteria: the percentage of missing genotypes, minor allele frequency, and linkage disequilibrium. The purpose of the data selection was to identify blocks of SNPs that were then used for the construction of haplotypes. Only haplotypes with a frequency higher than 25% were selected. DGV was predicted using four variants of a linear model with random haplotype effects and deregressed breeding values as the response variables. The accuracy of genomic prediction was checked by comparing DGVs with estimated breeding values (EBVs) using two methods: Pearson’s correlations and the regression of EBV on DGV. The use of high-frequency haplotypes showed a tendency to underestimate DGVs. None of the models tested was clearly superior with regard to the traits studied. DGVs of production and conformation traits as well as somatic cell score (medium or high heritability traits) were more accurate than those estimated for fertility traits (low heritability traits).

Profile and nutritional value of fatty acids in selected skeletal muscles of Polish Holstein-Friesian bu

The aim of the study was to compare the skeletal muscles (longissimus lumborum – LL vs. semitendinosus – ST) of Polish Holstein-Friesian bulls in terms of their chemical composition, fatty acid proportions and the degree to which they meet standards for selected nutrients. The proximate composition, that is, the content of water, ash, crude protein, fat and collagen, was determined in the muscle samples collected. The calorific value of 100 g of meat was calculated based on the total protein content and intramuscular fat, using energy equivalents: 4 kcal for protein and 9 kcal for fat. The fatty acid profile (FA) was determined by gas chromatography (GC-FID), and the following groups were distinguished: saturated fatty acids (SFA), monounsaturated fatty acids in the cis (MUFA cis) and the trans configuration (MUFA trans), as well as polyunsaturated fatty acids (PUFA). On the basis of the content of individual fatty acids, the ratio of PUFA/SFA and n-6/n-3 was calculated. In addition, the following indices were calculated: atherogenic index (AI), thrombogenic index (TI), saturation index (S/P), as well as nutritional value (NV) and the ratio of hypo- and hypercholesterolaemic fatty acids (h/H). The results obtained for fatty acids were expressed as 1) percentage of individual fatty acids in total FAs quantified and 2) as quantity (in mg) per 100 g of fresh meat. Statistical calculations were performed using Statistica software ver. 13. Differences between the muscles were verified with the t-test for independent samples, assuming significance levels of p ≤ 0.05 and p ≤ 0.01. The muscle type was found to significantly influence the fatty acid (FA) profile for four of the 24 FAs identified. Compared to ST, the LL muscle had a significantly higher share of C18:0 (18.95% vs. 16.55%; p ≤ 0.01) and CLA (0.38% vs. 0.29%; p ≤ 0.05) and significantly lower percentages of C16:1 c9 (3.17% vs. 3.74%; p ≤ 0.05) and C18:1 c9 (36.02% vs. 38.65%; p ≤ 0.05). With regard to particular groups of fatty acids, the LL muscle had significantly higher percentages of SFA (53.20% vs. 50.71%, p ≤ 0.05), PUFA (4.20% vs. 3.49%, p ≤ 0.05) and n-6 (2.69% vs. 2.10%, p ≤ 0.01) and a significantly lower percentage of cis MUFA (40.73% vs. 43.96%; p ≤ 0.01). The average amount of fat in 100 g of muscle tissue was 693.30 mg for SFA, 560.81 mg for MUFA cis, 54.74 mg for PUFA (including 33.87 mg of n-6 and 16.23 mg of n-3) and 24.63 mg for MUFA trans. The beef can be classified as a secondary source of fatty acids. The coverage of the recommended intake ranged from 2.5% to 3.8% for SFA, from 1.1% to 1.9% for MUFA, from 0.29% to 1.8% for n-3 acids, and was smaller than 1% for PUFA and n-6. The amount of EPA and DHA satisfied from 0.66% to 1.3% of the minimum daily requirement, while the amount of trans FA ranged from 0.9% to 1.4% of the maximum daily level. It is worth noting that 100 g of the beef provided on average 102.53 kcal, 1.46 g of fat and 22.34 g of protein, which cover, respectively, 5.1% of the daily calorie requirement, 1.9-3.3% of the fat requirement, and as much as 30-45% of the protein requirement for adults. Although the ST muscle, because of its 40% lower fat content and 2% lower protein content, was less caloric than the LL muscle, it also contained fewer biologically active FAs, including CLA, VA, ALA, LA, AA, EPA and DPA. Irrespective of the differences shown, the meat can be classified as a low-calorie and high-protein product, as 87% of its energy value came from protein.

Effect of addition of buserelin acetate to the extender on motility and viability of bovine spermatozoa

The present study was aimed to determine the effect of GnRH analog (buserelin acetate) on the quality of bovine spermatozoa stored at 16° C for 24 h. Semen collected in the summer season from June to September from healthy Polish Holstein–Friesian bulls. Ejaculates were centrifuged, divided and diluted to the final concentration of 240 × 106 spermatozoa/mL using animal protein–free commercial BIOXcell® extender (IMV Technologies, L’aigle, France) (Control) or with BIOXcell® extender supplemented with buserelin acetate and stored 0, 8 and 24 h. Sperm motility parameters analysis was performed using a computer-assisted sperm analysis (CASA) system. The viability of spermatozoa was performed using flow cytometer. The addition of buserelin acetate to BIOXcell® extender did positively affect the total motility (was higher in the observed samples with the addition of 2 µg/mL and 4 µg/mL than in the control group), progressive motile (forward progressing sperm was significantly increased (p < 0.05) over the control group at the 0 h and 8 h of incubation following the supplementation of 2, 4 and 8 μg/mL buserelin acetate) and viability of spermatozoa (the number of live spermatozoa was significantly higher (p < 0.05) in 2 µg/mL and 4 µg/mL samples with buserelin acetate at 8th hour of incubation and in sample with 4 µg/mL at 24th hour of incubation compared to the control group). We recommend adding 4 µg/mL to the extender to improve the quality of bovine semen.

Collagen profile and tenderness of strip loin and silverside originated from polish Holstein-Friesian bulls of the black and white variety

The aim of the study was to determine and compare the collagen profile of two beef carcass cuts: silverside (M. semitendinosus) and strip loin (M. longissimus lumborum), originated from Polish Holstein-Friesian bulls of the black and white variety. Silverside showed higher total, acid-soluble, total soluble, and insoluble collagen content than strip loin. Significant differences between silverside and strip loin were noted in their share of water-soluble and acid-soluble collagen (% total collagen, P&lt;0.05). The thermal treatment caused cooking losses, which reached 38% in strip loin and 40% in silverside. There were no significant differences in shear force values or organoleptic quality between the cuts, which indicates their similar usefulness as meat for roasting. The content and profile of intramuscular collagen did not influence the organoleptic quality or shear force values of silverside and strip loin.

Effect of ageing on the physicochemical properties of musculus longissimus lumborum of young bulls of five breeds

Recent years have seen increasing interest in the conservation and use of native breeds of livestock raised in traditional farming systems. The experience of many European countries shows that promotion of raw materials and products derived from these breeds through a labelling system has a beneficial effect on the sustainable development of rural areas, contributes to preservation of the cultural heritage of the countryside, and increases the population of the breeds. As yet no beef produced in Poland has been included on the European list of traditional and regional products. For this reason we conducted a study to evaluate selected physicochemical properties of the meat of young bulls of three native breeds, Polish Red, White-Backed and Polish Black-and- White, compared with the meat of young Simmental and Polish Holstein-Friesian bulls, during a 14-day ageing of vacuum-packed meat. The following parameters were measured in m. longissimus lumborum (MLL) taken from half carcasses of 50 young bulls (10 from each breed): pH, electrical conductivity (45 min., 24 h, 2, 7 and 14 days post mortem), colour (according to CIE L*a*b*), shear force and energy. The water-holding capacity of the meat (drip loss, cooking loss and free water by the Grau-Hamm method), TBARS value (on days 2, 7 and 14) and content of haem pigments were determined as well. The physicochemical parameters of the MLL muscle obtained from the native Polish breeds of bulls (Polish Red, White-Backed and Polish Black-and-White) had intermediate values between those of Polish Holstein- Friesian (dairy type) and Simmental (dual-purpose) cattle. No qualitative deviations, such as those associated with DFD syndrome (pH 48 h in the range of 5.51-5.72), were found in any of the samples, which indicates that the raw material is well suited to the production of beef for culinary purposes. The breed of cattle was found to significantly influence the water-holding capacity parameters. The highest (P &lt; 0.001) drip loss was reported on the 14th day post mortem for the MLL of young bulls of the Simmental (6.89%) and Polish Red breeds (6.47%). The highest cooking loss was found on the 7th day post mortem in the MLL of young bulls of the Polish Holstein-Friesian (30.66%) and Simmental breeds (30.92%). Significantly (P &lt; 0.01) the least favourable water-holding capacity (the largest amount of free water) was shown by the muscle of young bulls of the Simmental breed on the 2nd day post mortem (75.31 mg) and the Polish Red breed on the 7th and 14th days post mortem (67.42 mg and 60.36 mg, respectively). On the 2nd and 7th days post mortem, the most tender MLL muscle was found (according to WBSF shear force) in the Polish Holstein-Friesian (76.8 N and 69.3 N) and Polish Black-and-White breeds (89.5 N and 59.1 N). On the last, 14th day of ageing, the instrumental WBSF shear force for the breeds evaluated was definitely more homogeneous and did not differ significantly (shear force in the range of 56.3-65.7 N; P &gt; 0.05). Compared to the muscle of native breeds, that of the Polish Holstein-Friesians showed significantly lower haem pigments (on average 35 ppm less; P &lt; 0.01) and a lower proportion of redness (a*) (P &lt; 0.01) on the 2nd and 7th days post mortem. The MLL muscle of young bulls of the Polish Red breed had the lowest (P &lt; 0.01) percentage content of yellowness (b*) during the whole ageing period. Significantly (P &lt; 0.01) lower oxidative stability (higher TBARS value) was found in the meat from young bulls of the Polish Holstein-Friesian breed (on the 2nd and 7th days post mortem) and the White-Backed breed (on the 14th day) compared to all other breeds analysed. In general, the ageing time had a positive influence on the muscle quality, as the determinants of the visual and sensory attractiveness of the meat, which are also important in the meat industry, remained stable (pH), improved (colour and water-holding capacity G-H) or became more similar among the breeds (tenderness assessed on the basis of shear force, cooking loss)....

Cholesterol Deficiency - new genetic defect transmitted to Polish Holstein-Friesian cattle.

The aim of the study was to find out whether carriers of new genetic defect Cholesterol Deficiency (CD) occur in the population of Polish Holstein-Friesian bulls. Twenty seven bulls were included in the analysis. Bulls were selected as having in the pedigree known carrier of CD (Maughlin Storm CANM000005457798). All bulls were diagnosed by the test described by Menzi et al. (2016) by using allele-specific PCR. Among 27 bulls, 9 new CD carriers were found. Our results show that causal mutation for CD is already transmitted to Polish Holstein-Friesian cattle. The results are sufficient ground to take practical action in order to avoid further spreading of mutation causing CD.

Association between SOX5 Genotypes and Semen Quality in Polish Holstein-Friesian Bulls.

The aim of this study was to evaluate the effect of C/T missense mutation (SOX5) gene on selected parameters of non-frozen semen in Polish Holstein - Friesian bulls. Three hundred and sixty eight bulls were genotyped by the PCR-Rsa I technique. Semen was collected and evaluated by standardized procedure used in an AI station. Significant associations were found between SOX5 genotypes and sperm concentrations (p=0.020) and sperm motility (p=0.014). Bulls with TT genotype had the lowest values of both traits. Our results demonstrate that C/T missense mutation within the SOX5 gene is involved in bull sperm quality.

The influence of diet on collagen content and quality attributes of infraspinatus muscle from Holstein–Friesian young bulls

The aim of the study was to determine effects of feeding intensity on collagen content and eating quality of infraspinatus (INF) muscle. Twenty Polish Holstein-Friesian bulls (11-month-old) were fed either intensively (I, n=10, with triticale meal addition to total mixed ration) or semi-intensively (SI, n=10, without triticale meal) before slaughter at 19months. The animals from I group showed higher body weight at the end of fattening, average daily gain and dressing percentage than SI group. The INF muscle from I treatment had higher fat content and the proportion of water-soluble collagen, whereas lower insoluble collagen content compared with SI treatment. There were no differences in shear force values, cooking loss and eating quality between the treatments. In conclusion, feeding Holstein-Friesian bulls with increased energy value fodder beneficially affected its slaughter value and collagen profile in infraspinatus muscle.

Evaluation of the Mineral Concentration in Beef from Polish Native Cattle.

The aim of the study was to determine the content of macrominerals and microminerals in the longissimus lumborum (LL) and semitendinosus (ST) muscles of young bulls of five breeds—Polish Red (PR), White-Backed (WB), Polish Black-and-White (PBW), Simmental (SIM) and Polish Holstein-Friesian (PHF). The meat of the Polish Holstein-Friesian bulls was found to contain significantly less K, Mg and Ca and more Mn than other breeds. The meat of the White-Backed bulls contained significantly (P < 0.01) more Ca and less Na than the meat of the Polish Red, Simmental and Polish Holstein-Friesian breeds. Moreover, the meat of White-Backed bulls showed a significantly (P < 0.01) higher level of Mn and Cu in comparison with other native breeds (Polish Red and Polish Black-and-White) and the Simmental breed. Similar content of macronutrients was found in the LL and ST muscles. However, in the case of micronutrients, the LL muscle contained significantly more Zn, Fe and Cu as well as Mn (P > 0.05).