Holstein Breed Research Articles

Environmental factors affecting the conception rates of nulliparous and primiparous dairy cattle

Dairy cattle must allocate energy to milk production and reproduction. Therefore, understanding the environmental factors that affect conception rates in nulliparous and primiparous cows is helpful in appropriate feeding management strategies before and after calving. Accordingly, the aim of this study was to investigate the influence of environmental factors before and after the first calving on the conception rate, representing the starting point of milk production. The records of the first artificial insemination (AI) from Holstein nulliparous cows (n = 533,672) and primiparous cows (n = 516,710) in Hokkaido, Japan, were analyzed using separate multivariable logistic regression models. The mean conception rates for nulliparous and primiparous cows from 2012 to 2018 were 55.2 and 39.2%, respectively. In both nulliparous and primiparous cows, the conception rate of crossbreeding using Japanese Black (JB) semen was significantly higher than that for purebred Holstein breeding. The conception rate using sexed semen decreased in the warmer months only in nulliparous cows. Moreover, we grouped primiparous cows according to milk yield during peak lactation (PY; < 25, 25-30, 30-35, ≥35 kg) and the interval from calving to first insemination (CFI; < 60, 60-79, 80-99, ≥100 d), and evaluated their combined effect on the conception rate. Both PY and CFI strongly affected the conception rate in primiparous cows, which decreased with an increase in PY, even for the group with CFI ≥100 d; however, the conception rate increased for a CFI ≥60 d regardless of PY. Taken together, this study demonstrates the long-term effect of PY and an independent effect of CFI on the conception rate of cows. These results provide guidance for management to execute appropriate AI implementation strategies before and after lactation.

ADVANTAGES OF USING TETRA-PRIMER ARMS-PCR REACTION METHOD FOR DETECTING CARRIERS OF HH3, HH5 FERTILITY HAPLOTYPES IN CATTLE

the strategy for eliminating harmful mutations in the Holstein breed includes genetic monitoring of the prevalence of hidden hereditary anomalies using molecular genetic methods. Currently, there is a tendency to increase the number of hereditary diseases in highly productive breeding animals due to intensive selection and inbreeding. The aim of this study was to develop new and improve existing molecular genetic methods for diagnosing carriers of fertility haplotypes HH3, HH5 in Holstein cows and to study the incidence of these diseases. Diagnosis of heterozygous carriers of the mutation in the coding part of the SMC2 gene was carried out using the tetra-primer ARMS-PCR reaction, the sequences of external and internal primers were determined using the Primer 1 program. Allele-specific primers were used to detect carriers of the deletion in the TFB1M gene, the sizes of the PCR product in homozygous healthy animals 442 bp, in heterozygous carriers 442 bp. and 256 b.p. According to the results of genetic monitoring in the study population, the frequency of heterozygous carriers of the HH3 fertility haplotype was 3.23%, HH5 - 8.35%. It is recommended, in order to control the risk of morbidity of breeding stock with hereditary anomalies, to carry out genetic screening of breeding stock of dairy farms with the coverage of diagnostic tests ranging from 10% to 20% of the total livestock.

Immunogenetic monitoring of lines the breed of Sychevka cattle

The results of immunogenetic monitoring from 1986 to 2020 of the lines of Anis 4593 ZSV – 236 (n = 287), Liker 5412 ZSV-585 (n = 263), and Toreador 3032 ZS-485 (n = 627) of the breed of Sychevka cattle in the Smolensk region, using red blood cell antigenic factors EAB – locus of blood groups as genetic markers are presented. As a result of the line crosses carried out, as well as the introduction of genes of the Red-and-White Holstein breed, an expansion of genetic diversity is observed in each line. The coefficient of genetic similarity between the animals of the lines breed in 1986 and their descendants in the male line in 2020 is 52.8-61.9, which indicates a significant change in the genetic structure of each line. The number of animals carrying marker and, consequently, other alleles specific to the progenitors of the lines or their successors has decreased in the lines. Animals with other alleles inherited from the breeds of Sychevka and Holstein Red-and-White have become widespread. In the Anise line, its descendants are most common, marked with alleles of the EAB locus G2Y2'1Q` (27%), b (16,7%), O1I'Q` (9,1%); in the Liker line – B1I1T1A`1 (11,1%), E ' 3G`(10,1%), G2Y2E`1Q` (10,1%); in the Toreador line – O1I`Q` (19,5%), Y1A`1 (16%), G2Y2E`1Q` (11,3%).

Features of conformation type of black-andwhite cows of different origin estimated by linear classification method

The research was carried out in the aspect of studying features of conformation type cows of Ukrainian Black-and-White dairy and Holstein breeds estimated by linear classification method. As for the basis we took the herd of the company "Ukrlandfarming, private enterprise "Burynske", Pidlisniv branch in Sumy region. The aim was to conduct a comparative analysis of experimental breeds according to the assessment of linear classification and determine the impact of final score for type on milk productivity first-born cows. In general, first-born cows of both breeds were characterized by good linear estimation, especially on a 100-score scale. However, animals of Holstein breed in comparison with Ukrainian Black-and-White dairy were better in terms of body parts, which characterize the dairy type by 1.3 score, body - by 0.8 score, udder - by 1.2 score and the final assessment - by 0.8 score (P &lt;0.001).On the trait of chest width, Holstein animals were inferior to their Ukrainian Black-and-White dairy breeds with reliable difference of 1.3 score, but exceeded in angularity - by 1.2 score, strength of fore udder parts attachment - on 0.8 score, central ligament - by 1.1 score (P &lt;0.001).The final estimation level of first-born cows for conformation type directly proportionally determined their milk productivity in 305 days of the first lactation. Cows of Holstein and Ukrainian Black-and-White dairy breed with score - "very good" exceeded their peers with score - "good with plus" for milking by 785 and 589 kg (P˂0.01) respectively, and with score of "good" - by 1705 and 1502 kg (P˂0.001). The use in the selection process of dairy cattle, in determining cows breeding value, linear classification method will be a very effective means of objective definition breed features of conformation type. The presence of correlative relationship between the final score and milk productivity level will contribute to the effectiveness of selection in the indirect sampling of animals on these traits. Key words: Holstein, Ukrainian Black-and-White dairy, linear type assessment, conformation, milk yield.

Resequencing the Yaroslavl cattle genomes reveals signatures of selection and a rare haplotype on BTA28 likely to be related to breed phenotypes.

The genomes of local livestock could shed light on their genetic history, mechanisms of adaptations to environments and unique genetics. Herein we look into the genetics and adaptations of the Russian native dairy Yaroslavl cattle breed using 22 resequenced individuals and comparing them with two related breeds (Russian Kholmogory and Holstein), and to the taurine set of the 1000 Bull Genomes Project (Run 9). HapFLK analysis with Kholmogory and Holstein breeds (using Yakut cattle as outgroup) resulted in 22 regions under selection (q‐value < 0.01) on 11 chromosomes assigned to Yaroslavl cattle, including a strong signature of selection in the region of the KIT gene on BTA6. The F ST (fixation index) with the 1000 Bull Genomes Dataset showed 48 non‐overlapping top (0.1%) F ST regions of which three overlapped HapFLK regions. We identified 1982 highly differentiated (F ST > 0.40) missense mutations in the Yaroslavl genomes. These genes were enriched in the epidermal growth factor and calcium‐binding functional categories. The top F ST intervals contained eight genes with allele frequencies quite different between the Yaroslavl and Kholmogory breeds and the rest of the 1000 Bull Genomes Dataset, including KAT6B, which had a nearly Yaroslavl breed‐specific deleterious missense mutation with the highest F ST in our dataset (0.99). This gene is a part of a long haplotype containing other genes from F ST and hapFLK analyses and with a negative association with weight and carcass traits according to the genotyping of 30 phenotyped Yaroslavl cattle individuals. Our work provides the industry with candidate genetic variants to be focused on in breed improvement efforts.

Вплив країни походження та інбридингу на продуктивність бугаїв основних комерційних порід України

Goal. To monitor the productivity of Holstein, Ukrainian black and red-spotted dairy bulls, which were allowed to reproduce breeding stock in 2021, depending on the country of birth, quality of offspring, and degree of inbreeding to preserve the gene pool, selection methods, and improvement of economically useful traits in offspring. Methods. The study was conducted on bulls of Holstein (660 heads), Ukrainian red-spotted (65), and Ukrainian black-spotted (45 heads) dairy breeds, assessed by the quality of offspring in the country of birth. The average values of the selection index (SI), milk yield, fat and protein, and the limits of traits were determined by the methods of mathematical statistics. Results. Among Holstein bulls, most were born in the United States, Ukraine, and Canada. The daughters of Holstein bulls of Ukrainian origin had the least milk yield for lactation (2,801 kg), and the Canadian had the highest (14,302 kg). SI bulls of the Ukrainian red-spotted dairy breed were at the level of – 1051…+1426. Daughter descendants of bulls of this breed had milk yield for lactation 2559–10209 kg, fat and protein content in milk 3.41–4.18 and 2.83-3.42%, respectively. SI of bulls of the Ukrainian black-spotted dairy breed made – 1051…+1122, and milk yield of cows for lactation of 2022-9064 kg of milk with the fat content of 3,42–4,05% and protein — 3,04–3,23%. In the group of Holstein bulls, 82% of animals were inbred animals, in the Ukrainian red-spotted dairy breed — 68%, and in the Ukrainian black-spotted dairy breed — 51%. The highest milk yield for the daughters was provided by the breeders of Holstein and Ukrainian black-spotted dairy breeds of moderate inbreeding, Ukrainian red-spotted dairy breeds — distant. Conclusions. To increase milk yield in daughter offspring, it is advisable to use bulls of Holstein and Ukrainian black-spotted dairy breeds of moderate inbreeding (Fx=1.56–12.4%), Ukrainian red-spotted dairy breed — distant (Fx=0.2–1.55%).

Seroprevalence and risk factors associated with bovine herpesvirus 1 in dairy herds of Colombia.

Background and Aim:Infectious bovine rhinotracheitis (IBR) is an infectious disease widely distributed globally and is considered the main cause of various reproductive and respiratory tract diseases in cattle and buffaloes. This study aimed to estimate seroprevalence and determine risk factors associated with the presentation of IBR in the municipality of Sotaquirá, Boyacá (Colombia).Materials and Methods:A descriptive cross-sectional study with simple random sampling was performed, and the sample size was 1,000 cattle. Blood samples were obtained by coccygeal venipuncture and processed through indirect enzyme-linked immunosorbent assay using the Synbiotics® kit (Zoetis, New Jersey, USA) with a sensitivity and specificity of 96% and 98%, respectively. Data were processed using the statistical program EpiInfo® (Centers for Disease Control and Prevention; Atlanta, Georgia).Results:A high seroprevalence of 57.5% was established. Seroprevalence was the highest in cattle >4 years of age (65.0% apparent seroprevalence [AS]; 67% true seroprevalence [TS]) and in the Holstein breed (65.5% AS; 67.8% TS). The breed and age of the animals were significantly associated with each other. The Holstein breed, age group >4 years, uncertified semen, and fetal death were established as risk factors for IBR. In comparison, the age groups of <1 and 1–2 years and the Normande breed were established as protective factors against the bovine herpesvirus-1 virus.Conclusion:Management factors, such as livestock from other owners and animal purchases, which affect disease presentation, are evident. The implementation and development of novel prevention and control measures for IBR at the national level are necessary.

The importance of the feeding levels and adequacy on the meat quality and productivity performance of cross-bred bulls

The study aimed to determine the effect of the level and adequacy of feeding on the dynamics of live weight and meat productivity of Simmental × Holstein bulls with a close blood relationship (87.5%) for the Holstein breed. Three groups of bulls with 87.5% Holstein heredity in the genotype were formed, out of which two groups were experimental and one group served as a control group. The bulls of the control group received a diet compiled according to detailed standards, and their analogs from the experimental groups had a diet exceeding the norm by 10 and 20% respectively. During the entire growing period, the bulls of the 1st experimental group consumed 3,564 energetic feed units and 362.5 kg of digestible protein, the 2nd consumed 3,875 and 394.3 kg, and the control group 3,245 and 329.9 kg, respectively. In terms of carcass yield, bulls of the first and second experimental groups outperformed the ones from the control group by 2.41 and 3.92%. With an increase in the level of feeding in experimental bulls, fat deposition accelerated; thus, the meat of bulls of the experimental groups contained 2.13% and 2.54% more fat than in animals of the control group. At the same time, the protein content in the meat of experimental bulls decreased by 0.15 and 0.22% in comparison with the control group. The energy value of 1 kg of meat of experimental bulls was higher by 0.77-0.90 MJ. It can be concluded that a possible increase in the meat productivity of bulls-crossbreeds of the Holstein breed with a close blood relationship and the determination of planned indicators of animal growth should be taken into account when developing breeding programs.

Morphological and functional traits and main disadvantages of the udder in cows of Black-and-White breed

The object of research was the first-calf cows of Black-and-White breed. The groups were formed taking into account the part of blood of Holstein breed. The 1st group included animals with the part of blood than 50 % (an average of 37 % in the group), the 2nd with the part of blood of 50 % and the 3rd more than 50 % (an average of 63 % in the group). An increase in the part of blood in animals in the farm to 63 % had a positive effect on changing the shape of the udder. Thus, in the group of low the part of blood animals there were 78,2 % of cows with a cup-shaped shape and 21,8 % with a rounded one. Among half-blood cows with the cup-shaped udder accounted for 92,2 %, and with the rounded one it was 7,8 %, among the high part of blood it was 94,8 and 5,2 %%, respectively. In terms of udder length and depth measurements, cows with the high part of blood outperformed cows with the low part of blood by 2,5 cm (р &lt; 0,01) and 2,1 cm (р &lt; 0,01), respectively. In terms of udder decline, the difference between these groups of animals was 5,7 abs.% (р &lt; 0,01) in favor of animals with the higher proportion of Holstein breed blood. First-calf cows with half part of blood and the high part of blood of Holstein breed were ahead of their herd mates with the low part of blood in terms of the rate of milk speed out the difference was 0,3 kg/min (р &lt; 0,05) and 0,4 kg/min (р &lt; 0,001), respectively. The most common udder defect (10 %)was narrow rear teats, while in the group with the high part of blood cows its occurrence was the lowest 6,7 %. The sum of the frequencies of udder defects in cows with the high part of blood was 16,7 % versus 23,3 % in the other two groups. We recommend to use purebred Holstein sires for mating with low-blood heifers and cows, and using sires with the part of blood of Holstein breed of 62 to 75 % or breeding “inter se” on heifers and cows with the higher proportion of blood of Holstein breed.

Influence of the genotype of sires on zinc concentration in the muscle tissue of offspring

The selection of sires whose off spring are predisposed or resistant to the accumulation of chemical elements in muscle tissue is especially relevant for geochemical provinces with abnormal concentrations of trace elements. The concentration of zinc in the muscle tissue of 34 steers who were off spring of four sires of Holstein breed has been studied. Muscle tissue has been taken from a diaphragm weighing 100 g. The zinc level in the meat of steers was determined by atomic emission spectrometry with inductively coupled plasma on an IRIS Advantage spectrometer. The animals were housed in the Promyshlenskyareain the Kemerovo region under the same environmental conditions. Due to the small number of variants among the off spring of the sire Bonaer, robust indicators of descriptive statistics were calculated. In order to identify the influence of the genotype of sires on the level of zinc in the muscle tissue of off spring the Kraskell-Wallis criterion has been used. Median values of zinc levels in muscle tissue in the off spring of sires Bonaer, Brio, Malstrom and Fabio were 37, 46, 45 and 64 mg/kg, respectively. On this basis, the off spring of sires can be grouped into a ranked series: Bonaer&lt; Brio

Genomic predictions for crossbred dairy cows by combining solutions from purebred evaluation based on breed origin of alleles

Genomic predictions have been applied for dairy cattle for more than a decade with great success, but genomic estimated breeding values (GEBV) are not widely available for crossbred dairy cows. The large reference populations already in place for genomic evaluations of many pure breeds makes it interesting to use the accurate solutions, in particular the estimated marker effects, from these evaluations for calculation of GEBV for crossbred heifers and cows. Effects of marker alleles in crossbred animals can depend on breed origin of the alleles (BOA). Therefore, our aim was to investigate if reliable GEBV for crossbred dairy cows can be obtained by combining estimated marker effects from purebred evaluations based on BOA. We used data on 5,467 Danish crossbred dairy cows with contributions from Holstein, Jersey, and Red Dairy Cattle breeds. We assessed BOA assignment on their genotypes and found that we could assign 99.3% of the alleles to a definite breed of origin. We compared GEBV for 2 traits, protein yield and interval between first and last insemination of cows, with 2 models that both combine estimated marker effects from the genomic evaluations of the pure breeds: a breed of origin model that accounts for BOA and a breed proportion model that only accounts for genomic breed proportions in the crossbred animals. We accounted for the difference in level between the purebred evaluations by including intercepts in the models based on phenotypic averages. The predictive ability for protein yield was significantly higher from the breed of origin model, 0.45 compared with 0.43 from the breed proportion model. Furthermore, for the breed proportion model, the GEBVs had level bias, which made comparison across groups with different breed composition skewed. We therefore concluded that reliable genomic predictions for crossbred dairy cows can be obtained by combining estimated marker effects from the genomic evaluations of purebreds using a model that accounts for BOA.

Estrogen Concentration on Friesian Holstein Crossbred with Supplementation Feed Cassava Peel

The purpose of this study was to determine the ratio of estrogen concentrations given cassava peel feed supplementation. A total of 24 cows of Friesian Holstein, weighing 250-300 kg were divided into two groups and each group contains 12 replications. The first group is Friesian Holstein breeds with the condition that they are given elephant grass feed ad libitum and 25 kg of tofu dregs. The second group is Friesian Holstein breeds with the condition that they are fed ad libitum elephant grass, 25 kg of tofu dregs, and 25 kg of cassava peel. The milk samples were then taken to be tested for estrogen levels using the direct competitive ELISA. Analysis of estrogen concentration data was then carried out by normality test using Shapiro Wilk test then followed by the Paired T-test with a significance level of 5%. Based on the Paired T sample correlation test was 0.072 (p&gt;0.05), which means that the feed gave the cassava peel and not the cassava peel was negatively associated. Based on the Paired T-test is 0.193 (p&gt;0.05), which means there is no significant relationship between the 2 test groups. It can be concluded that there is no significant difference in the estrogen concentration of Friesian Holstein cattle fed with and without cassava peel supplementation.

Екстер’єрно-конституційні особливості корів-первісток молочних порід

Goal. To study the exterior features of cows of different genotypes obtained by purebred breeding and crossbreeding. Methods. Analysis of experimental research on the application of effective breeding methods, theoretical analysis, formulation of hypotheses, genealogical, biometric and statistical methods, and assessment of productive qualities of animals. Results. It was established that the breeders of Holstein, Montbeliard, and Norwegian red breeds were sufficiently consolidated in terms of exterior features and influenced the formation of the desired characteristics in their offspring. High rates of single milk yield of experimental cows indicated good development of the parenchyma and capacitive system of the udder. The bath-shaped form of the udder had mostly (73.7–76.7%) first-born cows obtained from Holstein breeders. This udder was quite close to the abdomen of the animals, forming only a small corner of the line of the abdomen and the front of the udder. Among the local firstborns of the genus 1/2UCheR1/2M, 63.4% of cows had a bath-shaped udder, and 33.4% — were cup-shaped. The conditional udder volume of first-born cows was almost the same and averaged from 2561.3±93.66 to 2985.4±94.48 cm3, respectively. This made it possible to obtain average daily milk yields of 26.6±1.54-31.0±1.94 kg from first-borns during 2 times milking. With the average degree of reliability (P>0.99) milk yield of cows correlated with measurements of the girth of the chest behind the shoulders (r=+0.210+0.254), oblique length of the torso (r=+0.212+0.241), and width in the macula (r=+0.137+0.185). A high degree of correlation was found between the amount of milk and udder measurements: width (r=+0.514+0.587; P>0.999), girth (r=+0.506+0.587; P>0.999), and volume (r=+0.504+0.650); P>0.999). Conclusions. The use of genetic material from the Norwegian Red and Holstein breeds contributed to the formation of an array of animals with a well-defined milk type. The possibility of first-borns with a rough, massive skeleton and polymastia in the herd should be taken into account when selecting breeders of Montbeliard breeds. There is a close relationship between milk productivity and udder measurements, which indicates the possibility of indirect selection of cows for milking at the beginning (1–2 months) of the first lactation.

Genotypic structure of four cattle breeds raised in Turkey by loci related to several diseases

This study aims to reveal the genotypic structure of four cattle breeds; Holstein (HS), Turkish Grey Steppe (TGS), Anatolian Black (AB) and East Anatolian Red (EAR), raised in Turkey in terms of CD14, MBL, ITGB6, SLC11A1 and TLR2 genes and to evaluate their usefulness in Marker Assisted Selection (MAS). It also assesses whether the loci associated with resistance to diseases are suitable for phylogenetic analysis. Desired alleles and/or genotypes were detected in native Turkish cattle breeds at different frequencies in terms of polymorphisms of CD14, MBL, ITGB6, SLC11A1 and TLR2 genes which were previously reported to be associated with mastitis, foot-and-mouth disease and tuberculosis. These variations offer opportunities to improve selection strategies against diseases in the future. These results preliminary indicate that associated studies between these variations and disease resistance in native Turkish cattle breeds should be conducted. On the other hand, phylogenetic tree constructed based on genetic distance clearly separated native Turkish cattle breeds from HS breed. The gene regions related to diseases can be used to distinguish native cattle breeds from exotic ones.

Four novel candidate causal variants for deficient homozygous haplotypes in Holstein cattle

Mendelian variants can determine both insemination success and neonatal survival and thus influence fertility and rearing success of cattle. We present 24 deficient homozygous haplotype regions in the Holstein population of Switzerland and provide an overview of the previously identified haplotypes in the global Holstein breed. This study encompasses massive genotyping, whole-genome sequencing (WGS) and phenotype association analyses. We performed haplotype screenings on almost 53 thousand genotyped animals including 114 k SNP data with two different approaches. We revealed significant haplotype associations to several survival, birth and fertility traits. Within haplotype regions, we mined WGS data of hundreds of bovine genomes for candidate causal variants, which were subsequently evaluated by using a custom genotyping array in several thousand breeding animals. With this approach, we confirmed the known deleterious SMC2:p.Phe1135Ser missense variant associated with Holstein haplotype (HH) 3. For two previously reported deficient homozygous haplotypes that show negative associations to female fertility traits, we propose candidate causative loss-of-function variants: the HH13-related KIR2DS1:p.Gln159* nonsense variant and the HH21-related NOTCH3:p.Cys44del deletion. In addition, we propose the RIOX1:p.Ala133_Glu142del deletion as well as the PCDH15:p.Leu867Val missense variant to explain the unexpected low number of homozygous haplotype carriers for HH25 and HH35, respectively. In conclusion, we demonstrate that with mining massive SNP data in combination with WGS data, we can map several haplotype regions and unravel novel recessive protein-changing variants segregating at frequencies of 1 to 5%. Our findings both confirm previously identified loci and expand the spectrum of undesired alleles impairing reproduction success in Holstein cattle, the world's most important dairy breed.

Genetics of mastitis resistance in dairy cattle

Mastitis is one of the most common diseases of dairy cattle that appreciates the enormous losses of farm worldwide. Current treatment and prevention developed at the moment does not guarantee the reliable protection of animals from the disease, given the polyethological nature of mastitis. An important method of combating this problem may be a selection aimed at improving the immunity of livestock to the inflammation of the breast.The purpose of the article was to search and systematize information on genes associated with the sustainability of dairy cattle towards the development of clinical mastitis and SCS in milk, mainly among the Holstein breed. Also, the publication presents data on the genomic assessment of the bull leader 395, obtained on the basis of St. Petersburg University of Veterinary Medicine, in terms of indicators related to the sustainability of the offspring to the Master.The relationship between the markers of high milk productivity and is low-resistant to the mastel, the protein composition of milk and the frequency of the inflammatory processes of udder. The general mechanisms for the formation of immunity, nonspecific resistance and stability to the mastel are illustrated. A correlation is indicated between allele variants of genes regulating cell cycle or modulating autoimmune processes, and the SCS level in milk. When implementing a genomic estimate of the bull, the leader 395 was identified by its potential as an improved indicators such as SCS, mastotustability, the form of udder, the fatness of milk in daughters.

LACTATION FUNCTION OF FIRST-CALF HEIFERS OF HOLSTEIN BREED OF DIFFERENT ECOGENESIS IN THE CONDITIONS OF INTENSIVE TECHNOLOGY

The largest contribution to milk production increase is made by large highly-technological complexes, occupied by animals of the Holstein breed, imported from Western European countries. It currently accounts for 26.47% in the dairy herd structure of the Russian Federation. In this regard, it is necessary to study milk productivity, quality characteristics and safety of Holstein cows’ milk produced in the conditions of industrial technology, which is the purpose of our research. The scientific experiment was carried out in the conditions of OOO Agroindustrial Complex Rus, the largest milk producer in Ryazan region. As a result, high milk productivity of first-calf heifers of Holstein breed, imported from the Netherlands, Hungary and own reproduction under intensive technology, was established. There are no significant differences in production of specified lactation. The milk of cows of the studied genotypes had a high concentration of dry matter and calorie content, as for the content of somatic cells, it met the established requirements of the European and national standards. The content of minor components of milk indicated the absence of ketosis (β-hydroxybutyric acid, acetone) and compliance of energy and protein in the diets of cows (urea). The highest realization level of PIC (parent index of cow) for milk yield was shown by first-calf heifers of domestic selection, as the most adapted to local conditions, and the lowest - analogues imported from the Netherlands, with the highest PIC for milk yield. Their realization level of productive potential of milk yield was lower compared to the first-calf heifers of Hungarian and domestic selection, respectively, by 14.8 (P&lt;0.001) and 20.1% (P&lt;0.001), the coefficient of lactation curve stability is less than in comparison with domestic peers by 2.3 (Р&lt;0.01), and imported from Hungary by 1.3 (Р&gt;0.05), which shows that the housing conditions do not correspond to biological status of the first heifers imported from the Netherlands.

Mitochondrial DNA Variation Contributes to the Aptitude for Dressage and Show Jumping Ability in the Holstein Horse Breed.

Simple SummaryIn the Holstein horse breed, maternal lineages are considered to be of major importance for the breeding success and can be examined through analysis of the maternally inherited mitochondrial DNA (mtDNA). Since mitochondrial genes are involved in energy metabolism, variation might contribute to differences in performance characteristics, as has already been pointed out in humans and racehorses with respect to endurance. No corresponding studies have yet been conducted for the athletic performance of warmblood breeds and, thus, the aim of this study was to investigate the influence of mitochondrial variation on the performance of Holstein mares. The data set used for this study was composed of both sequenced and non-sequenced mares of 75 maternal lineages as a previous study revealed that Holstein mares within a maternal lineage had identical mtDNA haplotypes regarding their non-synonymous variants. Association analyses were performed using estimated breeding values (EBVs) based on information from sport and breeding events. We observed mitochondrial single nucleotide polymorphisms (SNPs) significantly associated with one or more of the examined EBVs and identified mitochondrial haplogroups with a particular aptitude for dressage or show jumping.Maternal lineages are considered an important factor in breeding. Mitochondrial DNA (mtDNA) is maternally inherited and plays an important role in energy metabolism. It has already been associated with energy consumption and performances, e.g., stamina in humans and racehorses. For now, corresponding studies are lacking for sport performance of warmblood breeds. MtDNA sequences were available for 271 Holstein mares from 75 maternal lineages. As all mares within a lineage showed identical haplotypes regarding the non-synonymous variants, we expanded our data set by also including non-sequenced mares and assigning them to the lineage-specific haplotype. This sample consisting of 6334 to 16,447 mares was used to perform mitochondrial association analyses using breeding values (EBVs) estimated on behalf of the Fédération Équestre Nationale (FN) and on behalf of the Holstein Breeding Association (HOL). The association analyses revealed 20 mitochondrial SNPs (mtSNPs) significantly associated with FN-EBVs and partly overlapping 20 mtSNPs associated with HOL-EBVs. The results indicated that mtDNA contributes to performance differences between maternal lineages. Certain mitochondrial haplogroups were associated with special talents for dressage or show jumping. The findings encourage to set up innovative genetic evaluation models that also consider information on maternal lineages.

The prolonged effect of GLUTAM 1M biologically active preparation on dairy productivity and milk quality of cows

We have studied the effect of biologically active preparation of metabolic-neurotropic action “Glutam 1M” on milk productivity of cows and quality indicators of raw milk. This preparation was used for dry cows in the last trimester of pregnancy. Studies were performed in the private agricultural enterprise “Savertsi” of Popilnyansky district of Zhytomyr region on cows of Holstein breed. The biologically active preparation “Glutam 1M” has been administered to the cows of the experimental groups under the skin behind the shoulder blade in an amount of 20 ml, starting from 270 and 265 days of gestation, once a day for three consecutive days. Cows of control groups were injected with saline in the same dose. Using the biologically active preparation “Glutam 1M”, a milk yield decreased slightly by 2% (91.9 kg). The milk yield increased by 2.9% (141.5 kg) in the control group. 305-days milk yield in the control group of cows was almost the same as in the previous lactation period. During the experiment, the experimental group of cows – has decreased by 2.9% (136.5 kg). A similar situation has been observed during the biologically active preparation “Glutam 1M” on the 270 – 272th days of pregnancy. Milk yield in the experimental group of animals for the previous lactation and after the use of preparation remained almost at the same level in the control group – decreased by 4.7% (207.1 kg). 305-days milk yield in the control group of cows for the previous and post-lactation experiment period was almost the same. In the experimental group of animals, there was an increase in this indicator by 2.7% (128.7 kg). The use of the “Glutam 1M” preparation did not affect milk quality, namely the mass fraction of fat and protein; fluctuations of the above indicators stayed within the error.

Assessment of A1 and A2 variants in the CNS2 gene of some cattle breeds by using ACRS-PCR method

The aim of this study is to reveal β-casein polymorphism of some cattle breeds and also the potential to produce A2 milk from existing animals and to develop strategies in this area. Therefore, a total of 400 cattle, 100 animals from each breed of Holstein, Brown Swiss, Jersey and Simmental raised commonly in Turkey, were obtained, and C > A polymorphism in 67th amino acid in the 7th exons of β-casein gene was determined by TaqI enzyme with PCR-ACRS method. Blood samples were collected from dairy cattle farms raising Holstein, Brown Swiss and Jersey breeds from Konya province and Simmental breed from Kütahya province in Turkey. A1 and A2 allele frequencies in Holstein, Brown Swiss, Jersey and Simmental cattle breeds were determined as 0.475/0.525, 0.370/0.630, 0.215/0.785 and 0.440/0.560, respectively. The highest A2 allele frequency (0.785) was found in Jersey breed. A1A1 genotypes in Holstein, Brown Swiss, Jersey and Simmental breeds were 0.240, 0.150, 0.030 and 0.160, respectively; A1A2 genotypes were 0.470, 0.440, 0.370 and 0.560, respectively; A2A2 genotypes were determined as 0.290, 0.410, 0.600 and 0.280, respectively. In these breeds, the highest A2A2 genotype frequency was found in Jersey (0.600), the lowest A1A1 genotype frequency (0.030) was found in Jersey and the highest A1A2 genotype frequency (0.560) was found in Simmental. Holstein, Brown Swiss, Simmental and Jersey populations were at the level of Hardy-Weinberg in terms of β-casein gene (p > 0.05). The average Ho, He and PIC values were calculated as 0.460, 0.469 and 0.605, respectively. In conclusion, the frequency of commonly reared cattles in Turkey especially Brown Swiss, and Jersey breeds in A2A2 genotype are satisfactory, but it can be said that the use of animals with A2 allele in selection is extremely important for increasing A2 milk producing potential in the future.