Holstein Cows Research Articles

Clinical, magnetic resonance imaging and histopathological findings of a congenital hypomyelinating leukodystrophy in a Holstein Friesian calf

AbstractA 12‐day‐old, male Holstein Friesian calf was presented to the hospital due to progressive ataxia and tremors since birth. A diffuse central nervous system disorder primarily affecting white matter was suspected based on clinical neurological examination. Blood tests were unremarkable, except for positive serology for Schmallenberg virus. Magnetic resonance imaging of the brain demonstrated severe, diffuse abnormalities primarily affecting the white matter regions of the encephalon and cranial cervical spinal cord, consistent with leukoencephalomyelopathy. Euthanasia was performed at 8 weeks of age after no clinical improvement. A postmortem examination was performed. Histopathological examination of the central nervous system revealed changes compatible with hypomyelinating leukodystrophy, with no signs of infectious agents observed. The disorder was considered most likely to be hereditary, as Schmallenberg virus infections during pregnancy in cattle have not been reported to result in such clinical, magnetic resonance imaging or histopathological findings, and no viral genomic material was identified with polymerase chain reaction.

Evaluating the Potential of Double-Muscled Angus Sires to Produce Progeny from Dairy Cows to Meet Premium Beef Brand Specifications

In response to the increasing global demand for sustainable beef production, this review of the literature was undertaken to explore the possibility of using the progeny of cows in the pasture-based New Zealand dairy production system that are mainly of the Holstein–Friesian, Jersey, and Holstein–Friesian × Jersey-cross breeds, to produce beef that meets the standards demanded by the Certified Angus Beef® (CAB) standard. CAB is a United States of America (USA) benchmark for beef quality. Traditionally, the offspring of dairy breeds have not been suitable for producing high-quality beef due to their genetic makeup and physical characteristics. However, in the USA, breeding programmes have used genetic strategies to boost muscle meat yield in terminal-sire breeds like the Lim-Flex® and NuEra Genetics® T14 cattle lines. In these lines, selection has focused on enhancing muscling and other Angus traits, including ensuring the cattle are homozygous polled and black-coloured. The overall aim has been to alter the phenotypic characteristics of the offspring of dairy cows by terminal-sire crosses, so they resemble the phenotype of purebred Angus cattle and meet the CAB standard. The approach can involve using different alleles of the myostatin gene (MSTN) carried by the terminal Angus sires to increase carcass value from the dairy cow-derived male progeny (including the MSTN c.821(del11) allele or the myostatin protein p.F94L leucine-containing allele) to increase meat yield and eating characteristics. It is concluded that a targeted selection and mating strategy could provide another source of high-quality beef production, and one that also meets societal demands for better animal welfare and increased sustainability.

Dietary fiber source and direct-fed microbial supplementation effects on lactation performance and feeding behavior of high-producing dairy cows

The objective of this study was to evaluate the effects of dietary fiber source and direct-fed microbial supplementation on lactation performance and feeding behavior of high-producing dairy cows. Sixty-four multiparous Holstein cows (3.5 ± 1.6 lactations; 76 ± 22 DIM and 735 ± 67 kg of BW at covariate period initiation) and 32 gate feeders were enrolled in a study with a completely randomized design and a 2 × 2 factorial arrangement. Cows and gate feeders were randomly assigned to treatments (16 cows and 8 gate feeds per treatment). Cows were allowed 1 week to acclimate to feeding gates followed by a 2-week covariate period. During the acclimation and covariate periods, all cows were fed the same diet to meet or exceed the nutrient requirements. Following the covariate period, cows were enrolled in a 8-week treatment period during which cows were randomly assigned to 1 of 4 treatments consisting of forage inclusion in the diet, either 45.8% (LF) or 56.7% (HF) of DM, and the supplementation of 75 mL/hd/d of a direct-fed microbial (DFM) containing herbal extracts (mallow, mint, and sage), L. plantarum, L. buchneri, Saccharomyces cerevisiae, and sugar cane molasses (Valibiom Mix, Valibiotics, Traiskirchen, Austria) or without supplementation (CON). The average covariate period value of each variable was used as a covariate. Three-way interactions were observed for DMI and feed efficiency. Dry matter intake was 2 to 3 kg greater for LF-DFM than HF-CON and HF-DFM during wk 2, 3, 5, and 8 of the treatment period. Milk production was 2.1 kg/d greater for LF than HF diets. Both milk fat and MUN concentrations were greater for HF than LF diets. Conversely, milk protein concentration was lower for HF than LF diets. The respiration rate measured in the morning was lower with DFM supplementation than CON. Rectal temperature measured in the morning and averaged for the day were greater for LF than HF diets. Under the conditions of the present study, feeding high-forage diets may be an alternative for producers to reduce feeding costs depending on the price of purchased feeds. However, non-forage fiber sources (i.e., soy hulls) must be considered when producers are challenged by either forage shortages or forage with a lower nutritive value. Additionally, DFM supplementation reduced respiration rate in the morning and affected meal behavior of lactating cows.

Systemic interindividual DNA methylation variants in cattle share major hallmarks with those in humans

BackgroundWe recently identified ~ 10,000 correlated regions of systemic interindividual epigenetic variation (CoRSIVs) in the human genome. These methylation variants are amenable to population studies, as DNA methylation measurements in blood provide information on epigenetic regulation throughout the body. Moreover, establishment of DNA methylation at human CoRSIVs is labile to periconceptional influences such as nutrition. Here, we analyze publicly available whole-genome bisulfite sequencing data on multiple tissues of each of two Holstein cows to determine whether CoRSIVs exist in cattle.ResultsFocusing on genomic blocks with ≥ 5 CpGs and a systemic interindividual variation index of at least 20, our approach identifies 217 cattle CoRSIVs, a subset of which we independently validate by bisulfite pyrosequencing. Similar to human CoRSIVs, those in cattle are strongly associated with genetic variation. Also as in humans, we show that establishment of DNA methylation at cattle CoRSIVs is particularly sensitive to early embryonic environment, in the context of embryo culture during assisted reproduction.ConclusionsOur data indicate that CoRSIVs exist in cattle, as in humans, suggesting these systemic epigenetic variants may be common to mammals in general. To the extent that individual epigenetic variation at cattle CoRSIVs affects phenotypic outcomes, assessment of CoRSIV methylation at birth may become an important tool for optimizing agriculturally important traits. Moreover, adjusting embryo culture conditions during assisted reproduction may provide opportunities to tailor agricultural outcomes by engineering CoRSIV methylation profiles.

Reasons for disposal and cull cow value of Holstein cows compared with Holstein, Jersey, Montbeliarde, Normande, and Viking Red crossbred cows.

Cull cows from dairy farms in the United States account for 10% of the beef market; however, few studies have evaluated the effects of crossbreeding on reasons for disposal and cull value of dairy cows. The objective of the study was to compare reasons for disposal and cull cow value of Holstein and crossbred cows (n = 1,292) in an experimental dairy herd at the University of Minnesota West Central Research and Outreach Center, Morris, Minnesota. Cows were Holstein (n = 272), 1964 genetic control Holstein (n = 161), 3-breed crossbred cows (n = 538) composed of the Montbéliarde, Viking Red, and Holstein (MVH) breeds, and 3-breed crossbred cows (n = 321) composed of the Normande, Jersey, and Viking Red (NJV) breeds. The 1964 genetic control Holsteins cows originated from a design initiated at the University of Minnesota for comparison of the1964 Holstein and contemporary Holstein cows selected for production across time. Records spanned from January 2010 to December 2023. Reasons for disposal were recorded in PCDart Herd Management Software, and cull value and body weight were from receipts from livestock cull markets. For all cows, the primary reason for disposal was for reproduction (44.4%), mastitis (18%), other reasons (14.6%), died (10.3%), dairy purposes (8.4%), and low production (4.3%). Independent variables for statistical analysis of cull value were the fixed effects of body weight at time of culling, DIM at culling (0 to 49 DIM, 50 to 99 DIM, 100 to 149 DIM, 150 to 199 DIM, 200 to 249 DIM, 250 to 299 DIM, 300 to 350 DIM, and 350+ DIM), year (2010 to 2023), season (spring, summer, autumn, winter), parity (1, 2, 3, 4, 5+), primary reason for culling, breed group and sire breed group nested within breed group. Least squares means for bodyweight at culling was 558 kg for Holsteins, 543 kg for 1964 Holsteins, 551 kg for MVH crossbred cow, and 499 kg for NJV crossbred cows. For the analysis across time, 2014 had the highest cull value ($1,126.98) and 2020 had the lowest gross cull value ($515.21). Cows culled greater than 300 DIM had the highest cull value and cows culled less than 50 DIM had the lowest cull value. Cows culled during the spring and summer had higher cull value compared with cows culled during the autumn and winter. The Holstein cows ($730.04) had lower gross value compared with 1964 Holsteins ($804.38) cows and MVH ($767.39) cows. The NJV ($771.39) cows were not different from crossbreds sired by Montbeliarde, Viking Red, and Holstein bulls. Results for comparisons of breed group are from one experimental herd, so inferences to the wider dairy cow population should be undertaken with caution. In summary, dairy producers may receive greater cull value from crossbred cows compared with Holstein cows.

Genetic parameters and genome-wide association analyses for lifetime productivity in Chinese Holstein cattle

Lifetime productivity is a trait of great importance to dairy cattle populations as it combines information from production and longevity variables. Therefore, we investigated the genetic background of lifetime productivity in high-producing dairy cattle by integrating genomics and transcriptomics data sets. A total of 3,365,612 test-day milk yield records from 134,029 Chinese Holstein cows were used to define 6 lifetime productivity traits, including lifetime milk yield covering full lifespan and 5 cumulative milk yield traits covering partial lifespan. Genetic parameters were estimated based on univariate and bivariate linear animal models and the Restricted Maximum Likelihood (REML) method. Genome-wide association studies (GWAS) and weighted gene co-expression network analyses (WGCNA) were performed to identify candidate genes associated with lifetime productivity based on genomic data from 3,424 cows and peripheral blood RNA-seq data from 23 cows, respectively. Lifetime milk yield averaged 24,800.8 ± 14,396.6 kg (mean ± SD) across an average of 2.4 parities in Chinese Holstein population. The heritability estimates for lifetime productivity traits ranged from 0.05 (±0.01 for SE) to 0.10 (±0.02 for SE). The estimate of genetic correlation between lifetime milk yield and productive life is 0.88 (±0.3 for SE) while the genetic correlation with 305d milk yield in the first lactation was 0.49 (±0.08 for SE). Absolute values for most genetic correlation estimates between lifetime productivity and type traits were lower than 0.30. Moderate genetic correlations were found between udder related traits and lifetime productivity, such as with udder depth (0.33), rear udder attachment height (0.33), and udder system (0.34). Some single nucleotide polymorphisms and gene co-expression modules significantly associated with lifetime milk yield were identified based on GWAS and WGCNA analyses, respectively. Functional enrichment analyses of the candidate genes identified revealed important pathways related to immune system, longevity, energy utilization and metabolism, and FoxO signaling. The genes NTMT1, FNBP1, and S1PR1 were considered to be the most important candidate genes influencing lifetime productivity in Holstein cows. Overall, our findings indicate that lifetime productivity is heritable in Chinese Holstein cattle and important candidate genes were identified by integrating genomic and transcriptomic data sets.

Multispecies pasture diet and cow breed impacts on milk composition and quality in a seasonal spring-calving dairy production system

In recent years, there has been significant emphasis on the composition of pasture-based cow feed and the potential benefits of incorporating multispecies swards to improve sustainability and biodiversity. This study compared the effects of a conventional perennial ryegrass (PRG) monoculture supported by high chemical nitrogen (N) usage with a low chemical N application multispecies sward system (MSS) on the composition and quality of milk across lactation using spring-calving Holstein-Friesian (HF) and Jersey Holstein-Friesian (JFX) cows. Bulk milk samples (n = 144) were collected from each group at morning and evening milking on a weekly basis (n = 36) throughout lactation and analyzed for gross composition and physico-chemical properties. Cow breed had a significant impact on milk profile, with milk from HF cows having significantly smaller milk fat globule (MFG) size, higher instability index values, higher yield, and lower total solids levels, compared with JFX cows. Notably, HF cows had increased milk total solids and fat levels when fed on MSS, as opposed to the PRG-fed HF cows. Feeding MSS pasture increased creaming velocity values in mid and late lactation, and resulted in similar milk gross composition to PRG. In comparison to PRG, MSS-fed groups showed significantly increased total solids yield, including higher levels of protein and fat yield. In late lactation, MSS feeding was associated with reduced MFG size. All physicochemical properties studied (MFG size, creaming velocity, instability index) showed decreasing values from early to late lactation stage. Overall, these findings demonstrate the significant effects of cow diet, breed and stage of lactation on compositional and physico-chemical characteristics of milk, with important implications for milk processing and dairy product quality.

Effects of abomasal infusion of branched-chain amino acids or branched-chain keto-acids on liver function, inflammation, and oxidative stress in multiparous fresh cows

Reduced liver function, increased oxidative stress, and inflammation in early lactation negatively impact lactation performance and health of fresh cows. Previous findings from our group demonstrated that branched-chain amino acids (BCAA) infusion improved lactation performance and branched-chain ketoacids (BCKA) infusion decreased liver triglyceride (TG) in fresh cows. The objectives of this study were to determine the effect of BCAA and BCKA on blood and liver biomarkers of liver function, oxidative stress, and inflammation as well as expression of genes regulating inflammation and antioxidant metabolism in the liver. Thirty multiparous Holstein cows were used in a randomized block design receiving continuous abomasal infusion for 21 d after parturition. Treatments (10 cows each) were control (CON), cows abomasally infused with 0.9% saline; BCA, cows abomasally infused with BCAA (67 g valine, 50 g leucine, and 34 g isoleucine); and BCK, cows abomasally infused with BCKA (77 g ketovaline, 57 g ketoleucine, and 39 g ketoisoleucine). All cows were randomly assigned to treatments after parturition and received the same diet throughout the experimental period. Blood was collected at 3, 7, 14, and 21 d postpartum for liver function, oxidative stress, and inflammation biomarker profiling. Liver was also harvested on 7, 14, and 21 d postpartum for quantification of glutathione, protein carbonylation, and expression of genes. ANOVA was conducted for all data using PROC GLIMMIX in SAS. No treatment differences were observed for liver function biomarkers (bilirubin, gamma-glutamyl transferase, and aspartate aminotransferase). Cows receiving BCAA had lower blood NO2- and NO3- concentrations compared with CON. A tendency for lower advanced oxidized protein products was also observed in BCA cows compared with CON. Additionally, on d 7, BCA cows had lower protein carbonylation in the liver compared with CON. In contrast, BCK cows had higher plasma thiol and albumin, as well as liver reduced and total glutathione compared with CON cows. Compared with CON, BCK cows had higher expression glutathione reductase in the liver. Overall, these results suggest favorable alterations in oxidative stress and inflammation status in fresh cows receiving BCAA or BCKA infusion during the first 3 weeks of lactation, which likely contributed to previously-observed changes in lactation performance and liver TG concentrations. Future work is required to evaluate the interrelated metabolism of BCAA and BCKA to better understand their effects on oxidative and immune metabolism.

MAP3K1, SPEF2 and PLCZ1 genes association with fertility and semen quality traits of AI bulls in Andhra Pradesh

Bull fertility plays an important role in improving the economic value of the herd and is measured in terms of semen quality traits, which is influenced by both genetic and non-genetic factors. Polymorphism of MAP3K1/ CviQI (rs463712269), SPEF2/HpyCH4V (rs722354121) and PLCZ1/AvaII (rs208019489) and their association with scrotal circumference, sperm motility and plasma membrane integrity, respectively were studied on 239 bulls of different breeds reared in different frozen semen bull stations. The MAP3K1/CviQ1 assay revealed that T allele was more frequent in Ongole and Murrah population. RFLP at SPEF2/ HpyCH4V locus indicated fixation of T allele in both the exotic purebred cattle (Holstein Friesian and Jersey) whereas selective advantage of C allele was observed in Murrah buffaloes. Except in Holstein Friesian crossbred, other cattle genetic groups were with CC genotype for PLCZ1/AvaII assay and the Murrah population had low genetic diversity and heterozygosity excess. The PLCZ1/ AvaII genotypes had significant influence on the plasma membrane integrity of sperm in Holstein Friesian, Jersey and Ongole bulls. The plasma membrane integrity of sperm was reported to be high in heterozygotes (CG) of Jersey and Ongole cattle. The present study, concluded the importance of PLCZ1 gene as a marker for semen quality assessment and selection in bulls.

Effects of dam metabolic profile and seasonality (Spring vs. Winter) on their offspring' metabolism, health, and immunity: maternal factors in dairy calves' analytes.

Maternal status during the transition period can significantly impact the health and performance of Holstein dairy calves, with lasting effects on various variables. However, the relationship between maternal late gestation metabolic status, seasonality, and their impact on offspring remains unclear. This study aimed to assess the influence of maternal variables at calving on the performance, metabolism, and immunity of 28 dairy calves during their first month of life. Blood samples were collected from 28 Holstein cows at calving. Median results for maternal variables including non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), glucose, total protein (TP), albumin, triglycerides (TG), total cholesterol (TC), haptoglobin (Hp), body weight (BW), and body condition score (BCS) were determined. These median values served as a basis for categorizing the offspring into two groups based on their dams' high or low degree of each maternal variable. Additionally, calves were categorized by the season of birth (Spring vs. Winter), with 14 in each. Blood samples were collected from the calves at birth and on days 1, 7, 14, and 28 to assess IgG, biochemical parameters, and haptoglobin concentration. Reactive oxygen species (ROS) production by polymorphonuclear cells stimulated by various agents was also evaluated. Clinical assessments were conducted for diarrhea and bovine respiratory disease frequencies. Despite the overall health of the cows, differences were observed in the calves between maternal groups. Heavier cows with high maternal BCS tended to have larger offspring, while high maternal BCS was associated with increased diarrhea prevalence. Low maternal BCS resulted in a stronger innate immune response, indicated by higher ROS production. Calves from cows experiencing metabolic changes during calving displayed elevated Hp concentrations. Spring-born calves were larger but had lower serum IgG concentration and reduced innate immune response compared to winter-born calves. Additionally, spring-born calves exhibited higher Hp and increased diarrhea prevalence on day 28. These findings underscore the importance of the prenatal period in determining neonatal health and suggest further research to elucidate the long-term clinical implications of maternal effects on offspring health and growth. Investigating offspring constituents later in life can provide insight into the persistence of maternal effects over time.

Investigation of hereditary cholesterol deficiency (CD) in Holstein Cattle at the state farms in Türkiye

Türkiye is exposed to international animal and semen movements. For this reason, Türkiye is very affected by diseases and hereditary disorders. State Farms is a state organization that raises and distributes breeding cattle. This study was aimed at investigating the presence and distribution of mutant alleles causing cholesterol deficiency (CD) disorder in Holstein cattle on state farms. For this purpose, blood and sperm samples were collected from 466 Holstein cattle. The real-time PCR method was used for genotyping. A total of seven cattle were found to be heterozygous. The frequency of the mutant allele was determined to be 0.75%. The kinship of four cattle carrying the mutant allele with Mauglin Storm, the bull in which this disease was first detected, was determined. The presence of cattle carrying the mutant allele in Türkiye is quite low compared to other countries. The Apolipoprotein-B (APOB) mutant allele was found at low frequencies and detected for the first time at the State Farms in Türkiye. Therefore, it is necessary to develop control programs by screening other Holstein herds.

Immune cells phenotype and bioenergetic measures in CD4+ T cells differ between high and low feed efficient dairy cows

Identifying sources of variance that contribute to residual feed intake (RFI) can aid in improving feed efficiency. The objectives of this study were to investigate immune cells phenotype and bioenergetic measures in CD4+ T cells in low feed efficient (LE) and high feed efficient (HE) dairy cows. Sixty-four Holstein cows were enrolled at 93 ± 22 days in milk (DIM) and monitored for 7 weeks to measure RFI. Cows with the highest RFI (LE; n = 14) or lowest RFI (HE; n = 14) were selected to determine immune cells phenotype using flow cytometry. Blood was sampled in the same LE and HE cows at 234 ± 22 DIM to isolate peripheral blood mononuclear cells, followed by magnetic separation of CD4+ T lymphocytes using bovine specific monoclonal antibodies. The metabolic function of isolated CD4+ T lymphocytes was evaluated under resting and activated states. An increased expression of CD62L+ cells within CD8+ T lymphocytes and CD21+ B lymphocytes was observed in HE cows compared to LE cows. CD4+ T lymphocytes of HE cows exhibited an increased mitochondrial and glycolytic activity in resting and activated states compared to LE cows. These data suggest that immune cells in HE cows exhibit an increased metabolic function, which might influence nutrient partitioning and utilization and serve as a source of variation in feed efficiency that warrants future investigation.

Immune cells phenotype and bioenergetic measures in CD4+ T cells differ between high and low feed efficient dairy cows

Identifying sources of variance that contribute to residual feed intake (RFI) can aid in improving feed efficiency. The objectives of this study were to investigate immune cells phenotype and bioenergetic measures in CD4+ T cells in low feed efficient (LE) and high feed efficient (HE) dairy cows. Sixty-four Holstein cows were enrolled at 93 ± 22 days in milk (DIM) and monitored for 7 weeks to measure RFI. Cows with the highest RFI (LE; n = 14) or lowest RFI (HE; n = 14) were selected to determine immune cells phenotype using flow cytometry. Blood was sampled in the same LE and HE cows at 234 ± 22 DIM to isolate peripheral blood mononuclear cells, followed by magnetic separation of CD4+ T lymphocytes using bovine specific monoclonal antibodies. The metabolic function of isolated CD4+ T lymphocytes was evaluated under resting and activated states. An increased expression of CD62L+ cells within CD8+ T lymphocytes and CD21+ B lymphocytes was observed in HE cows compared to LE cows. CD4+ T lymphocytes of HE cows exhibited an increased mitochondrial and glycolytic activity in resting and activated states compared to LE cows. These data suggest that immune cells in HE cows exhibit an increased metabolic function, which might influence nutrient partitioning and utilization and serve as a source of variation in feed efficiency that warrants future investigation.

Relationship between Pelvic Dimensions and Maximum Traction Forces Required during Parturition in Holstein Cows Using a Biomechanical Obstetric Simulator.

The primary aim of this study was to investigate the effect of the pelvic dimensions of Holstein cows on the traction forces during parturition. Additionally, the relationship between calf measurements and traction forces was explored. For this purpose, a modified in vitro biomechanical model simulating obstetric tractions was used. For the requirements of the experiment, six bone pelvises of deceased Holstein cows were collected based on their estimated pelvic inlet area (EPA) and prepared. Additionally, six stillborn calves were collected based on their body weight (BW). The parameters of the pelvic inlet and cavity were measured using computed tomography (CT). Using the simulator, every calf was pulled in a random order through all pelvises, realizing a total of 36 obstetrical tractions, and the required forces were documented with appropriate software. In each extraction, three peaks of forces were recorded, with the first peak occurring at the entrance of the elbows into the maternal pelvic cavity, the second peak at the entrance of the thorax, and the third at the entrance of the calf's pelvis. Logistic regression revealed an exponential relationship between pelvic parameters and traction forces for the entrance of the elbows and the pelvis, with the recorded forces being higher in the two smallest pelvises and stabilizing at a lower level thereafter, while for the entrance of the thorax, the correlations were either exponential or linear. The adjusted coefficients of determination (r2) were generally above the threshold of 0.5 for the entrance of the elbows and pelvis and lower (0.3-0.4) regarding the thorax and were statistically significant (p < 0.05) in all cases. Regarding the relationships between the calf dimensions and the required traction forces, the types of correlations were primarily linear and of lower magnitude. The combination of pelvic and calf parameters in a multivariate model resulted in an r2 of 0.72 for the entrance of the elbows using the pelvic diagonal and calf's body weight, an r2 of 0.62 using the pelvic area and calf's thoracic circumference, and an r2 of 0.75 using the pelvic diagonal and calf's fetlock joint width. In conclusion, under the conditions of the present experimentation, the applied traction forces were mainly influenced by the pelvic dimensions in an exponential manner, whereas the calf body measurements showed a weaker effect. Based on these findings, critical cut-off points exist, different for every pelvic parameter, below which a significant increase in the required traction forces is expected.

Selection of the most informative wavenumbers to improve prediction accuracy of milk fatty acid profile based on milk mid‐infrared spectra data

AbstractMilk mid‐infrared (MIR) spectra have been shown to provide valuable information on a wide range of traits to be used in dairy cattle breeding programs. Selecting the most informative variables from complex data can improve the prediction accuracy and model robustness and, consequently, the interpretability of MIR spectra. Thus, we aimed to investigate the prediction performance of feature selection methods based on MIR spectra data, using the milk fatty acid (FA) profile as an example to illustrate the evaluated procedure. Data of MIR spectra, milk test‐day records, and reference FA concentrations of 155 first‐parity Holstein cows were used in the analyses. Four models comprising different explanatory variables and three feature selection methods were evaluated. The results indicated that competitive adaptive reweighted sampling (CARS) method can effectively select the most informative variables from the MIR spectra, resulting in higher prediction accuracies than other variable selection approaches. The model including selected MIR spectra and cow information variables yielded the best FA profile predictions based on partial least square regression. C8:0, C10:0, C14:1, C17:0 isomers, C18:1, C18:1 isomer, medium‐chain FA, unsaturation FA, monounsaturated FA, and polyunsaturated FA presented accuracies based on the determination coefficient ranging from 0.66 to 0.85 in internal validation and from 0.65 to 0.84 in external validation. The most related wavenumbers to 35 FAs were found within 1003 to 1145 cm−1. Generally, using CARS and cow information improved predictions of FAs based on MIR spectra in Chinese Holstein dairy cows. Additional validation studies should be conducted as larger datasets become available.

Selection of the most informative wavenumbers to improve prediction accuracy of milk fatty acid profile based on milk mid‐infrared spectra data

AbstractMilk mid‐infrared (MIR) spectra have been shown to provide valuable information on a wide range of traits to be used in dairy cattle breeding programs. Selecting the most informative variables from complex data can improve the prediction accuracy and model robustness and, consequently, the interpretability of MIR spectra. Thus, we aimed to investigate the prediction performance of feature selection methods based on MIR spectra data, using the milk fatty acid (FA) profile as an example to illustrate the evaluated procedure. Data of MIR spectra, milk test‐day records, and reference FA concentrations of 155 first‐parity Holstein cows were used in the analyses. Four models comprising different explanatory variables and three feature selection methods were evaluated. The results indicated that competitive adaptive reweighted sampling (CARS) method can effectively select the most informative variables from the MIR spectra, resulting in higher prediction accuracies than other variable selection approaches. The model including selected MIR spectra and cow information variables yielded the best FA profile predictions based on partial least square regression. C8:0, C10:0, C14:1, C17:0 isomers, C18:1, C18:1 isomer, medium‐chain FA, unsaturation FA, monounsaturated FA, and polyunsaturated FA presented accuracies based on the determination coefficient ranging from 0.66 to 0.85 in internal validation and from 0.65 to 0.84 in external validation. The most related wavenumbers to 35 FAs were found within 1003 to 1145 cm−1. Generally, using CARS and cow information improved predictions of FAs based on MIR spectra in Chinese Holstein dairy cows. Additional validation studies should be conducted as larger datasets become available.

Effect of Heat Stress on Subsequent Estrous Cycles Induced by PGF2α in Cross-Bred Holstein Dairy Cows.

This study aimed to determine the effect of heat stress (HS) on reproductive parameters (calving to first service (CTFS) and the first-service conception rate (FSCR)) and general physiological responses (rectal temperature (RT) and respiratory rate (RR)) in tropical cross-bred Holstein dairy cows raised in Ratchaburi province, Thailand. HS was determined using the temperature-humidity index (THI), calculated from temperature and humidity inside the barns, and was classified as moderate HS (THI: 80.67 ± 0.79) and mild HS (THI: 77.81 ± 1.09) in this study. Cows with detected corpus luteum were defined as cyclic cows and were injected with PGF2α at the beginning of the experimental period. Reproductive and physiological parameters were recorded. Cows showed significantly lower RT and RR in the mild HS group (38.47 ± 0.21 °C and 41.04 ± 4.55 bpm, respectively) than in the moderate HS group (38.87 ± 0.15 °C and 51.17 ± 10.52 bpm). The percentage of cows that ovulated after being induced by PGF2α and showed estrus signs was higher in the mild than the moderate HS groups (54.55% vs. 18.18%). Furthermore, the FSCR of cows under mild HS tended to be higher than that in the moderate HS group (42.11% and 15%, respectively) (p = 0.06), while the average CTFS interval was significantly shorter under mild HS than moderate HS (69.47 ± 18.18 and 84.60 ± 27.68 days, respectively). These results indicate that moderate HS impairs reproductive performance in crossbred Holstein cows, compared to mild HS conditions.

Congenital syndromic Chiari-like malformation (CSCM) in Holstein cattle: towards unravelling of possible genetic causes

BackgroundChiari malformation type II (CMII) was originally reported in humans as a rare disorder characterized by the downward herniation of the hindbrain and towering cerebellum. The congenital brain malformation is usually accompanied by spina bifida, a congenital spinal anomaly resulting from incomplete closure of the dorsal aspect of the spinal neural tube, and occasionally by other lesions. A similar disorder has been reported in several animal species, including cattle, particularly as a congenital syndrome. A cause of congenital syndromic Chiari-like malformation (CSCM) in cattle has not been reported to date. We collected a series of 14 CSCM-affected Holstein calves (13 purebred, one Red Danish Dairy F1 cross) and performed whole-genome sequencing (WGS). WGS was performed on 33 cattle, including eight cases with parents (trio-based; group 1), three cases with one parent (group 2), and three single cases (solo-based; group 3).ResultsSequencing-based genome-wide association study of the 13 Holstein calves with CSCM and 166 controls revealed no significantly associated genome region. Assuming a single Holstein breed-specific recessive allele, no region of shared homozygosity was detected suggesting heterogeneity. Subsequent filtering for protein-changing variants that were only homozygous in the genomes of the individual cases allowed the identification of two missense variants affecting different genes, SHC4 in case 4 in group 1 and WDR45B in case 13 in group 3. Furthermore, these two variants were only observed in Holstein cattle when querying WGS data of > 5,100 animals. Alternatively, potential de novo mutational events were assessed in each case. Filtering for heterozygous private protein-changing variants identified one DYNC1H1 frameshift variant as a candidate causal dominant acting allele in case 12 in group 3. Finally, the presence of larger structural DNA variants and chromosomal abnormalities was investigated in all cases. Depth of coverage analysis revealed two different partial monosomies of chromosome 2 segments in cases 1 and 7 in group 1 and a trisomy of chromosome 12 in the WDR45B homozygous case 13 in group 3.ConclusionsThis study presents for the first time a detailed genomic evaluation of CSCM in Holstein cattle and suggests an unexpected genetic and allelic heterogeneity considering the mode of inheritance, as well as the type of variant. For the first time, we propose candidate causal variants that may explain bovine CSCM in a certain proportion of affected calves. We present cattle as a large animal model for human CMII and propose new genes and genomic variants as possible causes for related diseases in both animals and humans.

Congenital syndromic Chiari-like malformation (CSCM) in Holstein cattle: towards unravelling of possible genetic causes

BackgroundChiari malformation type II (CMII) was originally reported in humans as a rare disorder characterized by the downward herniation of the hindbrain and towering cerebellum. The congenital brain malformation is usually accompanied by spina bifida, a congenital spinal anomaly resulting from incomplete closure of the dorsal aspect of the spinal neural tube, and occasionally by other lesions. A similar disorder has been reported in several animal species, including cattle, particularly as a congenital syndrome. A cause of congenital syndromic Chiari-like malformation (CSCM) in cattle has not been reported to date. We collected a series of 14 CSCM-affected Holstein calves (13 purebred, one Red Danish Dairy F1 cross) and performed whole-genome sequencing (WGS). WGS was performed on 33 cattle, including eight cases with parents (trio-based; group 1), three cases with one parent (group 2), and three single cases (solo-based; group 3).ResultsSequencing-based genome-wide association study of the 13 Holstein calves with CSCM and 166 controls revealed no significantly associated genome region. Assuming a single Holstein breed-specific recessive allele, no region of shared homozygosity was detected suggesting heterogeneity. Subsequent filtering for protein-changing variants that were only homozygous in the genomes of the individual cases allowed the identification of two missense variants affecting different genes, SHC4 in case 4 in group 1 and WDR45B in case 13 in group 3. Furthermore, these two variants were only observed in Holstein cattle when querying WGS data of > 5,100 animals. Alternatively, potential de novo mutational events were assessed in each case. Filtering for heterozygous private protein-changing variants identified one DYNC1H1 frameshift variant as a candidate causal dominant acting allele in case 12 in group 3. Finally, the presence of larger structural DNA variants and chromosomal abnormalities was investigated in all cases. Depth of coverage analysis revealed two different partial monosomies of chromosome 2 segments in cases 1 and 7 in group 1 and a trisomy of chromosome 12 in the WDR45B homozygous case 13 in group 3.ConclusionsThis study presents for the first time a detailed genomic evaluation of CSCM in Holstein cattle and suggests an unexpected genetic and allelic heterogeneity considering the mode of inheritance, as well as the type of variant. For the first time, we propose candidate causal variants that may explain bovine CSCM in a certain proportion of affected calves. We present cattle as a large animal model for human CMII and propose new genes and genomic variants as possible causes for related diseases in both animals and humans.

Mammary fat globules as a source of mRNA to model alterations in the expression of some milk component genes during lactation in bovines

BackgroundThe milk's nutritional value is determined by its constituents, including fat, protein, carbohydrates, and minerals. The mammary gland's ability to produce milk is controlled by a complex network of genes.Thereby, the fat, protein, and lactose synthesis must be boost in milk to increase milk production efficiency. This can be accomplished by fusing genetic advancements with proper management practices. Therefore, this study aimed to investigate the association between the Lipoprotein lipase (LPL), kappa casein CSN3, and Glucose transporter 1 (GLUT1) genes expression levels and such milk components as fat, protein, and lactose in different dairy breeds during different stages of lactation.MethodsTo achieve such a purpose, 94 milk samples were collected (72 samples from 36 multiparous black-white and red-white Holstein–Friesian (HF) cows and 22 milk samples from 11 Egyptian buffaloes) during the early and peak lactation stages. The milk samples were utilized for milk analysis and genes expressions analyses using non- invasive approach in obtaining milk fat globules (MFGs) as a source of Ribonucleic acid (RNA).ResultsLPL and CSN3 genes expressions levels were found to be significantly higher in Egyptian buffalo than Holstein–Friesian (HF) cows as well as fat and protein percentages. On the other hand, GLUT1 gene expression level was shown to be significantly higher during peak lactation than early lactation. Moreover, lactose % showed a significant difference in peak lactation phase compared to early lactation phase. Also, fat and protein percentages were significantly higher in early lactation period than peak lactation period but lactose% showed the opposite pattern of Egyptian buffalo.ConclusionTotal RNA can be successfully obtained from MFGs. The results suggest that these genes play a role in glucose absorption and lactose synthesis in bovine mammary epithelial cells during lactation. Also, these results provide light on the differential expression of these genes among distinct Holstein–Friesian cow breeds and Egyptian buffalo subspecies throughout various lactation phases.