Genetic association between fat-to-protein ratio and traits of economic interest in early lactation Holstein cows in Brazil

The aims of this study were to estimate the genetic parameters for fat-to-protein ratio (F:P) within the first 90 days of lactation and to examine their genetic associations with daily milk yield (MY), somatic cell score (SCS), and calving interval between the first and second calving (IFSC) and between the second and third calving (ISTC) during the first three lactations of Holstein cows. We utilized 200,626 production-related data officially recorded from 77,436 cows milked two or three times a day from 2012 to 2022, sourced from the Holstein Cattle Breeders Association of Paraná State, Brazil. The (co)variance components were estimated using animal models, adopting the restricted maximum likelihood (REML) method with single-trait analysis (for heritability and repeatability) and two-trait analysis (for genetic and phenotypic correlations), per lactation. Regardless of lactation number, heritability estimates were relatively low, ranging from 0.08 ± 0.005 to 0.10 ± 0.003 for F:P; 0.08 ± 0.01 to 0.18 ± 0.005 for MY; 0.04 ± 0.01 to 0.07 ± 0.004 for SCS; and 0.03 ± 0.01 for both IFSC and ISTC. Repeatability estimates within the same lactation were low for F:P (ranging from 0.17 ± 0.002 to 0.19 ± 0.03), high for MY (between 0.50 ± 0.003 and 0.53 ± 0.002), and moderate to high for SCS (between 0.39 ± 0.003 and 0.44 ± 0.004). Genetic correlations between F:P and MY ranged from -0.26 ± 0.03 to -0.15 ± 0.02; F:P and SCS, from -0.06 ± 0.03 to -0.03 ± 0.08; F:P and IFSC, 0.31 ± 0.01; F:P and ISTC, 0.20 ± 0.01; MY and IFSC, 0.24 ± 0.05; and MY and ISTC, 0.13 ± 0.08. The fat-to-protein ratio during early lactation showed low genetic variability, regardless of lactation number. Furthermore, it was genetically correlated with MY, IFSC, and ISTC, although there is an antagonistic and unfavorable correlation between traits that can limit genetic progress.

Short communication: Impact of corn grain particle size on production performance of lactating dairy cows

Corn grain particle size has the potential to influence the performance of lactating dairy cows and the overall profitability of a dairy farm. The objective of this study was to evaluate the productive performance of lactating cows fed diets containing finely or coarsely ground corn grain. Fifty lactating Holstein cows (n = 50; 10 primiparous and 40 multiparous), averaging (mean ± standard deviation, SD) 658 ± 64 kg of BW, 38.8 ± 7.3 kg of milk/d, and 155 ± 80 DIM, were fed diets with finely ground corn grain (FGC) or coarsely ground corn grain (CGC) in a randomized block design with a 28-d treatment period. Finely and coarsely ground corn grain had an average particle size of 660 and 915 µm, respectively. Dry matter intake (DMI) was reduced (p < 0.01) for cows fed FGC (22.1 vs. 21.2 kg d-1). Milk yield and efficiency were not affected by treatments (37.9 vs. 36.8 kg d-1; p = 0.12 and 1.78 vs. 1.79; p = 0.15). Concentrations of milk protein and fat, as well as other milk solids, were unaffected (p > 0.05) by treatments. Fecal starch (FS) concentrations were greater (p < 0.01) for cows fed CGC (7.0 vs. 4.9%), whereas plasma concentrations of D-lactate were greater (p < 0.05) for cows fed FGC (98.5 vs. 79.7 µM). Overall, feeding finely ground corn grain increased total-tract starch digestibility and reduced DMI while maintaining milk yield.

Associations of Body Condition Score at Calving, Parity, and Calving Season on the Performance of Dairy Cows and Their Offspring

This study aimed to evaluate the impact of body condition score (BCS) at calving, parity, and the calving season on the performance of dairy cows and their offspring. Data from 521 Holstein cows that calved a female calf and had their BCS evaluated at calving from a single commercial farm located in Southern Brazil were used. Cows were categorized into five BCS classes: class 1: <3.0 (n = 19), class 2: 3.0-3.25 (n = 134), class 3: 3.5-3.75 (n = 160), class 4: 4.0-4.25 (n = 142), and class 5: >4.25 (n = 66). Data were also categorized by calving order (primiparous and multiparous dams) and by calving season. The study was designed as a prospective cohort study. Variables with normal distribution were analyzed by the MIXED procedure of SAS, while binary outcomes were analyzed by the GLIMMIX procedure of SAS. Daughters from primiparous dams were born lighter (39.1 ± 0.42 vs. 41.4 ± 0.29 kg, p < 0.01), but they had the same weights as the daughters from multiparous cows at weaning (121.5 ± 1.67 vs. 120.4 ± 1.58 kg, p = 0.20). As expected, primiparous cows showed lower (p < 0.01) 305-day milk yields than multiparous ones: 8633 ± 363 vs. 10,761 ± 249 kg, respectively. Regarding the calving season, cows that calved in the winter were the most productive ones, and those that calved in the fall had lower milk yields (p = 0.01). Calves born in the winter were heavier at birth (p < 0.01), calved younger (p = 0.04), and produced more milk at first lactation (p = 0.03). The BCS class had an impact (p < 0.01) on calf birth weights; daughters from Class 1 cows (BCS < 3.0) were lighter (38.0 ± 1.0 kg) than the calves from Class 5 cows with a BCS > 4.25 (41.9 ± 0.57 kg). Calves from dams with a BCS < 3 (Class 1) had a 31.8% culling rate until weaning, while calves from cows with a BCS of 3.0-3.25 (Class 2) had a 9.6% culling rate (p = 0.12). These results suggest that maternal and environmental factors, such as calving season and parity, in addition to the dams' body condition score at calving, are associated with different offspring performances.

Characterization of dystocia in a herd of Holstein dairy cows in Brazil

Abstract The objective of this study was to characterize calvings with low and high difficulty based on the productive and reproductive performance of dairy cows. Calvings were grouped in no calving assistance, calving with low assistance, and calving with high assistance. The original data set comprised 1,902 calving records obtained from a large dairy farm in Southeast Brazil. Factor analysis was applied using the SAS® Studio 3.8 statistical program through the factor procedure, considering the Multivariate Analysis category. Milk fat (0.92–0.79) and total solids (0.91–0.80) were strongly correlated with Factor 1. Calving interval (0.87– 0.68) and the number of AI (artificial inseminations) per conception (0.87–0.71) showed high correlations with Factor 2. Milk yield (0.84–0.76) and accumulated milk yield (0.84–0.77) were strongly correlated with Factor 3. Based on the results, we conclude that the three calving scenarios were characterized by well-defined and independent factors. Cows which required a high assistance at calving showed a lower variance explained by the model for milk fat and total solids contents, calving interval, and the number of AIs per conception.

Caracterização da distocia em um rebanho de vacas da raça Holandesa no Brasil

Resumo O objetivo deste estudo foi caracterizar os partos com leve ou severa dificuldade e diferenciá-los com base no desempenho produtivo e reprodutivo de vacas leiteiras. Os partos foram agrupados em partos sem assistência, partos com baixa assistência e partos com elevada assistência. O banco de dados original continha 1902 registro de partos que foram obtidos de uma grande fazenda comercial localizada no Sudeste do Brasil. A análise fatorial foi aplicada através do programa estatístico SAS® Studio 3.8 por meio de procedimento fatorial, considerando a categoria de análise multivariada. Os teores de gordura do leite (0,92– 0,79) e de sólidos totais (0,91–0,80) foram altamente correlacionados com o fator 1. Intervalo entre partos (0,87–0,68) e número de IA (inseminações artificiais) por concepção (0,87–0,71) apresentaram alta correlação com o fator 2. Produção de leite (0,84–0,76) e produção acumulada de leite (0,84–0,77) foram altamente correlacionados com o fator 3. Baseados nos resultados, é possível concluir que as três situações de parto foram caracterizadas por fatores independentes e bem definidos. Vacas que necessitaram de alta assistência ao parto apresentaram menor variância explicada pelo modelo para teores de gordura e sólidos totais do leite, intervalo entre partos e número de IA por concepção.

Feed Intake of Growing Dairy Heifers Raised under Tropical Conditions: A Model Evaluation Using Meta-Analysis

Several models for predicting dry matter intake (DMI) of replacement dairy heifers have been developed; however, only a few have been evaluated using data from heifers of different breeds raised under tropical conditions. Thus, the objective of this study was to evaluate the DMI equations for dairy heifers managed under tropical conditions. A total of 230 treatment means from 61 studies using dairy heifers (n = 1513 heifers, average body weight = 246 kg) were used. The animals were grouped into two groups based on their genetics: (1) Bos taurus (Holstein, Jersey, Brown Swiss, and Holstein × Jersey) and (2) crossbred (Bos taurus × Bos indicus). Seven previously published DMI equations (HH, HHJ, QUI, STA, 2001 NRC, OFLin, and OFNLin) for heifers were evaluated using mean bias, slope bias, mean squared prediction errors (MSPE) and its decomposition, and other model evaluation statistics. For Bos taurus heifers, our results indicated that OFNLin and HHJ had lower mean bias (0.13 and 0.16 kg/d, respectively) than other models. There was no significant slope or mean bias for HHJ and OFNLin (p > 0.05), indicating agreement between the observed and predicted DMI values. All other models had a significant mean bias (p < 0.05), whereas the QUI model also presented a significant slope bias (p < 0.02). For crossbred heifers, the STA equation was the only one that did not present mean and slope bias significance (p > 0.05). All other DMI models had significant mean bias when evaluated using crossbred data (p < 0.04), and QUI, OFLin, and OFNLin also presented significant slope bias (p < 0.01). Based on our results, predictions from OFNLin and HHJ best represented the observed DMI of Bos taurus heifers (MSPE ≤ 1.25 kg²/d², mean bias ≤ 0.16 kg/d), whereas STA was the best model for crossbred heifers (MSPE = 1.25 kg²/d², mean bias = 0.09 kg/d). These findings indicate that not all available models are adequate for estimating the DMI of dairy heifers managed under a tropical climate, with HHJ and OFNLin for Bos taurus and STA for crossbreds being the most suitable models for DMI prediction. There is evidence that models from Bos taurus heifers could be used to estimate the DMI of heifers under tropical conditions. For heifer ration formulation is necessary to consider that DMI is influenced by breed, diet, management, and climate. Future work should also include animal genetic and environmental variables for the prediction of DMI in dairy heifers.

Expression Profiling of Glioblastoma Cell Lines Reveals Novel Extracellular Matrix-Receptor Genes Correlated With the Responsiveness of Glioma Patients to Ionizing Radiation

Glioblastoma (GBM) is the most lethal and frequent type of brain tumor, leading patients to death in approximately 14 months after diagnosis. GBM treatment consists in surgical removal followed by radio and chemotherapy. However, tumors commonly relapse and the treatment promotes only a slight increase in patient survival. Thus, uncovering the cellular mechanisms involved in GBM resistance is of utmost interest, and the use of cell lines has been shown to be an extremely important tool. In this work, the exploration of RNAseq data from different GBM cell lines revealed different expression signatures, distinctly correlated with the behavior of GBM cell lines regarding proliferation indexes and radio-resistance. U87MG and U138MG cells, which presented expressively reduced proliferation and increased radio-resistance, showed a particular expression signature encompassing enrichment in many extracellular matrix (ECM) and receptor genes. Contrasting, U251MG and T98G cells, that presented higher proliferation and sensibility to radiation, exhibited distinct signatures revealing consistent enrichments for DNA repair processes and although several genes from the ECM-receptor pathway showed up-regulation, enrichments for this pathway were not detected. The ECM-receptor is a master regulatory pathway that is known to impact several cellular processes including: survival, proliferation, migration, invasion, and DNA damage signaling and repair, corroborating the associations we found. Furthermore, searches to The Cancer Genome Atlas (TCGA) repository revealed prognostic correlations with glioma patients for the majority of genes highlighted in the signatures and led to the identification of 31 ECM-receptor genes individually correlated with radiation responsiveness. Interestingly, we observed an association between the number of upregulated genes and survivability greater than 5 years after diagnosis, where almost all the patients that presented 21 or more upregulated genes were deceased before 5 years. Altogether our findings suggest the clinical relevance of ECM-receptor genes signature found here for radiotherapy decision and as biomarkers of glioma prognosis.

AVALIAÇÃO MICROBIOLÓGICA DE COXA E SOBRECOXA DE FRANGO COMERCIALIZADAS A GRANEL EM SINOP-MT

Resumo O consumo de carne de frango tem aumentado nos últimos anos, favorecido por diferentes fatores. No entanto, quando esse alimento é manipulado sem cuidados higiênicos pode ser fonte de agentes etiológicos causadores de enfermidades. O objetivo deste estudo foi avaliar a qualidade microbiológica de 60 amostras de carnes de frango industrial resfriadas in natura, coletadas de 20 estabelecimentos comerciais do município de Sinop – Mato Grosso. As avaliações microbiológicas foram compostas por: enumeração de coliformes totais e termotolerantes, pesquisa de Escherichia coli e identificação de Salmonella spp. Em 100% das amostras foram encontrados coliformes totais. Seis amostras apresentaram valores de coliformes termotolerantes > 3NMP/g, porém não extrapolaram o padrão, 104NMP/g, exigido pela legislação brasileira. Das 60 amostras avaliadas, 8,3% apresentaram contaminação por E. coli e 8,3% estavam contaminadas por Salmonella spp. Em 30% dos mercados foram obtidas amostras contaminadas por E. coli (10%) e Salmonella spp. (20%), sendo consideradas impróprias para o consumo. Os sorovares de Salmonella spp. encontrados foram: Hadar, Minnesota, Heidelberg e Kentucky. Dessa forma, há a necessidade de que sejam aplicadas boas práticas de fabricação, higiene e manipulação de alimentos nos estabelecimentos a fim de reduzir a contaminação por microrganismos no produto final e os riscos para a saúde coletiva.

Multiple Tolerization Reduces Antibody Binding Against Tolerogen Cells: Implications for the Production of Monoclonal Antibodies

We report an immunization technique that can update the production of monoclonal antibodies (mAbs): the multiple tolerization subtractive immunization (MTSI). A total of 10 BALB/C mice were used. Animals in group 1 received one inoculation of RWPE-1 cells (nontumoral), followed by cyclophosphamide, and then received serial inoculations of nonirradiated PC3 cells (tumoral). Animals in group 2 received our MTSI protocol, as follows: one inoculation of RWPE-1 cells, followed by cyclophosphamide (Cy). This whole tolerization step was repeated three other times, with 14-day intervals between the last Cy exposure and the next RWPE-1 cell inoculation. Finally, the animals received the same nonirradiated PC3 cell exposure as group 1. Blood was taken from each animal, and their polyclonal sera individually tested against the nontumoral RWPE-1 cells in flow cytometry. We found out that, after the MTSI was employed, the serum of the immunized animals, in group 2, contained considerably less antibodies that reacted against the tolerogenic cells, compared with the serum of the animals that underwent regular subtractive immunization. We showed that, by repeating the tolerization cycles, the polyclonal antibodies produced by mice have a reduced specificity toward common/immunodominant epitopes present at nontumoral cells, and thus this technique can be readily used by others in studies involving murine mAb protocols.

Free gossypol supplementation frequency and reproductive toxicity in young bulls

The aim of the present study was to analyze seminal quality of young bulls subjected to different frequencies of gossypol supplementation. Forty-eight Nellore bulls, with 19 months of age and weighing 357.8 ± 7.2 kg, were used in this study. Animals were fed with 10.5 kg of standard supplement containing free-gossypol from whole cottonseed (WCS) at the following frequency: 3x/week (G3x), 5x/week (G5x) or 7x/week (G7x - Control). Additionally, a negative control was provided, and the treated animals received only mineral supplement (MM) ad libtum. The experiment lasted for 84 days and semen was collected at the beginning and at the end for analysis and cryopreservation. Fresh semen was used for initial analysis and plasma membrane integrity and sperm morphology were also determined. General motility using computer assisted sperm analysis (CASA), plasma and acrosomal membranes integrity, mitochondrial activity, and induced oxidative stress were assessed in post-thawed semen. The study design was completely randomized. Parametric data were analyzed by ANOVA and non-parametric data by the Wilcoxon test, using the statistical program SAS. Level of significance was set at 5%. Supplementation with WCS, regardless the frequency, increased total (P = .009) and head (P = .005) defects in comparison to animals receiving only forage and mineral supplement. Infrequent supplementation, particularly 5 times in the week (G5X), increased head (P = .026) and midpiece (P = .014) abnormalities. Sperm motility in fresh semen was lower in animals that received daily supplementation than those supplemented on alternate days (P = .021). Additionally, animals supplemented daily showed lower percentage of spermatozoa with intact acrosome compared to those supplemented on alternate days (P = .005). Thus, regardless the frequency of supplementation, free-gossypol supplementation affects sperm quality. Although the amount of free gossypol supplied weekly was the same among treatments, daily supplementation compromised sperm kinetics, differently from infrequent supplementation that led to sperm defects developed during spermatogenesis.

Enhanced immunization techniques to obtain highly specific monoclonal antibodies

Despite fast advances in genomics and proteomics, monoclonal antibodies (mAbs) are still a valuable tool for areas such as the evolution of basic research in stem cells and cancer, for immunophenotyping cell populations, diagnosing and prognosis of diseases, and for immunotherapy. To summarize different subtractive immunization approaches successfully used for the production of highly specific antibodies, we identified scientific articles in NCBI PubMed using the following search terms: subtractive immunization, monoclonal antibody, tolerization, neonatal, high-zone tolerance, masking immunization. Patent records were also consulted. From the list of results, we included all available reports, from 1985 to present, that used any enhanced immunization technique to produce either polyclonal or monoclonal antibodies. Our examination yielded direct evidence that these enhanced immunization techniques are efficient in obtaining specific antibodies to rare epitopes, with different applications, such as to identify food contaminants or tumor cells.

Blood cell and metabolic profile of Nellore bulls and their correlations with residual feed intake and feed conversion ratio

Due to the potential metabolic changes related to the residual feed intake (RFI), this study investigated the correlation of traditional RFI (RFI1), RFI adjusted for final rump fat thickness (RFI2) and feed conversion ratio (FCR) with the metabolic and blood profiles, as well as determined the possible different classes of RFI1 and RFI2. For this purpose, 46 Nellore bulls, 22 month-old and 411kg of weight at the beginning of the study were used. The animals were fed with the same diet for 84 days, and blood samples were collected every 21 days for evaluation of serum metabolites and blood cell profiles. No significant correlations were found between FCR and metabolic or blood traits, although there was a significant correlation between RFI1 and urea serum concentration. There were also differences between the RFI classes for creatinine, in which more efficient animals showed higher values. The RFI2 did not correlate with any metabolic and blood cell variable, but young bulls with smaller RFI2 had a smaller number of eosinophils when compared to animals with higher RFI2. These results suggest that animals with a high RFI can have greater energy expenditure due to protein synthesis and degradation process, resulting in a larger blood urea level.

Substituição parcial de farelo de soja por ureia de liberação lenta em rebanhos leiteiros comerciais

Dois experimentos foram conduzidos para avaliar a substituição parcial de farelo de soja por ureia encapsulada (Optigen®II, Alltech do Brasil, Curitiba, PR, Brasil). Na dieta Controle, 1kg de farelo de soja foi substituído por mistura isonitrogenada que continha 160g de Optigen®II + 2,5kg de silagem de milho no Exp.1, ou 150g de Optigen®II + 850g de milho moído fino no Exp.2. No Exp.1, 61 vacas Holandês foram blocadas e alocadas a um tratamento por 21 dias, e as medidas da mesma variável no final da padronização utilizadas como covariável. No Exp.2, 97 vacas foram alocadas a uma sequência dos dois tratamentos por 21 dias, em delineamento de reversão simples. A resposta aos tratamentos foi avaliada do dia 17 ao 21. Em ambos os experimentos, não houve diferenças entre os tratamentos na composição em nutrientes da dieta oferecida e das sobras, nas sobras como % do oferecido, no peso vivo e no escore de condição corporal dos animais. A produção diária de leite foi 38,4 kg/d no Controle e 38,9 no Optigen®II (P=0,62) no Exp.1, e 27,0kg/d e 27,2 no Exp.2 (P=0,64), respectivamente. A ureia encapsulada reduziu a porcentagem de gordura no leite no Exp.2 (P=0,04). O Optigen®II aumentou o nitrogênio ureico no leite de 16,3 para 17,3mg/dL no Exp.1 (P<0,01) e as relações entre o leite produzido e o alimento consumido (P=0,08) e entre a alantoína e a creatinina urinárias (P=0,03) no Exp.2. A substituição parcial de farelo de soja por Optigen®II não induziu queda no desempenho.

Neuroprotection by BDNF against glutamate-induced apoptotic cell death is mediated by ERK and PI3-kinase pathways

Neurotrophins protect neurons against glutamate excitotoxicity, but the signaling mechanisms have not been fully elucidated. We studied the role of the phosphatidylinositol 3-kinase (PI3-K) and Ras/mitogen-activated protein kinase (MAPK) pathways in the protection of cultured hippocampal neurons from glutamate induced apoptotic cell death, characterized by nuclear condensation and activation of caspase-3-like enzymes. Pre-incubation with the neurotrophin brain-derived neurotrophic factor (BDNF), for 24 h, reduced glutamate-evoked apoptotic morphology and caspase-3-like activity, and transiently increased the activity of the PI3-K and of the Ras/MAPK pathways. Inhibition of the PI3-K and of the Ras/MAPK signaling pathways abrogated the protective effect of BDNF against glutamate-induced neuronal death and similar effects were observed upon inhibition of protein synthesis. Moreover, incubation of hippocampal neurons with BDNF, for 24 h, increased Bcl-2 protein levels. The results indicate that the protective effect of BDNF in hippocampal neurons against glutamate toxicity is mediated by the PI3-K and the Ras/MAPK signaling pathways, and involves a long-term change in protein synthesis.