Metabolic and immunological changes in transition dairy cows: A review

Effect of FMD vaccination schedule of dams on the level and duration of maternally derived antibodies

Vaccination against Foot and Mouth Disease (FMD) in pregnant cows is crucial to produce greater immunity in new born calves, especially in late gestation, as this directly affects neonatal immunity. Therefore, we aimed to investigate how late gestation FMD vaccination of pregnant cows affects the maternally derived antibodies in their offspring. Pregnant cows were vaccinated with and without booster vaccination during the 3rd months (early gestation vaccination, EGV) or the 6.5th months (late gestation vaccination, LGV). Their offspring were investigated for passive immunity transfer, maternal antibody duration, and the first vaccination age of calves (when the maternal antibody has waned sufficiently to allow the first vaccination). Antibody titers were analyzed by a virus neutralization test (VNT). A digital Brix refractometer (% Brix) was used to estimate passive antibody transfer efficiency measuring total protein (TP) content of calf blood sera and also colostrum IgG content. Two linear mixed effects models were fitted: one for the antibody titer values of the dams, and the other for the antibody titer values of calves before the vaccination. A marginal fixed effects model was also fitted to explore the effects of the dam titers on the antibody titers of the calves after their vaccinations. As a result, the average neutralizing antibody titers did not differ between the EGV and LGV groups nor were any differences detected between dams that received a booster and those that were not boosted. However, the LGV calves' mean maternally derived antibody titers were significantly higher (p-values = 0.0001 for both groups) and the duration was longer than that of the EGV calves (120 days in LGV, 60 days in EGV, p < 0.05). Since no statistical difference was found between the titers of either group of dams at the beginning of the experiment and parturition, it does not appear that the higher VN titers in LGV calves compared to titers in EGV are directly related to the circulating antibody levels in the dams. Furthermore, the TP value (% Brix) of calf blood sera was higher than>8.4% in both calf groups (9.3 ± 0.33 in LGV and 8.6 ± 0.40 in EGV, p > 0.05) indicating that passive immunity transfer had occurred for both groups. In addition, we found that the % Brix mean colostrum IgG content of the LGV (25.8 ± 1.30) was higher than the EGV (21.8 ± 0.58) dams (p < 0.01) and a significant positive correlation found between the colostrum density of LGV dams and TP (% Brix) value of their offspring (r = 0.73, p < 0.01). Our results show that vaccination during the late gestation period increased the colostrum IgG content of dams of LGV in addition to the maternally derived antibody duration and potentially provided greater protection of the offspring.

Milk proteome from in silico data aggregation allows the identification of putative biomarkers of negative energy balance in dairy cows

A better knowledge of the bovine milk proteome and its main drivers is a prerequisite for the modulation of bioactive proteins in milk for human nutrition, as well as for the discovery of biomarkers that are useful in husbandry and veterinary medicine. Milk composition is affected by lactation stage and reflects, in part, the energy balance of dairy cows. We aggregated the cow milk proteins reported in 20 recent proteomics publications to produce an atlas of 4654 unique proteins. A multistep assessment was applied to the milk proteome datasets according to lactation stages and milk fractions, including annotations, pathway analysis and literature mining. Fifty-nine proteins were exclusively detected in milk from early lactation. Among them, we propose six milk proteins as putative biomarkers of negative energy balance based on their implication in metabolic adaptative pathways. These proteins are PCK2, which is a gluconeogenic enzyme; ACAT1 and IVD, which are involved in ketone metabolism; SDHA and UQCRC1, which are related to mitochondrial oxidative metabolism; and LRRC59, which is linked to mammary gland cell proliferation. The cellular origin of these proteins warrants more in-depth research but may constitute part of a molecular signature for metabolic adaptations typical of early lactation.

Effect of oleic acid on induction of steatosis and cytotoxicity in BRL 3A cells

Recent studies have shown that monounsaturated oleic acid induces steatosis in cultured hepatocyte steatosis in the form of nonalcoholic fatty liver disease models in vitro. However, the underlying mechanism of steatosis development is not completely understood. Therefore, we investigated the molecular mechanism of steatosis and the role of mitogen-activated protein kinase (MAPK)/toll-like receptor 4-related protein (TLR4) expression in this study. Rat hepatocyte cells were subjected to oleic acid in different concentrations (1.2-2.4 mM) for 24 hours. The cell morphological injury index and the changes in the MAPK/TLR4 signaling pathway-related proteins were evaluated. We found that the microstructure of the cells in the oleic acid treatment group was damaged, and higher phosphorylation levels of the MAPK pathway-related proteins were detected than those in the control group. In addition, the protein expression of TLR4, sterol regulatory element-binding protein-1, and fatty acid synthase were increased in the oleic acid treatment group. Our findings demonstrate that oleic acid causes toxic damage to rat hepatocyte cells, and the MAPK/TLR4 signaling pathway plays a significant role in lipid storage.

Sheep and goats raised in mixed flocks have diverse immune status around parturition

Several physiological and metabolic changes take place in dairy ruminants around parturition (late pregnancy, parturition, and early lactation). Dairy species are genetically selected for their higher milk production compared with non-dairy species. This fact causes a constant stress that impairs the immune status of the animal, with consequences for its welfare and performance. In the present study, we assessed the immune status of high-yield dairy sheep and goats by quantifying IgG and IgM concentrations, as well as chitotriosidase (ChT) and complement system [total complement system (TC) and alternative complement pathway (AC)] activity in blood plasma around parturition. We also measured IgG and IgM concentrations and ChT activity in colostrum and milk during the first 40 d postpartum. The lowest blood IgG concentration was at parturition in both species. We detected no differences in blood IgG concentrations between species. Blood IgM concentrations were constant in both species throughout the study period. However, blood IgM concentrations were greater in sheep than in goats. Blood ChT activity was greater in goats than in sheep, and both species showed constant activity of this enzyme throughout the study period. We observed no differences in complement system (TC and AC) activity between sheep and goats. In addition, both TC and AC activity were constant in both species throughout the experiment. In general, IgG and IgM concentrations were greater in sheep colostrum than in goat colostrum, but these differences disappeared after d 4 (IgG) and d 3 (IgM) postpartum. In both species, the highest IgG and IgM concentrations were measured in colostrum, gradually decreasing during the first days postpartum. Chitotriosidase activity decreased in both species from colostrum to milk, although goats always showed greater ChT activity than sheep. Both sheep and goats seemed to be more susceptible to infectious diseases around parturition. As well, goats showed greater ChT activity in blood, colostrum, and milk than sheep. This fact may give these animals additional protection against parasite and fungal infections.

Effect of heat-shock protein B7 on oxidative stress in adipocytes from preruminant calves

Dairy cows with ketosis display excessive lipolysis in adipose tissue. Heat-shock protein B7 (HSPB7), a small heat-shock protein, plays important roles in mediating cytoprotective responses to oxidative stress in rodent adipose tissue. Accordingly, it is assumed that HSPB7 may also play important roles in the antioxidant response in adipose tissue of ketotic cows. Therefore, the aim of this study is to investigate (1) the redox state of adipose tissue in ketotic cows and (2) the role and mechanism of HSPB7 on the regulation of oxidative stress in adipocytes from preruminant calves. An in vivo study consisting of 15 healthy and 15 clinically ketotic cows was performed to harvest subcutaneous adipose tissue and blood samples. In addition, adipocytes isolated from calves were treated with different concentrations of H₂O₂ (0, 12.5, 25, 50, 100, or 200 μM) for 2 h, transfected with adenovirus-mediated overexpression of HSPB7 for 48 h, or transfected with small interfering RNA of HSPB7 for 48 h followed by exposure to H₂O₂ (200 μM) for 2 h. Serum concentrations of nonesterified fatty acids and β-hydroxybutyrate were greater in cows with clinical ketosis, whereas serum concentration of glucose was lower. Compared with healthy cows, the malondialdehyde content was greater but the activity of glutathione peroxidase and superoxide dismutase was lower in adipose tissue of clinically ketotic cows. The abundance of HSPB7 and nuclear factor, erythroid 2 like 2 (NFE2L2) was greater in adipose tissue of clinically ketotic cows. In vitro, H₂O₂ treatment induced the overproduction of reactive oxygen species and malondialdehyde, and inhibited the activity of antioxidant enzymes glutathione peroxidase and superoxide dismutase in adipocytes from preruminant calves. The low concentration of H₂O₂ (12.5, 25, and 50 μM) increased the abundance of HSPB7 and NFE2L2, but high concentrations of H₂O₂ (100 or 200 μM) reduced the abundance of HSPB7 and NFE2L2. The overexpression of HSPB7 improved the H₂O₂-induced oxidative stress in adipocytes via increasing the abundance of NFE2L2 and its downstream target genes heme oxygenase-1 (HMOX1) and NADH quinone oxidoreductase 1 (NQO1). Knockdown of HSPB7 markedly inhibited the expression of NFE2L2, HMOX1, and NQO1 and further exacerbated H₂O₂-induced oxidative stress. Overall, these results indicate that activation of the HSPB7-NFE2L2 pathway increases cellular antioxidant capacity, thereby alleviating oxidative stress in bovine adipocytes.

Plasma metabolite changes in dairy cows during parturition identified using untargeted metabolomics

The metabolic responses of cows undergo substantial changes during the transition from late pregnancy to early lactation. However, the molecular mechanisms associated with these changes in physiological metabolism have not been clearly elucidated. The objective of this study was to investigate metabolic changes in transition cows from the perspective of plasma metabolites. Plasma samples collected from 24 multiparous dairy cows on approximately d 21 prepartum and immediately postpartum were analyzed using ultra-high-performance liquid chromatography/time-of-flight mass spectrometry in positive and negative ion modes. In conjunction with multidimensional statistical methods (principal component analysis and orthogonal partial least squares discriminant analysis), differences in plasma metabolites were identified using the t-test and fold change analysis. Sixty-seven differential metabolites were identified consisting of AA, lipids, saccharides, and nucleotides. The levels of 32 plasma metabolites were significantly higher and those of 35 metabolites significantly lower after parturition than on d 21 prepartum. Pathway analysis indicated that the metabolites that increased from late pregnancy to early lactation were primarily involved in lipid metabolism and energy metabolism, whereas decreased metabolites were related to AA metabolism.

Effect of BMP15 and/or AMH during in vitro maturation of oocytes from involuntarily culled dairy cows

The high metabolic activity to which the dairy cattle are exposed to maintain milk production altered steroid metabolism that affects reproductive physiology and reduce oocyte competence. Our aims were (a) to characterize the competence of immature oocytes collected from dairy cattle based on the expression of genes in cumulus cells (CCs) and (b) to improve oocyte competence to support preimplantation embryo development by the supplementation of maturation medium with bone morphogenetic protein 15 (BMP15) and/or anti-mullerian hormone (AMH). Oocyte donors were identified at the moment of ovary collection and grouped by involuntarily culled dairy cows (Holstein breed) or beef cattle. The embryo development speed to blastocyst of the cull dairy cattle versus beef cattle (control group) was lower. Besides, <10% of oocytes (with CC biopsies) derived from dairy cattle were able to develop to the blastocyst stage. In addition, a higher level of expression and a positive correlation were observed in the expression of most of the genes evaluated (LUM, KRT18, KRT8, CLIC3, BMPR1B, and SLC38A3) in the cumulus-oocyte complexes that produced blastocysts versus those which did not develop correctly (arrested development). Further, use of BMP15 in the maturation of oocytes from dairy cattle seems to increase competence, modulating the expression of OCT4, SOX2, CDX2, GATA6, and TP1 in resulting blastocysts.

Probability of pregnancy and risk factors of the Ovsynch program and its modification in dairy cows – a review

The Ovsynch programme is one of the most frequently used procedures in managing dairy cattle reproduction. There are many studies evaluating the effectiveness of the Ovsynch programme. However, few of them assess the impact of factors that can lead to a decrease in the pregnancy rate and thus, reduce the success of the Ovsynch programme. This review aims to examine the impact of both individual and environmental factors on the likelihood of pregnancy. The risk factors described include: the body condition, age, number and stage of lactation, production level, occurrence of diseases and postpartum complications, functional status of the ovaries, oestrous cycle phase, temperature, season and year, and program start-up after calving. Possible modifications of the Ovsynch programme are presented in order to increase its effectiveness and to determine the best time to start it. Additionally, attention was paid to pregnancy losses during the Ovsynch programme which ultimately decrease pregnancy rates. The impact of this many factors on the efficiency of the Ovsynch suggests the need to adjust the synchronization program each time to the individual situation of the herd.

Genetic variation in serum protein pattern and blood β-hydroxybutyrate and their relationships with udder health traits, protein profile, and cheese-making properties in Holstein cows

The aim of this study was to investigate in Holstein cows the genetic basis of blood serum metabolites [i.e., total protein, albumin, globulin, albumin:globulin ratio (A:G), and blood β-hydroxybutyrate (BHB)], a set of milk phenotypes related to udder health, milk quality technological characteristics, and genetic relationships among them. Samples of milk were collected from 498 Holstein cows belonging to 28 herds. All animal welfare and milk phenotypes were assessed using standard analytical methodology. A set of Bayesian univariate and bivariate animal models was implemented via Gibbs sampling, and statistical inference was based on the marginal posterior distributions of parameters of concern. We observed a small additive genetic influence for serum albumin concentrations, moderate heritability (≥0.20) for total proteins, globulins, and A:G, and high heritability (0.37) for blood BHB. Udder health traits (somatic cell score, milk lactose, and milk pH) showed low or moderate heritabilities (0.15-0.20), whereas variations in milk protein fraction concentrations were confirmed as mostly under genetic control (heritability: 0.21-0.71). The moderate and high heritabilities observed for milk coagulation properties and curd firming modeling parameters provided confirmation that genetic background exerts a strong influence on the cheese-making ability of milk, largely due to genetic polymorphisms in the major milk protein genes. Blood BHB showed strong negative genetic correlations with globulins (-0.619) but positive correlations with serum albumin (0.629) and A:G (0.717), which suggests that alterations in the serum protein pattern and BHB blood levels are likely to be genetically related. Strong relationships were found between albumin and fat percentages (-0.894), between globulin and α_S2-CN (-0.610), and, to a lesser extent, between serum protein pattern and milk technological characteristics. Genetic relationships between blood BHB and traits related to udder health and milk quality and technological characteristics were mostly weak. This study provides evidence that there is exploitable additive genetic variation for traits related to animal health and welfare and throws light on the shared genetic basis of these traits and the phenotypes related to the quality and cheese-making ability of milk.