Changes in metabolic and hormonal profiles during transition period in dairy cattle – the role of spexin

Background This study aimed to evaluate spexin as a novel blood marker and to describe the relationship of this peptide with selected biochemical metabolites measured during the transition period in dairy cows. Additionally, mRNA expression of the spexin gene as well as spexin receptors – galanin receptor type 2 and galanin receptor type 3, was investigated in several bovine tissues. Blood samples were collected at weekly intervals starting at 21 days before the estimated parturition day until 21 days in milk to determine concentrations of spexin, nonesterified fatty acids, β-hydroxybutyrate acid, total and active ghrelin, progesterone, glucose, insulin, IGF–I, triglycerides, cholesterol, leptin, corticosterone and 17-β-estradiol as well as the activity of aspartate transaminase, alkaline phosphatase and gamma-glutamyl transferase. Results Spexin concentration decreased from 21 d before parturition to calving day and next it rose during the first 14 d of lactation. The lowest concentration of spexin was recorded on the calving day and it differed from the mean level of this peptide before parturition as well as postpartum. Moreover, differences were observed between mean spexin concentrations before and after calving. Spexin levels were moderately negatively correlated with NEFA (r = − 0.39) and total ghrelin contents (r = − 0.41), weakly correlated with BHBA (r = − 0.35) while they showed a moderate positive relationship with progesterone concentrations (r = 0.42). Moreover, we detected that mRNA expression of GALR2, GALR3 and SPX is present in various bovine tissues (kidney, bowel, rumen, spinal cord, lung, skeletal muscle, liver, heart, fat and spleen). Conclusion A negative correlation between spexin concentration and NEFA, BHBA and total ghrelin contents as well as a positive relationship with levels of progesterone, metabolites and hormones, which are key players in the dairy cow transition period, may confirm an important function of this peptide in metabolism regulation. Thus measurement of spexin concentration could provide useful supplementary information for dairy cow herd health monitoring.

Serum Nonesterified Fatty Acids and Incident Stroke: The CHS

Background Significant associations between total nonesterified fatty acid (NEFA) concentrations and incident stroke have been reported in some prospective cohort studies. We evaluated the associations between incident stroke and serum concentrations of nonesterified saturated, monounsaturated, polyunsaturated, and trans fatty acids. Methods and Results CHS (Cardiovascular Health Study) participants (N=2028) who were free of stroke at baseline (1996–1997) and had an archived fasting serum sample were included in this study. A total of 35 NEFAs were quantified using gas chromatography. Cox proportional hazards regression models were used to evaluate associations of 5 subclasses (nonesterified saturated, monounsaturated, omega (n)‐6 polyunsaturated, n‐3 polyunsaturated, and trans fatty acids) of NEFAs and individual NEFAs with incident stroke. Sensitivity analysis was conducted by excluding cases with hemorrhagic stroke (n=45). A total of 338 cases of incident stroke occurred during the median 10.5‐year follow‐up period. Total n‐3 (hazard ratio [HR], 0.77 [95% CI, 0.61–0.97]) and n‐6 (HR, 1.32 [95% CI, 1.01–1.73]) subclasses of NEFA were negatively and positively associated with incident stroke, respectively. Among individual NEFAs, dihomo‐γ‐linolenic acid (20:3n‐6) was associated with higher risk (HR, 1.29 [95% CI, 1.02–1.63]), whereas cis ‐7‐hexadecenoic acid (16:1n‐9 c ) and arachidonic acid (20:4n‐6) were associated with a lower risk (HR, 0.67 [95% CI, 0.47–0.97]; HR, 0.81 [95% CI. 0.65–1.00], respectively) of incident stroke per standard deviation increment. After the exclusion of cases with hemorrhagic stroke, these associations did not remain significant. Conclusions A total of 2 NEFA subclasses and 3 individual NEFAs were associated with incident stroke. Of these, the NEFA n‐3 subclass and dihomo‐γ‐linolenic acid are diet derived and may be potential biomarkers for total stroke risk.

256 Effects of Transition Period Nutrition on Uterine Health

The transition from gestation to lactation, also known as the transition period, is a critical time for dairy cows. This phase is typically defined as 3 wk before parturition through 3 wk after parturition. Peak disease incidence (shortly after parturition) corresponds with the time of greatest negative energy balance (NEB), the peak in blood concentrations of nonesterified fatty acids, and the greatest acceleration of milk yield. Decreased fertility in the face of increasing milk production may be attributable to greater severity of postpartal NEB resulting from inadequate transition management or increased rates of disease. The depth and duration of NEB is highly related to dry matter intake. Formulation and delivery of appropriate diets that limit total energy intake to requirements but also provide proper intakes of all other nutrients (including the most limiting amino acids Met and Lys) before calving can help lessen the extent of NEB after calving. Cows that received controlled-energy diets during the last 3 wk prepartum had shorter days to pregnancy than cows that consumed high-energy diets in this time period. Additionally, a fully acidified prepartum diet formulated with a higher Ca concentration improved reproductive performance and uterine immune function in the postpartum period through the decrease of days to first ovulation, a tendency to decrease service per conception rate, improved glandular morphology, a tendency to increase polymorphonuclear neutrophil infiltration, and a tendency to increase the tight-junction protein occludin. Supplementation of rumen-protected methionine during the transition period resulted in improved uterine immune function through improved glandular morphology, increased neutrophil infiltration number after calving, and discovery of neutrophil extracellular trap formation in bovine endometrial tissue. In conclusion, nutritional strategies during the transition impact uterine health and fertility in dairy cows.

Influence of calcium concentrations on the metabolic profile of dairy goats during the transitional period

In order to differentiate groups of hypocalcemic (G1) and normocalcemic animals (G2) and infer the influence of subclinical hypocalcemia on metabolic profiles, this study determined calcium concentrations during the transitional period in 35 dairy goats healthy, pregnant, primiparous or multiparous, crossbreed or pure-bred dairy goats producing average 3 kg/day/goat. Therefore, blood samples were collected before (30, 20 and 10 days before parturition), on the day of delivery and after parturition (10, 20, 30, 40, 50 and 60 days postpartum). The variables measured were glucose, nonesterified fatty acids, β-hydroxybutyrate, cholesterol, triglycerides, amylase, total protein, albumin, urea, creatinine, aspartate aminotransferase, gamma glutamyl transferase, creatine kinase, total calcium, phosphorus, magnesium, chlorides, cortisol and insulin, as well as ionized calcium (Ca++), sodium and potassium. Goats were considered to have subclinical hypocalcemia if Ca++ ≤0.72 mmol/L. The data were analyzed by ANOVA. In subclinically hypocalcemic goats, serum concentrations of Ca++ decreased earlier (10dbp) than in normocalcemic goats (parturition) and remained lower throughout the transitional period (p=0,004). Among the measured variables, Ca++ showed greater influence on the NEFA, glucose, insulin and total calcium but also influenced the protein profile. Lower food intake by goats with subclinical hypocalcemia was one of the main factors interfering with the metabolic profile and likely the productivity of these animals. Studies should be conducted to measure the effects of subclinical disease on the production rates and on the emergence of other transitional period diseases.

Lycopsamine Attenuates Diabetes Mellitus via The Nuclear Factor Kappa B-Induced 5′ Adenosine Monophosphate-Activated Protein Kinase Signal Pathway

Diabetes mellitus is a metabolic disorder characterized by inflammation, abnormal glycolipid metabolism, insulin resistance, and mitochondrial dysfunction leading to hyperglycemia. The aim of the present investigation was to determine the efficacy of lycopsamine in a rat model of diabetes mellitus to understand its mechanism. Lycopsamine treatment markedly lowered the level of total cholesterol, triglyceride, nonesterified fatty acids, and low-density lipoprotein in diabetic rats. There was also a reduction in interleukin-6, interleukin-10, C-reactive protein, and tumor necrosis factor-α levels. Lycopsamine treatment normalized the metabolism of lipid and glucose, insulin resistance, and body weight of diabetic rats. Findings of immunohistochemical analyses exhibited rise in precipitation of immunocytes in renal cells. Results potentially demonstrated that lycopsamine treatment remarkably reduced the nuclear factor-kappa B level and enhanced the 5′ adenosine monophosphate-activated protein kinase expression. Altogether, administration of lycopsamine suppressed the expression of inflammatory cytokines and attenuated the metabolic symptoms in diabetes mellitus experimental rats.

Sirtuin 3 Restores Synthesis and Secretion of Very Low-Density Lipoproteins in Cow Hepatocytes Challenged with Nonesterified Fatty Acids In Vitro

Fatty liver is closely associated with elevated concentrations of nonesterified fatty acids (NEFA) and a low level of very low-density lipoproteins (VLDL) in blood of dairy cows. High NEFA inhibit the VLDL synthesis and assembly, and cause hepatic triacylglycerol (TAG) deposition. Sirtuin 3 (SIRT3), a mitochondrial deacetylase, antagonizes NEFA-induced TAG accumulation through modulating expressions of fatty acid synthesis and oxidation genes in cow hepatocytes. However, the role of SIRT3 in the VLDL synthesis and assembly was largely unknown. Here we aimed to test whether SIRT3 would recover the synthesis and assembly of VLDL in cow hepatocytes induced by high NEFA. Primary cow hepatocytes were isolated from 3 Holstein cows. Hepatocytes were infected with SIRT3 overexpression adenovirus (Ad-SIRT3), SIRT3-short interfering (si) RNA, or first infected with Ad-SIRT3 and then incubated with 1.0 mM NEFA (Ad-SIRT3 + NEFA). Expressions of key genes in VLDL synthesis and the VLDL contents in cell culture supernatants were measured. SIRT3 overexpression significantly increased the mRNA abundance of microsomal triglyceride transfer protein (MTP), apolipoprotein B100 (ApoB100) and ApoE (p < 0.01), and raised VLDL contents in the supernatants (p < 0.01). However, SIRT3 silencing displayed a reverse effect in comparison to SIRT3 overexpression. Compared with NEFA treatment alone, the Ad-SIRT3 + NEFA significantly upregulated the mRNA abundance of MTP, ApoB100 and ApoE (p < 0.01), and increased VLDL contents in the supernatants (p < 0.01). Our data demonstrated that SIRT3 restored the synthesis and assembly of VLDL in cow hepatocytes challenged with NEFA, providing an in vitro basis for further investigations testing its feasibility against hepatic TAG accumulation in dairy cows during the perinatal period.

Changes of Plasma Analytes Reflecting Metabolic Adaptation to the Different Stages of the Lactation Cycle in Healthy Multiparous Holstein Dairy Cows Raised in High-Welfare Conditions

Here, we tested the changes occurring in several plasma analytes during different stages of the lactation cycle of high welfare raised multiparous Holstein cows, and provided reference intervals (RI) for plasma analytes concentrations. Eleven high-welfare farms (HWF) located in Northern Italy were selected and their herds used to recruit 361 clinically healthy cows undergoing the dry (from −30 to −10 days from real calving; DFC), the postpartum (from 3 to 7 DFC), the early lactation (from 28 to 45 DFC) and the late lactation phases (from 160 to 305 DFC). Cows affected by subclinical diseases (SCD) were retrospectively excluded, and a subset of 285 cows was selected. Data of plasma analytes underwent ANOVA testing using physiological phases as predictors. The individual effect of each phase was assessed using a pairwise t-test assuming p ≤ 0.05 as a significance limit. A bootstrap approach was used to define the reference interval (RI) for each blood analyte within physiological phases having a pairwise t-test p ≤ 0.05. The concentration of nonesterified fatty acids, albumin, cholesterol, retinol, paraoxonase and tocopherol changed throughout all the physiological phases, whereas the concentration of K, alkaline phosphatase and thiol groups remained stable. Triglycerides, Zn, and ferric ion reducing antioxidant power in the dry phase and BHB, Ca, myeloperoxidase, haptoglobin, reactive oxygen metabolites and advanced oxidation of protein product in postpartum differed compared with other physiological phases. During the dry phase, Packed cell volume, Cl, and urea concentrations were similar to during the postpartum phase. Similarly, Na, γ-glutamyl transferase and β-carotene concentrations were similar to during the early lactation phase; fructosamine and bilirubin concentrations were similar to during the late lactation phase. During the postpartum phase, fructosamine and P concentrations were similar to during the early lactation phase, and the aspartate transaminase concentration was similar to during the late lactation phase. During the early lactation phase, Mg, creatinine, total protein, globulin and ceruloplasmin concentrations were similar to during the postpartum phase, while the urea concentration was similar to during the late lactation phase. All these plasma analytes differed among the other phases. This study identifies physiological trends affecting plasma analytes concentrations during the different stages of the lactation cycle and provides a guideline for the duration and magnitude of their changes when animals are healthy and raised in optimal welfare conditions.