Effects of Ruminal Administration of Propylene Glycol or Sucrose on Ruminal, Blood, and Hepatic Parameters in Nonlactating Cows With High Plasma Nonesterified Fatty Acid Concentrations.

During the transition period, dairy cows often experience negative energy balance, which can induce metabolic and immunological disturbances. Previous work has shown that there is a relationship between the dysfunction of immune cells and the increase in blood nonesterified fatty acid (NEFA) concentration. Nevertheless, it is difficult to determine the exact effect of NEFA on the immune system, as other metabolic and hormonal perturbations occur simultaneously during the transition period. In the present study, we have determined the effect of NEFA on immune functions using an experimental model designed to assess the effects independently of energy balance, as well as hormonal and metabolic changes due to parturition. Six dry and nonpregnant cows were infused with either sterile water (control treatment) or a lipid emulsion (Intralipid 20%, Frenesius Kabi, lipid treatment) at a rate of 1 mL/kg per hour for 6 h according to a crossover design. Blood concentrations of NEFA, β-hydroxybutyrate (BHB), and glucose were measured every hour throughout the infusion period, and 1 and 18 h after the end of infusion. Proliferation and interferon-γ secretion of lymphocytes, phagocytosis, and oxidative burst of neutrophils and blood insulin concentration were evaluated before, during, and at the end of the infusion. For NEFA, BHB, and glucose, treatment × time interactions were present. When compared with the control condition, NEFA and BHB levels were greater in the plasma of cows infused with lipids from 1 h after the start of infusion until 1 h after the end of infusion. Glucose level also increased in response to lipid infusion from 2 h of infusion until 1 h after the end of treatment. For sterile water and lipid infusions, respectively, maximal concentrations were 0.06 ± 0.10 mM and 1.39 ± 0.10 mM for NEFA, 0.70 ± 0.05 mM and 1.06 ± 0.05 mM for BHB, and 4.56 ± 0.27 mM and 6.90 ± 0.27 mM for glucose. For all blood metabolites, there were no differences between treatments 18 h postinfusion. Lipid infusion significantly increased blood insulin concentration at 3 and 6 h of infusion. However, it returned to its basal concentration 18 h after the end of the infusion. Lymphoproliferation declined as early as 3 h after the start of the lipid infusion. At 3 and 6 h of infusion, lipid treatment significantly reduced INF-γ concentration in the culture cell supernatant. The lipid infusion did not affect neutrophil phagocytosis. Nevertheless, the efficacy of the response was affected by a reduction of neutrophils' oxidative burst. These results confirm that NEFA inhibits immune functions independently of energy balance and other changes that occur during the transition period. They also indicate that high blood lipid concentration causes insulin resistance.

Simple SummaryThe objective of this study was to evaluate the effects of administration of propylene glycol (PG) or sucrose (SC) on health and production outcomes in dairy cows with elevated non-esterified fatty acids (NEFA) levels of 0.3 mEq/L or higher during the close-up period. Thirty-five cows from two farms in Hokkaido were assigned to PG, SC, or untreated control groups, with treatments administered for 5 days starting from the blood testing. In PG and SC cows, blood profiles related to energy metabolism, including NEFA and β-hydroxybutyrate concentrations, improved after calving compared with controls, and liver function was maintained as well. Cows in both treatment groups exhibited significant decreases in postpartum culling rates. These findings suggest that prophylactic administration of PG or SC may contribute to postpartum productivity.The purpose of this study was to evaluate the preventive effects of propylene glycol (PG) or sucrose (SC) in dairy cows with high levels of non-esterified fatty acids (NEFAs) during the close-up period. From July 2021 to August 2022, blood samples were collected from 193 cows between 14 and 7 days prior to the expected calving date in two farms, and 35 multiparous cows with serum NEFA ≥ 0.3 mEq/L were randomly assigned to PG (500 mL/day, n = 11), SC (1000 mL/day of 50% solution, n = 11), and untreated control (HC; n = 13) groups. Treatments were administered orally for 5 consecutive days. Compared with HC cows, the serum NEFA concentration tended to be lower in SC cows at 3 days in milk (DIM) and was significantly lower in PG cows at 14 DIM. Serum β-hydroxybutyrate concentrations tended to be lower in SC cows at 21 DIM. Blood glucose concentrations were higher in both treatment groups at 3 DIM, and the serum total bilirubin concentration remained lower until 14 DIM in PG cows and until 7 DIM in SC cows. At 7 DIM, PG cows showed significantly higher total very low-density lipoprotein levels and PG and SC cows had significantly or tendentially higher low-density lipoprotein triglyceride concentrations. Cows in both treatment groups had significantly reduced culling after calving. These results suggest that prophylactic administration of PG or SC improves energy metabolism by supporting liver function, thereby reducing postpartum culling, with the PG group showing a more consistent effect.

Effects of lipid and propionic acid infusions on feed intake of lactating dairy cows

Most lipid emulsions for parenteral feeding of premature infants are based on long-chain triacylglycerols (LCTs), but inclusion of medium-chain triacylglycerols (MCTs) might provide a more readily oxidizable energy source. The influence of these emulsions on fatty acid composition and metabolism was studied in 12 premature neonates, who were randomly assigned to an LCT emulsion (control) or an emulsion with a mixture of MCT and LCT (1:1). On study day 7, all infants received [13C]linoleic (LA) and [13C]alpha-linolenic acid (ALA) tracers orally. Plasma phospholipid (PL) and triacylglycerol (TG) fatty acid composition and 13C enrichments of plasma PL fatty acids were determined on day 8. After 8 days of lipid infusion, plasma TGs in the MCT/LCT group had higher contents of C8:0 (0.50 +/- 0.60% vs. 0.10 +/- 0.12%; means +/- SD) and C10:0 (0.66 +/- 0.51% vs. 0.15 +/- 0.17%) than controls. LA content of plasma PLs was slightly lower in the MCT/LCT group (16.47 +/- 1.16% vs. 18.57 +/- 2.09%), whereas long-chain polyunsaturated derivatives (LC-PUFAs) of LA and ALA tended to be higher. The tracer distributions between precursors and products (LC-PUFAs) were not significantly different between groups. Both lipid emulsions achieve similar plasma essential fatty acid (EFA) contents and similar proportional conversion of EFAs to LC-PUFAs. The MCT/LCT emulsion seems to protect EFAs and LC-PUFAs from beta-oxidation.

Introduction: The aim of the study was to investigate changes in the serum levels of adiponectin and TNF-α, as well as insulin sensitivity, and to elucidate the possible relationship among the parameters and negative energy balance during the periparturient period of dairy cows. Material and Methods: Thirty primiparous Holstein dairy cows were selected for the study. Blood samples were collected from each cow seven days before the expected calving date, on the calving day, and 7, 14, and 21 days after calving. Blood non-esterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), glucose, insulin, adiponectin, and TNF- α levels were measured. Revised Quantitative Insulin Sensitivity Check Index (rQUICKI) was calculated using data on NEFA, insulin, and glucose concentrations. Results: When compared to prepartum levels, serum concentration of adiponectin significantly increased on day 21 postpartum. The rQUICKI increased and NEFA levels decreased on day 7 after parturition. Insulin and glucose levels decreased on days 7, 14, and 21 postpartum when compared with prepartum levels. BHBA levels decreased on day 21 and TNF- α concentration also decreased on days 7, 14, and 21 postpartum. Adiponectin levels positively correlated with NEFA during the preparturient period. Negative correlation was detected between adiponectin and rQUICKI on calving day and on 14th day after parturition. TNF- α concentration positively correlated with glucose levels on day 7 prepartum and on 21st day postpartum and with rQUICKI on 21st day postpartum. Negative correlation was detected between adiponectin level and insulin sensitivity. Conclusion: Based on the results of the study, we concluded that adiponectin could possibly increase insulin sensitivity when blood NEFA concentrations are elevated.

Negative energy balance (NEB) occurs in dairy cows during the transition period, during which time the blood concentrations of nonesterified fatty acids (NEFA) and metabolic ketones such as β-hydroxybutyric acid (BHBA) are elevated. These increased levels may disrupt immune functions and are regarded as risk factors associated with postparturient inflammatory disorders. Therefore, the aim of this study was to investigate the effects of NEFAs and BHBA on inflammatory cytokine expression in bovine peripheral leukocytes in vitro. Peripheral blood mononuclear cells (PBMCs) and peripheral polymorphonuclear leukocytes (PMNLs) were collected from 16 Holstein cows and treated for 4 h with NEFA (0.1, 0.6, and 1.5 mM) or BHBA (5 and 10 mM), alone or combination with lipopolysaccharides (LPS, 1 µg/mL). The expression levels of the inflammatory cytokines TNF-α, IL-1β, IL-6, IL-8, and IL-10 were then determined. The results indicated that PBMCs and PMNLs responded to NEFA but tolerated BHBA. NEFA treatment dose-dependently induced the expression of TNF-α, IL-1β, IL-8, and IL-10 in PBMCs and that of IL-1β, IL-6, IL-8, and IL-10 in PMNLs. Combination treatment of LPS with NEFA further increased the levels of IL-10 expression in PBMCs and IL-1β and IL-6 expression in PMNLs. Taken together, these findings suggest that NEFA and BHBA enhance the expression of inflammatory cytokines in PBMCs and PMNLs and may disrupt the immune regulation of peripheral leukocytes, leading to an increased risk of inflammatory disorders. Preventing increases in blood NEFA concentration may thus help to reduce the risk of inflammatory disorders in dairy cows during the transition period. Highlights In cows with NEB, during the transition period, NEFA but not BHBA induced proinflammatory cytokine expression in PBMCs and PMNLs. NEFA enhanced LPS-induced proinflammatory cytokine expression in both PBMCs and PMNLs.

Excessive or prolonged periparturient negative energy balance (NEB) is an important issue for dairy producers, and may be associated with increased risk of clinical disease and impaired production and reproductive performance. Affected cows commonly have elevated circulating levels of non-esterified fatty acids (NEFA) prior to calving and increased beta-hydroxybutyrate (BHB) postpartum. Monitoring the incidence of subclinical ketosis postpartum has been the recommended method of surveillance for this problem. Prepartum, blood NEFA concentration may be used to detect cows at risk for problems with severe NEB. Serum NEFA greater than 0.4 mEq/L NEFA has been proposed to identify excessive prepartum NEB. Measuring NEFA has traditionally involved submission of serum to a diagnostic laboratory. The DVM NEFA test (Veterinary Diagnostics. Newburg, Wisconsin, USA) is a new, rapid, spectophotometry method to determine NEFA concentration in serum through light absorbance. The objective of this study was to determine the test characteristics of the DVM NEFA test and its usefulness as a method of identifying problems with NEB in prepartum dairy cows.

The objective of this study was to quantify the effects of supplementing transition dairy cows with a low inclusion dry glycerol product in the pre- and postpartum periods on feed intake, metabolic markers, and milk yield and components. Multiparous Holstein dairy cows (n = 60) were enrolled in a 2-by-2 factorial design study. Starting 21 d before expected parturition, cows individually received a dry cow diet with (1) 250 g/d glycerol product supplementation [66% pure glycerol (United States Pharmacopeia grade); GLY], or (2) no supplementation (CON) mixed to their total mixed ration. After parturition, cows, again, were individually assigned to either GLY, or (2) no supplementation (CON) to their partial mixed ration for the first 21 d in milk (DIM). Cows were milked by an automated milking system and offered a target of 5.4 kg DM/d pellet (23% of target total dry matter intake, DMI) in the automated milking system and followed for 42 d into lactation. Blood samples were collected 6.3 ± 3.47 d before calving for all blood measures and 3, 7, 10, and 14 DIM for analysis of glucose and β-hydroxybutyrate, as well as 3 and 7 DIM for nonesterified fatty acids (NEFA) and haptoglobin. Initial dry cow body weight (BW), calf birth weight, previous 305-d milk, and month of parturition were used as covariates in the statistical model. Cows supplemented with GLY prepartum lost less BW and consumed more DMI pre- and postpartum, as well as had lower postpartum blood β-hydroxybutyrate and NEFA concentrations compared with those fed the CON treatment prepartum. Cows supplemented with GLY postpartum had lesser DMI in the first 42 DIM than cows fed CON postpartum, but also had reduced blood NEFA concentrations, odds of a high haptoglobin test, odds of a low blood glucose test, and lesser preformed fatty acid concentrations and yields in their milk. Cows supplemented glycerol both pre- and postpartum lost the least total BW from -21 to 21 DIM. No treatment effects were detected for milk yield; however, cows receiving GLY postpartum had lower milk fat. Overall, glycerol supplementation during the transition period, particularly during the 21 d before calving, was associated with markers of improved metabolic status.

Measurement of concentrations of glucose and nonesterified fatty acids (NEFA) in blood is common in nutrition and physiology studies. Proper collection and preparation conditions of the blood have been less well studied in dairy cattle. The objective of this experiment was to determine concentrations of glucose and NEFA in blood prepared with different anticoagulants (heparin vs. EDTA), use of fluoride as a glycolysis inhibitor, time until centrifugation (<30 min to 2.5 h), and plasma versus serum. Blood samples were obtained from 30 lactating cows and 15 milk-fed calves into 5 evacuated test tubes. Three of the tubes contained K3 EDTA and 1 tube contained heparin as anticoagulants to prepare plasma, and the fifth tube was a serum separator tube. One of the EDTA tubes was inverted and divided into 2 tubes containing NaF. One of the tubes with NaF and 1 EDTA tube were centrifuged within 30 min of collection and the others were held on ice for another 2 h before centrifugation. The heparin tube and the serum separator tube were centrifuged within 30 min. Glucose and NEFA were measured in the samples using enzymatic kits. Data were divided into 2 data sets representing normal dairy cow values or elevated values for glucose and NEFA. For glucose concentrations, results indicated that fluoride decreased concentrations, that a 2-h holding time before centrifugation did not affect results, and that serum and EDTA plasma resulted in lower glucose than heparin plasma. For low NEFA concentrations, addition of fluoride to the EDTA tubes resulted in a significant decrease of NEFA concentration. The effect of time sitting before centrifugation was significant for low NEFA samples, but contrary to our expectations, the effect was to decrease NEFA rather than increase it. Heparin as an anticoagulant did not affect NEFA concentrations in the low NEFA samples relative to EDTA. Heparin resulted in lower NEFA than serum in low NEFA samples. Serum and EDTA plasma resulted in similar NEFA concentrations. In the high NEFA samples, experimental power was limited due to the small sample size, but fluoride and time did not affect NEFA concentrations. Heparin tended to result in greater NEFA relative to EDTA. Serum produced greater NEFA values compared with EDTA but did not differ from heparin plasma. While differences among preparation methods were small and of limited biological significance, these results provide guidance for collection and processing of blood samples intended for glucose and NEFA assay.

The effect of animal handling procedures on the blood non-esterified fatty acid and glucose concentrations of lactating dairy cows

Summary In dairy cows, overfeeding during the dry period leads to overcondition at calving and to depression of appetite after calving. As a consequence, at calving overconditioned high‐producing dairy cows inevitably go into a more severe negative energy balance (NEB) postpartum than cows that have a normal appetite. During the period of NEB, the energy requirements of the cow are satisfied by lipolysis and proteolysis. Lipolysis results in an increased concentration of non esterified fatty acids (NEFA) in the blood. In the liver, these NEFA are predominantly esterified to triacylglycerols (TAG) that are secreted in very low density lipoproteins (VLDL). In early lactation in cows with a severe NEB, the capacity of the liver to maintain the export of the TAG in the form of VLDL in balance with the hepatic TAG production is not always adequate. As a result, the excess amount of TAG accumulates in the liver, leading to fatty infiltration of the liver (hepatic lipidosis or fatty liver). The NEB and/or fatty liver postpartum are frequently associated with postparturient problems. In general, a severe NEB induces changes in biochemical, endocrinological, and metabolic pathways that are responsible for production, maintenance of health, and reproduction of the postparturient dairy cow. These changes include a decrease in blood glucose and insulin concentrations, and an increase in blood NEFA concentrations. High NEFA concentrations caused by intensive lipolysis are accompanied by impairment of the immune system, making the cows more vulnerable to infections. Metabolic diseases such as ketosis, milk fever, and displaced abomasum are related to overcondition at calving. The changes in biochemical, endocrinological, and metabolic pathways are associated with delay of the first visible signs of oestrus, an increase in the interval from calving to first ovulation, a decrease in conception rate, and a prolonged calving interval. It is possible that the increased blood NEFA concentration directly impairs ovarian function.

Peripartal metabolic stress is characterized by increased lipid mobilization, when non-esterified fatty acids (NEFA) are increased, as well as by increased ketogenesis, when the concentration of beta-hydroxybutyrate (BHB) is increased. NEFA are metabolized in all tissues but the main organ is the liver. Possible processes are: a) complete oxidation of NEFA, b) partial oxidation and synthesis of ketone bodies (BHB), c) development of triglycerides from NEFA that can be transported or stay in the liver when fatty liver is apparent. Moreover, increased lipolysis and ketogenesis can cause oxidative stress because concentrations of MDA and/or TBARS are positively correlated with NEFA and BHB concentrations. The increase in NEFA during the peripartal period affects the cellular immunologic response by changing intracellular signals, gene expressing control, activation of transcriptional factors, apoptosis induction and by modifying mediators of lipid production. Increased proportion of cows with high NEFA and BHB concentrations in the herd can cause reduced milk yield at the end of a standard 305-day lactation. NEFA concentrations can be related to postpartal ovarian activity, especially given that blood NEFA concentrations represent NEFA concentrations in the ovarian follicular fluid. Cows on farms with lower scores of animal welfare and nutrition have higher concentrations of cortisol, NEFA, BHB, bilirubin, glucose and urea. NEFA and BHB concentrations in early lactation can be used for estimating metabolic adaptation in the first 8 weeks after calving. For the estimation of metabolic adaptation, increased lipolysis has a greater significance than decreased anabolic parameters.

Mid-infrared spectroscopic analysis of raw milk to predict the blood nonesterified fatty acid concentrations in dairy cows

Insulin signaling, inflammation, and lipolysis in subcutaneous adipose tissue of transition dairy cows either overfed energy during the prepartum period or fed a controlled-energy diet

The aim of the study was to assess the relationship between acute and subacute metabolic and endocrine effects after intravenous administration of the beta2-adrenergic agonist clenbuterol in a growth-promoting dose to female pigs. Acute metabolic and endocrine effects were assessed by measuring the blood glucose, serum insulin and nonesterified fatty acid (NEFA) concentrations during 300 min after a single administration of clenbuterol. Significantly higher serum insulin and NEFA concentrations (19.90 +/- 2.50 microU/ml, p<0.01, and 0.69 +/- 0.04 mmol/L, p<0.001, respectively) were measured 30 min after the preprandial administration of clenbuterol in female pigs. Over the same period, the levels of blood glucose (4.42 +/- 0.30 mmol/L) showed no difference from those of control pigs. The postprandial serum NEFA concentration decreased moderately during 210 min after feeding. Postprandial blood glucose and insulin concentrations increased and reached maximal levels 120 min after clenbuterol administration (10.91 +/- 0.60 mmol/L and 85.22 +/- 7.24 microU/ml, respectively), and returned to basal levels at 300 min (4.20 +/- 0.21 mmol/L and 7.75 +/- 1.60 microU/ml, respectively) after the administration of clenbuterol. Subacute metabolic and endocrine effects were assessed by measuring the blood glucose, serum insulin and NEFA concentrations for 21 days after the repeated doses of clenbuterol. In addition, the influence of clenbuterol administration on the endocrine regulation of the onset of the next expected oestrus in female pigs was assessed by measuring their serum 17beta-oestradiol and progesterone concentrations. Blood glucose, serum insulin and NEFA concentrations after the last administration of clenbuterol did not differ significantly from those in control animals. The onset of the next expected oestrus occurred regularly without any significant difference in serum 17beta-oestradiol or progesterone concentrations between the treated (9.83 +/- 2.60 pg/ml and 0.15 +/- 0.03 ng/ml) and control pigs (8.52 +/- 2.70 pg/ml and 0.25 +/- 0.06 ng/ml). The study results suggest the duration of intravenous administration of clenbuterol in a growth-promoting dose necessary to influence the metabolic and endocrine activities in female pigs.