Clinical ketosis

Characterization of histone lysine β-hydroxybutyrylation in bovine tissues, cells, and cumulus-oocyte complexes

Besides their canonical roles as energy sources, short-chain fatty acids act as metabolic regulators of gene expression through histone posttranslational modifications. Ketone body β-hydroxybutyrate (BHB) causes a novel epigenetic modification, histone lysine β-hydroxybutyrylation (Kbhb), which is associated with genes upregulated in starvation-responsive metabolic pathways. Dairy cows increase BHB in early lactation, and the effects of this increase on cellular epigenomes are unknown. We searched for and identified that Kbhb is present in bovine tissues in vivo and confirmed that this epigenetic mark is responsive to BHB in bovine and human fibroblasts cultured in vitro in a dose-dependent manner. Maturation of cumulus-oocyte complexes with high concentrations of BHB did not affect the competence to complete meiotic maturation or to develop until the blastocyst stage. BHB treatment strongly induced H3K9bhb in cumulus cells, but faintly in oocytes. RNA-seq analysis in cumulus cells indicated that BHB treatment altered the expression of 345 genes. The downregulated genes were mainly involved in glycolysis and ribosome assembly pathways, while the upregulated genes were involved in mitochondrial metabolism and oocyte development. The genes and pathways altered by BHB will provide entry points to carry out functional experiments aiming to mitigate metabolic disorders and improve fertility in cattle.

High concentrations of β-hydroxybutyrate alter the kinetics of bovine spermatozoa

Postpartum cows, mainly with metabolic diseases, such as ketosis, usually experience an increased number of services per conception. During ketosis, high concentrations of β-hydroxybutyrate (BHBA) in follicular, uterine and oviductal fluid have been considered to cause subfertility in cows. However, the effect of sperm exposure to an environment with high BHBA concentration is not known. This study investigated the influence of high levels of BHBA on kinetics, oxidative status and morphology of bovine spermatozoa. To assess the effect of BHBA after sperm selection, bovine spermatozoa were incubated (180 min) with different BHBA concentrations: 0 (Control), 0.8, 2.4 or 5 mM. Sperm kinetics was evaluated after 30, 60, 120 and 180 min, and oxidative status and morphology were analysed at 180 min. Oxidative status was evaluated through the production of reactive oxidative species (ROS), total antioxidant capacity and lipid peroxidation. High concentrations of BHBA decreased the curvilinear velocity, straight line velocity, mean path velocity, linearity, straightness and hyperactivity of spermatozoa. However, there was no effect of BHBA on oxidative and antioxidant capacity as well as on sperm morphology. In conclusion, exposure of bovine spermatozoa to high levels of BHBA impairs sperm kinetics without altering oxidative and antioxidant mechanisms.

Invited Review: Ketosis Diagnosis and Monitoring in High-Producing Dairy Cows

This work reviews the current impact and manifestation of ketosis (hyperketonemia) in dairy cattle, emphasizing the practical use of laboratory methods, field tests, and milk data to monitoring this disease. Ketosis is a major issue in high-producing cows, easily reaching a prevalence of 20% during early postpartum when the negative energy balance is well established. Its economic losses, mainly related to decreasing milk yield, fertility, and treatment costs, have been estimated up to €250 per case of ketosis/year, which can double if associated diseases are considered. A deep relationship between subclinical or clinical ketosis and negative energy balance and related production diseases can be observed mainly in the first two months postpartum. Fourier transform infrared spectrometry methods gradually take place in laboratory routine to evaluates body ketones (e.g., beta-hydroxybutyrate) and probably will accurately substitute cowside blood and milk tests at a farm in avenir. Fat to protein ratio and urea in milk are largely evaluated each month in dairy farms indicating animals at risk of hyperketonemia. At preventive levels, other than periodical evaluation of body condition score and controlling modifiable or identifying non-modifiable risk factors, the ruminatory activity assessment during the peripartum seems to be a valuable tool at farms. We conclude that a technological advance progressively takes place to mitigate the effects of these metabolic diseases, which challenge the high-yielding cows.

Performance, metabolic and hormonal responses of grazing Nellore cows to an energy-protein supplementation during the pre-partum phase

BACKGROUND

Supplementation programs for prepartum beef cows are usually adopted because the nutritional status of the cows upon calving is a main factor impacting reproductive performance of the next production cycle. This study evaluated the effects of 60-d pre-partum energy-protein supplementation on performance, metabolic and hormonal responses during the peripartum phase of grazing beef cows. Thirty-eight pregnant multiparous Nellore cows were assigned to a completely randomized design with two treatments: control (no supplement) and supplementation (1.5 kg of energy-protein per d with 30% crude protein, dry matter basis).

RESULTS

The supplemented cows had higher ADG pre-partum (P < 0.10), but postpartum ADG did not differ between treatments. Supplementation did not affect BCS and calf BW upon calving, on days 45 and 90, milk yield and composition (P > 0.10). No differences were found for forage intake and neutral detergent fiber digestibility (P > 0.10). The intake and digestibility of CP and OM increased in response to supplementation (P < 0.10). An interaction occurred between supplementation and peripartum days for BUN, βHB, T3 and T4, which had higher concentrations for supplemented cows at pre-partum period (P < 0.10). Concentration of others blood parameters significantly changed along peripartum days (P < 0.10). There was no difference in pregnancy rates and days from calving to conception between treatments (P > 0.10).

CONCLUSIONS

Providing an energy and protein supplement to grazing Nellore cows over the last 60 d of gestation improved their pre-partum energy balance. However, no post-partum carryover effects were detected.

Metabolic gene expression and epigenetic effects of the ketone body β-hydroxybutyrate on H3K9ac in bovine cells, oocytes and embryos

The rapid decline in fertility that has been occurring to high-producing dairy cows in the past 50 years seems to be associated with metabolic disturbances such as ketosis, supporting the need for research to improve our understanding of the relations among the diet, metabolism and embryonic development. Recently, the ketone body β-hydroxybutyrate (BOHB) was demonstrated to be a potent inhibitor of histone deacetylases (HDACs). Herein, we performed a series of experiments aiming to investigate the epigenetic effects of BOHB on histone acetylation in somatic cells, cumulus-oocyte complexes (COCs) and somatic cell nuclear transfer (SCNT) embryos. Treatment with BOHB does not increase histone acetylation in cells but stimulates genes associated with ketolysis and master regulators of metabolism. We further demonstrated that maturing COCs with high levels of BOHB does not affect their maturation rate or histone acetylation but increases the expression of PPARA in cumulus cells. Treatment of somatic cell nuclear transfer zygotes with BOHB causes hyperacetylation, which is maintained until the blastocyst stage, causing enhanced FOXO3A expression and blastocyst production. Our data shed light on the epigenetic mechanisms caused by BOHB in bovine cells and embryos and provide a better understanding of the connection between nutrition and reproduction.

Effects of a combination of plant bioactive lipid compounds and biotin compared with monensin on body condition, energy metabolism and milk performance in transition dairy cows

The aim of this study was to test whether a combination of plant bioactive lipid compounds (also termed ‘essential oils’) and biotin (PBLC+B) could decrease the mobilization of body reserves and ketosis incidence in postpartum dairy cows. We compared non-supplemented control (CON) cows with cows receiving monensin (MON) as a controlled-release capsule at d -21, and with cows receiving PBLC+B from day (d) -21 before calving until calving (Phase 1) and further until d 37 after calving (Phase 2), followed by PBLC+B discontinuation from d 38 to d 58 (Phase 3). The PBLC+B cows had higher body weight and higher back fat thickness than CON cows and lesser body weight change than MON and CON cows in Phase 3. Body condition score was not different among groups. Milk protein concentration tended to be higher on the first herd test day in PBLC+B vs. CON cows. Milk fat concentration tended to be highest in PBLC+B cows throughout Phases 2 and 3, with significantly higher values in PBLC+B vs. MON cows on the second herd test day. Yields of energy-corrected milk were higher in PBLC+B vs. CON and MON cows in Phase 2 and higher in PBLC+B and MON cows vs. CON cows in Phase 3. The incidence of subclinical ketosis was 83%, 61% and 50% in CON, PBLC+B and MON cows, respectively, with lower mean β-hydroxybutyrate values in MON than in PBLC+B cows in Phase 1 prepartum. The serum triglyceride concentration was higher in PBLC+B vs. CON cows on d 37. No differences were observed in serum glucose, urea, non-esterified fatty acids, cholesterol and bilirubin concentrations. Aspartate transaminase and γ-glutamyltranspeptidase but not glutamate dehydrogenase activities tended to be highest in MON and lowest in PBLC+B in Phase 2. We conclude that PBLC+B prevent body weight loss after parturition and are associated with similar ketosis incidence and partly higher yields of energy-corrected milk compared to MON supplementation of dairy cows.

Effects of Dexamethasone and Insulin Alone or in Combination on Energy and Protein Metabolism Indicators and Milk Production in Dairy Cows in Early Lactation - A Randomized Controlled Trial

OBJECTIVES

This study investigated the effects of dexamethasone and insulin, when administered at 3rd or 10th day of lactation on energy and protein metabolism in dairy cows.

MATERIALS AND METHODS

Two hundred Holstein cows were enrolled in a randomized controlled clinical trial. The cows were randomly assigned to receive 1 of 4 treatments at 3 or 10 days in milk: control group, 10-mL i.m. injection of sterile water, group insulin, s.c. injection of 100 units of insulin, group dexamethasone, i.m. injection of 20 mg of dexamethasone, group insulin plus dexamethasone, i.m. injection of 20 mg of dexamethasone and 100 units of insulin. The cows randomly assigned to receive the treatments on 3 or 10 days of lactation. Serum samples obtained at the time of enrollment, time of treatment and at 2, 4, 7 and 14 days after intervention. The sera were analyzed for β-hydroxybutyrate (BHBA), nonesterified fatty acids (NEFA), glucose, cholesterol, albumin, urea, and aspartate amino transferase (AST). Data were analyzed using a repeated measures mixed model that accounted for the effects of parity, body condition score, dystocia, retained placenta, metritis and the random effect of cow.

RESULTS

There was no significant interaction of group of treatment and time of intervention (day 3 or 10 post-partum) on serum components. Cows that received insulin or dexamethasone alone or in combination, had lower BHBA 2 days after treatment compared with control cows, whereas concentrations of NEFA, were unaffected suggesting that glucocorticoids lipolytic effects do not appear to be important in healthy cows. AST activities significantly reduced in cows that received dexamethasone with or without insulin at 2 and 4 days after treatment. Albumin and urea concentrations 2 days after treatment were higher for cows that received dexamethasone only or dexamethasone plus insulin compared with control and Ins received cows. There were no treatment effects on test-day milk production, milk fat and protein percentages.

CONCLUSIONS

The results suggested that administration of glucocorticoids in early lactation resulted in short-term improvement of metabolism in postpartum dairy cows in biochemical terms.

Elevated non-esterified fatty acids and β-hydroxybutyrate and their association with transition dairy cow performance

Dairy cows pass through a period of negative energy balance as they transition from late gestation to early lactation. Poor adaptation through this period, expressed as excessively elevated concentrations of non-esterified fatty acids (NEFAs) pre- or post-partum and elevated concentrations of β-hydroxybutyrate post-partum, increases an individual animal's risk of post-partum disease, removal from the herd, reproductive difficulty, and reduced milk production. Field studies have shown that subclinical ketosis often affects 40% of cows in a herd although the incidence can be as high as 80%. Peak incidence occurs at 5 days in milk, and cows that develop subclinical ketosis in the first week of lactation have a higher risk of negative effects and reduced milk production than cows that develop subclinical ketosis in the second week of lactation. Herds with more than a 15-20% prevalence of excessively elevated concentrations of NEFAs and β-hydroxybutyrate in early lactation have higher rates of negative subsequent events, poorer reproduction, and lower milk yield than herds with a lower prevalence of negative energy balance. This paper reviews (1) strategies for testing of energy-related metabolites, (2) consequences of poor adaptation to negative energy balance (for individual animals and for herds), (3) treatment approaches for affected cows, and (4) economic considerations for testing and treating cows with poor adaptation to negative energy balance.

Some immunohormonal changes in experimentally pregnant toxemic goats

Pregnancy toxemia was induced in nine pregnant goat does with twins by the stress of fasting with access to water in late pregnancy to investigate the effect of pregnancy toxemia on immunoglobulins (IgA, IgM, and IgG), cortisol, insulin, thyroid, and growth hormones and their correlations with the plasma levels of glucose and β-Hydroxybutyrate. Plasma samples were collected at 0, 12, 24, 36, 48, and 72 hours after induction of pregnancy toxemia. The result revealed that experimental animals developed neurological findings with convulsions and acetone odor from the mouth with recumbency after 72 hours. Laboratory findings showed a significant increase in β-Hydroxybutyrate, cortisol, and insulin while there were significant decreases in glucose, thyroid, and immunoglobulins (IgA, IgM, and IgG). Plasma glucose concentrations had significant negative correlations with β-hydroxybutyrate, cortisol, and insulin while the correlations were significantly positive with immunoglobulins and thyroid hormone. Plasma β-hydroxybutyrate concentration was significantly positively correlated with cortisol and negatively correlated with immunoglobulins, insulin, and thyroid hormone. From this study we can conclude that pregnancy toxemia might affect humoral immune responses as well as insulin, cortisol, and thyroid hormones. Moreover, insulin might have a compensatory role to increase suppressive effect on ketogenesis in experimentally pregnant toxemic goats.

Effect of Isoflupredone Acetate With or Without Insulin on Energy Metabolism, Reproduction, Milk Production, and Health in Dairy Cows in Early Lactation

Glucocorticoids are commonly used to treat cows with clinical ketosis and fatty liver disease, but their use is controversial. The objectives of the present study were to investigate the effects of isoflupredone acetate alone or with insulin on the energy metabolism of dairy cows in early lactation in a large double-blind, randomized clinical trial. A total of 1,162 Holstein cows and first-lactation heifers were randomly assigned to receive 1 of 3 treatments between the day of parturition and 8 DIM: group A, 20-mg i.m. injection of isoflupredone and 100 units of insulin; group B, 20-mg i.m. injection of isoflupredone; group C (control group), 10-mL i.m. injection of sterile water. Treatments were randomized across 24 dairy farms located near Guelph, Ontario, Canada. Serum samples obtained at the time of treatment and at wk 1 and 2 following treatment were analyzed for beta-hydroxybutyrate, nonesterified fatty acids, glucose, calcium, potassium, sodium, and chloride. Cows were assigned a body condition score at the time of enrollment. Data were analyzed using a repeated-measures mixed model that accounted for the effects of parity and body condition score, and the random effects of cow and farm. Cows that received isoflupredone with insulin and isoflupredone alone had higher beta-hydroxybutyrate and nonesterified fatty acid concentrations 1 wk after treatment compared with control cows. Cows that received isoflupredone acetate plus insulin had lower glucose concentrations at 1 wk after treatment. Calcium concentrations 1 wk after treatment were lower for cows that received isoflupredone and insulin or isoflupredone only compared with control cows. Serum sodium, potassium, and chloride concentrations were not influenced by treatment. The effect of treatment on the proportion of cows with subclinical ketosis was evaluated with a logistic regression model. Over the 2 wk following treatment, a significant increase in the prevalence of subclinical ketosis was observed in the isoflupredone plus insulin group relative to the control group. Among 972 cows that were not ketotic at enrollment, cows that received isoflupredone acetate plus insulin or isoflupredone acetate only were, respectively, 1.72 and 1.59 times more likely than control cows to develop subclinical ketosis 1 wk after treatment. There were no treatment effects on test-day milk production, milk fat and protein percentages, or the intervals from calving to first insemination or pregnancy.

Suppression of feed intake after parenteral administration of D-beta-hydroxybutyrate in pygmy goats

The effect of intraperitoneal injection of D,L- or D-beta-hydroxybutyrate on feed intake and plasma metabolites was investigated in pygmy goats. The combined intraperitoneal injection of D,L-beta-hydroxybutyrate or D-beta-hydroxybutyrate (15 mmol/kg0.75) and 1,3-butanediol (6.6 mmol/kg0.75), a ketogenic substrate, decreased cumulative food intake while the same dose of 1,3-butanediol or DL-beta-hydroxybutyrate alone had no effect. The decrease in food intake after combined injection of D-beta-hydroxybutyrate and 1,3-butanediol was characterized by a significant decrease in meal frequency and a prolongation of the latency to eat. The hypophagic effect of the combined injection of D-beta-hydroxybutyrate and 1,3-butanediol was significant for 8 h, while the hypophagia after D,L-beta-hydroxybutyrate and 1,3-butanediol was significant for only 2 h after injection. Injection of D,L-beta-hydroxybutyrate increased plasma D-beta-hydroxybutyrate levels to 0.55 mmol/l and decreased plasma free fatty acids. Addition of 1,3-butanediol (6.6 mmol/kg0.75) to the injection increased plasma D-beta-hydroxybutyrate level up to 0.75 mmol/l. The results show that parenteral administration of D-hydroxybutyrate reduces feed intake in pygmy goats and that the hypophagia appears to be related to the amount of D-beta-hydroxybutyrate injected. The hypophagia seems to be related to elevated plasma D-beta-hydroxybutyrate concentration, and the threshold concentration appeared to be about 0.7 mmol/l under the experimental conditions of this study.

Evaluation of additional acetone and urea analyses, and of the fat-lactose-quotient in cow milk samples in the herd recording system in Norway

The purpose of this study was to evaluate the use of additional acetone and urea analyses to the established herd recording system (protein, fat, lactose, and somatic cell count) in cow milk samples every second month. Samples were obtained from 43/82 herds (800/1368 cows) in a lowland/highland area. Acetone concentration (mmol/l) were classified into acetone classes 1 (<0.7); 2 (0.7-1.4); and 3 (>1.4). There was an association between increasing acetone class and increasing ketosis incidence in herd (Kendall's Tau-b = 0.13). The highest percentage frequencies of acetone classes 2 and 3 were in weeks 4-6 postpartum. Milk yield, urea, and lactose were significantly lower; milk protein not different, and milk fat was significantly higher in herds with high ketosis incidence and in cows in acetone classes 2 and 3. General linear models, obtained by backward elimination of non-significant variables, showed that milk protein was negatively associated to milk yield and positively associated to milk fat. Milk yield decreased, and milk fat concentration increased with increasing acetone level. Milk fat and milk lactose were negatively associated, and a fat-lactose-quotient might be promising in a model to rule out subclinical ketosis cows.

Etiology of lipid-related metabolic disorders in periparturient dairy cows

Plasma NEFA concentrations increase prior to and at parturition, resulting in increased fatty acid uptake by the liver, fatty acid esterification, and triglyceride storage. Liver triglyceride concentration increases four- to fivefold between d 17 prior to calving and d 1 following calving. Increases in liver triglyceride following calving do not appear to be dramatic. Severity of fatty liver 1 d postpartum is correlated negatively with feed intake 1 d prepartum. Export of newly synthesized triglyceride as very low density lipoprotein occurs slowly in ruminants and is a major factor in the development of fatty liver. Nutritional strategies to minimize the elevation in plasma NEFA prior to calving results in lower liver triglyceride at calving. Fatty liver probably precedes clinical spontaneous ketosis. Liver triglyceride to glycogen ratio may be used to predict susceptibility of cows to ketosis. Consequently, strategies to reduce liver triglyceride at calving may decrease incidence of ketosis. Research to determine methods to reduce fatty acid delivery to the liver or to enhance hepatic export of very low density lipoprotein near calving is warranted. Identification of the cause for the slow rate of assembly and secretion of hepatic very low density lipoprotein in ruminants will be required to assess the feasibility of increasing export of very low density lipoprotein.

Effects of ketones, acetate, and glucose on in vitro immunoglobulin secretion by bovine lymphocytes

Individual and combined effects of ketones, acetate, and glucose on IgM secretion by bovine blood lymphocytes were evaluated in vitro. Supernatants from 14-d cultures of unstimulated and mitogen- or antigen-stimulated mono-nuclear leukocytes were harvested and analyzed for total and antigen-specific IgM. Ketones, acetate, and 1,3-butanediol individually added up to 6.25 mM had no effect on total IgM secreted by cells grown in medium containing 11.1 mM glucose. However, butyrate at 6.25 mM inhibited IgM secretion. Addition of a mixture of ketones approximating plasma levels of severely ketotic cows inhibited mitogen-induced IgM secretion in 11.1 mM glucose-supplemented cultures. Results from experiments evaluating effects of glucose concentrations on IgM secretion indicated that plasma glucose concentration associated with the ketotic state (1.66 mM), compared with normal plasma glucose concentration (3.33 mM), did not affect total or antigen-specific IgM secretion. Supplementation of cultures containing up to 3.33 mM glucose with ketones, acetate, or both either had no effect or a modest stimulatory effect. These data indicate that effects of ketones and acetate on IgM secretion are dependent on the concentration of glucose in culture and suggest that changes in plasma glucose, ketone, and acetate concentrations associated with bovine ketosis do not alter IgM secretion in vivo.

Dry cow nutrition. The key to improving fresh cow performance

Evidence supports the concept of the dry period being a critical component to lactation preparation rather than an insignificant rest period between lactations. Required nutrient amounts for the dry cow are the sum of maintenance, pregnancy, and reserve replenishment needs with additional requirements for growth during the first two pregnancies. Maintenance energy requirements can be dramatically increased by level of activity and adverse environmental conditions. A wide variety of feed ingredients can be successfully fed to dry cows as long as rations are appropriately formulated to meet energy, protein, mineral, and vitamin requirements. A early and close-up dry program best matches increasing pregnancy requirements and declining intake capacity with management capabilities. The early dry cow ration is formulated for high fiber/low energy density while the close-up ration contains higher energy density with less fiber. Both rations contain sufficient other nutrients based on determined intake. This two-group system provides maximal flexibility in managing for optimum body condition at calving. Environmental stresses and dramatic dietary changes should be minimized during the transition period from late gestation to lactation. A sound dry cow program results from integration of quality nutrition and cow management practices as described. A dry cow program that enacts these guidelines should result in reduced incidence of clinical mastitis, successfully complete pregnancy with a viable calf, maximize genetic potential for milk production, minimize incidence of health disorders, and allows cows to breed back within an economically optimum time interval. Overall, a sound dry cow program is a critical key to improved fresh cow performance.