Increase In Non-esterified Fatty Acids Research Articles

Lactation performance, feed efficiency, and blood metabolites of dairy cows treated with recombinant bovine somatotropin: A systematic review and meta-analysis

A systematic review and meta-analysis were conducted to assess the impact of recombinant bovine somatotropin (rbST) on lactation performance, feed efficiency, and blood metabolites in dairy cows. In the systematic review, articles were selected based on the following criteria: (1) Data focusing on the influence of bovine somatotropin doses on milk production; (2) Submission of original data; (3) Articles published in journals; and (4) Articles in English or Portuguese. The analysis of variance was used with a completely randomized design and mixed models methodology. Polynomial regression was applied to significant fixed effects (rbST dose). The use of rbST resulted in increased milk yield and 4% fat-corrected milk yield, while fat, protein, and lactose contents remained unaffected. Dry matter and metabolizable energy intakes, as well as milk/feed efficiency, exhibited a linear increase, but body condition score (BCS) was negatively impacted. The administration of rbST led to higher blood concentrations of triglycerides and insulin. Cows treated with rbST showed a 23% increase in non-esterified fatty acid (NEFA) concentrations compared to non-treated cows. Additionally, growth factors IGF-1 and IGF-2 displayed a linear increase with rbST treatment. In summary, rbST administration increased milk yield and fat-corrected milk yield without affecting milk components. However, despite increasing intake, it resulted in BCS losses and alterations in blood parameters such as NEFA, IGF-1, and IGF-2.

Effect of two recombinant bovine somatotropin formulations on feeding behavior and metabolism of Holstein cows

This study evaluated the effect of two commercial forms of recombinant bovine somatotropin (rbST; Later® and Fast®; 500 mg) on feed variability, feeding behavior, zootechnical parameters, and milk production of Holstein cows after peak production. Eighteen cows were randomly divided into two groups and treated with injectable of rbST every 14 days for 70 days. Blood samples were collected on day 1, 4, and 7 of each cycle, to assess circulating levels of non-esterified fatty acids (NEFA). Weight and body condition score (BCS) assessments were performed. Milk yields were measured daily using the DelPro™ software (DeLaval®). Feed consumption and feeding behavior was obtained daily using automatic individual feeders (Intergado®). No difference was observed in dry matter intake (DMI) between groups (P=0.07), and no impact was noted on dietary variability (P=0.64). In addition, animals treated with rbST-Fast exhibited more frequent visits to feeders, longer time in consumption, and higher relative DMI (per percentage of live weight) (P<0.01). Animals in the rbST-Fast group produced more milk than those in the rbST-Later group (P=0.03). Furthermore, the weight of the cows was significantly different (P=0.05) between groups. The weight of the rbST-Fast animals was smaller and varied more than thot of the rbST-Later animals (P <0.01). Nonetheless, no difference was noted in BCS (P=0.30) between the groups. The animals in the rbST-Fast group had higher concentrations of NEFA than those in the rbST-Later group (P<0.01). In conclusion, behavioral and metabolic shifts that sustained greater milk production in the cows receiving rbST-Fast. Nonetheless, these shifts are likely linked to lipomobilization and not dietary variability or consumption, as evidenced by the increase in NEFA and greater weight loss in that group.

Assessment of Mastitis Patterns in Serbian Dairy Cows: Blood Serum Metabolic Profile and Milk Composition Parameters.

Mastitis is one of the most important diseases in dairy cows, leading to substantial economic losses associated with decreased milk production and quality. Early detection of changes in metabolic and milk parameters is crucial for maintaining animal welfare and milk quality. This study aimed to detect patterns in metabolic and milk composition parameters in Serbian dairy cows affected by mastitis. It also examined the relationship between these factors in cows with clinical and subclinical mastitis, as well as in healthy cows. This study included 60 Holstein-Friesian cows with the same body score condition that were in the same lactation phase. They were divided into three groups of 20: clinical and subclinical mastitis and a control group of healthy cows. The categorization was based on clinical udder health and the California mastitis test. Blood serum metabolic profiles were measured using a Rayto spectrophotometer (Shenzhen, China), and milk composition was determined using MilcoScanTM (Foss, Hilleroed, Denmark) and FossomaticTM (Foss, Hilleroed, Denmark) instruments. Significant increases in non-esterified fatty acids (NEFAs), beta-hydroxybutyrate (BHB), total protein, globulin, urea, total bilirubin, magnesium, and enzyme activity were noted in mastitis-affected cows compared to healthy ones. Additionally, mastitis-affected cows had higher total protein and globulin levels and increased somatic cell counts (SCCs), while albumin concentrations were decreased. Furthermore, a negative correlation between total protein and lactose suggested inflammation leading to reduced lactose levels due to cell damage, infection, and lactose use by mastitis pathogens. Hence, indicators of the energy and protein status of the metabolic profile, together with the chemical composition of milk, may be significant diagnostic tools for detecting, monitoring, and predicting the outcome of mastitis in cows.

Vitamin E reduces the reactive oxygen species production in dominant follicle during the negative energy balance in cattle.

In the postpartum period, there is an increase in non-esterified fatty acids (NEFA) in both serum and follicular fluid (FF) of cattle. The increase in fatty acid concentration results in increased production of reactive oxygen species (ROS) that can compromise bovine fertility. The objectives of this study were to characterize the lipid profile found in the FF of cows experiencing induced negative energy balance (NEB) and to evaluate the effect of α-tocopherol in the prevention of oxidative stress in the serum and FF of cows. Twenty-nine beef cows were divided into groups: (1) control; (2) Fasting for 24 days; and (3) Fasting + VitE. Between D0 and D4 blood samples were taken to assess concentrations of NEFA, ROS production, total antioxidant capacity (FRAP), lipid peroxidation, and α-tocopherol (vitamin E). On D4, follicular aspiration was performed for analysis of FF from the dominant follicle. Our results demonstrate that fasting was effective in causing increased fat mobilization in animals. The increase in serum concentration of C18:1c9 was reflected in the FF of fasting cows. Serum α-tocopherol concentration was higher in the control and Fasting + VitE groups compared to the Fasting group. In FF, there was an increase of α-tocopherol in the Fasting + VitE group in comparison to Fasting cows. There was an increase in ROS production in the serum of fasting cows. ROS production in FF was higher in the Fasting compared to the Fasting + VitE group. Vitamin E has beneficial effects in reducing ROS production in the dominant follicle of cows in NEB.

Altered Fecal Microbiome and Correlations of the Metabolome with Plasma Metabolites in Dairy Cows with Left Displaced Abomasum.

Left displaced abomasum (LDA) in postpartum dairy cows contributes to significant economic losses. Dairy cows with LDA undergo excessive lipid mobilization and insulin resistance. Although gut dysbiosis is implicated, little is known about the role of the gut microbiota in the abnormal metabolic processes of LDA. To investigate the functional links among microbiota, metabolites, and disease phenotypes in LDA, we performed 16S rDNA gene amplicon sequencing and liquid chromatography-tandem mass spectrometry (LC-MS/MS) of fecal samples from cows with LDA (n = 10) and healthy cows (n = 10). Plasma marker profiling was synchronously analyzed. In the LDA event, gut microbiota composition and fecal metabolome were shifted in circulation with an amino acid pool deficit in dairy cows. Compared with the healthy cows, salicylic acid derived from microbiota catabolism was decreased in the LDA cows, which negatively correlated with Akkermansia, Prevotella, non-esterified fatty acid (NEFA), and β-hydroxybutyric acid (BHBA) levels. Conversely, fecal taurolithocholic acid levels were increased in cows with LDA. Based on integrated analysis with the plasma metabolome, eight genera and eight metabolites were associated with LDA. Of note, the increases in Akkermansia and Oscillospira abundances were negatively correlated with the decreases in 4-pyridoxic acid and cytidine levels, and positively correlated with the increases in NEFA and BHBA levels in amino acid deficit, indicating pyridoxal metabolism-associated gut dysbiosis and lipolysis. Changes in branched-chain amino acids implicated novel host-microbial metabolic pathways involving lipolysis and insulin resistance in cows with LDA. Overall, these results suggest an interplay between host and gut microbes contributing to LDA pathogenesis. IMPORTANCE LDA is a major contributor to economic losses in the dairy industry worldwide; however, the mechanisms associated with the metabolic changes in LDA remain unclear. Most previous studies have focused on the rumen microbiota in terms of understanding the contributors to the productivity and health of dairy cows; this study further sheds light on the relevance of the lower gut microbiota and its associated metabolites in mediating the development of LDA. This study is the first to characterize the correlation between gut microbes and metabolic phenotypes in dairy cows with LDA by leveraging multi-omics data, highlighting that the gut microbe may be involved in the regulation of lipolysis and insulin resistance by modulating the amino acid composition. Moreover, this study provides new markers for further research to understand the pathogenesis of the disease as well as to develop effective treatment and prevention strategies.

Evaluation of metabolic and oxidative profile in ovine pregnancy toxemia and to determine their association with diagnosis and prognosis of disease.

This study was conducted on ewes with pregnancy toxemia (PT) with an attempt to evaluate metabolic and oxidative profile in subclinical and clinical ovine pregnancy toxemia and to determine their association with diagnosis and prognosis of the disease. A total of 20 ewes having beta-hydroxy butyric acid (β-HBA) > 2.5mmol/L and proven clinical sings of PT, categorized as clinical PT (CPT); 12 ewes having β-HBA 0.8-2.5mmol/L and no clinical signs of PT, categorized at subclinical PT (SPT); and 10 ewes having β-HBA ≤ 0.8mmol/L, categorized as healthy control (CON) were enrolled. Among 20 CPT ewes, 11 had negative outcomes (non-survivors), six ewes had positive outcomes (survivors), and three were lost during follow-up. A significant increase in non-esterified fatty acid, β-HBA, triglycerides, gamma-glutamyl transferase, lactate dehydrogenase, and malondialdehyde levels and a significant decrease in fructosamine were observed in CPT and SPT compared to CON. A significant increase in cholesterol, aspartate amino transferase, and creatinine kinase and a significant decrease in albumin, potassium, calcium, superoxide dismutase, and catalase were observed in CPT only. Glucose was significantly decreased in SPT only. The highest area under the curve (AUC) was observed for fructosamine (89.7% and 87.5% for CPT and SPT, respectively) with the optimum cutoff point calculated on the basis of maximum sensitivity (SE) and specificity (SP) being 0.607mmol/L (SE: 89.3% and SP: 72.2%) and 1.005mmol/L (SE: 90.0% and SP: 75.3%) for CPT and SPT, respectively. At the cutoff limit of 0.607mmol/L and 1.005mmol/L, the odds ratio was 10.8 and 8.0 for CPT and SPT, respectively. A significant decrease in fructosamine and potassium and a significant increase in creatinine, lactate dehydrogenase, and malondialdehyde were observed in non-survivors compared to survivors. It was thus concluded that fructosamine was the best diagnostic indicator of both CPT and SPT followed by non-esterified fatty acid. Fructosamine, creatinine, potassium, lactate dehydrogenase, and malondialdehyde were the best prognostic indicators of PT.

Nutrigenetic Interaction of Spontaneously Hypertensive Rat Chromosome 20 Segment and High-Sucrose Diet Sensitizes to Metabolic Syndrome.

Several corresponding regions of human and mammalian genomes have been shown to affect sensitivity to the manifestation of metabolic syndrome via nutrigenetic interactions. In this study, we assessed the effect of sucrose administration in a newly established congenic strain BN.SHR20, in which a limited segment of rat chromosome 20 from a metabolic syndrome model, spontaneously hypertensive rat (SHR), was introgressed into Brown Norway (BN) genomic background. We mapped the extent of the differential segment and compared the genomic sequences of BN vs. SHR within the segment in silico. The differential segment of SHR origin in BN.SHR20 spans about 9 Mb of the telomeric portion of the short arm of chromosome 20. We identified non-synonymous mutations e.g., in ApoM, Notch4, Slc39a7, Smim29 genes and other variations in or near genes associated with metabolic syndrome in human genome-wide association studies. Male rats of BN and BN.SHR20 strains were fed a standard diet for 18 weeks (control groups) or 16 weeks of standard diet followed by 14 days of high-sucrose diet (HSD). We assessed the morphometric and metabolic profiles of all groups. Adiposity significantly increased only in BN.SHR20 after HSD. Fasting glycemia and the glucose levels during the oral glucose tolerance test were higher in BN.SHR20 than in BN groups, while insulin levels were comparable. The fasting levels of triacylglycerols were the highest in sucrose-fed BN.SHR20, both compared to the sucrose-fed BN and the control BN.SHR20. The non-esterified fatty acids and total cholesterol concentrations were higher in BN.SHR20 compared to their respective BN groups, and the HSD elicited an increase in non-esterified fatty acids only in BN.SHR20. In a new genetically defined model, we have isolated a limited genomic region involved in nutrigenetic sensitization to sucrose-induced metabolic disturbances.

Effect of feed restriction on dairy cow milk production: a review.

In the dairy cow, negative energy balance affects milk yield and composition as well as animal health. Studying the effects of negative energy balance on dairy cow milk production is thus essential. Feed restriction (FR) experiments attempting to reproduce negative energy balance by reducing the quantity or quality of the diet were conducted in order to better describe the animal physiology changes. The study of FR is also of interest since with climate change issues, cows may be increasingly faced with periods of drought leading to a shortage of forages. The aim of this article is to review the effects of FR during lactation in dairy cows to obtain a better understanding of metabolism changes and how it affects mammary gland activity and milk production and composition. A total of 41 papers studying FR in lactating cows were used to investigate physiological changes induced by these protocols. FR protocols affect the entire animal metabolism as indicated by changes in blood metabolites such as a decrease in glucose concentration and an increase in non-esterified fatty acid or β-hydroxybutyrate concentrations; hormonal regulations such as a decrease in insulin and insulin-like growth factor I or an increase in growth hormone concentrations. These variations indicated a mobilization of body reserve in most studies. FR also affects mammary gland activity through changes in gene expression and could affect mammary cell turnover through cell apoptosis, cell proliferation, and exfoliation of mammary epithelial cells into milk. Because of modifications of the mammary gland and general metabolism, FR decreases milk production and can affect milk composition with decreased lactose and protein concentrations and increased fat concentration. These effects, however, can vary widely depending on the type of restriction, its duration and intensity, or the stage of lactation in which it takes place. Finally, to avoid yield loss and metabolic disorders, it is important to identify reliable biomarkers to monitor energy balance.

The Effects of Vehicle Type, Transport Duration and Pre-Transport Feeding on the Welfare of Sheep Transported in Low Temperatures.

Simple SummarySheep are often transported in cold conditions. Some of the coldest exist in northern China and we tested the effects of transporting sheep in these conditions. In order to find out how to limit any of the cold temperatures’ adverse effects, we tested journeys of two durations, in covered and open trucks, and investigated the effects of feeding sheep before transport. We found that sheep had less evidence of cold stress in a covered vehicle. Longer journeys actually allowed the sheep to warm up, but sheep appeared more stressed after the long journeys. Feeding the sheep before transport also helped to ameliorate the adverse effects of cold stress.Low temperatures can provide a risk to the welfare of sheep during transport because of increased ventilation chilling the sheep, and we examined the importance of three factors—covering the vehicle, duration of transport, and feeding prior to transport—on the welfare of sixty transported 4-month-old Dorper × Mongolian female sheep in a cold climate. Sheep in a covered vehicle had greater increases in head and ear temperatures than those in an open vehicle. Sheep transported for 2 h increased their leg temperatures, whereas those transported for 1 h had reduced leg temperatures. Increases in non-esterified fatty acids (NEFA) and lactate dehydrogenase (LDH) in the blood samples during the long transport suggested that sheep had more muscular and metabolic activity, compromising their well-being. Feeding prior to transport did not affect body temperatures, but those not fed prior to transport had reduced alanine transferase, HSP and cortisol in their blood, whereas those that were fed had reduced NEFAs, LDH and creatine kinase. Prior feeding had no effect on the sheep temperature indices over a two-hour transport period. Thus, the sheep most at risk of the adverse effects of cold temperatures were those transported in open vehicles, those transported for a longer time, and those not fed before transport.

Association between metabolic indicators and clinical endometritis during the transition period in Brown Swiss cows

The objective of the current study was to evaluate the relationship between the serum macromineral, metabolite profiles, and the clinical endometritis during the transition period in Brown Swiss dairy cows. Sixty Brown Swiss dairy cows were used in the present study. Blood samples collected at d 10 (± 4) antepartum and 3, 10 and 30 (± 4) days in milk (DIM) to determine calcium (Ca), phosphorus, glucose, cholesterol, non-esterified fatty acid (NEFA) levels. Beta-hydroxybutyric acid (BHB) concentration measured during the postpartum period. Receiver operating characteristics (ROC) curves were used to determine the cow-level thresholds for the subsequent development of clinical endometritis. In addition, pairwise comparisons were made of the area under the curve (AUC) of ROC curves for the thresholds of NEFA, Ca, and glucose predicting clinical endometritis. The mean Ca concentration at 3 DIM was 8.85 ± 0.20 mg/dL in healthy cows compared to 8.30 ± 0.22 mg/dL in cows that subsequently developed endometritis (P < 0.05). NEFA concentrations at 10 DIM and BHB concentration at 10 and 30 ± 4 DIM were higher (P < 0.05) in cows that subsequently developed endometritis. Serum NEFA concentration at 10 days postpartum is the best predictor for diagnosis of clinical endometritis with the AUC values of 0.741. The cows with clinical endometritis also had significantly higher values of glucose at 3 DIM and lower BCS at 10 DIM (P < 0.05). While 58.6% of the cows that developed clinical endometritis were cyclic, 64.5% were cyclic in healthy cows at 30 ± 4 DIM. Serum NEFA concentration was the only risk factor for clinical endometritis at 10 DIM. In addition, a decrease in serum Ca at 3 DIM and increase in NEFA and BHB concentrations at 10 and 30 ± 4 DIM may be associated with clinical endometritis and delayed resumption activity on the ovaries.

Effect of feeding bypass fat to dairy animals- A Review

The last 3 weeks each of pregnancy and early lactation are very critical for the dairy animals because of the challenges posed by metabolic and hormonal changes in the body. The dry matter intake of these animals starts declining during advanced pregnancy and gets reduced up to 30% just 3 weeks before parturition. Most of the energy is utilized for the production of colostrum and milk after parturition due to which the animal faces negative energy balance. The animal also loses its body condition score due to the utilization of its body fat to meet energy requirements that lead to an increase in non-esterified fatty acids in the blood. The animals are prone to metabolic disorders and decreased production of milk when its body fats are depleted. The energy requirements of such animals could be met by increasing the energy density of their diet. There is an increase in rumen acidosis if more quantity of concentrate is offered to such animals. Acidosis leads to the poor digestion of fibers in the rumen. There is increased production of propionate in comparison to acetate which is responsible for less percentage of fat in the milk of these animals. The ill effects of negative energy balance may be eliminated if these animals are offered bypass fat in their diet. The cellulose digesting bacteria stay unharmed due to bypass fat where as ordinary fat may harm these bacteria if more than 1% of its dry matter intake is fed. Therefore, it is advisable to offer bypass or prilled fat to the animals during transition period.

Abstract 15205: MANP: A Novel ANP Analog for Hypertension Associated With Obesity and Metabolic Syndrome

Introduction: Atrial natriuretic peptide (ANP) plays an important role in blood pressure (BP) regulation via the second messenger cGMP. ANP also induces lipolysis by increasing plasma levels of non-esterified fatty acids (NEFA). MANP is a new Mayo Clinic designed ANP analog consisting of the native ANP with a novel 12-amino-acid C-terminus extension. In experimental models, MANP is more potent than ANP in reducing BP and inducing natriuresis. These actions are mediated by the activation of the pGC-A receptor and generation of cGMP. To date, the BP pressure lowering, cGMP generating and lipolytic actions of MANP remain unexplored along with its safety and tolerability in subjects with hypertension (HTN) associated with metabolic disease. Hypothesis: In subjects with HTN, obesity and metabolic syndrome (MS), MANP administration is safe, well tolerated, activates cGMP and exerts BP lowering and lipolytic properties. Methods: Double-blind, placebo-control clinical trial in 22 subjects (17 receiving MANP) with HTN, obesity and MS involving a single subcutaneous (SQ) injection of MANP (2.5 μg/Kg) or placebo. Subjects were monitored and cardiovascular, cGMP and metabolic parameters were collected during 24 hours after the injection. Results: In all subjects, MANP was safe and well-tolerated with no serious adverse side effects. MANP increased mean cGMP plasma levels after 30 minutes (delta: 4.8 ± 2.0 pmol/mL, p=0.02) and 1 hour (delta: 2.9 ±1.3 pmol/mL, p=0.03) when compared to baseline. Six hours after MANP injection systolic BP decreased by 5.7 ± 2.9 mmHg (p=0.06) whereas subjects receiving placebo had no decrease in blood pressure values compared to baseline. During fasting period, one hour after the administration of MANP, NEFA plasma levels increased by 108.2 ± 37.4 μM (p=0.01). Conclusions: In subjects with HTN, obesity and MS, SQ MANP is safe, well tolerated and activates the pGC-A receptor as measured by a significant increase in the second messenger cGMP. Subjects receiving MANP showed a borderline significant decrease in systolic BP and a significant increase in NEFA circulating levels supporting anti-hypertensive and lipolytic properties. Our findings support MANP as a potential novel therapy for HTN associated with metabolic disease.

Effects of abomasal infusion of essential fatty acids together with conjugated linoleic acid in late and early lactation on performance, milk and body composition, and plasma metabolites in dairy cows

Rations including high amounts of corn silage are currently very common in dairy production. Diets with corn silage as forage source result in a low supply of essential fatty acids, such as α-linolenic acid, and may lead to low conjugated linoleic acid (CLA) production. The present study investigated the effects of abomasal infusion of essential fatty acids, especially α-linolenic acid, and CLA in dairy cows fed a corn silage-based diet on performance, milk composition, including fatty acid (FA) pattern, and lipid metabolism from late to early lactation. Rumen-cannulated Holstein cows (n = 40) were studied from wk 9 antepartum to wk 9 postpartum and dried off 6 wk before calving. The cows were assigned to 1 of 4 treatment groups. Cows were abomasally supplemented with coconut oil (CTRL, 76 g/d), linseed and safflower oil (EFA, 78 and 4 g/d; linseed/safflower oil ratio = 19.5:1; n-6/n-3 FA ratio = 1:3), Lutalin (CLA, 38 g/d; BASF SE, Ludwigshafen, Germany; isomers cis-9,trans-11 and trans-10,cis-12 each 10 g/d) or EFA+CLA. Milk composition was analyzed weekly, and blood samples were taken several times before and after parturition to determine plasma concentrations of metabolites related to lipid metabolism. Liver samples were obtained by biopsy on d 63 and 21 antepartum and on d 1, 28, and 63 postpartum to measure triglyceride concentration. Body composition was determined after slaughter. Supplementation of CLA reduced milk fat concentration, increased body fat mass, and improved energy balance (EB) in late and early lactation, but EB was lowest during late lactation in the EFA group. Cows with CLA treatment alone showed an elevated milk citrate concentration in early lactation, whereas EFA+CLA did not reveal higher milk citrate but did have increased acetone. Milk protein was increased in late lactation but was decreased in wk 1 postpartum in CLA and EFA+CLA. Milk urea was reduced by CLA treatment during the whole period. After calving, the increase of nonesterified fatty acids in plasma was less in CLA groups; liver triglycerides were raised lowest at d 28 in CLA groups. Our data confirm an improved metabolic status with CLA but not with exclusive EFA supplementation during early lactation. Increased milk citrate concentration in CLA cows points to reduced de novo FA synthesis in the mammary gland, but milk citrate was less affected in EFA+CLA cows, indicating that EFA supplementation may influence changes in mammary gland FA metabolism achieved by CLA.

Transition Period of the Dairy Cow Revisited: II. Homeorhetic Stimulus and Ketosis With Implication for Fertility

Dairy cows have been selected during the last century primarily for milk production, which has been increased by a factor 3-5 per lactation during this period without a concomitantly adequate increase of dry matter intake (DMI). This discrepancy between input and output is caused by a negative or minutely positive genetic correlation between milk yield and DMI and leads, in high-producing dairy cows in early lactation, to a severe and long-lasting negative energy balance (NEB) with distinct hormonal and metabolic alterations. Milk production during this period is regulated by homeorhesis with high priority for this trait, which is relatively uncoupled from DMI, and hence with possible restrictions of other functions. The extent and duration of the current NEB is a health risk and is probably one of the reasons for genetic correlations between milk yield and disease. The gap between input and output is closed by the mobilization of reserves characterized by a rapid increase of non-esterified fatty acids (NEFA) above the acute requirement, in turn leading to ectopic fat disposition in the liver and other organs. Therefore, fat liver and ketosis occur during early lactation within a phase of the priority of the homeorhetic (genetic) regulation of milk production at insufficient DMI. Ketosis is correlated with an impairment of fertility. The correlation between an early cause (ketosis) and a later effect (impaired fertility) cannot be explained satisfactorily, but possible epigenetic alterations look promising for future research. The revealed connection between homeorhesis, fat liver and ketosis, and the impairment of fertility provides an approach for discussions of these topics as a complex. The convergence between these issues should furthermore be extended to other production diseases. Since the genetic background of this interaction must not be neglected, the current breeding system should include further health traits with a predominant emphasis on parameters of metabolism and energy balance.

Effects of pretransport diet, transport duration, and type of vehicle on physiological status of young veal calves

This study aimed to investigate effects of pretransport diet (rearing milk vs. electrolytes), type of vehicle (open vs. conditioned truck), and transport duration (6 vs. 18 h) on physiological status of young calves upon arrival at the veal farm. A total of 368 calves were transported in 2 consecutive batches from a collection center to a veal farm. Blood samples were collected from calves before transport; immediately posttransport (T0); and 4, 24, and 48 h, and 1, 3, and 5 wk posttransport. Blood was analyzed for glucose, urea, lactate, nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), creatine kinase, albumin, total protein, osmolality, calcium, sodium, magnesium, and hematological variables. Body weight, rectal temperature, and skin elasticity were determined before and immediately posttransport. Blood glucose, NEFA, and urea concentrations at T0 showed an interaction between pretransport diet and transport duration. Milk-fed and electrolyte-fed calves transported for 18 h did not significantly differ in plasma glucose concentration or serum NEFA concentrations. However, after 6 h of transport, milk-fed calves had higher plasma glucose and lower serum NEFA concentrations (4.71 mmol/L and 586.5 µmol/L, respectively) than electrolyte-fed calves (3.56 mmol/L and 916 µmol/L, respectively). After 18 h of transport, milk-fed calves had lower urea concentrations (5.40 mmol/L) than electrolyte-fed calves (7.38 mmol/L). In addition, at T0, after 6 h of transport, milk-fed calves gained weight (Δ = 0.41 kg), whereas electrolyte-fed calves lost weight (Δ = -0.16 kg). After 18 h of transport, both milk-fed and electrolyte-fed calves showed body weight losses (Δ = -0.67 and -0.74 kg, respectively). Type of vehicle had a limited influence on blood parameters. Concentrations of NEFA and BHB reached the maximum values at T0 and then decreased until wk 5 posttransport. The increase in NEFA and BHB concentrations between prior to and just posttransport (T0) was less pronounced in calves transported for 6 h (746.1 µmol/L and 0.38 mmol/L, respectively) than in calves transported for 18 h (850.6 µmol/L and 0.50 mmol/L). Overall, the recovery rate of calves at the veal farm seemed rapid; all blood parameters returned to (below) pretransport values within 48 h posttransport. We concluded that feeding milk before short-term transport helps young veal calves cope with transport, whereas this is not the case during long-term transport.

Plasma mtDNA copy numbers are associated with GSTK1 expression and inflammation in type 2 diabetes.

Mitochondrial dysfunction is involved in the pathogenesis of type 2 diabetes. Glutathione S-transferase kappa 1 (GSTK1) is critical to maintain mitochondrial function and homeostasis. We aimed to investigate whether a potential link exists between mitochondrial DNA (mtDNA) copy numbers and inflammation, non-esterified fatty acids (NEFA) and GSTK1 expression in type 2 diabetes. We assessed mtDNA copy numbers in plasma and GSTK1 expression in white blood cells in 123 people with type 2 diabetes and in 121 healthy controls using a quantitative polymerase chain reaction (qPCR). An automatic chemistry or immunoassay analyser was used to determine serum glucose, lipids and inflammatory markers. Multiple linear regression and multivariable logistic regression models were used to evaluate associations and risks. Compared with healthy controls, individuals with diabetes showed higher mtDNA copy numbers (t=-3.938, P<0.001) and lower GSTK1 expression (Z=-2.985, P=0.002). mtDNA copy number was associated with type 2 diabetes risk [odds ratio (OR)=1.80, 95% confidence intervals (CI) 1.25-2.58, P=0.001] after controlling for confounding factors. In individuals with diabetes, mtDNA copy number was negatively associated with GSTK1 expression (β=-0.235, P=0.036) and positively associated with serum high-sensitive C-reactive protein (hsCRP) (β=0.839, P<0.001), tumour necrosis factor alpha (TNF-α) (β=0.549, P<0.001), interleukin-6 (IL-6) (β=0.589, P=0.006) and NEFA (β=0.001, P=0.020). In the diabetic group, individuals with an abnormal increase in NEFA, hsCRP, TNF-α and IL-6 showed significantly elevated mtDNA copy numbers (all P<0.05). mtDNA copy numbers in plasma might have an important role in the progression of diabetic chronic inflammation via inhibition of GSTK1 and could be a potential biomarker for type 2 diabetes.

The role of altered immune function during the dry period in promoting the development of subclinical ketosis in early lactation

Subclinical ketosis (SCK) may impair white blood cell (WBC) function and thus contribute to the risk of disease postpartum. This preliminary study investigated changes occurring in the immune system before disease onset to elucidate their role in the occurrence of SCK. A group of 13 Holstein dairy cows were housed in tie-stalls and retrospectively divided into 2 groups based on their levels of β-hydroxybutyrate (BHB) measured in plasma between calving day and 35 d from calving (DFC). Levels of BHB <1.4 mmol/L were found in 7 cows (control cows, CTR group) and levels >1.4 mmol/L were found in 6 cows at ≥1 of 6 time points considered (cows with SCK, KET group). From -48 to 35 DFC, body condition score, body weight, dry matter intake, rumination time, and milk yield were measured, and blood samples were collected regularly to assess the hematochemical profile and test the WBC function by ex vivo challenge assays. Data were submitted for ANOVA testing using a mixed model for repeated measurements that included health status and time and their interactions as fixed effects. Compared with CTR cows, KET cows had more pronounced activation of the immune system (higher plasma concentrations of proinflammatory cytokines, myeloperoxidase, and oxidant species, and greater IFN-γ responses to Mycobacterium avium), higher blood concentrations of γ-glutamyl transferase, and lower plasma concentrations of minerals before calving. Higher levels of nonesterified fatty acids, BHB, and glucose were detected in KET cows than in CTR cows during the dry period. The effect observed during the dry period was associated with a reduced dry matter intake, reduced plasma glucose, and increased fat mobilization (further increases in nonesterified fatty acids and BHB) during early lactation. A reduced milk yield was also detected in KET cows compared with CTR. The KET cows had an accentuated acute-phase response after calving (with greater concentrations of positive acute-phase proteins and lower concentrations of retinol than CTR cows) and impaired liver function (higher blood concentrations of glutamate-oxaloacetate transaminase and bilirubin). The WBC of the KET cows, compared with CTR cows, had a reduced response to an ex vivo stimulation assay, with lower production of proinflammatory cytokines and greater production of lactate. These alterations in the WBC could have been driven by the combined actions of metabolites related to the mobilization of lipids and the occurrence of a transient unresponsive state against stimulation aimed at preventing excessive inflammation. The associations identified here in a small number of cows in one herd should be investigated in larger studies.

Investigation changes in production, some blood hormones, and metabolites, serum and colostrum IgG of calves of Holstein cows fed with two levels of zinc supplement in transitional period

ABSTRACT The aim of experiment was to investigate the effect of feeding high level of zinc on cow production, and health and immunity of calves. The cows in each period of pre and post calving were allocated to two treatments containing 75 and 150 mg/kg Zn, respectively, as control, and containing 110 and 250 mg/kg, respectively, as second treatment. On days −25, −5, 7 and 21 relative to parturition, blood samples were obtained from 24 cows per each treatment. High level of zinc in the diet increased serum zinc, leptin and insulin in both periods but serum glucose was constant. Serum non-esterified fatty acids (NEFA) was increased by high Zn in diet, but beta hydroxybutyrate (BHBA) decreased on day 7 of lactation. In compared to the control, milk Zn on days 1 and 7 of lactation had a significant increase. High level of Zn increased colostrum IgG, calves serum IgG and total protein. Obese cows had more serum leptin and NEFA but BHBA was higher only on day 7 of lactation. In conclusion, increased serum Zn increases leptin and insulin before and after calving. It seems that their cumulative effect in spite of an increase in NEFA had a beneficial effect on milk production and calves immunity.

Dynamic of Metabolic Indicators, Insulin Like-growth Factor I (IGF-I) and Cortisol in Holstein Cows during the Transition Period

Background: Physiological events occur in the transition period marked by negative energetic balance, where the energetic demand is higher due to fetal nutrition and lactogenesis and intensified by the decrease of the dry matter intake in the pre-partum period. The adaptation of cows is dependent of homeostatic and homeorhetic mechanisms regulated by catecholamine, cortisol, GH, IGF-I, insulin and glucagon but the priorization of homeorhetic mechanisms could result in metabolic diseases. Considering the scarce longitudinal studies about the Brazilian conditions the aim of this project was to evaluate the influence of transition period on metabolic indicators, cortisol and IGF-I in Holstein cows.Materials, Methods &amp; Results: Thirteen cows, from 2nd to 4th lactation were evaluated weakly from week -2 to week +3 in relation to calving to determine the body condition score (BCS), metabolic and endocrine profile. The BCS decreased between week -2 (BCS = 4.0) and +1 (BCS = 3.0), followed by and slight increase on weeks +2 and +3 (P = 0.000). The most of metabolic indicators and hormones have changed during the transition period (P ≤ 0.05), especially around calving. It was possible to detect the peak of cortisol, glucose, non-esterified fatty acids (NEFA), ß-hydroxibutyrate (BHB), and aspartate aminotransferase (AST) on delivery and week +1. On the other hand, total calcium, triglycerides (TG) and cholesterol (CHOL) decreased was observed around parturition. Insulin like growth factor type I (IGF-I) showed marked reduction between pre and postpartum, and the lowest value was observed in the week +1. TP and GLOB had the lowest value on calving and globulin has a gradual increase from delivery to week +3.Discussion: Cows included in this experiment had dystocia (4/13, 30.8%), retention of placenta (1/13, 7.7%) and clinical hypocalcemia (1/13, 7.7%). One of the animals with episodes of dystocia was also aggravated by ketosis in week +1 and +2 (1/13, 7.7%). Uterine infections were observed in five animals (5/13, 38.4%). Of this total of animals with uterine infection (5/13), three had already expressed earlier disturbances: two cows had dystocia and one cow with retention of placenta. The weight loss observed between pre and postpartum may be due to an increase of energy demand for fetal maintenance and the concomitant initiation of lactation, in conjunction with an approximately 30% reduction in dry matter intake during the transitional period. The hyperglycemia concomitant with the peak of cortisol at delivery may be explaining by the activation of the somatotropic axis, due to the stress of calving. The increase of NEFA, BHB and AST around calving associated with decreased of TG and CHOL could be associated with homeorhetic mechanisms, especially lipolysis and gluconeogenesis. The IGF-I decrease in postpartum may be by the decreased expression of receptors for growth hormone (GH) in the liver, and consequently reduced synthesis and/or IGF-I hepatic clearance, which reduce of the negative feedback of IGF-I on GH secretion. The total calcium concentrations were below the threshold (8.50 mg/dL) established by Goff [10] at parturition, week +1 and +2 and probably is due to the secretion of 20-30 g of calcium per day during the colostrum synthesis. Total protein and albumin have a slight variation, except for the peak observed on week +3 due to uterine infection.Keywords: body condition score, non-esterified fatty acids, ß-hydroxibutyrate, total calcium, hormones.

Metabolites able to predict uterine diseases in crossbred dairy cows during the transition period

This study aimed to identify possible metabolites able to predict puerperal uterine diseases in crossbred dairy cows (Holstein x Gir) in the transition period. We hypothesized that, as what has been observed for Holstein cows, a negative energy balance (NEB) may increase the incidence of uterine diseases. Thirty-four lactating crossbred cows (½HG, ¼HG, ¾HG, and 5/8HG) were evaluated during prepartum (-60d and -30d), calving, and postpartum (+14d, +21d, and +35d) periods, being divided into two groups (with and without uterine diseases). NEB evaluations were based on the concentrations of non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHBA) at calving and 14 days postpartum. Nearly 1/3 of the crossbred cows presented an NEB, characterized by a significant increase in NEFA with no BHBA increase; however, it was less intense than that observed in Holstein cows during the transition period. There was a significant difference between cows with and without uterine diseases in NEFA and calcium concentrations at partum, as well as body condition score (BCS) during prepartum. In conclusion, the occurrence of uterine diseases during the transitional period is related to the BCS in the prepartum period, besides serum NEFA and calcium concentrations at partum.