Early Warning for Ovarian Diseases Based on Plasma Non-esterified Fatty Acid and Calcium Concentrations in Dairy Cows

Inactive ovaries (IO) and ovarian (follicular or luteal) cysts (FC or LC) are two common ovarian diseases leading to infertility in dairy cattle. Both disorders are associated with altered metabolites and hormones. There are currently no known effective biomarkers that can be used for early diagnosis of ovarian diseases. The purpose of this study was to identify the plasma biomarkers of ovarian diseases in Holstein dairy cows that facilitate an early diagnosis of the diseases and control its progression. The experiment was performed from 3 weeks postpartum and last for 7 weeks. Seventy-six multiparous Holstein cows (mean age, 4.36 years; weight, 635.63 kg) were divided into healthy control group (HC, n = 22), FC group (n = 18), LC group (n = 18) and IO group (n = 18) by rectal palpation or ultrasonography during the last 2 weeks before trial end. Blood was collected via tail vein for measurement of plasma energy metabolites, liver function indicators, minerals, and hormones at 3 and 8 weeks postpartum. Data were analyzed by Mann-Whitney U, Kruskal-Wallis, Spearman correlation, binary logistic regression analysis and receiver operating characteristic analysis, where applicable. At 8 weeks postpartum, FC cows had a more severe body condition score loss and these had greater levels of non-esterified fatty acids (NEFA) and estradiol, and lesser levels of alanine aminotransferase (ALT), progesterone and insulin-like growth factor 1 (IGF-1) levels than HC cows (P < 0.05). LC cows had a lower milk yield, higher NEFA and progesterone levels, and lower calcium, phosphorus and magnesium levels than HC cows (P < 0.05). IO cows had a lower body condition score, higher NEFA levels, and lower ALT, calcium, phosphorus, magnesium, estradiol, progesterone and IGF-1 levels than HC cows (P < 0.05). At 3 weeks postpartum, cows with ovarian diseases had greater (P < 0.05) concentrations of NEFA, and lesser concentrations of ALT, calcium, phosphorus and IGF-1 than HC cows. Early warning values for ovarian diseases were plasma NEFA concentrations >0.50 mmol/L, or calcium concentrations <2.02 mmol/L. Therefore, plasma NEFA and calcium could be used as early-warning indicators for ovarian diseases in dairy cows.

PSIII-15 The interactions of change in nutrition after artificial insemination on plasma metabolites, steroid hormones, and uterine histotroph in beef heifers

The objective was to evaluate the impact of nutritional changes after artificial insemination (AI) on plasma metabolites, steroid hormones, and uterine histotroph. Beef heifers (n = 50) were randomly assigned to a post-AI dietary treatment (High=161.5% or Low=77.45% of maintenance energy) until uteri were flushed for embryo recovery (d14). Blood samples were collected on d -3, 0 (AI), 3, 6, 9, 12, and 14 for analysis of plasma non-esterified fatty acid (NEFA), total protein (protein), glucose, cholesterol, and progesterone concentrations. Uterine flushes (UF) were analyzed for concentrations of Mg, P, S, K, Ca, Cu, Zn, Se, Mn, Co, B, Cr, and Fe. Plasma NEFA, protein, glucose, cholesterol, and progesterone concentrations were analyzed as repeated measures in SAS (PROC MIXED). Mineral concentrations in UF were analyzed using the MIXED procedures in SAS. Diet influenced plasma NEFA concentrations, with Low heifers having elevated concentrations (P < 0.01); however, diet did not influence plasma protein, glucose, cholesterol, or progesterone concentrations (P > 0.10). Plasma NEFA, glucose, and progesterone concentrations changed over time (P < 0.05), but protein and cholesterol did not differ over time (P > 0.10). Diet by time interactions influenced plasma NEFA, protein, and cholesterol concentrations (P < 0.05), but glucose and progesterone concentrations were not different (P > 0.10). Presence of a recovered embryo by time interaction influenced plasma protein concentrations (P < 0.04), but NEFA, glucose, cholesterol, and progesterone concentrations were not affected by the interaction (P > 0.10). Embryo recovery and diet by embryo recovery by time did not impact plasma NEFA, protein, glucose, cholesterol and progesterone concentrations (P > 0.10). When an embryo was recovered, Mg (P = 0.02) and S (P = 0.02) were decreased in UF. Diet and diet by embryo recovery did not affect UF mineral concentrations (P>0.10). In conclusion, post-AI nutrition influenced plasma NEFA, protein, glucose, cholesterol, and progesterone concentrations. Additionally, uterine histotroph mineral concentrations were affected by presence of an embryo.

Intranasal oxytocin treatment on the day of weaning does not decrease walking behavior or improve plasma metabolites in beef calves placed on pasture

The purpose of this study was to evaluate the effect that intranasal oxytocin administered at abrupt weaning (day 0) had on weaning stress behaviors such as walking distance and time devoted to walking, calf body weight, and plasma non-esterified fatty acids (NEFA), β-hydroxybutyrate (β-HB), and cortisol. Twenty Simmental × Angus heifer calves were randomly assigned to one of two treatments, intranasal oxytocin (OXT; n = 10) or intranasal saline (CON; n = 10). All calves were given the respective intranasal treatment on the day of weaning (day 0), and then placed on pasture together. Calves were weighed and a blood sample was obtained on days 0, 1, 7, and 14 post-weaning. Blood samples were subsequently used to quantify plasma NEFA, β-HB, and cortisol concentrations. All calves in both treatment groups were fitted with an individual global positioning system (GPS) that recorded calf location every ten seconds for a 16 hour period on days 0, 7, and 14 to quantify and evaluate walking behaviors. There was no treatment × day effect for distance walked (P = 0.82), walking time (P = 0.80), non-walking time (P = 0.88), area utilization index (P = 0.84), calf body weight (P = 0.82), average daily gain (P = 0.54), NEFA (P = 0.22), or cortisol concentrations (P = 0.32). There was a tendency for a treatment × day effect observed for average walking speed (P = 0.09) and β-HB (P = 0.10), such that calves in the CON treatment tended to have lesser average walking speeds on day 14 and tended to have greater β-HB concentration after weaning. There was a treatment effect (P = 0.02) for NEFA concentrations, with the CON calves having a greater plasma NEFA concentration throughout the study compared with OXT calves. These data imply that OXT calves may have had differing metabolic responses immediately after weaning that could have altered the mobilization of NEFA, but this change was not substantial enough to impact body weights or walking behaviors.

The Interplay between Non-Esterified Fatty Acids and Plasma Zinc and Its Influence on Thrombotic Risk in Obesity and Type 2 Diabetes

Thrombosis is a major comorbidity of obesity and type-2 diabetes mellitus (T2DM). Despite the development of numerous effective treatments and preventative strategies to address thrombotic disease in such individuals, the incidence of thrombotic complications remains high. This suggests that not all the pathophysiological mechanisms underlying these events have been identified or targeted. Non-esterified fatty acids (NEFAs) are increasingly regarded as a nexus between obesity, insulin resistance, and vascular disease. Notably, plasma NEFA levels are consistently elevated in obesity and T2DM and may impact hemostasis in several ways. A potentially unrecognized route of NEFA-mediated thrombotic activity is their ability to disturb Zn2+ speciation in the plasma. Zn2+ is a potent regulator of coagulation and its availability in the plasma is monitored carefully through buffering by human serum albumin (HSA). The binding of long-chain NEFAs such as palmitate and stearate, however, trigger a conformational change in HSA that reduces its ability to bind Zn2+, thus increasing the ion’s availability to bind and activate coagulation proteins. NEFA-mediated perturbation of HSA-Zn2+ binding is thus predicted to contribute to the prothrombotic milieu in obesity and T2DM, representing a novel targetable disease mechanism in these disorders.

Post-exercise changes in myocellular lipid droplet characteristics of young lean individuals are affected by circulatory non-esterified fatty acids

Intramyocellular lipid (IMCL) content is an energy source during acute exercise. Non-esterified fatty acid (NEFA) levels can compete with IMCL utilization during exercise. IMCL content is stored as lipid droplets (LDs) that vary in size, number, subcellular distribution and in coating with LD protein PLIN5. Little is known about how these factors are affected during exercise and recovery. Here, we aimed to investigate the effects of acute exercise with and without elevated NEFA levels on intramyocellular LD size and number, intracellular distribution and PLIN5 coating, using high-resolution confocal microscopy. In a cross-over study, 9 healthy lean young men performed a 2h moderate intensity cycling protocol in the fasted (high NEFA levels) and glucose-fed state (low NEFA levels). IMCL and LD parameters were measured at baseline, directly after exercise and 4h post-exercise. We found that total IMCL content was not changed directly after exercise (irrespectively of condition), but IMCL increased 4h post-exercise in the fasting condition, which was due to an increased number of LDs rather than changes in size. The effects were predominantly detected in type I muscle fibers and in LDs coated with PLIN5. Interestingly, subsarcolemmal, but not intermyofibrillar IMCL content, was decreased directly after exercise in the fasting condition and was replenished during the 4h recovery period. In conclusion, acute exercise affects IMCL storage during exercise and recovery, particularly in type I muscle fibers, in the subsarcolemmal region and in the presence of PLIN5. Moreover, the effects of exercise on IMCL content are affected by plasma NEFA levels.

Effect of pre-shipment preconditioning and injectable antioxidant trace elements (Cu, Mn, Se, Zn) and vitamins (A, E) on plasma metabolite and hormone concentrations and growth in weaned beef cattle

Weaning and transport represent a high stress time for calves. Preconditioning (PC) by weaning before the transport separate these stressors. The stressors generate oxidative stress, which can be reduced by mineral and vitamin supplementation (MVS) with an antioxidant capacity. Our objective was to evaluate the effect of PC and MVS on performance of steers. The experiment used a 2 × 2 factorial arrangement design, considering a 26-d PC treatment from weaning to transport to the feedlot (d 0); and injectable MVS on d -45, -26, and 0. The MVS consisted of Cu, Zn, Mn, Se, vitamin E (0.2, 0.8, 0.2, 0.1, and 1 mg/kg body weight (BW), respectively), and vitamin A (1190 IU/kg). Sixty Angus-crossbred steers (186.4 ± 27.6 kg) were randomly assigned to the four treatments (MVS+PC; N+PC; MVS+N; N+N; n = 15/treatment). Body weight (BW) was recorded on d -45, -26, 0, 8, 15, and 29. On d 0, an additional BW was taken 30 minutes after the 5-hour transportation (d 0.5). Between d 0 to 29, dry matter intake (DMI) and average daily gain (ADG) to DMI ratio (G:F) were measured. Between d -26 to 29 plasma concentrations of glucose, free fatty acids (NEFA), cortisol, insulin, total antioxidant status (TAS), and thiobarbituric acid-reactive substances (TBARS) were evaluated. Data were analyzed using the MIXED procedure of SAS with repeated measures, using treatment, time, and treatment × time as fixed effects, and steer as a random effect. Between d -26 to 0, there was an interaction of MVS × PC (P ˂ 0.01) for ADG. From d -26 to 0, N+N and N+PC had the greatest and lesser ADG, respectively. On d 0.5, no-PC steers tended to lose BW while the PC steers tended to gain BW (P = 0.09). In the period d 0 to 8, there were no differences (P ≥ 0.27) in DMI, but the PC steers had greater G:F and ADG (P < 0.01) compared with no-PC steers. Plasma NEFA concentration on d 0 was affected by MVS×PC (P < 0.01), because MVS decreased plasma NEFA concentration in no-PC steers, but it increased in the PC steers. Plasma concentrations of glucose, insulin, and cortisol did not differ among treatments (P ≥ 0.23). There was a MVS×PC interaction (P = 0.09) for TAS on d 0; N+N had the greatest and MVS+N had the lowest TAS concentrations. In conclusion, a 26-d PC decreased steers BW compared with no-PC steers. The BW loss during preconditioning was not recovered 29-d after feedlot entry. Despite this BW loss, MVS treatment decreased BW loss in the steers allocated to PC treatment on the day of transport.

PSI-12 Effects of supplementing propionate in a finishing diet on dry matter intake, glucose clearance, and blood metabolites

The objective of this experiment was to determine if supplementing propionate alters DMI, glucose clearance rate, and blood metabolite concentrations in steers fed a finishing diet. Holstein (n = 15) steers were individually fed a finishing diet ad-libitum. Steers were allocated by BW to receive: no Ca propionate (CON), 100 g/d (LOW), or 300 g/d (HIGH) in the diet. Orts were collected and weighed daily to determine DMI. Blood samples were collected on d 0, 7, and 21, and BW recorded on d 0, 14, and 28. A glucose tolerance test was conducted on d 14 and 28 of the trial. Samples were analyzed for whole blood glucose and lactate, and plasma NEFA. Data were analyzed using a mixed model with treatment, day and their interaction included, with day as a repeated measure. The CON treatment had greater (P < 0.01) DMI than LOW and HIGH. BW was greater for CON throughout the experiment and all treatments had an increased BW on day 28 (P = 0.03 for the interaction). Whole blood glucose concentrations tended (P = 0.09) to be higher on d 21 than d 0 and 7, but was not affected by treatment (P = 0.58). Plasma NEFA concentrations were lower (P = 0.05) for CON than other treatments, and greater (P = 0.002) on d 0 than d 7 and 21. Whole blood lactate concentrations were greater (P = 0.05) on d 7, than d 0 and 21, but was not effected by treatment (P = 0.13). There was no treatment (P ≥ 0.16) or day effect (P ≥ 0.36) on glucose peak, plateau, or clearance rate. These data indicate that supplemental propionate may decrease dry matter intake but might not alter glucose clearance rate.

Mid-Infrared Spectroscopic Analysis of Raw Milk to Predict the Blood Plasma Non-Esterified Fatty Acid Concentration in Dairy Cows

ABSTRACTIn high yielding dairy cattle, severe postpartum negative energy status is often associated with metabolic and infectious disorders that negatively affect production, fertility and welfare. Mobilization of adipose tissue associated with a negative energy status is reflected through an increased level of non-esterified fatty acids (NEFA) in the blood plasma. Earlier, identification of a negative energy status through the detection of increased blood plasma NEFA concentration required laborious and stressful blood sampling. More recently there have been attempts to predict blood NEFA concentration from milk samples. This study aimed to develop and validate a model to predict the blood plasma NEFA concentration using milk mid-infrared (MIR) spectra that are routinely measured in the context of milk recording. To this end, blood plasma and milk samples were collected in weeks 2, 3 and 20 post-partum for 192 lactations in 3 different herds. The blood plasma samples were taken in the morning, while representative milk samples were collected during the morning and evening milk session on the same day. To predict the blood plasma NEFA concentration from the milk MIR spectra, partial least squares regression models were trained on part of the observations from the first herd. The models were then thoroughly validated on all other observations of the first herd and on the observations of the two independent herds to explore their robustness and wide applicability. The final model can accurately predict blood plasma NEFA concentrations below 0.6 mmol/L with a root mean square error of prediction (RMSE) of less than 0.143 mmol/L. However, for blood plasma with more than 1.2 mmol/L NEFA, the model clearly underestimates the true level. Additionally, it was found that morning blood plasma NEFA levels were predicted with a significantly higher accuracy (p = 0.009) using MIR spectra of evening milk samples compared to morning samples, with RMSEP values of respectively 0.182 and 0.197 mmol/L and R2 values of 0.613 and 0.502. These results suggest a time delay between variations in blood plasma NEFA and related milk biomarkers. Based on the MIR spectra of evening milk samples, cows at risk for a negative energy status, indicated with detrimental morning blood plasma NEFA levels (> 0.6 mmol/L), could be identified with a sensitivity and specificity of respectively 0.831 and 0.800. As this model can be applied to millions of historical and future milk MIR spectra, it opens opportunities for regular metabolic screening and improved resilience phenotyping.

Niacin nutrition and rumen-protected niacin supplementation in dairy cows: an updated review

As the precursor to NAD+ and NADP+, niacin is important for catabolic and anabolic redox reactions. In addition, niacin is known for its anti-lipolytic action via a hydroxycarboxylic acid-2-receptor-dependent mechanism. The anti-lipolytic effects of traditional free niacin supplementation during transition periods had been studied extensively, but the reported effects are ambiguous. In the past decade, a series of studies were conducted to evaluate the effects of rumen-protected niacin (RPN) on production performance and metabolic status in early lactation and on heat stress in dairy cows. Feeding RPN seems more effective than free niacin regarding increasing circulating niacin concentration. The rebound of plasma NEFA was found after termination of niacin abomasal infusion. Feeding RPN or infusion of niacin via the abomasum could suppress lipolysis and reduce insulin resistance in early lactation. Additionally, RPN supplementation could possibly relieve heat stress through vasodilation during moderate to severe heat stress condition. However, these beneficial effects of niacin supplementation have not always been observed. The inconsistent results across studies may be related to dosages of niacin supplementation, rebound of plasma NEFA concentration, stage of lactation or severity of heat stress. Overall, the current review is to present updated information on niacin nutrition in dairy cows and the recommendations are given for future research.

90 The influence of supplemental zinc, zinc source, and dietary energy level on performance measures of beef steers

The objective was to determine if steer performance improved with supplemental Zn above recommended concentrations with increasing growth rate. Angus steers (n = 72; 324 ± 2.1kg BW) were blocked by BW within growing diets to one of three Zn strategies (ZNTRT) 1) no supplemental Zn (analyzed 36 mg Zn/kg DM; CON), 2) supranutritional Zn as ZnSO4(CON + 120 mg Zn/kg DM; INZN), or 3) supranutritional Zn blend (CON + 60 mg Zn/kg as ZnSO4 + 60 mg Zn/kg as Zn-amino acid complex; ZNBLD) fed for 60 d, then assigned to dietary energy strategies (ENERGY) targeting growth rates of 1.6 (LOW) or 2 kg/d (HI). On d 60, HI steers were transitioned for 7 d and all animals received respective treatments for an additional 91 d finishing period (n = 12). Data were analyzed as a 3×2 factorial in Proc Mixed of SAS with block as fixed effect; steer was experimental unit. After 60 d of dietary treatment BW tended to be greater in Zn-fed steers vs. CON (P = 0.07). Finishing DMI within HI was similar between INZN and ZNBLD, which were greater than CON, while within LOW no differences were detected due to ZNTRT (ZNTRT×ENERGY; P = 0.01). Neither ZNTRT×ENERGY nor ZNTRT effects (P ≥ 0.37) were detected for finishing ADG, HCW, marbling score, yield grade or backfat. However, finishing period ADG, hot carcass weight, marbling score, yield grade, and back fat were greater in HI vs. LOW (P ≤ 0.05). Plasma NEFA concentrations were lesser for steers receiving HI vs. LOW (P = 0.02), while BUN was unaffected by ZNTRT or ENERGY (P ≥ 0.42). Steer performance was influenced by supranutritional Zn and dietary energy.