Non-esterified Fatty Acid Concentrations Research Articles

The effect of acute and 14-day exogenous ketone supplementation on glycemic control in adults with type 2 diabetes: two randomized controlled trials.

Acute ingestion of the exogenous ketone monoester supplement [(R)-3-hydroxybutyl-(R)-3-hydroxybutyrate] lowers blood glucose, suggesting therapeutic potential in individuals with impaired glucose metabolism. However, it is unknown how acute or repeated ingestion of exogenous ketones affects blood glucose control in individuals with type 2 diabetes (T2D). We conducted two randomized, counterbalanced, double-blind, placebo-controlled crossover trials to determine if 1) acute exogenous ketone monoester (0.3 g/kg body mass; N = 18) or 2) 14-day thrice daily premeal exogenous ketone monoester (15 g; N = 15) supplementation could lower blood glucose in individuals living with T2D. A single dose of the ketone monoester supplement elevated blood β-OHB to ∼2 mM. There were no differences in the primary outcomes of plasma glucose concentration (acutely) or serum fructosamine (glycemic control across 14 days) between conditions. Ketone monoester ingestion acutely increased insulin and lowered nonesterified fatty acid concentrations; plasma metabolomics confirmed a reduction in multiple free fatty acids species and select gluconeogenic amino acids. In contrast, no changes were observed in fasting metabolic outcomes following 14 days of supplementation. In the context of these randomized controlled trials, acute or repeated ketone monoester ingestion in adults with T2D did not lower blood glucose when consumed acutely in a fasted state and did not improve glycemic control following thrice daily premeal ingestion across 14 days. Future studies exploring the mechanistic basis for the (lack of) glucose-lowering effect of exogenous ketone supplementation in T2D and other populations are warranted.NEW & NOTEWORTHY Exogenous ketone supplements can acutely lower blood glucose, suggesting therapeutic potential in individuals with impaired glucose metabolism. However, the effect of exogenous ketones on glucose metabolism in adults with type 2 diabetes has not been investigated in a controlled setting. In adults with type 2 diabetes, ketone monoester ingestion did not lower blood glucose acutely in a fasted state and did not improve glycemic control across thrice daily premeal ingestion across 14 days.

Near-infrared spectroscopy analysis of blood plasma for predicting nonesterified fatty acid concentrations in dairy cows

During the transition period, dairy cows are often exposed to negative energy balance (NEB), leading to lipid mobilization from adipose tissue into nonesterified fatty acids (NEFA), a common indicator of heightened illness risk. This study aimed to use blood near-infrared (NIR) spectra data to classify NEB into high or low categories, based on early-lactation cow NEFA thresholds. We collected a total of 186 plasma samples from 100 Holstein cows. The samples were categorized into critical thresholds, based on previous literature, of ≥0.60 and ≥0.70 mEq/L for identifying high NEB. Spectral data were preprocessed before the development of the predictive modes, which included the implementation of multiplicative scatter correction, standard normal variate (SNV), and first and second derivatives. The classification was performed using partial least square discriminant analyses (PLS-DA), and predictive performance was assessed using leave-one-out cross-validation. Predictive quality for each class was evaluated through specificity, precision, sensitivity, and F1 score. The study showed promising results, with the SNV technique achieving higher F1 scores. The model found 72.7% specificity, 78.9% precision, 80.8% sensitivity, and 79.8% F1 score to classify animals with NEFA levels of ≥0.60 mEq/L, and 82.1% specificity, 78.7% precision, 80.8% sensitivity, and 79.7% F1 score to classify animals with NEFA levels ≥0.70 mEq/L. These results indicate that NIR spectroscopy could serve as a tool for detecting cows under severe NEB, also showing potential for broader application across the entire transition period, as the spectral signal carried relevant information regarding cow metabolism. Furthermore, the combination of predictors derived from plasma spectra and other cow-level information can lead to more accurate disease alerts, given their relationship with the NEB.

Impact of corn silage substitution for dry alfalfa on milk fatty acid profile, nitrogen utilization, plasma biochemical markers, rumen fermentation, and antioxidant capacity in Mahabadi lactating goats

This study aimed to investigate the effects of substituting conventional dry forage with corn silage, a more cost-effective supplementary feed, on a variety of parameters in lactating Mahabadi goats, native to arid and semi-arid regions. A total of fifty lactating Mahabadi goats, aged between 2 and 5 years and weighing an average of 45.3 ± 7.20 kg, were randomly allocated into two experimental groups. The experimental treatments consisted of a control diet and a diet incorporating corn silage at 20 % of dry matter (DM). Various measurements were conducted to assess milk compositions, fatty acid profiles, rumen fermentation parameters, selected plasma biochemical parameters, nitrogen balance, and antioxidant capacity. The results revealed that the substitution of dry forage with corn silage had no statistically significant impact on milk yield, dry matter intake (DMI), body weight, as well as the proportions of monounsaturated and unsaturated fatty acids, and specifically C18:1C9 in milk, non-esterified fatty acid content in milk, rumen concentration of volatile fatty acids (VFA), microbial nitrogen, and nitrogen balance (p > 0.05). Nonetheless, this substitution led to a reduction in the percentage of milk polyunsaturated fatty acids and plasma urea nitrogen content (p < 0.05). It is noteworthy that goats fed with corn silage exhibited a notably higher antioxidant capacity in rumen liquor (p < 0.05), plasma, and milk (p < 0.01) compared to those receiving the control diet. The substitution of conventional dry forage with corn silage exhibited no adverse effects on the performance of lactating Mahabadi goats. On the contrary, it contributed to an enhancement in the antioxidant status. These findings offer valuable insights for optimizing dietary composition by incorporating corn silage at 20 % of DM, thereby improving milk quality, reducing costs, and promoting overall health in lactating goats, particularly within arid and semi-arid regions.

Effects of supplementary thyme on immunity responses, antioxidant indices, rumen enzymes concentrations and rumen bacteria composition in Hu sheep

The thyme (Thymus vulgaris L.) plant contains volatile oils, flavonoids and monoterpenoids, which are reputed to possess medicinal properties. The present study examined the effects of supplementary thyme intake on immunity responses, antioxidant indices, rumen enzymes concentrations and rumen bacteria composition in sheep. Six rumen-fistulated, 12-month-old Hu rams (63.1 ± 8.54 kg) were used in a replicated 3 × 3 Latin square design in which three levels of air-dried thyme were offered: 0 g/d (CON), 16 g/d (T16) and 80 g/d (T80). The serum concentrations of albumin (p = 0.06), total proteins (p = 0.06) and β-hydroxybutyric acid (p = 0.07) tended to increase linearly with an increase in thyme intake. Concentration of serum non-esterified fatty acids increased (p = 0.03) and changed quadratically (p = 0.02) with an increase in thyme intake. Serum antioxidant indices were not affected by thyme intake. The concentration of rumen lipase increased linearly (p < 0.01) with an increase in thyme intake, and was greater in the T80 than the CON rams. Thyme intake increased (p < 0.05) the abundance of the rumen probiotics f__Lactobacillaceae, g__Lactobacillus and o__Lactobacillales, and the abundance of g__UCG-002 and g__Eubacterium_saphenum_group. It was concluded that thyme can: 1) promote protein synthesis and utilization; 2) enhance immunity responses; 3) mediate energy metabolism; and 4) increase the abundance of rumen probiotics in sheep. In the current study, the best response was observed at an intake of 80 g of air-dried thyme/d.

Effects of prepartum concentrate feeding on reticular pH, plasma energy metabolites, acute phase proteins, and milk performance in grass silage–fed dairy cows

We investigated how concentrate feeding during the last 21 d of pregnancy affects reticular pH, inflammatory response, dry matter (DM) intake, and production performance of dairy cows. We hypothesized that adding concentrates to dairy cows' diet before calving reduces the decrease in reticular pH postpartum and thus alleviates inflammatory response. We also hypothesized that prepartum concentrate feeding increases DM intake postpartum and consequently improves milk performance. Two feeding experiments were conducted using a randomized complete block design. In each experiment, 16 multiparous Finnish Ayrshire cows were paired based on parity, expected calving date, body weight, and milk yield of the previous lactation. Within the pairs, cows were randomly allocated on one of the 2 dietary treatments 21 d before expected calving. In experiment 1 (Exp1), diets were ad libitum feeding of grass silage as a sole feed or supplemented with increasing amounts of concentrate offered separately (increased to 4 kg/d by d -7). In experiment 2 (Exp2), diets were ad libitum feeding of a total mixed ration containing either grass silage, barley straw, and rapeseed meal (64%, 28%, and 8% on DM basis, respectively) or grass silage, barley straw, and cereal-based concentrate mixture (49%, 29%, and 30% on DM basis, respectively). Following calving, all the cows were fed similarly and observed until d 56 postpartum. Feed intake and milk yield were recorded daily, and reticular pH was monitored continuously by reticular pH bolus. Blood samples were collected at the beginning of the experiments, 7 d before the expected calving date, 1 d (in Exp1) or 5 d (in Exp2), 10 d, and 21 d postpartum. In Exp1, concentrate feeding increased metabolizable energy intake and tended to increase DM and crude protein intake prepartum. Moreover, prepartum concentrate feeding increased the concentrations of plasma β-hydroxybutyrate and insulin, but differences in nonesterified fatty acids, glucose, or acute phase proteins were not observed. After calving, prepartum diet did not affect DM or nutrient intake, plasma energy metabolites, or milk production in Exp1. Although prepartum concentrate feeding increased reticular pH on the first day of lactation, it elevated plasma concentrations of serum amyloid-A and haptoglobin postpartum in the grass silage-based diet. In Exp2, adding concentrates to the diet based on a mixture of grass silage and straw did not affect prepartum DM intake or plasma concentrations of nonesterified fatty acids, glucose, or insulin. Adding concentrates to prepartum diet increased plasma concentration of β-hydroxybutyrate before calving as in Exp1. After calving, prepartum concentrate feeding increased DM and nutrient intake during the second week of lactation in Exp2, but no effects were observed thereafter. In contrast to our hypothesis, prepartum concentrate feeding decreased reticular pH after calving in Exp2, but no differences in inflammatory markers were observed. Based on this study, close-up concentrate feeding in diets based on grass silage with or without straw does not alleviate the decrease in reticular pH or mitigate inflammatory response postpartum.

Inositol-requiring enzyme 1α and c-Jun N-terminal kinase axis activation contributes to intracellular lipid accumulation in calf hepatocytes

During the perinatal period, dairy cows undergo negative energy balance, resulting in elevated circulating levels of nonesterified fatty acids (NEFA). Although increased blood NEFA concentrations are a physiological adaptation of early lactation, excessive NEFA in dairy cows is a major cause of fatty liver. Aberrant lipid metabolism leads to hepatic lipid accumulation and subsequently the development of fatty liver. Both inositol-requiring enzyme 1α (IRE1α) and c-Jun N-terminal kinase (JNK) have been validated for their association with hepatic lipid accumulation, including their regulatory functions in calf hepatocyte insulin resistance, oxidative stress, and apoptosis. Meanwhile, both IRE1α and JNK are involved in lipid metabolism in nonruminants. Therefore, the aim of this study was to investigate how IRE1α and JNK regulate lipid metabolism in bovine hepatocytes. An experiment was conducted on randomly selected 10 healthy cows (hepatic triglyceride [TG] content <1%) and 10 cows with fatty liver (hepatic TG content >5%). Liver tissue and blood samples were collected from experimental cows. Serum concentrations of NEFA and β-hydroxybutyrate (BHB) were greater, whereas serum concentrations of glucose and milk production were lower in cows with fatty liver. The western blot results revealed that dairy cows with fatty liver had higher phosphorylation levels of JNK, c-Jun, and IRE1α in the liver tissue. Three in vitro experiments were conducted using primary calf hepatocytes isolated from 5 healthy calves (body weight: 30-40 kg; 1 d old). First, hepatocytes were treated with NEFA (1.2 mM) for 0.5, 1, 2, 3, 5, 7, 9, or 12 h, which showed that the phosphorylated levels of JNK, c-Jun, and IRE1α increased in both linear and quadratic effects. In the second experiment, hepatocytes were treated with high concentrations of NEFA (1.2 mM) for 12 h with or without SP600125, a canonical inhibitor of JNK. Western blot results showed that SP600125 treatment could decrease the expression of lipogenesis-associated proteins (PPARγ and SREBP-1c) and increase the expression of fatty acid oxidation (FAO)-associated proteins (CPT1A and PPARα) in NEFA-treated hepatocytes. The perturbed expression of lipogenesis-associated genes (FASN, ACACA, and CD36) and FAO-associated gene ACOX1 were also recovered by JNK inhibition, indicating that JNK reduced excessive NEFA-induced lipogenesis and FAO dysregulation in calf hepatocytes. Third, short hairpin RNA targeting IRE1α (sh-IRE1α) was transfected into calf hepatocytes to silence IRE1α, and KIRA6 was used to inhibit the kinase activity of IRE1α. The blockage of IRE1α could at least partially suppressed NEFA-induced JNK activation. Moreover, the blockage of IRE1α downregulated the expression of lipogenesis genes and upregulated the expression of FAO genes in NEFA-treated hepatocytes. In conclusion, these findings indicate that targeting the IRE1α-JNK axis can reduce NEFA-induced lipid accumulation in bovine hepatocytes by modulating lipogenesis and FAO. This may offer a prospective therapeutic target for fatty liver in dairy cows.

PSIX-22 Performance, Digestibility, and Blood Parameters in Pregnant Beef Cows Fed Total Mixed Ration Silages

Abstract The aim of this study was to investigate the effects of two total mixed ration (TMR) silages (low and high rumen undegradable protein; RUP) on digestibility, blood parameters, and performance in pregnant beef cows. Thirty-three mid-gestation (~130 d of gestation) Tabapua beef cows were randomly assigned to 1 of 2 treatments: 1) a TMR silage containing Brachiaria grass, soybean hulls, urea, and mineral mix (low RUP; n = 16) or 2) a TMR silage containing Brachiaria grass, DDG, and mineral mix (high RUP; n = 17). The concentration of A1 fraction was, on average, 12.9% and 34.0% of N in low and high RUP silages, respectively. A preservative with a blend of organic acids, surfactants, and activated propionates was applied in both silages. Pressed bag silos were used to conserve silages for 7 wk. Cows were housed in individual pens for 100 d. During a 4-d digestion period (at 50 d of housing), fecal samples were collected for measurement of nutrient digestibility using undigested neutral detergent fiber as a marker. Blood parameters were collected at the last day of housing. Statistical analysis of experimental data was performed using the GLM procedure of SAS 9.4. Diet, calf sex (male or female), and interactions between these factors were considered fixed effects. No differences were obtained for initial BW. High RUP diet showed greater final BW (P = 0.0004) and ADG (P = 0.0003). Cows fed high RUP gained 50 g/d, while cows fed low RUP diet lost 445 g/d. Dry matter intake was greater by 23% (P &amp;lt; 0.0001) in cows consuming high RUP silage. Dry matter, CP, and NDF digestibility did not differ between treatments. Regarding blood parameters, no differences were observed for glucose at 0 h and 4 h post-feeding. Plasma urea at 0 h post-feeding was greater in cows fed low RUP silage (P = 0.0003). However, no differences were observed for plasma urea at 4 h post-feeding. The plasma concentrations of non-esterified fatty acids (P = 0.017) and beta-hydroxy-butyric acid (P = 0.002) were greater in cows consuming low RUP diet. Overall, feeding pregnant cows during mid-gestation with TMR silage containing high RUP promotes greater performance.

Effect of shortening the dry period on colostrum and milk quality, blood parameters and some reproductive parameters in high-producing Holstein cows of different body condition score.

This study aimed to evaluate the effect of shortening the dry period in high-yielding cows of different body condition scores (BCS). We report colostrum and milk quality, some serum metabolites, BCS changes, and some reproductive parameters with measurements being made over the first two months of lactation. Cows were grouped based on the length of the dry period (normal: about 50 d and short: about 28 d) and BCS (moderate: 2.75 to 3.5 and high ≥ 3.5). Short dry period decreased colostrum volume and, in combination with high BCS only, caused a decrease in milk production. Short dry period moderate BCS cows had the highest serum insulin concentration on day 14 after calving and highest glucose concentration on day 28, but neither differed significantly when measured over the whole period. By contrast, short dry period cows had significantly lower concentrations of non-esterified fatty acids and beta-hydroxybutyrate measured over the whole period. Post-partum loss of BCS was less in short and especially so in the short, moderate BCS group. Following a synchronization protocol at 35 d postpartum. The cows with a short dry period and moderate BCS had lower open days, days to first postpartum estrus and services per conception. It was concluded that short dry periods and moderate BCS had a positive influence on serum metabolites, BCS changes and reproductive parameters.

12 Amino Acid Nutrition in Dairy Cattle: Beyond Milk Protein

Abstract The transition from gestation to lactation, also known as the transition period, is a critical time for dairy cows. This phase is typically defined as 3 weeks before parturition through 3 weeks after parturition. Peak disease incidence (shortly after parturition) corresponds with the time of greatest negative energy balance (NEB) and negative protein balance (NPB), the peak in blood concentrations of nonesterified fatty acids, and the greatest acceleration of milk yield. Decreased fertility in the face of increasing milk production may be attributable to greater severity of postpartum NEB and NPB resulting from inadequate transition management or increased disease rates. The depth and duration of NEB and NPB are highly related to dry matter intake. Formulating and delivering appropriate diets that limit total energy intake to requirements but also provide proper intakes of all other nutrients [including the indispensable amino acids (IAA) Met and Lys] before calving can help lessen the extent of NEB and NPB after calving. Supplementation of rumen-protected methionine (RPM) during the transition period improved uterine immune function through improved glandular morphology, increased neutrophil infiltration after calving, and discovery of neutrophil extracellular trap formation in bovine endometrial tissue. Its supplementation has been reported to reduce the incidence of health complications, better lactation performance, and more favorable biomarker and plasma AA profiles, common in cows with increased liver functionality index. Cows supplemented with rumen-protected lysine (RPL) had decreased liver oxidative stress (SOD1, superoxide dismutase 1) and acute phase response (SAA3, serum amyloid A3) and reduced gene expression of NFKB1 (nuclear factor kappa B1) leading to increased proinflammatory IL1B postpartum, likely indicating improved immune activation when cows consumed RPL, a necessary component of early postpartum health. Our group has reported that a prepartum supply of RPL altered uteroplacental metabolism and glucose transport. This was demonstrated through increased expression of uterine transcripts involved in energy metabolism (GLUT3, glucose transporter 3; PCK1, phosphoenolpyruvate carboxykinase 1) and placental metabolism (FGF2, fibroblast growth factor 2; FGF2R, fibroblast growth factor 2 receptor; and PGF, placental growth factor). We also have demonstrated that RPL prepartum increased the placental protein abundance of FGF2 and LRP1 (low-density lipoprotein receptor-related protein 1), indicating possible enhanced placental metabolic activity, probably linked to trophoblast proliferation and migration processes. Finally, calves from dams fed RPL prepartum had improved overall growth and intake than calves from dams not receiving RPL. In conclusion, providing RPM and RPL during the transition period impacts dairy cows' health, uterine environment, and offspring.

26 Effect of Steroidal Implants and Zinc Supplementation on Circulating Metabolites and Insulin Sensitivity in Feedlot Steers

Abstract Angus-cross steers (n = 144; 362 kg ± 20.4) were used to determine the interaction of Zn and steroidal implants on circulating metabolites and insulin sensitivity in feedlot steers. Steers (n = 6 steers/pen) were stratified by BW in a 3 × 2 factorial design. Dietary treatments were fed for 60 days pre-implant, during this time cattle were transitioned from a roughage-based to a high concentrate diet. Dietary treatments (8 pens per treatment; Zn as ZnSO4) included: 1) no supplemental Zn (analyzed 54 mg Zn/kg DM; Zn0); 2) 30 mg supplemental Zn/kg DM (Zn30); 3) 100 mg supplemental Zn/kg DM (Zn100). Within Zn treatment, steers received a steroidal implant treatment on d 0: 1) no implant; NO; or 2) high potency combination implant (TE-200, Elanco, Greenfield, IN; 200 mg TBA, 20 mg E2; TE200). Blood was collected from all steers on d 0, 20, 40, and 84 for analysis of serum glucose, insulin, non-esterified fatty acids (NEFA), and urea-N (SUN) in a subset of steers (n = 12 steers/treatment). Glucose, NEFA, and insulin concentrations were used to determine revised quantitative insulin sensitivity check index (RQUICKI) which was calculated as: RQUICKI = 1/[log(Glucose) + log(Insulin) + log(NEFA)]. Data were analyzed as repeated measures in Proc Mixed of SAS. A tendency for a Zn x day effect on serum insulin (Zn × day; P = 0.07) showed no difference between Zn treatments on d 0, 20, or 40 but on d 84 Zn100 was greater than Zn30 while Zn0 was intermediate. An implant × day effect (P = 0.02) for serum insulin was driven by a 45% increase from d 0 to 20 in NO while TE200 cattle did not change in that time. Serum insulin increased with days on feed (P = 0.01). Day 0 serum glucose concentration was greatest in Zn0 and Zn 100; however, on days 40 and 84, Zn100 had greater serum glucose concentration compared with Zn0 while Zn30 was intermediate (Zn × day; P = 0.07). Overall, serum glucose was unchanged over time until a decrease from day 40 to 84 (P = 0.01). A three-way interaction was noted for serum NEFA (Zn × implant × day; P = 0.04) driven by variation in serum NFEA concentration at d 0. Serum urea-N differed by day (P = 0.01) but was otherwise unaffected (P ≥ 0.16). RQUICK1 was greater for TE200 (P = 0.03) cattle on d 40 compared with NO cattle, indicating implanted cattle were more insulin sensitive. RQUICKI index value decreased with days on feed (P = 0.01) indicating lesser insulin sensitivity over time. These data indicate implants influence insulin sensitivity of late-stage finishing cattle and Zn and implants influence circulating metabolites indicative of energetic state.

Association of vitamin D status with redox balance and insulin resistance and its predicting ability for subclinical pregnancy toxemia in pregnant sheep

The study aimed to evaluate the role of vitamin D on redox balance, insulin resistance and its predicting value for subclinical pregnancy toxemia (SPT) in pregnant ewes. At four weeks pre-lambing, fifteen healthy pregnant ewes were divided into two groups, ewes with sufficient vitamin D (25-hydroxy-vitamin D (25VitD) (SVD, n = 9) and ewes with insufficient 25VitD (ISVD, n = 6). Blood samples were collected at 4 weeks pre-lambing using modified frequently sampled intravenous glucose tolerance test for the estimation of various metabolites. The baseline glucose, insulin, non-esterified fatty acid (NEFA), fructosamine, beta-hydroxy butyric acid (β-BHA), calcium, phosphorus concentration and total oxidant status (TOS) did not differ significantly between the two groups, however, total antioxidant capacity (TAC) was significantly (p = 0.031) low in ISVD ewes. Area under the curve for glucose, insulin, elimination rate of glucose and peak insulin also did not differ significantly between the two groups. Correlation analysis revealed, positive association of 25VitD with fructosamine, calcium and TAC, and negative correlation with NEFA and TOS. Subsequent blood sampling at 2 weeks pre-lambing and at lambing showed significant difference in NEFA (p = 0.001), β-HBA (p = 0.001), and fructosamine(p = 0.012) between the two groups. A significant time x group interaction was observed in NEFA (p = 0.019), β-HBA (p = 0.031), and fructosamine (p = 0.026) concentration. The NEFA concentrations were increased and fructosamine decreased at 2 weeks pre-lambing and at lambing along with significantly increased β-HBA at 2 weeks pre-lambing in ISVD compared to SVD. Taking 0.8 mmol/L β-HBA as the cut off limit for SPT, ISVD ewes had higher odds of developing SPT two weeks prior to lambing (OD 16.00; p = 0.042) and at lambing (OD 10; p = 0.077). This study concludes that 25VitD significantly influence redox balance and energy profile and serves as a valuable predictor for SPT in pregnant sheep.

Chromium propionate in turkeys: effects on insulin sensitivity

The objective of this study was to evaluate the effects of dietary chromium (Cr), as Cr propionate (Cr Prop), on measures of insulin sensitivity in turkeys. Plasma glucose and nonesterified fatty acid (NEFA), and liver glycogen concentrations were used as indicators of insulin sensitivity. One-day-old Nicholas Large White female poults (n=336) were randomly assigned to dietary treatments consisting of 0 (control), 0.2, 0.4, or 0.6 mg supplemental Cr/kg diet. Each treatment consisted of 12 replicate cages with 7 turkeys per cage. Final BW were taken on d 34, and on d 35 two birds from each cage were sampled for plasma glucose and NEFA, and liver glycogen determination at the initiation (fed state) and termination (fasted state) of a 24-h fast. Following a 24-h fast, 2 turkeys per cage were refed (refed state) their treatment diet for 4 h, and then harvested. Feed/gain and ADG did not differ between control and Cr-supplemented turkeys over the 34-d study, but feed intake tended (P=0.071) to be greater for controls than turkeys receiving 0.4 mg Cr/kg diet. Fed turkeys had greater plasma glucose (P=0.002) and liver glycogen (P=0.001) concentrations, and lower (P=0.001) NEFA concentrations than fasted birds. Turkeys refed after fasting had greater (P=0.001) plasma glucose and liver glycogen concentrations, and lower (P=0.001) plasma NEFA levels than fed turkeys. Liver glycogen and plasma NEFA concentrations did not differ among control and Cr-supplemented birds in the fed, fasted, or refed state. Plasma glucose concentrations were not affected by treatment in fed or fasted turkeys. Turkeys supplemented with 0.2 or 0.4 mg Cr/kg and refed after fasting had lower (quadratic, P=0.038) plasma glucose concentrations than controls. Plasma glucose concentrations in refed birds did not differ among Cr-supplemented turkeys. The lower plasma glucose concentration in Cr-supplemented turkeys following refeeding is consistent with Cr enhancing insulin sensitivity.

Higher circulating levels of non-esterified fatty acids are associated with faster kidney function decline in post-menopausal women with type 2 diabetes: a pilot prospective study.

Currently, there is little and inconsistent evidence regarding the possible adverse effects of circulating levels of non-esterified fatty acids (NEFA) on kidney function decline in patients with type 2 diabetes mellitus (T2DM). We followed for a median of 4.6 years 85 post-menopausal women with non-insulin-treated T2DM and preserved kidney function at baseline. Serum NEFA concentrations were measured using an enzymatic colorimetric method. Glomerular filtration rate (eGFR) was estimated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Enrolled patients had a baseline mean eGFRCKD-EPI of 83 ± 12mL/min/1.73m2 and a median serum NEFA concentration of 662uEq/L (interquartile range 524-842uEq/L). During the follow-up period, 13 patients developed kidney function decline at follow-up (defined as an eGFRCKD-EPI decline ≥ 30% from baseline). In Cox proportional hazards regression analyses, higher serum NEFA levels were significantly associated with an increased risk of developing kidney function decline (adjusted-hazard ratio 3.67, 95% CI 1.64-8.22, p < 0.001; for each 1-SD increment, i.e., 262uEq/L), even after adjustment for waist circumference, hemoglobin A1c, C-reactive protein, HOMA-estimated insulin resistance, hypertension, dyslipidemia, microalbuminuria, baseline eGFRCKD-EPI, as well as temporal changes in HbA1c levels or the use of renin-angiotensin system inhibitors over the follow-up. The findings of this exploratory prospective study show that in post-menopausal women with T2DM and preserved kidney function at baseline, higher circulating levels of NEFA were strongly associated with a faster kidney function decline, even after adjustment for established renal risk factors and potential confounders.

Changes in Body Reserves, Non-Esterified Fatty Acids, and Leptin during the Reproductive Lifespan of the Rabbit Female.

The aim of this work is to study changes in body weight, perirenal fat thickness (PFT), and non-esterified fatty acid (NEFA) and leptin concentrations throughout the reproductive life of the rabbit female and their correlations when a semi-intensive reproductive rhythm is applied. A total of 46 lactating females were used. Body weight, PFT, and NEFA and leptin concentration were recorded at 12 weeks of age, at first mating and delivery, and at second, third, and fourth mating, 12th d of gestation, and delivery. The highest body weight was detected on the 12th d of any gestation, around 4280 g, and the lowest weight was at delivery, around 4030 g. PFT increased until third mating. NEFA and leptin concentration showed a cyclical pattern throughout the reproductive lifespan of the females. NEFAs presented the highest concentration at delivery within each reproductive cycle and levels decreased over the course of the deliveries (0.423 mmol/L at first delivery, 0.406 mmol/L at second delivery, 0.371 mmol/L at third delivery, and 0.309 mmol/L at fourth delivery). Similar NEFA concentrations at mating and on the 12th d of gestation were obtained. Leptin showed the highest concentrations at mating within each reproductive cycle. Leptin decreased between mating and delivery in all reproductive cycles and it was close to 1 ng/mL HE. Low or null correlations were shown between body weight, PFT, and NEFA and leptin concentration at mating, 12th d of gestation, and delivery. In conclusion, females are able to maintain a semi-intensive reproductive rhythm across four parities weighing around 4 kg from first mating. Females had an increased perirenal fat thickness until third delivery, and their NEFA concentration was maximum at delivery and leptin concentration was maximum at mating. Body weight, PFT, and NEFA and leptin concentration should be measured during critical moments of reproductive life in order to determine body condition and energy mobilization, due to their low or null correlations.

Invited Review: Increasing Milk Yield and Negative Energy Balance: A Gordian Knot for Dairy Cows?

The continued increase in milk production during the last century has not been accompanied by an adequate dry matter intake (DMI) by cows, which therefore experience a negative energy balance (NEB). NEB is low and of minor importance at low milk yield (MY), such as for the nutrition of one calf, and under these circumstances is considered "natural". MY and low DMI around parturition are correlated and are the reason for the genetic correlation between increasing MY and increasing NEB up to 2000 MJ or more for 2-3 months postpartum in high-genetic-merit dairy cows. The extension and duration of NEB in high-producing cows cannot be judged as "natural" and are compensated by the mobilization of nutrients, particularly of fat. The released non-esterified fatty acids (NEFAs) overwhelm the metabolic capacity of the cow and lead to the ectopic deposition of NEFAs as triglycerides (TGs) in the liver. The subsequent lipidosis and the concomitant hampered liver functions cause subclinical and clinical ketosis, both of which are associated with "production diseases", including oxidative and endoplasmatic stress, inflammation and immunosuppression. These metabolic alterations are regulated by homeorhesis, with the priority of the physiological function of milk production. The prioritization of one function, namely, milk yield, possibly results in restrictions in other physiological (health) functions under conditions of limited resources (NEB). The hormonal framework for this metabolic environment is the high concentration of growth hormone (GH), the low concentration of insulin in connection with GH-dependent insulin resistance and the low concentration of IGF-1, the so-called GH-IGF-1 axis. The fine tuning of the GH-IGF-1 axis is uncoupled because the expression of the growth hormone receptor (GHR-1A) in the liver is reduced with increasing MY. The uncoupled GH-IGF-1 axis is a serious impairment for the GH-dependent stimulation of gluconeogenesis in the liver with continued increased lipolysis in fat tissue. It facilitates the pathogenesis of lipidosis with ketosis and, secondarily, "production diseases". Unfortunately, MY is still increasing at inadequate DMI with increasing NEB and elevated NEFA and beta-hydroxybutyric acid concentrations under conditions of low glucose, thereby adding health risks. The high incidences of diseases and of early culling and mortality in dairy cows are well documented and cause severe economic problems with a waste of resources and a challenge to the environment. Moreover, the growing public concerns about such production conditions in agriculture can no longer be ignored.

Interaction between gestational plane of nutrition and lactation diet composition on lactation performance of Alpine goats of different parities

A study was conducted with 48 multiparous and 31 primiparous Alpine goats to determine the effects of different nutritional planes during gestation and lactation on feed intake, body weight, body condition score and mass index, blood constituent concentrations, and milk yield and composition. Two gestation supplement treatments (GS; Moderate versus High) were imposed for approximately 5.5 months and two lactation diets (LD; Moderate vs. High) within each GS were fed for 16 wk. The Moderate GS (14.2% crude protein; CP) was given at 1.125% body weight (BW; dry matter basis) and the High GS (16.2% CP) was consumed ad libitum, with alfalfa hay available free-choice to all animals. Moderate and High LD contained 16.0 and 16.9% CP and 34.7 and 30.4% neutral detergent fiber, respectively. Body weight (77.5 vs. 72.0 kg) and body condition score (BCS; 3.22 vs. 3.04) at 11 days before kidding were greater (P < 0.05) for High versus Moderate GS, but BW at kidding (62.6 and 64.9 kg; SEM = 1.32) and 3 days later (60.9 and 63.6 kg for Moderate and High GS, respectively; SEM = 1.32) was similar. Litter size (1.9 and 2.4; SEM = 0.59), kid birth weight (3.72 and 3.59 kg; SEM = 0.097), and litter weight (6.55 and 7.13 kg for Moderate and High GS, respectively; SEM = 0.316) were similar between GS diets. However, kid birth weight (3.44 and 3.87 kg; SEM = 0.096) and litter weight (6.23 and 7.46 kg; SEM = 0.364) were greater (P < 0.05) for multiparous versus primiparous goats. Dry matter intake during lactation was greater for Moderate than for High GS (P ≤ 0.051) in kg/day, % BW, and g/kg BW0.75. However, milk fat (3.81, 4.14, 3.85, and 3.77%; SEM = 0.132) and protein concentrations (2.49, 2.50, 2.47, and 2.49%; SEM = 0.047), and raw (2.22, 2.59, 2.39, and 2.45 kg; SEM = 0.173) and energy yields of milk (6.02, 7.42, 6.51, and 6.63 MJ/day for Moderate GS-Moderate LD, Moderate GS-High LD, High GS-Moderate LD, and High GS-High LD, respectively; SEM = 0.453) were not affected by GS, LD, or their interaction. Dry matter intake, milk and its component yields, and heat energy (MJ/day) were higher (P < 0.05) for does than for doelings, but BCS and milk protein and fat concentrations were lower (P < 0.05) for does. Blood nonesterified fatty acid concentration was not affected by any diets, but there was interaction (P < 0.05) between GS and LD for betahydroxybutyric acid concentration. In conclusion, minor to moderate magnitudes of difference in nutritional planes during gestation and lactation had little effect on reproductive and lactation performance, reflecting the considerable capacity of lactating dairy goats for compensatory changes such as feed intake and tissue mobilization and accretion.

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.

Does the peroral chromium administration in young Hariana calves reduce the risk of calf diarrhea by ameliorating insulin response, lactose intolerance, antioxidant status, and immune response?

BackgroundThe reduction in insulin sensitivity during rumen development may predispose dairy calves towards lactose intolerance, which could be the reason behind neonatal calf diarrhea (NCD). Chromium (Cr) results in a range of effects when fed to ruminants, but most studies have shown improved insulin sensitivity. The aim of this study was to determine the effect of Cr supplementation on insulin sensitivity, lactose intolerance, diarrhoea and antioxidant, and immune response in young Hariana calves. MethodsA total of 20 milk-fed Hariana calves were randomly assigned to 1 of 2 treatments, each consisted of 10 calves: (1) a control group without supplemental Cr and (2) a 0.15 mg Cr as Cr-picolinate (CrPic)/kg BW0.75 supplemented group (Cr0.15). ResultsA more rapid glucose disappearance with unaltered insulin kinetics during intravenous glucose tolerance test (IVGTT) and oral lactose tolerance test (OLTT) indicates greater insulin sensitivity in Cr supplemented calves. Better insulin sensitivity in Cr supplemented calves was further confirmed by higher values of the quantitative insulin sensitivity check index (QUICKI), revised quantitative insulin sensitivity check index (RQUICKI) and insulin receptor substrate-1 (IRS-1) and lower (P < 0.05) values of homeostasis model assessment-insulin resistance (HOMA-IR) and glucose-to-insulin ratio in Cr supplemented calves during IVGTT. Cr supplementation resulted in a lower (P < 0.05) serum cortisol concentration, whereas serum non-esterified fatty acid (NEFA) concentrations during IVGTT did not differ among the groups. The rise in serum glucose concentrations within 2 h post lactose infusion during OLTT peaked at more than twice the basal glucose concentration, therefore calves were not considered as lactose intolerant. Within monthly blood samples, concentrations of serum insulin were similar among treatments, whereas the Cr supplemented group had lower (P < 0.05) serum glucose concentration and glucose-to-insulin ratio compared with the control group. No treatment differences were detected in the biomarkers of antioxidant status and immunity. Serum Cr concentrations were higher (P < 0.05) in Cr supplemented calves while concentrations of other studied minerals were remained unaltered. The incidence, duration of diarrhea, and faecal score were better (P < 0.05) in calves fed on Cr supplemented diet whereas, no treatment effect was observed on average daily gain (ADG). During the study period, no calves died, and no calves were found to have pneumonia, navel or joint disease. ConclusionFeeding a Cr-supplemented diet improved insulin sensitivity and reduced the risk of diarrhoea in milk-fed young calves, but had no or minimal effects on lactose intolerance, antioxidant status, immune response, and growth performance.

Combination of milk variables and on-farm data as an improved diagnostic tool for metabolic status evaluation in dairy cattle during the transition period

Milk composition, particularly milk fatty acids, has been extensively studied as an indicator of the metabolic status of dairy cows during early lactation. In addition to milk biomarkers, on-farm sensor data also hold potential in providing insights into the metabolic health status of cows. While numerous studies have explored the collection of a wide range of sensor data from cows, the combination of milk biomarkers and on-farm sensor data remains relatively underexplored. Therefore, this study aims to identify associations between metabolic blood variables, milk variables, and various on-farm sensor data. Second, it seeks to examine the supplementary or substitutive potential of these data sources. Therefore, data from 85 lactations on metabolic status and on-farm data were collected during 3 wk before calving up to 5 wk after calving. Blood samples were taken on d 3, 6, 9, and 21 after calving for determination of β-hydroxybutyrate (BHB), nonesterified fatty acids (NEFA), glucose, insulin-like growth factor-1 (IGF-1), insulin, and fructosamine. Milk samples were taken during the first 3 wk in lactation and analyzed by mid-infrared for fat, protein, lactose, urea, milk fatty acids, and BHB. Walking activity, feed intake, and body condition score (BCS) were monitored throughout the study. Linear mixed effect models were used to study the association between blood variables and (1) milk variables (i.e., milk models); (2) on-farm data (i.e., on-farm models) consisting of activity and dry matter intake analyzed during the dry period ([D]) and lactation ([L]) and BCS only analyzed during the dry period ([D]); and (3) the combination of both. In addition, to assess whether milk variables can clarify unexplained variation from the on-farm model and vice versa, Pearson marginal residuals from the milk and on-farm models were extracted and related to the on-farm and milk variables, respectively. The milk models had higher coefficient of determination (R2) than the on-farm models, except for IGF-1 and fructosamine. The highest marginal R2 values were found for BHB, glucose, and NEFA (0.508, 0.427, and 0.303 vs. 0.468, 0.358, and 0.225 for the milk models and on-farm models, respectively). Combining milk and on-farm data particularly increased R2 values of models assessing blood BHB, glucose, and NEFA concentrations with the fixed effects of the milk and on-farm variables mutually having marginal R2 values of 0.608, 0.566, and 0.327, respectively. Milk C18:1 was confirmed as an important milk variable in all models, but particularly for blood NEFA prediction. On-farm data were considerably more capable of describing the IGF-1 concentration than milk data (marginal R2 of 0.192 vs. 0.086), mainly due to dry matter intake before calving. The BCS [D] was the most important on-farm variable in relation to blood BHB and NEFA and could explain additional variation in blood BHB concentration compared with models solely based on milk variables. This study has shown that on-farm data combined with milk data can provide additional information concerning the metabolic health status of dairy cows. On-farm data are of interest to be further studied in predictive modeling, particularly because early warning predictions using milk data are highly challenging or even missing.

Effects of dietary chromium supplementation on blood biochemical parameters in dairy cows: A multilevel meta-analytical approach

Chromium (Cr) has been reported to modulate blood biochemistry in dairy cows. However, there is a discrepancy in the literature regarding the effects of dietary Cr supplementation on various blood parameters. This meta-analysis aimed to evaluate the effects of Cr supplementation in dairy cows on blood glucose, insulin, glucagon, nonesterified fatty acid (NEFA), cortisol, and serum total protein (STP) concentrations. Following relevant literature data extraction, a 3-level meta-analytical random effect model was fitted to the data expressed as standardized mean difference (SMD) of outcome measures of control versus Cr-supplemented cows (i.e., difference in mean between control and treatment group or pooled standard deviation). The SMD can be categorized as having a small effect (0.20), a moderate effect (0.50), and a large effect (0.80). The meta-regression identified the potential sources of heterogeneity, including the body weight of cows, experimental duration/duration of Cr supplementation, blood sampling time (3 wk before parturition until 4 wk after parturition categorized as the transition period, else as the nontransition period), and form of Cr complexes. Blood glucose did not differ significantly between control and Cr-supplemented cows with an estimated SMD of μ = 0.0071 (95% confidence interval [CI]: -0.212 to 0.226). The effect of Cr supplementation on blood insulin was also nonsignificant with an SMD of μ = 0.0007 (95% CI: -0.191 to 0.193). Cows receiving Cr supplements had significantly higher levels of glucagon than controls (95% CI: 0.116 to 0.489), with an estimated SMD = 0.303. Combined transition and nontransition data suggest Cr supplementation did not affect the concentration of NEFA. However, in transition cows, Cr supplementation significantly decreased blood NEFA levels as compared with controls (95% CI: -0.522 to -0.0039), with estimated SMD = -0.263. The estimated SMD was μ = -0.1983 (95% CI: -0.734 to 0.337) for cortisol and -0.0923 (95% CI: -0.316 to 0.131) for total protein. In summary, Cr supplementation in the transition cows decreased NEFA concentration. Blood glucose, insulin, cortisol, and STP concentrations were unaffected. However, Cr supplementation increased glucagon concentration.