Non-esterified Fatty Acid Concentrations Research Articles

Early-life milk replacer feeding mediates lipid metabolism disorders induced by colonic microbiota and bile acid profiles to reduce body weight in goat model

BackgroundDysregulation of lipid metabolism and its consequences on growth performance in young ruminants have attracted attention, especially in the context of alternative feeding strategies. This study aims to elucidate the effects of milk replacer (MR) feeding on growth, lipid metabolism, colonic epithelial gene expression, colonic microbiota composition and systemic metabolism in goat kids compared to breast milk (BM) feeding, addressing a critical knowledge gap in early life nutrition.MethodsTen female goat kids were divided into 2 groups: those fed breast milk (BM group) and those fed a milk replacer (MR group). Over a period of 28 d, body weight was monitored and blood and tissue samples were collected for biochemical, transcriptomic and metabolomic analyses. Profiling of the colonial microbiota was performed using 16S rRNA gene sequencing. Intestinal microbiota transplantation (IMT) experiments in gnotobiotic mice were performed to validate causality.ResultsMR-fed pups exhibited reduced daily body-weight gain due to impaired lipid metabolism as evidenced by lower serum and liver total cholesterol (TC) and non-esterified fatty acid (NEFA) concentrations. Transcriptomic analysis of the colonic epithelium revealed upregulated genes involved in negative regulation of lipid metabolism, concomitant with microbiota shifts characterized by a decrease in Firmicutes and an increase in Actinobacteria. Specifically, genera such as Bifidobacterium and Prevotella were enriched in the MR group, while Clostridium and Faecalibacterium were depleted. Metabolomics analyses confirmed alterations in bile acid and fatty acid metabolic pathways. IMT experiments in mice recapitulated the metabolic phenotype observed in MR-fed goats, confirming the role of the microbiota in modulating host lipid metabolism.ConclusionsMilk replacer feeding in goat kids disrupts lipid metabolism and gut microbiota dynamics, resulting in reduced growth rates and metabolic alterations. These findings highlight the importance of early nutritional intervention on metabolic programming and suggest that modulation of the gut microbiota may be a target for improving growth and metabolic health in ruminants. This study contributes to the understanding of nutritional management strategies in livestock and their impact on animal health and productivity.

Accuracy and precision of diets fed to close-up cows on dairy farms and its association with early lactation performance

Ensuring a consistent ration is critical for maximizing lactating cow performance, but this is not known for dry cows. The objectives of this cohort observational study were to: 1) characterize close-up dry cow diets fed on commercial farms in Ontario, Canada, 2) describe the accuracy of the nutrient composition between the formulated close-up diet and the diet offered to the cows, 3) describe the precision of the close-up diets across time, and 4) explore potential associations of that accuracy and precision with blood metabolic parameters and milk yield of cows in early lactation. Forty free-stall dairy farms were visited once every 4 wk, for a total of 6 visits to each farm, from April to October 2022. At each visit, samples of the close-up diet were collected and analyzed for dry matter (DM) content and chemical composition. Close-up diet formulations were also obtained by each farm's nutritionists. During each visit, fresh cows (0 to 14 d in milk [DIM]) had blood samples taken for blood metabolites. The same cows were also monitored for milk yield up to 120 DIM. Multivariable models were used to analyze associations between variability (in relation to the formulated diet and across time) of nutrients in the close-up diet, as measured by coefficient of variation (CV), and outcomes in fresh cows. Corn silage (67.6% of farms) and straw (24.3% of farms) were the predominant primary forage sources used in the close-up dry cow diets. Soybean meal (37.8% of farms) and canola meal (18.9% of farms) were the main ingredients used as primary concentrate sources. Overall, the diets offered did not accurately represent the formulated diets. With the exception of net energy for lactation (NEL), the CVs for the other nutrients were all greater than 5%. Diet variability, both between fed and formulated diets and from visit to visit during the close-up period, was associated with metabolic markers and dairy cow production. Lower variability in non-fiber carbohydrates (NFC) between the fed and formulated diets was associated with better liver health index scores. Visit-to-visit variability in fat% and NFC% were associated with blood β-hydroxybutyrate (BHB) concentrations, while NFC% variability was associated with blood glucose levels. Serum nonesterified fatty acids (NEFA) concentrations were associated with visit-to-visit variability in DM% and CP%. These results underscore the importance of maintaining consistency between diet formulations and feeding practices over time to optimize early-lactation dairy herd performance and health, granted that these diets are correctly formulated to meet the nutritional needs of cows in the close-up period and applied with recommended feeding practices.

Effects of Soybean Isoflavones on the Growth Performance and Lipid Metabolism of the Juvenile Chinese Mitten Crab Eriocheir sinensis

In order to study the effects of soybean isoflavones on the growth performance and lipid metabolism of juvenile Chinese mitten crabs, six experimental diets were formulated by gradient supplementation with 0%, 0.004% and 0.008% soybean isoflavones at different dietary lipid levels (10% and 15%). The groups were named as follows: NF-0 group (10% fat and 0% SIFs), NF-0.004 group (10% fat and 0.004% SIFs), NF-0.008 group (10% fat and 0.008% SIFs), HF-0 group (15% fat and 0% SIFs), HF-0.004 group (15% fat and 0.004% SIFs) and HF-0.008 group (15% fat and 0.008% SIFs). All crabs with an initial weight of 0.4 ± 0.03 g were fed for 8 weeks. The results showed that dietary supplementation with 0.004% or 0.008% SIFs significantly increased the weight gain and specific growth rate of crabs. Diets supplemented with 0.004% or 0.008% SIFs significantly reduced the content of non-esterified free fatty acids and triglycerides in the hepatopancreas of crabs at the 10% dietary lipid level. Dietary SIFs significantly decreased the relative mRNA expressions of elongase of very-long-chain fatty acids 6 (elovl6), triglyceride lipase (tgl), sterol regulatory element-binding protein 1 (srebp-1), carnitine palmitoyltransferase-1a (cpt-1a), fatty acid transporter protein 4 (fatp4), carnitine palmitoyltransferase-2 (cpt-2), Δ9 fatty acyl desaturase (Δ9 fad), carnitine palmitoyltransferase-1b (cpt-1b), fatty acid-binding protein 10 (fabp10) and microsomal triglyceride transfer protein (mttp) in the hepatopancreas of crabs. At the 15% dietary lipid level, 0.008% SIFs significantly increased the relative mRNA expressions of fatty acid-binding protein 3 (fabp3), carnitine acetyltransferase (caat), fatp4, fabp10, tgl, cpt-1a, cpt-1b and cpt-2 and significantly down-regulated the relative mRNA expressions of Δ9 fad and srebp-1. In conclusion, SIFs can improve the growth and utilization of a high-fat diet by inhibiting genes related to lipid synthesis and promoting lipid decomposition in juvenile Chinese mitten crabs.

Metabolites and physical scores as possible predictors for postpartum culling in dairy cows

The purpose of the study was to explore the associations of serum non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA) concentrations with the body condition score (BCS) and rumen fill score (RFS) in order to predict the risk of postpartum culling, and to further investigate effective monitoring stages during the dry period. From October 2012 to March 2014, clinically healthy Holstein heifers and cows were sampled once before calving, and the occurrence of culling within 60 days in milk (DIM) was investigated. The discriminatory ability of each parameter was evaluated using receiver operating characteristic (ROC) analysis. Of the 720 cows sampled between 14 and 2 days before the actual day of calving in the study, 42 cull cows (mean DIM ± SE: 22.0 ± 2.6) were confirmed. The areas under the curve (AUC) of the ROC for predicting culling using serum NEFA concentrations were 0.6 and 0.7 at 14 to 2 and 7 to 2 days before calving, respectively. The AUC for the RFS was 0.7 for both periods, indicating the same diagnostic level as the serum NEFA concentration. Both the serum NEFA concentration and RFS were possible predictors in cows with ≥ 2 parities, but not in cows with 0–1 parity sampled even at 7 to 2 days before calving. The serum BHBA concentration and BCS were not suitable predictors of culling for any period or parity. These results indicate that RFS has a discriminatory ability comparable to the serum NEFA concentration for predicting culling within 60 DIM.

Fetal sex effects on maternal health can now be tested via randomization: A first-in-class illustration in cows on glucoregulatory outcomes

BackgroundThe maternal-offspring relationship, such as whether fetal sex influences maternal health, is essential to explore to advance prenatal and maternal health. While associations exist between fetal sex and maternal health outcomes, it is unclear whether these reflect a causal relationship. ObjectiveTo demonstrate that fetal sex can be randomly assigned to test the causal effect of fetal sex on maternal outcomes. MethodsHolstein dairy cows were stratified and randomized using sealed opaque envelopes to be artificially inseminated with either X- or Y-sorted bull semen until 40 cows became pregnant. Monthly body weight measurements were recorded, and an intravenous glucose tolerance test was performed 30 days before the expected calving day. The primary outcome was insulin area under the curve (AUC), and secondary outcomes were clearance rate, half-life, and AUC for glucose, insulin, and non-esterified fatty acid concentrations. An intention-to-treat (ITT) approach using multiple imputation was employed for primary analysis, and an as-treated (AT) approach was used for secondary analysis. ResultsWe demonstrated that we could successfully randomize the assignment of fetal sex to dams and test for causal effects of fetal sex on glucoregulatory outcomes using dairy cows as a model. Insulin AUC was not statistically different between groups (ITT p = 0.857, AT p = 0.874), and other outcomes were also not statistically different (p > 0.05). ConclusionWe demonstrated that causal effects of fetal sex on maternal outcomes can be causally tested in dairy cows. Our study did not provide statistical evidence to support an effect of fetal sex on maternal glucose-related outcomes.

Nephron specific ATP6AP2 knockout increases urinary excretion of fatty acids and decreases renal cortical megalin expression

ATP6AP2 knockout in the renal nephron impairs receptor-mediated endocytosis, increasing urinary albumin and glucose excretion and impairing weight gain. Nonesterified fatty acids (NEFA) in urine are bound to albumin and reabsorbed in the proximal tubule through receptor-mediated endocytosis by the megalin–cubilin complex. We hypothesized that ATP6AP2 knockout increases urinary NEFA excretion through a reduction in megalin. Ten-week-old male C57BL/6 mice with nephron specific inducible ATP6AP2 knockout and noninduced controls were fed either normal diet (ND 12% fat) or high fat diet (HFD 45% fat) for 6 months. ATP6AP2 knockout significantly increased urine albumin:creatinine ratio in both ND and HFD fed mice while normalized urine NEFA concentration increased 489% and 259% in ND and HFD knockout mice compared to respective controls. Knockout decreased renal cortical megalin mRNA by 47% on ND and 49% on HFD while megalin protein expression decreased by 36% and 44% respectively. At the same time, markers of mTOR activity were increased while autophagy was impaired. Our results indicate that nephron specific ATP6AP2 knockout increases urinary NEFA excretion in the setting of impaired receptor-mediated endocytosis. Further investigation should determine whether ATP6AP2 contributes to obesity related ectopic lipid deposition in the proximal tubule.

Performance and Metabolic Responses of Nellore Cows Subjected to Different Supplementation Plans during Prepartum.

This study assessed the effects of different prepartum supplementation plans on Nellore cows' performance, metabolic responses, and early offspring development. Thirty-nine pregnant Nellore cows (224 ± 2.67 days of pregnancy, 5.3 ± 0.29 years of age, body weight 520 ± 15.2 kg, initial body condition score 6.0 ± 0.07) were assigned to one of four treatments: a control group receiving only mineral mixture ad libitum, and three groups receiving daily protein-energy supplements of 2, 4, or 6 g/kg BW for 60 days prepartum. Weights and body condition scores were evaluated at the start of the experiment, 7 days before calving, and at 45 and 90 days postpartum. Cows supplemented with 4 and 6 g/kg BW showed improved body weight and body condition scores prepartum and postpartum and had a shorter service period (p < 0.05). The highest blood urea nitrogen concentrations were observed in cows receiving 6 g/kg BW (p = 0.0124). There was a reduction in blood urea nitrogen at calving for the 6 g/kg BW group, while the control group showed an increase (p < 0.001). Non-esterified fatty acids concentrations were lower 21 days before calving for the 4 and 6 g/kg BW groups compared to the control (p < 0.05) and decreased postpartum for all treatments (p < 0.001). No significant differences were observed in calf birth weight or performance. Supplementing with 4 g/kg BW of protein-energy is recommended to enhance metabolic health and overall performance.

Evaluation of cottonseed oil as a substitute for fish oil in the commercial diet for juvenile swimming crab (Portunus trituberculatus)

A six-week feeding trial was carried out to determine the feasibility of cottonseed oil (CSO) as a viable substitute for fish oil (FO) in the commercial diet of swimming crab. Ninety healthy swimming crabs (initial body weight 34.28 ± 0.59 g) were randomly assigned to 90 plastic baskets. Three isonitrogenous and isolipidic diets (450 g/kg protein and 120 g/kg lipid) were formulated replacing FO with CSO at 0%, 50% and 100% (CSO-0, CSO-50, and CSO-100), respectively. Each diet was randomly allocated to three replicates, each consisting of 10 crabs. Results indicated that crabs fed with CSO-100 diet had the lowest the percent weight gain (PWG), specific growth rate (SGR) and survival among all treatments (P < 0.05). Albumin (ALB), alkaline phosphatase (ALP), glucose (GLU), triglyceride (TAG), total cholesterol (T-CHO), low-density lipoprotein cholesterol (LDL-C), non-esterified fatty acid (NEFA) contents and alanine amino transferase (ALT) activity in hemolymph were significantly affected by dietary substitution of FO with CSO (P < 0.05). The contents of total saturated fatty acids (SFA), total mono-unsaturated fatty acids (MUFA) and total long-chain polyunsaturated fatty acids (LC-PUFA) in the hepatopancreas and muscle were negatively correlated with the substitution level, whereas total n-6 polyunsaturated fatty acids (n-6 PUFA) and linoleic acid (18:2n-6) contents increased significantly with increasing levels of dietary substitution of FO with CSO (P < 0.05). Dietary substitution of FO with CSO resulted in changes in the composition of volatile substances in muscle, with 16 volatile substances in muscle significantly affected (P < 0.05). The relative expression of genes related to lipid synthesis such as fatty acid synthase (fas), acetyl-CoA carboxylase (acc) and glycerol-3-phosphate acyltransferase 1 (gpat1) in the hepatopancreas were significantly up-regulated in the CSO-50 group compared to other treatment groups (P < 0.05). The relative expression of fatty acid anabolism-related genes fatty acyl desaturase 2 (fads2) and elongase 4 (elovl4) were significantly down-regulated with the increase of dietary substitution of FO with CSO (P < 0.05). In conclusion, 50% substitution with CSO had no negative effects on growth performance, promoted lipid synthesis and metabolism, facilitated lipid accumulation. However, complete substitution of FO with CSO inhibited fatty acid synthesis and metabolism, resulting in a lower tissue LC-PUFA content and an altered composition of muscle volatiles.

Effects of dietary rosemary ultrafine powder supplementation on aged hen health and productivity: a randomized controlled trial

Recently, poultry industry has been seeking antibiotic residue-free poultry products and safe nutritious feed additives. Whether rosemary ultrafine powder (RUP) affects productive performance by regulating the intestinal microbiome of aged layers remains unclear. Here, we investigated the effects of dietary RUP supplementation on the production performance, egg quality, antioxidant capacity, intestinal microbial structure, and metabolome of aged hens. The results indicate that RUP had no significant effect on production performance but significantly enhanced Thick albumen height, Haugh unit, yolk color (P < 0.05), daily feed intake, and qualified egg rate. Serum content of non-esterified fatty acids, catalase, and glutathione peroxidase increased significantly (P < 0.05). Furthermore, the liver total protein content was significantly increased (P < 0.05). 16S rRNA sequence analysis revealed that RUP significantly impacted both α- and β-diversity of the caecum microbiota. Linear discriminant analysis of effect size and random forest identified Bacteroides, Muribaculum, Butyricimonas, Odoribacter, and Prevotella as biomarkers in groups A and B. In comparing groups A and C, Barnesiella, Turicibacter, and Acholeplasma were critical bacteria, while comparing groups A and D highlighted Barnesiella and Candidatus Saccharimonas as differential bacteria. FAPROTAX analysis of the caecum microbiota revealed that the functional genes associated with harmful substance biodegradation were significantly increased in the RUP-fed group. Based on Spearman correlation analysis, alterations in microbial genera were associated with divergent metabolites. In summary, dietary RUP can improve egg quality and antioxidant capacity and regulate the intestinal microbiome and metabolome in aged breeders. Therefore, RUP can potentially be used as a feed additive to extend breeder service life at an appropriate level of 1.0 g/kg.

Do concentrations of non-esterified fatty acids change during gestation and lactation in healthy bitches?

During the gestation and lactation period, the energy demand in pregnant and lactating bitches is elevated. Non-esterified fatty acids (NEFAs) are utilized either directly from the fed diet or from body fat storage. High NEFA concentration in the blood plasma leads to an increased risk for diseases. Therefore, measuring blood NEFA concentrations may be an indicator for a period of scarcity. The aim of this study is to explore if serum NEFA concentrations in healthy bitches change during gestation and lactation. Healthy pregnant and lactating bitches were sampled on three appointed dates around parturition. NEFA values were examined with a multiparameter clinical chemistry analyser. All statistical analyses were performed using R. Overall, 38 bitches were enrolled in the study. Twenty-one bitches were sampled on all three appointed dates. The median NEFA concentration antepartum was 0.73 mmol/L (IQR: 0.59, 1.01); during peak lactation, it was 0.57 mmol/L (IQR: 0.44, 0.82); and around weaning, it was 0.58 mmol/L (IQR: 0.46, 0.73). NEFA concentrations rose slightly with litter size in late gestation. Body condition score had no influence on observed NEFA values. We conclude that NEFA concentrations widely remain within reference ranges in well-fed pregnant and lactating bitches. Nevertheless, they may be a valuable parameter to assess the actual metabolic status of malnourished pregnant and lactating bitches.

Association between non-esterified fatty acids and calcium concentrations at calving with early lactation clinical diseases, fertility and culling in grazing dairy cows in Uruguay

This study describes the association of non-esterified fatty acids (NEFA) and calcium concentrations at calving with early lactation disease, reproductive performance and culling in 646 dairy cows from 13 commercial grazing dairy herds in Uruguay. During one year, health events were recorded from calving to 30 days in milk (DIM). The first author visited each farm every 20 days. During each visit, body condition score (BCS) was recorded (scale 1–5), defining BCS < 3 as suboptimal and BCS > 3 as optimal, and a blood sample was taken from cows between 0 and 4 DIM for metabolite determination. To evaluate the association between health events (i.e., retained placenta-metritis and clinical mastitis) and risk factors (parity, BCS, high NEFA (> 0.6 mmol/L) and subclinical hypocalcemia (SCH) (< 2.10 mM)) data were analysed using multivariable logistic regression models. To evaluate the association of health events and risk factors with reproductive performance and culling, data were analysed using Cox proportional hazard regression models. A risk factor and an outcome of interest were assumed to be associated at P < 0.05 and a tendency to be associated was defined at P < 0.10. Overall, 47 % (n = 303) of the cows showed elevated NEFA concentration and 77 % (n = 499) had SCH. In addition, 21.5 % (n = 139) of the cows recorded at least one clinical disease. Cumulative incidence was 17 % (n = 109) for clinical mastitis, 4.2 % (n = 27) for retained placenta (RP)-metritis and 1.4 % (n = 7) for lameness. Clinical mastitis was associated with parity, with lower odds in primiparous (PP) cows (OR = 0.42, P < 0.01). Cows in an optimal BCS also tended to have lower odds (OR = 0.66, P = 0.07). Moreover, high NEFA and SCH cows had higher odds of CM (OR = 4.5, P = 0.01 and OR = 1.75, P = 0.04, respectively). Retained placenta-metritis tended to be associated with high NEFA concentration (OR = 2.2, P = 0.06). Primiparous cows with suboptimal BCS showed an increased first insemination rate (HR = 2.34; P < 0.01). The risk of culling was lower in PP cows (HR = 0.19; P < 0.01) and in cows with optimal BCS and low NEFA concentration (HR = 0.38; P = 0.03). Our data show that metabolic challenge (defined as peripartum suboptimal BCS, high NEFA or SCH) is associated with increased odds of clinical mastitis and RP-metritis, decreased probability of insemination and increased hazard of culling. Under grazing conditions, we suggest that farm management to improve the metabolic adaptation to lactation represents an opportunity to enhance cow performance in terms of health, fertility and longevity.

Magnitude of change in prepartum feed intake: Estimations using multiple classes of predictors and associations with transition metabolism, health, and milk production

The objectives of this study were to identify factors associated with the relative change in prepartum DMI (RCDMI) of 273 cows fed individually, evaluate the performance of linear models to estimate RCDMI using different classes of predictors, and characterize the implications of RCDMI to transition metabolism, health, and subsequent milk production. Two periods of interest were established. Period 1 comprised d -21 to -12 relative to calving, when DMI was stable. Period 2 comprised d -4 to -1, when average DMI was distinctly declined. The RCDMI from period 1 to 2 was calculated as a percentage value, which ranged from -75% to 15% and averaged -18.1% (± 15.0%). Season, parity, body fatness, body weight, milk production in the previous lactation and at dry-off, and length of dry period were associated with RCDMI and explained 11% of the variation in all cows, and 19% when only parous cows were considered. Performance of linear models to predict RCDMI was improved when data on rumination and physical activities and target blood metabolites were added. The adjusted R2 increased to values between 0.45 and 0.55, and selected models performed consistently in cross-validation analyses. To evaluate the implications of RCDMI, cows were ranked within parity according to RCDMI and classified into terciles as large decline (LDec), moderate decline (MDec), or small decline (SDec). By design, DMI did not differ between tercile groups in period 1 (13.3 ± 0.2 kg/d), but differed substantially in period 2 (LDec = 8.8; MDec = 11.2; SDec = 12.7 ± 0.2 kg/d), creating important differences in RCDMI among groups (LDec = -33.8; MDec = -16.2; SDec = -3.4% ± 0.8%). At enrollment, cows in the LDec and MDec groups were heavier (LDec = 788; MDec = 775; SDec = 750 ± 7 kg), and the proportion of cows with BCS >3.5 was higher in LDec (LDec = 63%; MDec = 47%; SDec = 38%). An interaction between group and time was observed for postpartum DMI, which started lower in LDec than in SDec cows, equaled by the end of transition, and inverted at wk 13 and 14 after calving. Yields of ECM were greater in LDec than in SDec cows, and both groups did not differ from MDec (LDec = 41.0; MDec = 40.3; SDec = 39.0 ± 0.5 kg/d). The LDec cows had decreased energy balance and greater concentrations of nonesterified fatty acids, β-hydroxybutyrate, and aspartate aminotransferase in serum, and greater glutathione peroxidase activity in plasma than SDec cows. Larger declines in prepartum DMI were also associated with increased risk for postpartum disease, although the associations were only weak to moderate. In conclusion, a large decline in prepartum DMI of cows fed ad libitum was associated with important adjustments in the energy metabolism and antioxidants activities, and greater milk production in the subsequent lactation. These findings indicate that feed intake decline close to parturition is likely a normal response to physiological adaptations at the onset of lactation when cows are fed ad libitum.

Biochemical profile differences during the transition period based on different levels of non-esterified fatty acids at 7 weeks before parturition in Mediterranean Italian dairy buffaloes (Bubalus bubalis).

Metabolic adaptations to negative energy balance, as well as lipomobilization, influence inflammatory responses, immune function, and oxidative stress in animals. This study aimed to evaluate the biochemical profile of Mediterranean buffaloes with different levels of lipomobilization from the prepartum to the postpartum period. A total of 76 Mediterranean buffaloes were enrolled, and a weekly blood sample was taken from 7 weeks before to 6 weeks after calving. The concentration of non-esterified fatty acids (NEFAs) was determined in serum and was used to categorize buffaloes into three lipomobilization groups 7 weeks before calving: mild (NEFA-I; NEFA ≤ 0.29 mEq/L; n = 18), medium (NEFA-II; 0.29 < NEFA < 0.57 mEq/L; n = 20), and severe (NEFA-III; NEFA ≥ 0.57 mEq/L; n = 38). Two-way repeated measures ANOVA was used to assess changes within and between the groups and over time. Significant differences were found in the concentration levels of NEFA, β-hydroxybutyrate, glucose, cholesterol, protein profile, oxygen radicals, antioxidants, lysozyme, complement, and minerals. These results suggest that both medium and severe lipomobilization groups are associated with metabolic alterations. In conclusion, buffaloes with higher NEFA levels (>0.29 mEq/L; NEFA-II and NEFA-III) at 7 weeks before calving should be monitored more closely to reduce the risk of metabolic diseases. Furthermore, the medium (NEFA-II) and severe (NEFA-III) lipomobilization groups could be associated with differences in the animals' ability to manage their metabolic status. Specifically, the severe mobilization group was most associated with a greater energy deficit during both the prepartum and postpartum periods without oxidative stress. On the contrary, the medium mobilization group was associated with a less severe energy deficit but was also associated with an inflammatory status and oxidative stress during the prepartum period. These distinctions highlight the need for tailored management strategies to address varying levels of metabolic stress in dairy buffaloes.

Effects of postbiotic products from Saccharomyces cerevisiae fermentation on lactation performance, antioxidant capacities, and blood immunity in transition dairy cows

This study aimed to evaluate the effects of dietary supplementation with different types of Saccharomyces cerevisiae fermentation products (SCFP) on lactational performance, metabolism, acute phase protein response, and antioxidant capacities in dairy cows from -21 to 56 d in milk (DIM). One hundred and 80 multiparous Holstein dairy cows were blocked by parity, expected calving date, pre-trial body condition score, and previous 305-d ME yield, and then randomly assigned to 1 of 3 dietary treatments: basal diet (CON; n = 60), basal diet supplemented with 40 g/d of SCFP1 (XPC; n = 60; XPC, Diamond V, Cedar Rapids, IA), and basal diet supplemented with 19 g/d of SCFP2 (NTK; n = 60, NutriTek®, Diamond V, Cedar Rapids, IA). Blood (n = 15, 13 and 12 in the CON, XPC and NTK groups, respectively) was sampled at -7 ± 3, + 3, + 7, + 21, and + 28 d, and milk samples (n = 19, 18 and 15 in the CON, XPC and NTK groups, respectively) was sampled during 1-8 wk from a subset of cows from -21 to 56 d relative to calving. Data were analyzed using the MIXED procedure in SAS (SAS Institute Inc.). All data were subjected to repeated measures ANOVA. Dietary treatment (TRT), time, and their interaction (TRT × time) were considered as fixed effects and cow as the random effect. Cows fed XPC and NTK had greater energy-corrected milk (ECM). Supplementing NTK increased milk fat content and yield, and 3.5% fat-corrected milk (FCM) yield compared with CON. Milk urea nitrogen (MUN) was lower in XPC cows than CON. SCFP supplementation decreased plasma β-hydroxybutyrate (BHB), ceruloplasmin (CER), haptoglobin (HPT), and interleukin-1β (IL-1β) concentrations, whereas increased plasma phosphorus (P) concentrations. In addition, cows fed NTK showed lower creatinine (CR) and cortisol (COR) concentrations but increased plasma calcium (Ca) and myeloperoxidase (MPO) concentrations than those in the CON cows. In addition, cows fed NTK and XPC both had reduced plasma concentrations of serum amyloid-A (SAA) at 3 DIM of lactation compared with CON fed cows. Furthermore, SCFP cows had greater concentrations of plasma glucose (GLU) and calcium (Ca) than CON cows at 7 DIM, and greater concentrations of plasma phosphorus (P) at 21 DIM. Between different SCFP type fed groups, plasma concentrations of nonesterified fatty acids (NEFA), MDA, creatinine (CR), SAA, and HPT were lower in cows fed NTK compared with cows fed XPC at 7 DIM. Overall, our results indicate the potential benefits of supplementing SCFP in transition dairy cows by modulating immunity, liver metabolic function and supporting ECM yield. The results also suggest that NutriTek at 19 g/d appears to support the performance and health of dairy cows better compared with XPC at 40 g/d, based on improved metabolic and inflammatory status during the transition period.

Metabolic adaptation to lactation of dairy cows in two contrasting facilities involving partial confinement plus grazing or total confinement

Context The increasing intensification of pasture-based systems has subjected the cows to different productive environments, which could affect physiological responses and, consequently, their productive performance. Aims The aim was to determine the effect of contrasting housing facilities (outdoor soil-bedded vs compost-bedded pack barn) used in partial confinement in pasture-based systems, on the metabolic adaptation during early lactation and its impact on productive and reproductive performance of autumn- and spring-calving dairy cows, having as a positive control a zero-grazing confined system in compost barn. Methods Multiparous Holstein dairy cows that calved in autumn (n = 36) and spring (n = 48) were distributed in the following three treatments from calving to 90 days in milk (DIM): outdoor soil-bedded–grazing (OD-GRZ), compost barn–grazing (CB-GRZ), compost barn–total mixed ration (CB-TMR). Milk production, total milksolids (TMS), body condition score, non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), cholesterol, insulin, insulin-like growth factor-1 (IGF-1), and the proportion of cows with corpus luteum were determined in repeated measurements. Key results In both calving seasons, milk production and TMS yields did not differ between OD-GRZ and CB-GRZ, but were greater in CB-TMR (P &lt; 0.0001). In autumn, NEFA and BHB were not affected by treatments, but cholesterol increased faster in CB-TMR (P = 0.0500). In spring, NEFA and cholesterol concentrations were not affected by treatment, but BHB remained greater in OD-GRZ until 90 DIM than in the other treatments. IGF-1 and insulin did not differ between treatments in autumn, but in spring, IGF-1 was greater in CB-TMR (P &lt; 0.0001). The proportion of cows with corpus luteum was not different between pasture-based treatments, but both were greater than CB-TMR up to 40 DIM in autumn (P = 0.0489) and during the entire study in spring CB-TMR (P = 0.0285). Conclusions Although no differences were found among housing facilities in partial confinement, except that in spring OD-GRZ cows had greater BHB concentrations, confined cows prioritised milk production instead of reproductive function, despite presenting better energy indicators than did pasture-based cows. Implications Outdoor housing combined with grazing can increase the risk of greater BHB concentrations, indicative of subclinical ketosis, under heat-stress conditions, when compared with indoor housing. Confined cows increased milk production but had a delay in the resumption of ovarian cyclicity, even having a better energy status than pasture-based cows.

Effect of glycerol supplementation in early lactation on metabolic health, milking activity, and production of dairy cows in automated milking system herds

The objective of this study was to quantify the effects of supplementing early-lactation cows with a dry pure glycerol product, delivered through the automated milking system (AMS) concentrate, in the first 21 d in milk (DIM) on metabolic markers, milking behavior, and milk production. In 5 commercial AMS dairy herds, 389 dairy cows were randomly assigned, controlling for parity, 21 d before expected calving to 1 of 2 treatments, within farm: (1) control group (CON) receiving the standard AMS pellet (n = 213) from 1 to 150 DIM, or (2) glycerol group (GLY) receiving the treatment AMS pellet (n = 176) formulated to deliver 250 as fed g/d of glycerol product from 1 to 21 DIM (mean actual = 249 g/d dry matter [DM]), then they received the standard AMS pellet from 22 to 150 DIM. Across all farms, cows were fed partial mixed rations (PMR) that were similar in ingredient and nutrient composition. One prepartum blood sample and 5 postpartum blood samples were collected from each cow to determine serum nonesterified fatty acids (NEFA), blood β-hydroxy butyrate (BHB), and blood glucose concentrations. Cow body condition score (BCS) was recorded every 21 d from -21 to 63 DIM. Data were collected and analyzed for the treatment period (1 to 21 DIM) and a follow-up period (22 to 150 DIM). There was no detected treatment effect on serum NEFA concentrations in the first week of lactation. There was a treatment by time interaction for blood BHB and blood glucose, where GLY cows tended to have increased BHB concentrations at 5 DIM and had decreased glucose concentrations at 9 and 12 DIM. There was an interaction of BCS with treatment on the incidence of BHB ≥1.2 mmol/L, whereby over-conditioned CON cows (BCS ≥3.5) were 3.5x more likely to have a high BHB test than CON cows with normal prepartum BCS. During the treatment period GLY cows had 0.1 ± 0.05 more successful milkings/d, were delivered 0.27 ± 0.05 DM kg/d more AMS concentrate and tended to yield 0.8 ± 0.47 kg/d more milk. During the follow-up period GLY cows had 0.1 ± 0.04 more successful milkings/d, were delivered 0.18 ± 0.06 DM kg/d more AMS concentrate, and yielded 1.5 ± 0.53 kg/d more milk than CON cows. Glycerol supplementation allowed cows to maintain better BCS, as GLY cows lost less BCS from calving to 63 DIM than CON cows. Overall, the results of this study demonstrate that supplementing pure glycerol through the AMS concentrate for the first 21 DIM can reduce BCS loss in early lactation, improve milking behavior, and increase milk yield to mid lactation.

Metabolic clusters of early-lactating dairy cows based on blood β-hydroxybutyrate trajectories and predicted from milk compounds

High-yielding dairy cows encounter metabolic challenges in early lactation. Typically, BHB, measured at a specific time point, is employed to diagnose the metabolic status of cows based on a predetermined threshold. However, in early lactation, BHB is highly dynamic, with high interindividual variability in its time profile. This could limit the effectiveness of the single measurement and threshold-based diagnosis and could contribute to the disparities in reports linking metabolic status with productive and reproductive outcomes. This research examines the trajectories of BHB to unveil intercow variations and identify latent metabolic groups. We compiled a dataset from 2 observational studies involving a total of 195 lactations from multiparous Holstein Friesian cows. The dataset encompasses measurements of BHB, nonesterified fatty acids (NEFA), and insulin from blood samples collected at 3, 6, 9, and 21 DIM, along with weekly determinations of milk composition and fatty acids (FA) proportions in milk fat. In both experiments, milk yield (MY) and feed intake were recorded daily during the first month of lactation. We explored interindividual and intraindividual variations in metabolic responses using the trajectories of blood BHB and evaluated the presence of distinct metabolic groups based on such variations. For this purpose, we employed the growth mixture model, a trajectory clustering technique. Our findings unveil novel insights into the diverse metabolic responses among cows, encompassing both trajectory patterns and the magnitude of blood BHB concentrations. Specifically, we identified 3 latent metabolic groups: the quickly increasing BHB (QuiBHB) cluster (≈10%) exhibited a higher initial BHB concentration than other clusters, peaked on d 9 (average maximum BHB of 2.4 mM) and then declined by d 21; the slowly increasing BHB (SloBHB) cluster (≈23%) started with a lower BHB concentration, gradually increased until d 9, and reached the highest BHB concentration at d 21 (1.6 mM serum BHB at the end of the experimental period); and the low BHB (LoBHB) cluster (≈67%) began with the lowest serum BHB concentration (serum BHB <0.75 mM) and remained relatively stable throughout the sampling period. Notably, the 3 metabolic groups exhibited significant physiological disparities, which were evident in blood NEFA and insulin concentrations. The QuiBHB and SloBHB cows exhibited higher NEFA and lower insulin concentrations as compared with the LoBHB cows. Interestingly, these metabolic differences extended to MY and DMI during the first month of lactation. The elevated BHB concentrations observed in QuiBHB cows were linked with lower DMI and MY as compared with SloBHB and LoBHB cows. Accordingly, these animals were considered metabolically impaired. Conversely, SloBHB cows displayed higher MY along with increased DMI, and thus the elevated BHB might be indicative of an adaptive response for these cows. The QuiBHB cows also displayed higher proportions of UFA, MUFA, and total C18:1 FA in milk during the first week of lactation. Prediction of the QuiBHB cows using these FA and test day variables resulted in moderate predictive accuracy (area under the receiver operating characteristic curve >0.7). Given the limited sample size for the development of prediction models and the variation in DIM among samples in the same week, the result is indicative of the predictive potential of the model and room for model optimization. In summary, distinct metabolic groups of cows could be identified based on the trajectories of blood BHB in early lactation.

Dietary foundations for pollinators: nutritional profiling of plants for bee health

Human activities, including urban expansion, intensive farming practices, and the application of pesticides have significantly reshaped bee habitats. Understanding the nutritional content of pollen, the primary source of bees’ proteins and lipids, is important for maintaining their diet and health. In this study, we set out to determine the nutritional composition of pollen from various plant families and genera. Our objectives were to analyze the levels of non-esterified fatty acids (NEFAs), amino acids (AAs), protein-to-lipid (P:L) ratios, and omega-6:3 ratios of 57 pollen species native to North America. These data suggest a potential trade-off between NEFA and AA content within pollen, suggesting that a diverse floral diet may benefit bees more than a single pollen source. The AA profiles showed considerable diversity, with all pollen species providing the essential amino acids (EAAs) required for bee health, except for methionine which was lacking in Rhus glabra pollen. The plant family Asteraceae was especially abundant in EAAs. P:L ratios varied widely further emphasizing bees’ need for access to a diverse array of nutritional profiles. There were no overall nutritional differences between pollen from native and introduced plant species. This study highlights the significance of a diverse array of floral resources to meet the comprehensive nutritional needs of bees, contributing to the support of pollinator populations and the broader ecological system.

Altered bile acid and correlations with gut microbiome in transition dairy cows with different glucose and lipid metabolism status

The transition from pregnancy to lactation is critical in dairy cows. Among others, dairy cows experience a metabolic stress due to a large change in glucose and lipid metabolism. Recent studies revealed that bile acids (BA), besides being involved in both the emulsification and solubilization of fats during intestinal absorption, can also affect the metabolism of glucose and lipids, both directly or indirectly by affecting the gut microbiota. Thus, we used untargeted and targeted metabolomics and 16S rRNA sequencing approaches to investigate the concentration of plasma metabolites and BA, the composition of the rectum microbial community, and assess their interaction in transition dairy cows. In Experiment 1, we investigated BA and other blood parameters and gut microbiota in dairy cows without clinical diseases during the transition period, which can be seen as well adapted to the challenge of changed glucose and lipid metabolism. As expected, we detected an increased plasma concentration of β-hydroxybutyrate (BHBA) and nonesterified fatty acids (NEFA) but decreased concentration of glucose, cholesterol, and triglycerides (TG). Untargeted metabolomic analysis of the plasma revealed primary BA biosynthesis was one of the affected pathways, and was consistent with the increased concentration of BA in the plasma. A correlation approach revealed a complex association between BA and microbiota with the host plasma concentration of glucose and lipid metabolites. Among BA, chenodeoxycholic acid derivates such as glycolithocholic acid, taurolithocholic acid, lithocholic acid, taurochenodeoxycholic acid, and taurodeoxycholic acid were the main hub nodes connecting microbe and blood metabolites (such as glucose, TG, and NEFA). In Experiment 2, we investigated early postpartum dairy cows with or without hyperketonemia (HPK). As expected, HPK cows had increased concentration of NEFA and decreased concentrations of glucose and triglycerides. The untargeted metabolomic analysis of the plasma revealed that primary BA biosynthesis was also one of the affected pathways. Even though the BA concentration was similar among the 2 groups, the profiles of taurine conjugated BA changed significantly. A correlation analysis also revealed an association between BA and microbiota with the concentration in plasma of glucose and lipid metabolites (such as BHBA). Among BA, cholic acid and its derivates such as taurocholic acid, tauro α-muricholic acid, and taurodeoxycholic acid were the main hub nodes connecting microbe and blood metabolites. Our results indicated an association between BA, intestinal microbe, and glucose and lipid metabolism in transition dairy cows. These findings provide new insight into the adaptation mechanisms of dairy cows during the transition period.

Effects of calving interval of dairy cows on development, metabolism, and milk performance of their offspring

Extending the voluntary waiting period (VWP) for insemination in dairy cows is of interest as a strategy to reduce the frequency of calving events and inseminate at a moment with fewer fertility problems. Little is known about the calves born from dams with a different VWP followed by a different calving interval (CInt). The objective of the current study was to identify the effect of dam's CInt on body condition, metabolic status, and milk production of their offspring from birth until 100 DIM of the offspring's first lactation. Holstein-Friesian dairy cows (n = 154, 41 primiparous, 113 multiparous) were blocked according to parity, milk yield, and SCC and randomly assigned to a VWP of 50, 125, or 200 d. Female calves (n = 62) from cows with different CInt were monitored from birth until their first calving event as heifer. Certain dams were not successfully inseminated soon after the planned VWP, resulting in differences between the intended VWP and the actual CInt. Calves were regrouped according to their dam's actual CInt (CInt_1: 324-408 d; CInt_2: 409-468 d; CInt_3: 469-586 d). The dam's CInt did not affect calf birth weight. From birth to weaning, the calves born to dams in CInt_1 had a higher plasma nonesterified fatty acids (NEFA) concentration (0.34 mmol/L; CI: 0.30, 0.37) than CInt_2 (0.28 mmol/L; CI: 0.26, 0.31) and CInt_3 (0.26 mmol/L; CI: 0.24, 0.29) calves. Calves born to dams with a shorter CInt (CInt_1) had greater IgG and IgM against keyhole limpet hemocyanin (KLH) than CInt_3 (IgG: 6.05 ± 0.30 vs. 4.64 ± 0.30; IgM: 6.45 ± 0.17 vs. 5.89 ± 0.16, respectively; mean ± SE) before weaning. After weaning till calving, CInt_1 calves tended to have greater plasma NEFA concentration than CInt_3-calves. During the first 100 DIM, a longer CInt of the dams resulted in lower plasma IGF_1 (CInt_2), lower milk lactose (CInt_3), and lower fat- and protein-corrected milk (FPCM; CInt_2) in offspring, compared with shorter CInt of the dams (CInt_1). Collectively, a longer CInt in dams did not affect birth weight of their calves or BW during the weaning or rearing phase. From birth till weaning, a longer CInt in dams resulted in less anti-KLH IgG and lower plasma NEFA concentration in plasma of the calves. During the first lactation of their offspring, a longer CInt in dams can result in a lower plasma IGF_1 and FPCM during the first 100 DIM, although effects were not present in all CInt categories.