Non-esterified Fatty Acid Concentrations Research Articles

Effect of energy nutrition in the last third of gestation in beef cows on the productive and reproductive performance of their progeny

The present thesis evaluated the impact of restrictive and non-restrictive energy nutrition in beef cows in the last third of gestation on the productive and reproductive performance of the progeny. In addition, the effect of consumption of low-energy diets in pregnant cows in the last third of gestation on their own productive and reproductive variables was considered. Thirty-one multiparous, fixed-time inseminated, gestating British cows were assigned on day -90 (day 0 = calving) to two levels of energy intake relative to maintenance requirements until calving: i- 125 % (ALTO; n = 15) and ii- 75 % (BAJO; n = 16). At calving, energy-restricted cows had higher concentration of non-esterified fatty acids (AGNE) (P < 0.01) and lower insulin concentration (P < 0.03) relative to unrestricted cows. During lactation, restricted cows had lower body condition (P < 0.05) and lower AGNE concentration (P = 0.05) with respect to non-restricted cows. Milk production was not significantly affected (P > 0.05) by energy restriction. Regarding the characteristics evaluated in placentas, they were not affected by the treatments. Live weight (BW), morphometry and calf behaviour at birth were not significantly affected by the treatments. In contrast, energy restriction of cows affected PV at weaning (P < 0.05) and daily liveweight gain (GD) at weaning (P < 0.05) of (F1). From weaning to puberty, the GD and PV of the (F1) was not affected by the treatments. Similarly, the variables of (F2) were not affected by the treatments. In the present study, the undernourished cows mobilized body reserves and maintained milk production. Energy-restricted cows mobilized pre- and postpartum body reserves sufficient to supply fetal and milk production demands. Possibly, breeding cows grazing native range may develop similar resilient mechanisms, at least for the conditions of the present work. Specifically, there was no evident effect on calf growth and development parameters.

Ovarian and Energy Status in Lame Dairy Cows at Puerperium and Their Responsiveness in Protocols for the Synchronization of Ovulation.

The purpose of this study was to assess the ovarian and energy status of multiparous lame dairy cows at the end of puerperium and investigate their responsiveness to estrous synchronization treatment regimens. Initial lameness scoring was performed at 28 ± 5 and 37 ± 5 d post partum, followed by lesion documentation and treatment. Cows were blocked by lameness severity and were randomly allocated to an estrous synchronization treatment regimen with seven days of progesterone supplementation (group LP, n = 26) or with an administration of PGF2α twice, 14 d apart (group LC, n = 26). Non-lame cows served as controls (group C, n = 27) and the same treatment regimen was imposed as that for group LC. Twelve days after estrous presynchronization, an Ovsynch treatment regimen and timed AI were imposed. Ultrasonography of the ovaries and blood sampling for progesterone were used to assess cyclicity status, whereas β-hydroxybutyrate (BHBA) and non-esterified fatty acids (NEFA) were used to assess energy status. Lame cows were to a greater proportion non-cycling (36.5% vs. 11.1%; p = 0.02), had greater overall NEFA concentrations (0.32 ± 0.02 vs. 0.26 ± 0.02 mEq/L; p = 0.02) and a greater incidence of elevated NEFA concentrations (53.9% vs. 29.6%, p = 0.04) compared to control cows. However, no interaction between energy and lameness status was evident regarding non-cycling cows. The percentage of cows responding to the presynchronization, synchronization and ovulating did not differ between groups LP, LC, and C. The first-service conception rate (FSCR) tended to be greater for group C (37.0%) compared to group LP (16.0%; p = 0.08). Long-term reproductive performance did not differ between lame and control cows, although culling rates did (21.2% vs. 0%, respectivly; p = 0.01). The severity of lameness had an effect on culling rates (30.6% vs. 0% for cows with marked vs. moderate lameness; p = 0.01), whereas the type of lesion largely explained poor reproductive performance (FSCR 13.9% vs. 40.0% for cows with claw horn disruptions vs. infectious lesions; p = 0.04). Conclusively, cows that were lame during puerperium are at a greater risk of not cycling irrespective of energy status. Treatment regimens for the synchronization of ovulation seem to be efficient at resuming ovarian cyclicity. Marked lameness was detrimental to survivability, whereas cows with claw horn lesions had compromised reproductive capacity.

Physiological traits of newborn piglets associated with colostrum intake, neonatal survival and preweaning growth

Colostrum intake, which is critical for piglet survival after birth and growth up to weaning, greatly depends on piglet weight and vitality at birth. Our aim was to identify a set of biological variables explaining individual variations in colostrum intake, preweaning growth and risk of dying. Farrowing traits, morphological traits and colostrum intake were determined for 504 piglets born alive from 37 Landrace × Large White sows. A subset of 203 of these piglets was used to measure plasma neonatal concentrations of metabolites and hormones in blood collected from the umbilical cord at birth. From univariate analyses, we established that colostrum intake was positively associated with plasma neonatal concentrations of IGF-I, albumin, thyroid hormones (P < 0.001), and non-esterified fatty acids (P < 0.05), and was negatively associated with concentrations of lactate (P < 0.001). In a multivariable analysis, the variables explaining the variation in colostrum intake were piglet birth weight and rectal temperature 1 h after birth (positive effect, P < 0.001), time of birth after the onset of parturition, and fructose plasma concentrations at birth (negative effects, P < 0.001 and P < 0.05, respectively). Piglets that died within 3 days after birth had lower neonatal concentrations of albumin (P < 0.001), IGF-I and thyroxine (P < 0.01) than surviving piglets. Preweaning growth was positively associated with neonatal concentrations of IGF-I, thyroxine (P < 0.001), albumin and insulin (P < 0.05). Cortisol and glucose concentrations at birth were not related to colostrum intake, neonatal survival or preweaning growth. Multivariable analyses confirmed that colostrum intake was the predominant factor influencing piglet survival within 3 days after birth and preweaning growth. These results provide physiological indicators of piglet colostrum intake, besides birth weight. They also confirm the impact of time of birth during farrowing on colostrum intake and the crucial importance of physiological maturity at birth for postnatal adaptation.

Site-specific tissue lipolysis and fat metabolism differs between men and women during a treadmill-based heat tolerance test without differences in circulating biomarkers

Purpose: To test the hypothesis that measures of lipid metabolism and substrate utilization differ between men and women exposed to extreme exercise-heat stress. Methods: Physically active men (n=6, 30±8 yrs, 78.8±11.0 kg, body fat 19.4±9.8%, VO2max 49.9±2.9 mL -1· kg -1· min -1 ) and women (n=6, 25±3 yrs, 60.6±4.1 kg, 25.2±6.8%, 46.3±4.5mL -1· kg -1· min -1 ) completed a treadmill-based heat tolerance test (HTT) (2 hours, 3.1 mph, 2% grade in extreme environmental conditions (104°F, 40% relative humidity). Differences (pre-, post-, change, percentage change, mean difference (MD)) within and between groups were analyzed with nonparametric inferential statistical tests. Subcutaneous abdominal adipose tissue (SCAAT) interstitial glycerol concentration and adipose tissue blood flow (i.e., ethanol Output: Input (O:I)) pre-exercise, every 30 minutes (min) of exercise, and during recovery was measured with microdialysis and assay of biofluids. Circulating concentrations of non-esterified fatty acids (NEFAs), insulin, insulin-like growth factor (IGF-1), epinephrine (EPI), and norepinephrine (NE), and cortisol were measured with commercially available kits. Resting energy expenditure (REE) was measured pre- and post-exercise using a metabolic cart. Exercising substrate utilization and metabolic heat production (MHP) were collected during 30 and 90 mins of the HTT. Results: Despite no sex differences in markers associated with stress-related metabolic signaling (cortisol, EPI, NE), endocrine response (IGF-1, insulin), or systemic concentrations of NEFAs, fat oxidation (g·min -1 ) was higher in men (vs. women) at 30 min of HTT (men (M), women (W): 0.56±0.03, 0.45±0.05, p=0.005) and at 90 min of HTT (0.61±0.05, 0.48±0.12, p=0.05). SCAAT interstitial glycerol and O:I were similar across all time points between sexes (baseline glycerol ranges (mmol·L -1 ): 92.8-530.7 (W), 321.8-588.8 (M); O:I ratio ranges: 0.42-0.79 (W), 0.55-0.77 (M). However, women had significantly greater percent change in interstitial glycerol concentration from baseline (vs. M) (W vs. M: 275 ± 287.56% vs. -8.69 ± 32.41%, p=0.003). Pre- and post-exercise REE were 16.9% (MD:371.6 kcal·day -1 , p=0.003) and 15.5% (MD:343.5kcal·day -1 , p=0.050) lower in W compared to M. Mean MHP was higher in men (MD 85W). Conclusion: Fat oxidation and SCAAT lipolysis rates were higher in men vs. women after an acute bout of strenuous exercise-heat stress. Ongoing analyses are investigating sex, energy expenditure, and heat production contributions to differences between men and women observed in our study. Our findings suggest potential for sex-specific dietary recommendations during stress exposures. DoD BA200299, HRPO E02882.1a This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

130 Association between nonesterified fatty acids concentration and subclinical hypocalcemia at calving with early lactation clinical diseases and fertility in grazing dairy cows

130 Association between nonesterified fatty acids concentration and subclinical hypocalcemia at calving with early lactation clinical diseases and fertility in grazing dairy cows

136 Association of transient, delayed or persistent elevated non-esterified fatty acids concentration around parturition with pregnancy rate in grazing dairy cows

136 Association of transient, delayed or persistent elevated non-esterified fatty acids concentration around parturition with pregnancy rate in grazing dairy cows

Biomarkers of oxidative stress and liver function in early lactation and their relationship with the reproductive efficiency of multiparous grazing dairy cows in Argentina. A retrospective study.

This study aimed to analyze the possible relationship between days to conception and different oxidative stress (OS) biomarkers and liver functional parameters in multiparous dairy cows. Besides, a fast reliable method for the accurate measurement of malondialdehyde (MDA) by liquid chromatography-tandem mass spectrometry was developed in several matrices. During lactation, the days to conception of 28 cows were determined for a retrospective study. According to this parameter, cows were divided into two groups: high and low days to conception (HDC and LDC, respectively). Blood, urine and liver biopsies were sampled 21days before the expected calving date, and 7 and 21days after calving. The method developed for MDA was validated according to international requirements. The lower limit of quantification was 0.25µmol/L for plasma and urine and 10.00µmol/L for liver tissue. No differences between groups were observed in the systemic concentration of non-esterified fatty acids, β-hydroxybutyric acid and liver triacylglycerol content (P > 0.05). Cholesterol concentration was higher in the LDC than in the HDC group (P < 0.05). Plasma 3-nitrotyrosine (3-NT) concentration was lower in the LDC than in the HDC group on day 21 post-calving (P < 0.05). Superoxide dismutase activity was higher in the LDC than in the HDC group (P < 0.05). Particularly, in the liver, 3-NT and MDA concentrations were lower in the LDC than in the HDC group (P < 0.05). These results allow inferring that the amelioration of OS biomarkers in plasma and liver could be related to a better reproductive performance of dairy cows.

Association of precalving serum NEFA concentrations with postpartum diseases and reproductive performance in multiparous Holstein cows: Cut-off values.

High concentrations of NEFA relative to a defined reference or 'cut-point' values before calving can predict the risk of specific or collective periparturient disease events. A field-based cohort study was conducted to evaluate the value and critical points of serum nonesterified fatty acids (NEFA) at the precalving time to predict the occurrence of postpartum diseases and reproductive performance in dairy cows. Blood samples were taken from 521 high-yielding dairy cows at 1 week (±3days) before calving and NEFA levels were measured. Health and reproduction information of each cow includes dystocia, retained placenta, milk fever, metritis, mastitis, pregnancy in the first insemination and pregnancy in the first two inseminations, and culling in the first 60 days of lactation and milk production. Our results show that there are significant relationships between precalving NEFA with the probability of pregnancy at the first and the first two inseminations after calving. The cows that had NEFA concentrations less than 0.5mmol/L at the last week of pregnancy were 3.51 and 3.15 times more likely to be pregnant at first insemination and the first two inseminations, respectively. Also, our results showed that there are significant relationships between precalving NEFA concentration and the likelihood of dystocia and milk fever. The probability of dystocia and milk fever occurrence were 2.56 and 1.91 times greater in those cows that had NEFA concentrations more than 0.3mmol/L, respectively. The present results indicated that Increasing NEFA during the prepartum period could adversely affect the reproductive efficiency of dairy cows.

Lipid metabolites, interleukin-6 and oxidative stress markers in follicular fluid and their association with serum concentrations in mares.

The application of trans-vaginal ovum pick up (OPU) and intracytoplasmic sperm injection (ICSI) is well established for commercial in vitro embryo production in horses. These assisted reproductive techniques are especially applied during the non-breeding season of the mare. However, little is known about how the health of the oocyte donor may affect the biochemical composition of the follicular fluid (FF) in small and medium-sized follicles routinely aspirated during OPU. This study aimed to investigate associations between systemic and FF concentrations of interleukin-6 (IL-6), total cholesterol, triglycerides, non-esterified fatty acids (NEFA), reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), and oxidative stress index (OSI) during the non-breeding season in mares. At the slaughterhouse, serum and FF of small (5-10mm in diameter), medium (> 10-20mm in diameter), and large (> 20-30mm in diameter) follicles were sampled from 12 healthy mares. There was a strong positive association (P < 0.01) between the concentration of IL-6 in serum and those measured in small (r = 0.846), medium (r = 0.999), and large (r = 0.996) follicles. Serum concentrations of NEFA were positively correlated (P < 0.05) with those measured in small (r = 0.726), medium (r = 0.720), and large (r = 0.974) follicles. Values of total cholesterol and OSI in serum and medium follicles were significantly associated (r = 0.736 and r = 0.696, respectively). The serum concentrations of all lipid metabolites were markedly higher than those measured in FF of small- and medium-sized follicles. Values of IL-6 and OSI did not change significantly between serum and all follicle classes (P ≥ 0.05). To conclude, changes in the blood composition associated with inflammation, oxidative stress, and disturbed lipid metabolism of mares may lead to an inadequate oocyte microenvironment, which could affect oocyte quality and the success rate of OPU/ICSI programs. Further research should indicate whether these changes may ultimately affect in vitro oocyte developmental capacity and subsequent embryo quality.

Longitudinal Data to Assess Relationships among Plasma Folate, Vitamin B12, Non-esterified Fatty Acid, and β-Hydroxybutyrate Concentrations of Holstein Cows during the Transition Period.

It is well established that the plasma metabolite profile changes during metabolic dysfunction, such as elevated non-esterified fatty acid (NEFA) release when body reserve mobilization is excessive in early lactation cows. Relationships between changes in plasma concentrations of metabolites caused by a metabolic impairment and the status of vitamins, such as folates and vitamin B12, have barely been studied in cattle. This study was undertaken to assess relationships between peripartum plasma concentrations of folates, vitamin B12, NEFA, and beta-hydroxybutyrate (BHB). Longitudinal data of 48 multiparous Holstein cows from 5 studies were taken from days -14 to 21 relative to calving. Blood samples were taken weekly before calving and either twice or thrice per week postpartum, and plasma was analyzed for folate, vitamin B12, NEFA, and BHB concentrations. Postpartum plasma NEFA and BHB concentrations were negatively related to plasma folate concentration at days -14 and -7 relative to parturition, whereas the opposite relationship was noted for the plasma vitamin B12:folate ratio. The plasma folate and NEFA areas under the curve from the whole studied period were negatively associated, and the opposite was observed with the association between the plasma vitamin B12:folate ratio and NEFA as well as the BHB areas under the curve. The results suggest that there is an increased use of folate for metabolic functions during elevated concentrations of plasma NEFA and BHB. Future research should focus on finding an optimal plasma vitamin B12:folate ratio to favor cow health during the challenging period of parturition.

Effect of Dietary Manganese on the Growth Performance, Lipid Metabolism, and Antioxidant Capacity in the Post-Larval Coho Salmon (Oncorhynchus kisutch).

In this study, post-larval coho salmon Oncorhynchus kisutch (initial weight 0.37 ± 0.03 g) were fed with 6 experimental diets with increasing manganese (Mn) content (2.4, 8.5, 14.8, 19.8, 24.6, and 33.7 mg kg-1) for 12 weeks. Our results indicated that the feed conversion rate (FCR), specific growth rate (SGR), condition factor (CF), crude protein, moisture, crude lipid, ash, whole-body Mn, and vertebral Mn were affected by the elevation of Mn content in the diet. The activities of hepatic GSH-PX, Mn-SOD, and CAT were enhanced with increasing Mn content in the diet and reached the highest value at 19.8 mg kg-1 Mn. However, the level of hydrogen peroxide (H2O2), superoxide anion (O2·-), and malondialdehyde (MDA) was reduced with increasing Mn content in the diet. In addition, the activity of hepatic lipase (HL) and lipoprotein lipase (LPL) was increased with the elevation of dietary Mn content and reached a peak value at 14.8 mg kg-1 Mn. The activity of fatty acid synthetase (FAS) and the content of nonesterified fatty acid (NEFA) were increased following the elevation of Mn content from 2.4 to 19.8 mg kg-1 in the diet. The results indicated that the appropriate dietary Mn supplementation improved the feeding efficiency, lipid metabolism, and antioxidant capacity of coho salmon. The dietary Mn requirement for post-larval coho salmon was 17.35 mg kg-1 and 19.75 mg kg-1 based on the SGR and FCR, respectively. An optimal dietary level of Mn enhances hepatic lipid metabolism, and the signaling pathway of PI3K/AKT/mTOR may be involved in regulating the activity of enzymes related to lipid metabolism.

Beef cows' performance and metabolic response to short nutritional challenges in different months of lactation

Lactating cows can react to changes in nutrient availability with a range of behavioural and physiological mechanisms, which may differ among lactation stages. We investigated the effects of short feed restriction and refeeding periods on beef cows' performance and metabolic status in different months of lactation. For this, Parda de Montaña beef cows [n = 31; 626 ± 47.7 kg body weight (BW)] were subjected to short nutritional restriction and refeeding cycles, which were repeated in months 2, 3 and 4 of lactation. Each month, cows were consecutively fed a diet to meet 100% of their energy and protein requirements during a 4-day basal period, 55% during a 4-day restriction period, and again 100% during a 4-day refeeding period. The performance (energy balance, BW, milk yield and composition) and plasma metabolite concentrations (glucose, non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), urea and malondialdehyde) were measured daily. Most of the traits were significantly affected by the interaction between feeding period and lactation month. Feed restriction induced milk yield loss, decreased milk protein and increased milk urea contents to different extents. The plasma NEFA concentrations rose with restriction in months 2, 3 and 4 but BHB and urea concentrations increased only in month 4. Most of these metabolites lowered to basal values during refeeding. These results suggest that beef cows use different adaptation strategies to cope with nutritional challenges as lactation advances, body fat mobilisation predominates in early lactation and protein catabolism prevails at later stages.

Syndecan-3 Coregulates Milk Fat Metabolism and Inflammatory Reactions in Bovine Mammary Epithelial Cells through AMPK/SIRT1 Signaling Pathway.

Transcriptome sequencing showed that syndecan-3 (SDC3) was differentially expressed in high-fat and low-fat mammary epithelial cells of Chinese Holstein cows. Previous studies found that SDC3 plays an important role in inflammatory diseases and virus infection. However, those studies did not confirm whether or not the functional gene SDC3, which plays an important role in regulating milk fat metabolism, has an effect on susceptibility to breast tissue diseases. Therefore, we studied the effects of SDC3 on milk lipid metabolism and inflammation in bovine mammary epithelial cells (BMECs) and further explored the common regulatory pathway of SDC3 in both. The overexpression of SDC3 increased the contents of triglycerides and cholesterol, reduced the content of non-esterified fatty acids, inhibited the expression of inflammatory factors (IL-6, IL-1β, TNF-α and COX-2), and reduced the production of ROS in BMECs. However, silenced SDC3 had the opposite effect. Further exploring the mechanisms of SDC3, we found that SDC3 upregulated the expression of peroxisome proliferator-activated receptor gamma (PPARG) through the AMPK/SIRT1 signal pathway to promote milk fat synthesis. It also regulated the activation of the NF-κB pathway through the AMPK/SIRT1 signal pathway, reducing the expression of inflammatory factors and ROS production, thus inhibiting the inflammatory response of BMECs. Nuclear factor kappa B subunit 1 (NF-κB p50) was an important target of SDC3 in this process. To sum up, our results showed that SDC3 coregulated milk fat metabolism and inflammation through the AMPK/SIRT1 signaling pathway. This study laid a foundation for the comprehensive evaluation of breeding value based on multi-effect functional genes in dairy cow molecular breeding.

Supplementing pre- and probiotic ingredients to feedlot steers: effects on health, growth performance, and physiological responses.

Feedlot diets are often enriched with additives to mitigate health disorders and promote cattle performance, including the feed-grade antimicrobials monensin and tylosin. However, alternative feeding strategies are warranted given the increasing regulations regarding the use of antimicrobials in feedlot diets. This study evaluated the performance, physiological, and health responses of feedlot cattle offered a synbiotic supplement (yeast-derived prebiotic+Bacillus subtilis probiotic), which replaced or was fed in conjunction with monensin and tylosin. Angus-influenced steers (n=192) from four different cowherds were weaned on day -1 and transported (800km) to the feedlot. Steers were allocated to 1 of 24 pens (eight steers/pen) upon arrival on day 0. Pens were assigned to receive (n=8/treatment) a total-mixed ration (TMR) containing: (1) monensin and tylosin (RT; 360mg/steer daily from Rumensin and 90mg/steer daily from Tylan; Elanco Animal Health, Greenfield, IN, USA), (2) yeast-derived ingredient and B. subtilis probiotic (CC; 18g/steer daily of Celmanax and 28g/steer daily of Certillus; Church and Dwight Co., Inc., Princeton, NJ, USA), or (3) a combination of RT and CC (RTCC). Steers were slaughtered according to BW in four groups balanced by treatment and pens and received treatments for 252±4days. No treatment effects were detected (P≥0.17) for steer BW gain and morbidity responses. Mean TMR intake was greater and gain:feed ratio was less (P≤0.01) in CC compared with RT and RTCC steers. Mean plasma leptin concentration was greater (P≤0.05) in CC compared with RT and RTCC steers. Steers receiving CC had greater (P≤0.04) concentrations of plasma cortisol, haptoglobin, glucose, and beta-hydroxybutyrate, and less (P≤0.05) concentration of non-esterified fatty acids compared with RT and RTCC steers on day 14 of the experiment. Carcass marbling was greater (P=0.01) in CC compared with RT steers and tended to be greater (P=0.07) in RTCC compared with RT steers. Proportion of carcasses that graded Choice or better and Longissimus muscle area were greater (P≤0.05) in CC and RTCC compared with RT steers. Incidence of liver abscesses was less (P=0.01) in RTCC compared with CC steers and tended to be less (P=0.09) in RT compared with CC steers. Results from this experiment indicate that the synbiotic supplement may replace monensin and tylosin without reducing steer BW gain, with potential improvements to carcass quality traits.

Supplementation of feed and water after long-duration road transportation: The effects on welfare and rumen fermentation in goats.

Water and feed are needed for livestock during their long-duration road transportation. However, limited information is available on the need to supply water and feed to livestock at temporary holding stations after road transportation. This study aimed to evaluate the effect of providing water and feed at holding stations on the welfare of goats in mimic surroundings. A total of 24 Guizhou black goats were randomly divided into three groups of eight goats each as follows: deprived of water and feed (TRT0), supplemented with water ad libitum (TRT1), and supplemented with water and feed ad libitum (TRT2). Blood and rumen fluid samples were collected before loading (denoted as "PRE" in this article) and after transport (denoted as "POST" in this article). Statistical analysis was performed via the SAS procedure PROC MIXED. The 10-h road transportation period reduced body weight in TRT0 goats (p < 0.05) but not in TRT1 and TRT2 (p > 0.05). TRT0 and TRT1 goats had POST plasma glucose concentrations above their PRE values (p < 0.05). The PRE-plasma urea nitrogen (PUN) levels were higher in TRT2 compared to TRT0 (p < 0.05) goats, while the POST-PUN levels increased in TRT1 compared to TRT0 goats. The POST non-esterified fatty acid (NEFA) concentration was higher for TRT0 compared to that in TRT1 and TRT2 (p < 0.05) goats. No difference was observed for plasma profiles of malondialdehyde (MDA) and superoxide dismutase (SOD) (p > 0.05). TRT2 goats had higher POST glutathione peroxidase (GSH-Px) activity than TRT0 and TRT1 (p < 0.05) goats. TRT0 goats had higher POST plasma glucagon (GC) compared to TRT2 (p < 0.05) and had increased values compared to their own PRE level as a result of road transportation (p < 0.05). TRT2 goats resulted in a lower POST plasma heat-stressed protein-70 (HSP-70) level than TRT0. There was no difference in ruminal pH (p > 0.05). Ruminal total VFA (acetate, propionate, butyrate), and the NH3-ammonia profiles showed a decrease (p < 0.05) after transportation in all groups. Ruminal microcrystalline cellulose, xylanase, cellobiase, and carboxymethyl cellulose activities were unaffected (p > 0.05). These combined results imply that water and feed supplementation to livestock can effectively alleviate stress responses in goats subjected to road transportation and emphasize the necessity to establish water and feed supplies even at a temporary holding pen.

Eucalcemia during lipopolysaccharide challenge in postpartum dairy cows: I. Clinical, inflammatory, and metabolic response

Hypocalcemia induced by immune activation is a conserved response across mammalian species; however, administration of Ca is discouraged in other species as it is associated with increased morbidity and mortality. Early postpartum cows experience a decrease in circulating Ca concentration following acute inflammation. Corrective Ca therapy during the transition period, particularly in dairy cows experiencing acute disease, is common practice. However, the effect of Ca administration on the inflammatory response during acute immune activation is unknown. Our objective was to compare the clinical, inflammatory, and metabolic response to an intravenous (IV) lipopolysaccharide (LPS) challenge between postpartum cows infused, or not, with IV Ca to maintain eucalcemia. Cows (n = 14, 8 ± 1 d in milk) were enrolled in a matched-pair randomized controlled design to receive IV Ca (IVCa) or sterile 0.9% NaCl (CTRL) during an IV LPS challenge (0.040 or 0.045 µg of LPS/kg of body weight over 1 h). Ionized Ca (iCa) was monitored cow-side, and IV Ca infusion was adjusted in a eucalcemic clamp for 12 h following the start of LPS infusion. Cows were monitored during the 24 h following challenge and serial blood samples were collected to quantify concentrations of glucose, β-hydroxybutyrate, nonesterified fatty acids, urea nitrogen, cytokines, acute-phase proteins, and cortisol. Blood iCa concentration decreased to 0.87 ± 0.03 mM in CTRL during challenge, and by design, iCa concentration was maintained within 3% of baseline in IVCa. Body temperature, heart rate, and respiratory rate were monitored for 24 h following the start of challenge and did not differ between groups. A treatment × time interaction was identified such that serum cortisol concentrations increased in both groups at 2 h but decreased to a greater extent at 6 h in IVCa compared with CTRL. Rumination time (min/h) over the first 12 h following challenge was greater in IVCa, but total rumination time in the 24 h following challenge did not differ from CTRL. Serum glucose and nonesterified fatty acid concentrations decreased, and β-hydroxybutyrate and urea nitrogen concentrations increased over time, but did not differ between groups. Acute leukopenia occurred in both groups at 4 h before leukocytosis was observed at 24 h with total white blood cell counts returning to baseline within 72 h. Plasma concentrations of tumor necrosis factor (TNF) and interleukin-10 (IL-10) increased within 1 h following the start of challenge and did not differ between groups. Serum haptoglobin and serum amyloid A concentrations increased within the 24 h following challenge and were elevated through 72 h but did not differ between groups. Eucalcemia during the acute systemic inflammatory response did not alter the TNF or IL-10 cytokine response, or the acute-phase protein SAA and haptoglobin response in this LPS challenge model; however, eucalcemia was associated with a more rapid decline in cortisol response and greater rumination time in the first 12 h following challenge. We did not find evidence that eucalcemia exacerbated the inflammatory response in early postpartum cows, but Ca administration may alter the clinical response to acute systemic inflammation.

Metabolic profile of transition period in ewes and its influence on passive immunity transference in lambs.

The intensification of ewe production, focusing on increasing prolificity, results in a higher incidence of metabolic disorders, especially in the transition period, which can lead to production losses with consequences for the health of the animals. The objective of this study was to evaluate the metabolic profile in transition period Lacaune ewes according to the parity and litter size born and its influence on the transference of passive immunity. Nineteen Lacaune ewes, with initial mean body weight of 76.36 ± 10.37kg (SD), kept in a semi-extensive system and receiving the same diet, were used. Ewes were classified according to parity (primiparous and multiparous) and the litter size born at parturition (1, 2, and 3). On days - 14, - 7, and - 4 of the expected date of parturition and on days 1, 4, 7, and 14days postpartum, blood sampling, the evaluation of the body condition score (BCS), and the weighing of animals were performed. Blood samples were taken from the lambs 48h after birth. Colostrum was collected up to 6h postpartum to determine the brix percentage. Serum concentrations of total plasma proteins (TPP), albumin, aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), paraoxonase (PON1), calcium (Ca), and magnesium (Mg) were evaluated. In lambs, the blood parameters evaluated were TPP, albumin, GGT, and PON1. Lamb plasma was used to estimate colostrum efficiency, brix percentage immunity, and total plasma protein (PPT). Productive data, pre- and postpartum metabolic variables for ewes, lambs, and those related to colostrum brix were analyzed. The BCS had a reduction (p < 0.0001) in the postpartum period, which is evidenced on days 7 and 14 (2.88 and 2.73, respectively). Serum concentration of BHB presented the highest concentrations in the prepartum period for ewes that gave birth to triplets, from day - 14, and for ewes that gave birth to twins on day - 4 (p = 0.0245). Serum concentration of NEFA demonstrated the highest value on day 14 in primiparous (1.07; p = 0.0402). Calcium had the lowest concentrations on day 1 (8.85mg/dl, p < 0.0001) and magnesium on day 3 (1.79mg/dl, p < 0.0001) postpartum. The multiparous with two lambs had higher brix percentages (30.5%), and the lowest value was observed in primiparous ewes that gave birth to a single lamb (27.06%; p = 0.0395). Triplet lambs had the lowest weight (3.73kg, p = 0.0007), and the best brix percentage in plasma was observed in twins (10.29%, p = 0.0174). Regardless of the parity, the ewes that presented the greatest metabolic challenge were those that gave birth to triplets, and these lambs presented the worst immunity and the lowest live weight. The quality of colostrum was influenced by the parity, and multiparous ewes that gave birth to triplets had the lowest brix percentage in the colostrum.

Abstract P308: The Determinants of Fasting and Post-Load Non-Esterified Fatty Acids in Older Adults: The Cardiovascular Health Study

Aim: Non-esterified fatty acids (NEFA) are associated with key cardiometabolic diseases of aging and are potential targets for prevention, but their population-level correlates remain uncertain. We sought to identify modifiable factors associated with higher fasting and post-load NEFA levels in older adults. Methods: We used linear multivariable regression models to determine the cross-sectional associations of demographic, anthropometric, lifestyle characteristics, and medication use with serum fasting and post-load NEFA concentrations amongst community-dwelling older adults enrolled in the Cardiovascular Health Study (n = 1,924). Results: In general, fasting NEFA levels demonstrated a broader set of determinants, while post-load NEFA were more consistently associated with metabolic factors. Waist circumference and weight were associated with higher fasting and post-load NEFA. Cigarette smoking and caffeine intake were associated with lower levels of both species, and moderate alcohol intake was associated with higher fasting levels whereas greater consumption was associated with lower post-load levels. Unique factors associated with higher fasting NEFA included female sex, higher age, loop and thiazide diuretic use and calcium intake, while factors associated with lower fasting levels included higher educational attainment, beta-blocker use, and protein intake. Hours spent sleeping during the daytime were associated with higher post-load NEFA, while DASH score were associated with lower levels. Conclusion: Fasting and post-load NEFA appear to have both common and unique modifiable risk factors, including sociodemographics, anthropometric, medications, and diet. Post-load NEFA were particularly sensitive to metabolic factors, while a broader range of determinants were associated with fasting levels. These factors warrant further study as targets for lowering levels of NEFA in older adults..

Association between Tryptophan Metabolism and Inflammatory Biomarkers in Dairy Cows with Ketosis

Dairy cows with ketosis have high circulating beta-hydroxybutyric acid (BHBA) concentrations alongside which inflammation is concomitantly developed. Tryptophan (Trp) is an essential amino acid that participates in the regulation of the inflammatory response. However, the association between Trp metabolism and inflammation in dairy cows with ketosis remains unclear. Therefore, blood samples from healthy (n = 10) and ketotic (n = 10) primiparous dairy cows were collected at the calving date and the day of ketosis diagnosis (7 days in milk (7 DIM)). Serum levels of non-esterified fatty acids (NEFA), BHBA, haptoglobin (HP), serum amyloid A (SAA), lipopolysaccharide, and cortisol were analyzed. Tryptophan and its metabolites were quantified using liquid chromatography-tandem mass spectrometry. At 7 DIM, the concentrations of NEFA, BHBA, HP, and SAA were higher and the levels of Trp, kynurenine (KYN), indoleacetic acid, indole-3-lactic acid, and 3-indoxyl sulfate were lower in the dairy cows with ketosis compared with those in the healthy cows. However, the KYN/Trp and melatonin/Trp ratios increased in the cows with ketosis. At the calving date, the serum lipopolysaccharide levels did not differ between the healthy and ketotic cows, whereas the levels of NEFA, HP, and cortisol increased in the ketotic cows. Correlation analysis showed that Trp deficiency and elevated Trp metabolism in the dairy cows occurred during ketosis. Overall, our results suggest that abnormal Trp metabolism may contribute to the pathogenesis of ketosis.

Association of maternal late-gestation lipid mobilization and their offspring's disease risk during the pre-weaned period and performance through first lactation: A cohort study in a dairy herd.

Excessive maternal lipid mobilization in late gestation may impact the immune function of the newborn. However, the long-term effects remain unknown. The objective was to explore associations between excessive maternal lipid mobilization in the last 2 weeks of gestation with offspring health and performance. A retrospective study was performed including 1,511 calves (heifer = 692, bull = 819) born between 2015 and 2020 in one MI farm. Plasma non-esterified fatty acids (NEFA) was measured from cows 7 to 14 d before calving. Calves were categorized in 2 groups based NEFA concentration: physiological lipid mobilization (PLM = 1,373; NEFA <0.3 mM) and excessive lipid mobilization (ELM = 138; NEFA ≥0.3 mM). Calf records were obtained from the herd's management software. Outcomes of interest were the hazard of pre-weaned digestive and respiratory disease, pre-weaned ADG, age at first breeding and calving, first lactation 305 d mature equivalent milk yield (305ME), and survival until first calving. Statistical models included dam NEFA category adjusted by year and season of birth, parity of the dam, and sex of the calf. Cox proportional analysis was used to determine the hazard of a pre-weaned health event, first breeding, and first calving. Linear regression was used to evaluate ADG and 305ME. The survival until first calving was analyzed with logistic regression. No difference was detected in the hazard of diarrhea (HRPLM vs. ELM = 1.06; 95% CI = 0.82-1.38) and respiratory disease (HRPLM vs. ELM = 1.29; 95% CI = 0.79-2.10) by NEFA category in the pre-weaned period. Also, no difference was detected for the LSM (±SE) of pre-weaned ADG (PLM = 0.77±1.55, ELM = 0.72±2.76 kg/d). In heifers, the hazard for first breeding favored the PLM group (HRPLM vs. ELM = 1.59; 95% CI = 1.18-2.12), with a reduced median age at first breeding (PLM = 400 d, 95% CI = 397-402; ELM = 412 d, 95% CI = 404-421). However, NEFA category was not associated with the hazard of first calving (HRPLM vs. ELM = 0.94; 95% CI = 0.69-1.27), first lactation 305ME (PLM = 16,665±165 kg; ELM = 16,256±532), the odds of presenting at least 1 health event in the first lactation (ORPLM vs. ELM = 0.78; 95% CI = 0.41-1.49), or the odds of leaving the herd before first calving (ORPLM vs. ELM = 1.21; 95% CI = 0.56-2.02). Overall, dam ELM affected the hazard of first breeding but no other indicators of health or long-term performance. However, associations between maternal lipid mobilization and calf outcomes cannot be excluded, as the NEFA cut-off used has not been established as a predictor of offspring health and performance.