Energetic metabolism, milk production, and inflammatory response of transition dairy cows fed rumen-protected glucose

Effects of dietary rumen-protected glucose level and taurine supplementation on weight change and oxidative stress state of yaks after transport

Rumen-protected glucose (RPG) and taurine (TAU) are crucial for the nutrition and physiology of ruminants, enhancing production performance and mitigating negative energy balance. This study aimed to assess the impact of RPG levels and TAU supplementation on the body weight, antioxidant capacity, immune function and stress responses in yaks before and after transport. Thirty-two healthy male yaks, aged 3 years and weighing 172.5 ± 10.2 kg, were randomly assigned to one of four dietary treatments: (1) low RPG and low TAU (LRLT), with 1% RPG and 5 g/d TAU; (2) low RPG and high TAU (LRHT), with 1% RPG and 15 g/d TAU; (3) high RPG and low TAU (HRLT), with 3% RPG and 5 g/d TAU; and (4) high RPG and high TAU (HRHT), with 3% RPG and 15 g/d TAU. The yaks were treated with the corresponding diet for 7 days, then received 9 h of transportation, and finally fed the same diet at their destination for 30 days. The weight was measured before and on days 0 and 30 after transport, and the plasma was collected before and on day 0, 10, and 30 after transport for analysis of biochemical, antioxidant, immune, and stress response indicators. We observed that transport increased plasma concentrations of total cholesterol, total protein, lactate dehydrogenase, creatine kinase, malondialdehyde, cortisol and lipopolysaccharides of yaks among treatments, while decreased their BW and plasma IL-10 concentration. Increasing TAU supplementation reduced weight loss (8.42 vs. 11.9 kg) and weight loss percent (4.83% vs. 6.87%) in yaks after transport. The concentration of MDA in plasma was lower in HRHT than in LRLT at day 0 after transport (p = 0.03). The activity of GSH-PX was higher in HRHT than in LRLT at day 10 after transport (p = 0.04). Concentrations of IL-10 at day 0 and 10 after transport was higher in HRHT than in LRLT and HRLT (p = 0.02, p = 0.01, respectively). With the increase of TAU supplementation, concentrations of IL-1β at day 30 after transport (p = 0.02), TNF-α at day 0 after transport (p = 0.02), COR at day 10 (p = 0.03) and 30 (p = 0.05) after transport as well as LPS at day 0 after transport (p = 0.04) decreased. In addition, concentrations of COR at day 0 after transport was lower in LRHT and HRHT than in LRLT (p = 0.03). Based on all the results, we demonstrated that increasing TAU supplementation levels reduced post-transport weight loss in yaks, improved their antioxidant capacity and immune function, and alleviated stress responses. Considering the effect of resistance to transport stress and costs, the optimal treatment identified in this study involved a diet containing 1% RPG and supplemented with 15 g/d TAU.

Effects of a multistrain Bacillus-based direct-fed microbial on gastrointestinal permeability and biomarkers of inflammation during and following feed restriction in mid-lactation Holstein cows

Objectives were to evaluate the effects of a multistrain Bacillus-based (Bacillus subtilis and Bacillus pumilus blend) direct-fed microbial (DFM) on production, metabolism, inflammation biomarkers and gastrointestinal tract (GIT) permeability during and following feed restriction (FR) in mid-lactation Holstein cows. Multiparous cows (n = 36; 138 ± 53 DIM) were randomly assigned to 1 of 3 dietary treatments: (1) control (CON; 7.5 g/d rice hulls; n = 12), (2) DFM10 (10 g/d Bacillus DFM, 4.9 × 109 cfu/d; n = 12) or 3) DFM15 (15 g/d Bacillus DFM, 7.4 × 109 cfu/d; n = 12). Before study initiation, cows were fed their respective treatments for 32 d. Cows continued to receive treatments during the trial, which consisted of 3 experimental periods (P): P1 (5 d) served as baseline for P2 (5 d), during which all cows were restricted to 40% of P1 DMI, and P3 (5 d), a "recovery" where cows were fed ad libitum. On d 4 of P1 and on d 2 and 5 of P2, GIT permeability was evaluated in vivo using the oral paracellular marker Cr-EDTA. As anticipated, FR decreased milk production, insulin, glucagon, and BUN but increased nonesterified fatty acids. During recovery, DMI rapidly increased on d 1 then subsequently decreased (4.9 kg) on d 2 before returning to baseline, whereas milk yield slowly increased but remained decreased (13%) relative to P1. The DFM10 cows had increased DMI and milk yield relative to DFM15 during P3 (10%). Overall, milk lactose content was increased in DFM cows relative to CON (0.10 percentage units), and DFM10 cows tended to have increased lactose yield relative to CON and DFM15 during P3 (8% and 10%, respectively). No overall treatment differences were observed for other milk composition variables. Circulating glucose was quadratically increased in DFM10 cows compared with CON and DFM15 during FR and recovery. Plasma Cr area under the curve was increased in all cows on d 2 (9%) and 5 (6%) relative to P1. Circulating LPS binding protein (LBP), serum amyloid A (SAA), and haptoglobin (Hp) increased in all cows during P2 compared with baseline (31%, 100%, and 9.0-fold, respectively). Circulating Hp concentrations continued to increase during P3 (274%). Overall, circulating LBP and Hp tended to be increased in DFM15 cows relative to DFM10 (29% and 81%, respectively), but no treatment differences were observed for SAA. Following feed reintroduction during P3, fecal pH initially decreased (0.62 units), but returned to baseline levels whereas fecal starch markedly increased (2.5-fold) and remained increased (82%). Absolute quantities of a fecal Butyryl-CoA CoA transferase (but) gene associated with butyrate synthesis, collected by fecal swab were increased in DFM10 cows compared with CON and DFM15 cows. In summary, FR increased GIT permeability, caused inflammation, and decreased production. Feeding DFM10 increased some key production and metabolism variables and upregulated a molecular biomarker of microbial hindgut butyrate synthesis, while DFM15 appeared to augment immune activation.

Intravenous lipopolysaccharide challenge in early- versus mid-lactation dairy cattle. II: The production and metabolic responses

Most immunometabolic research uses mid-lactation (ML) cows. Cows in early lactation (EL) are in a presumed state of immune suppression/dysregulation and less is known about how they respond to a pathogen. Study objectives were to compare the production and metabolic responses to i.v. LPS and to differentiate between the direct effects of immune activation and the indirect effects of illness-induced hypophagia in EL and ML cows. Cows in EL (n = 11; 20 ± 2 DIM) and ML (n = 12; 131 ± 31 DIM) were enrolled in a 2 × 2 factorial design containing 2 experimental periods (P). During P1 (3 d), cows were fed ad libitum and baseline data were collected. At the initiation of P2 (3 d), cows were randomly assigned to 1 of 2 treatments by lactation stage (LS): (1) EL (EL-LPS; n = 6) or ML (ML-LPS; n = 6) cows administered i.v. a single bolus of 0.09 µg LPS/kg of BW; Escherichia coli O55:B5 or (2) pair-fed (PF) EL (EL-PF; n = 5) or ML (ML-PF; n = 6) cows administered i.v. saline. Administering LPS decreased DMI and this was more severe in EL-LPS than ML-LPS cows (34% and 11% relative to baseline, respectively). By design, P2 DMI patterns were similar in the PF groups compared with their LPS counterparts. Milk yield decreased following LPS (42% on d 1 relative to P1) and despite an exacerbated decrease in EL-LPS cows on d 1 (25% relative to ML-LPS), remained similar between LS from d 2 to 3. The EL-LPS cows had increased milk fat content, but no difference in protein and lactose percentages compared with ML-LPS cows. Further, cumulative ECM yield was increased (21%) in EL-LPS compared with ML-LPS cows. During P2, EL-LPS cows had a more intense increase in MUN and BUN than ML-LPS and EL-PF cows. Administering LPS did not cause hypoglycemia in either EL-LPS or ML-LPS cows, but glucose was increased (33%) in EL-LPS compared with EL-PF. Hyperinsulinemia occurred after LPS, and insulin was further increased in ML-LPS than EL-LPS cows (2.2-fold at 12 h peak). During P2, circulating glucagon increased only in EL-LPS cows (64% relative to all other groups). Both EL groups had increased NEFA at 3 and 6 h after LPS from baseline (56%), but NEFA in EL-LPS cows gradually returned to baseline thereafter and were reduced relative to EL-PF until 36 h (50% from 12 to 24 h). Alterations in BHB did not differ between ML groups, but EL-LPS had reduced BHB compared with EL-PF from 24 to 72 h (51%). Results indicate that there are distinct LS differences in the anorexic and metabolic responses to immune activation. Collectively, EL cows are more sensitive to the catabolic effects of LPS than ML cows, but these exacerbated metabolic responses appear coordinated to fuel an augmented immune system while simultaneously supporting milk synthesis.

Differences of serum glucose and lipid metabolism and immune parameters and blood metabolomics regarding the transition cows in the antepartum and postpartum period

This study aims to investigate differences in metabolism regarding the transition cows. Eight cows were selected for the test. Serum was collected on antepartum days 14th (ap14) and 7th (ap7) and postpartum days 1st (pp1), 7th (pp7), and 14th (pp14) to detect biochemical parameters. The experiment screened out differential metabolites in the antepartum (ap) and postpartum (pp) periods and combined with metabolic pathway analysis to study the relationship and role between metabolites and metabolic abnormalities. Results: (1) The glucose (Glu) levels in ap7 were significantly higher than the other groups (p < 0.01). The insulin (Ins) levels of ap7 were significantly higher than pp7 (p = 0.028) and pp14 (p < 0.01), and pp1 was also significantly higher than pp14 (p = 0.016). The insulin resistance (HOMA-IR) levels of ap7 were significantly higher than ap14, pp7, and pp14 (p < 0.01). The cholestenone (CHO) levels of ap14 and pp14 were significantly higher than pp1 (p < 0.01). The CHO levels of pp14 were significantly higher than pp7 (p < 0.01). The high density lipoprotein cholesterol (DHDL) levels of pp1 were significantly lower than ap14 (p = 0.04), pp7 (p < 0.01), and pp14 (p < 0.01), and pp14 was also significantly higher than ap14 and ap7 (p < 0.01). (2) The interferon-gamma (IFN-γ) and tumor necrosis factor α (TNF-α) levels of ap7 were significantly higher than pp1 and pp7 (p < 0.01); the immunoglobulin A (IgA) levels of pp1 were significantly higher than ap7 and pp7 (p < 0.01); the interleukin-4 (IL-4) levels of pp7 were significantly higher than ap7 and pp1 (p < 0.01), the interleukin-6 (IL-6) levels of ap7 and pp1 were significantly higher than pp7 (p < 0.01). (3) Metabolomics identified differential metabolites mainly involved in metabolic pathways, such as tryptophan metabolism, alpha-linolenic acid metabolism, tyrosine metabolism, and lysine degradation. The main relevant metabolism was concentrated in lipid and lipid-like molecules, organic heterocyclic compounds, organic acids, and their derivatives. The results displayed the metabolic changes in the transition period, which laid a foundation for further exploring the mechanism of metabolic abnormalities in dairy cows in the transition period.

Effects of cashew nut shell extract supplementation on production, rumen fermentation, metabolism, and inflammatory biomarkers in transition dairy cows

Cashew nut shell extract (CNSE) is a byproduct of the cashew nut industry, containing bioactive compounds that alter rumen fermentation patterns. Therefore, study objectives were to evaluate the effects of CNSE (59% anacardic acid and 18% cardol) on production, rumen fermentation variables, metabolism, and inflammation in transition dairy cows. A total of 51 multiparous Holstein cows were used in a randomized design and assigned to treatment based on their previous 305-d mature equivalent milk and parity. Cows were assigned to 1 of 2 treatments 21 d before expected calving: (1) CON (control diet; n = 17) or (2) CNSE-5.0 (control diet and 5.0 g/d CNSE granule [containing 50% CNSE]; n = 34). Following parturition, 17 cows (preselected at initial treatment assignment) from the CNSE-5.0 treatment were reallocated into a third treatment group: CNSE-2.5 (control diet and 2.5 g/d CNSE granule; n = 17), resulting in 3 total treatments postpartum: (1) CON, (2) CNSE-2.5, and (3) CNSE-5.0. Prepartum rumen pH was unaltered by treatment; however, postpartum rumen pH was increased (0.31 units) in CNSE cows relative to CON. Prepartum rumen ammonia N concentration tended to be decreased (34%) in CNSE-5.0 cows compared with CON, and there tended to be a quadratic effect on postpartum ammonia N, as it was decreased in CNSE-2.5 compared with CON and CNSE-5.0. Prepartum dry matter intake (DMI) was unaffected by treatment; however, postpartum DMI was increased (8%) in CNSE cows relative to CON. No treatment differences were observed in pre- or postpartum digestibility measurements. Milk and protein yields from cows fed CNSE tended to be increased (6% and 7%, respectively) relative to CON. No treatment differences were detected for energy-corrected milk, feed efficiency, body weight, body condition score, energy balance, milk composition, milk urea nitrogen, or somatic cell count. Prepartum fecal pH decreased (0.12 units) in CNSE-5.0 cows relative to CON cows but was similar between treatments postpartum. Supplementing CNSE did not affect prepartum glucose, nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), or insulin. However, prepartum circulating blood urea nitrogen tended to be decreased and glucagon was decreased in CNSE-5.0 cows compared with CON (9 and 20%, respectively). Additionally, CNSE supplementation decreased glucose and insulin concentrations postpartum relative to CON cows (6% and 20%, respectively). Quadratic effects were detected for postpartum circulating NEFA and BHB such that their levels were increased in CNSE-2.5 cows relative to CON and CNSE-5.0. Pre- and postpartum circulating serum amyloid A, lipopolysaccharide-binding protein, and haptoglobin were unaffected by treatment. Overall, CNSE influenced some key rumen fermentation variables, altered postabsorptive metabolism, and increased production parameters in transition dairy cows.

Effects of Bacillus subtilis PB6 supplementation on production, metabolism, inflammatory biomarkers, and gastrointestinal tract permeability in transition dairy cows

Objectives were to evaluate the effects of Bacillus subtilis PB6 (BSP) on gastrointestinal tract permeability, metabolism, inflammation, and production parameters in periparturient Holstein cows. Multiparous cows (n = 48) were stratified by previous 305-d mature equivalent milk yield and parity and assigned to 1 of 2 top-dressed dietary treatments 21 d before expected calving through 63 DIM: (1) control (CON; 13 g/d calcium carbonate; n = 24) or (2) BSP (13 g/d BSP; CLOSTAT, Kemin Industries, Des Moines, IA; n = 24). Gastrointestinal tract permeability was evaluated in vivo using the oral paracellular marker chromium (Cr)-EDTA. Effects of treatment, time, and treatment × time were assessed using PROC MIXED of SAS version 9.4 (SAS Institute Inc.). Prepartum dry matter intake (DMI) was unaffected by treatment; however, BSP supplementation decreased postpartum DMI relative to CON (0.7 kg). Milk yield, energy-corrected milk (ECM), fat-corrected milk (FCM), and solids-corrected milk (SCM) increased in BSP cows compared with CON (1.6, 1.8, 1.6, and 1.5 kg, respectively). Decreased DMI and increased production collectively improved feed efficiency of milk yield, ECM, FCM, and SCM for BSP cows (6, 5, 5, and 5%, respectively). No treatment differences were observed for concentrations of milk fat, protein, total solids, somatic cell count, somatic cell score, body weight, or body condition score. Milk urea nitrogen concentrations decreased (5%), whereas milk protein and lactose yield increased (5 and 2%, respectively) with BSP supplementation. Prepartum fecal pH did not differ among treatments; conversely, postpartum fecal pH was increased with BSP supplementation (0.09 pH units). Prepartum fecal dry matter percentage, starch, acetic acid, propionic acid, butyric acid, and ethanol did not differ among treatments. Postpartum concentrations of the aforementioned fecal parameters were also unaffected by treatment, but fecal propionic acid concentration was decreased (24%) in BSP cows relative to CON. Circulating glucose, nonesterified fatty acids, l-lactate, and insulin were similar between treatments both pre- and postpartum. Prepartum β-hydroxybutyrate (BHB) did not differ between treatments, but postpartum BSP supplementation decreased (21%) circulating BHB relative to CON. Regardless of treatment, inflammatory markers (serum amyloid A and haptoglobin) peaked immediately following parturition and progressively decreased with time, but this pattern was not influenced by treatment. Postpartum lipopolysaccharide binding protein tended to be decreased on d 3 in BSP relative to CON cows (19%). Neither treatment nor time affected Cr-EDTA area under the curve. In summary, supplementing BSP had no detectable effects prepartum, but increased key postpartum production parameters. Bacillus subtilis PB6 consistently increased postpartum fecal pH and decreased fecal propionate concentrations but did not appear to have an effect on gastrointestinal tract permeability.

Review of the Heat Stress-Induced Responses in Dairy Cattle

In the dairy cattle sector, the evaluation of the effects induced by heat stress is still one of the most impactful and investigated aspects as it is strongly connected to both sustainability of the production and animal welfare. On the other hand, more recently, the possibility of collecting a large dataset made available by the increasing technology diffusion is paving the way for the application of advanced numerical techniques based on machine learning or big data approaches. In this scenario, driven by rapid change, there could be the risk of dispersing the relevant information represented by the physiological animal component, which should maintain the central role in the development of numerical models and tools. In light of this, the present literature review aims to consolidate and synthesize existing research on the physiological consequences of heat stress in dairy cattle. The present review provides, in a single document, an overview, as complete as possible, of the heat stress-induced responses in dairy cattle with the intent of filling the existing research gap for extracting the veterinary knowledge present in the literature and make it available for future applications also in different research fields.

Evaluating the Rumen Degradation of Novel Protected Gelatin Capsules Containing Fish Oil Fed to Lactating Dairy Cows

The objective of this study was to assess the effects of feeding gelatin capsules containing fish oil, treated with alcoholic solutions of flavoring agents followed by drying, on lactation performance, rumen fatty acids content and milk enrichment of fatty acids. In Trial 1, four multiparous ruminally fistulated Holstein cows were randomly assigned to one of four dietary treatments sequences in a 4 × 4 Latin square design. Treatments consisted of (1) Control with no capsules, (2) Control plus 200 untreated capsules per cow/day, mixed with the TMR, (3) Control plus 200 treated capsules per cow/day placed directly into the rumen, (4) Control plus 200 treated capsules per cow/day, mixed with the TMR. In Trial 2, three fistulated Holstein and three fistulated Jersey multiparous cows were randomly assigned to three dietary treatments sequences in a replicated 3 × 3 Latin square design. Treatments consisted of (1) Control with no capsules fed to the cows, (2) Control plus 180 untreated capsules per cow/day, (3) Control plus 180 treated capsules per cow/day. Compared to control, feeding fish oil capsules significantly (Trial 1) or numerically (Trial 2) reduced milk fat concentration and yield. Furthermore, in both trials, the feeding of untreated or treated capsules had no effect on animal performance or milk composition. In both trials, compared to controls, supplementing the diet with fish oil capsules consistently increased total trans C18:1 isomers and DHA concentration in the rumen and milk fat. However, for both trials, capsule protection treatment had a minimal effect on the concentration of any of the reported rumen and milk fatty acids. When assessed under laboratory control conditions, due to water absorption, the treated capsule weight was increased by 40% while resistance to pressure decreased by 84% after 2 h of incubation in water. The results of this study suggest that due to a reduction in the capsule shell's resistance to abrasion, treated capsules marginally prevented the release of fish oil in the rumen.

[The lipidosis of the liver of dairy cows: Part 1 - Role of insulin and the Growth Hormone-IGF-1 axis]

Lipidosis of the liver of dairy cows is a metabolic disease known since many years and is caused by an uptake of nonesterified fatty acids (NEFA) into the liver cells, limited metabolism of NEFA (oxidation and production of β-hydroxybutyrate), and resynthesis in relation to a low efflux as triglyceride (TG). The pathogenesis of lipidosis includes a) an augmented release of NEFA by mobilisation of adipose tissue, b) uptake of NEFA into the liver cells, c) metabolism of NEFA and d) re-synthesis of triglyceride and e) an efflux of TG as very low density lipoprotein (VLDL). The steps a-e are postpartum modified by hormones as an increase of growth hormone, a pronounced insulin resistance in combination with a decreased insulin and of IGF-1 concentrations. These hormonal changes are related to an uncoupling of the growth hormone-IGF-1-axis with enhanced lipolysis and consequences mentioned above. These alterations are associated with inflammation, oxidative and endoplasmatic stress. The metabolic and hormonal alterations are the result of the selection of dairy cows primarily for milk production without adequate food intake with the consequence of lipidosis, ketosis and further health risks (production diseases).

Effects of hindgut acidosis on inflammation, metabolism, and productivity in lactating dairy cows fed a high-fiber diet

Hindgut acidosis (HGA) may cause or contribute to the inflammatory state of transition dairy cows by compromising the intestinal barrier. Previous experiments isolating the effects of HGA on inflammatory metrics have generated inconsistent results, which may be explained by acclimation to low- versus high-starch diets. Thus, study objectives were to evaluate the effects of HGA in cows acclimated to a high-fiber diet. Ten rumen-cannulated Holstein cows (38 ± 5 kg/d milk yield; 243 ± 62 d in milk; 1.6 ± 1.1 parity; 663 ± 57 kg of body weight) were enrolled in a study with 2 experimental periods (P). Before P1, all cows were acclimated to a high-fiber, low-starch diet (50% neutral detergent fiber, 15% starch) for 17 d. During P1 (4 d), baseline data were collected for use as covariates. During P2 (7 d), cows were assigned to 1 of 2 abomasal infusion treatments: (1) control (CON; 1.5 L of H₂O/infusion; n = 4) or (2) starch infused (ST; 1 kg of corn starch + 1.5 L of H₂O/infusion; n = 6). All cows were infused with their respective treatments every 6 h daily at 0000, 0600, 1200, and 1800 h, such that ST cows received a total of 4 kg of corn starch/d. Starch infusions successfully induced HGA, as indicated by a marked decrease in fecal pH (1.2 units) relative to CON. However, in contrast to our assumptions, infusing starch had no deleterious effects on milk yield, energy-corrected milk, or voluntary dry matter intake during P2. Milk protein, lactose, their yields, fat yield, and somatic cell score remained unaffected by starch infusions, whereas milk fat content and urea nitrogen were decreased in ST relative to CON (8 and 17%, respectively). Overall, circulating glucose and β-hydroxybutyrate concentrations remained similar between treatments, but starch infusions decreased nonesterified fatty acids on d 3 relative to CON. Blood urea nitrogen decreased throughout P2 in ST (38%) relative to CON. In contrast to our hypothesis, HGA did not alter circulating serum amyloid A or lipopolysaccharide binding protein, nor did it affect rectal temperature. In summary, HGA moderately altered metabolism but did not affect production or elicit an inflammatory response in lactating dairy cows previously acclimated to a high-fiber diet.

Effects of hindgut acidosis on production, metabolism, and inflammatory biomarkers in feed-restricted lactating dairy cows

Study objectives were to evaluate the effects of hindgut acidosis (HGA) on production, metabolism, and inflammation in feed-restricted (FR) dairy cows. Twelve rumen-cannulated cows were enrolled in a study with 3 experimental periods (P). During P1 (5 d), baseline data were collected. During P2 (2 d), all cows were FR to 40% of their baseline feed intake. During P3 (4 d), cows remained FR and were assigned to 1 of 2 abomasal infusion treatments: (1) control (FR-CON; 6 L of H₂O/d; n = 6) or (2) starch (FR-ST; 4 kg of corn starch + 6 L of H₂O/d; n = 6). Respective treatments were partitioned into 4 equal doses (1 kg of corn starch/infusion) and were abomasally infused daily at 0000, 0600, 1200, and 1800 h. All 3 P were analyzed independently and the effects of treatment, time, and treatment × time were assessed using PROC MIXED, and P1 and P2 data were analyzed using the treatments cows were destined to be assigned to during P3. Hallmark production and metabolic responses to feed restriction were observed in both treatments, including decreased milk yield (39%) and energy-corrected milk (32%), circulating glucose (12%), insulin (71%), and increased circulating nonesterified fatty acids (3.2-fold) throughout both P2 and P3, relative to P1. However, despite a marked reduction in fecal pH (0.96 units), the aforementioned metrics were unaltered by HGA. During P3, starch infusions increased circulating β-hydroxybutyrate, with the most pronounced increase occurring on d 2 (81% relative to FR-CON). Further, feed restriction decreased blood urea nitrogen during P2 (17% relative to P1) in both treatments, and this was exacerbated by starch infusions during P3 (31% decrease relative to FR-CON). In contrast to our hypothesis, neither feed restriction nor HGA increased circulating acute-phase proteins (serum amyloid A and lipopolysaccharide binding protein) relative to P1 or FR-CON, respectively. Thus, despite marked reductions in fecal pH, prior feed restriction did not appear to increase the susceptibility to HGA.

Effects of hindgut acidosis on metabolism, inflammation, and production in dairy cows consuming a standard lactation diet

Postruminal intestinal barrier dysfunction caused by excessive hindgut fermentation may be a source of peripheral inflammation in dairy cattle. Therefore, the study objectives were to evaluate the effects of isolated hindgut acidosis on metabolism, inflammation, and production in lactating dairy cows. Five rumen-cannulated lactating Holstein cows (32.6 ± 7.2 kg/d of milk yield, 242 ± 108 d in milk; 642 ± 99 kg of body weight; 1.8 ± 1.0 parity) were enrolled in a study with 2 experimental periods (P). During P1 (4 d), cows were fed ad libitum a standard lactating cow diet (26% starch dry matter) and baseline data were collected. During P2 (7 d), all cows were fed the same diet ad libitum and abomasally infused with 4 kg/d of pure corn starch (1 kg of corn starch + 1.25 L of H₂O/infusion at 0600, 1200, 1800, and 0000 h). Effects of time (hour relative to the first infusion or day) relative to P1 were evaluated using PROC MIXED in SAS (version 9.4; SAS Institute Inc.). Infusing starch markedly reduced fecal pH (5.84 vs. 6.76) and increased fecal starch (2.2 to 9.6% of dry matter) relative to baseline. During P2, milk yield, milk components, energy-corrected milk yield, and voluntary dry matter intake remained unchanged. At 14 h, plasma insulin and β-hydroxybutyrate increased (2.4-fold and 53%, respectively), whereas circulating glucose concentrations remained unaltered. Furthermore, blood urea nitrogen increased at 2 h (23%) before promptly decreasing below baseline at 14 h (13%). Nonesterified fatty acids tended to decrease from 2 to 26 h (40%). Circulating white blood cells and neutrophils increased on d 4 (36 and 73%, respectively) and somatic cell count increased on d 5 (4.8-fold). However, circulating serum amyloid A and lipopolysaccharide-binding protein concentrations were unaffected by starch infusions. Despite minor changes in postabsorptive energetics and leukocyte dynamics, abomasal starch infusions and the subsequent hindgut acidosis had little or no meaningful effects on biomarkers of immune activation or production variables.

Rumen-protected glucose hastens uterine involution and increases numbers of ovarian follicles in early post-partum dairy cows

The primary objectives were to investigate the effects of feeding a new rumen-protected glucose (RPG) on uterine involution and ovarian follicular dynamics in recently calved dairy cattle. From 4 to 30 days after calving, 16 Holsteins (first to third lactation, mean parity 1.75) were randomly assigned to be fed either a basal diet top-dressed with either 600 g RPG (RPG group) or 600 g of the coating material and glucose (CONT group). Based on transrectal ultrasonography, conducted every 3 days starting 20 days after calving, the interval from calving to complete uterine involution was shorter in RPG versus CONT (27.1 vs. 30.4 days, p < .01). Furthermore, based on transrectal ultrasonography conducted every 2 days, cattle fed RPG had smaller (3.0-4.9 mm) ovarian follicles (2.96 vs. 0.9, p < .001) and more total follicles (5.26 vs. 2.85, p < .01). Feeding RPG had increased serum insulin concentrations (4.59 ± 0.54 vs. 3.13 ± 0.57, p < .05), but had no significant effects on serum glucose concentrations, dry matter intake or milk yield. In conclusion, we inferred that cattle fed RPG had increased glucose turnover that was responsible for higher insulin concentrations, faster uterine involution, and more ovarian follicles.

Metabolism-epigenetic interactions on in vitro produced embryos

Metabolism and epigenetics, which reciprocally regulate each other in different cell types, are fundamental aspects of cellular adaptation to the environment. Evidence in cancer and stem cells has shown that the metabolic status modifies the epigenome while epigenetic mechanisms regulate the expression of genes involved in metabolic processes, thereby altering the metabolome. This crosstalk occurs as many metabolites serve as substrates or cofactors of chromatin-modifying enzymes. If we consider the intense metabolic dynamic and the epigenetic remodelling of the embryo, the comprehension of these regulatory networks will be important not only for understanding early embryonic development, but also to determine in vitro culture conditions that support embryo development and may insert positive regulatory marks that may persist until adult life. In this review, we focus on how metabolism may affect epigenetic reprogramming of the early stages of development, in particular acetylation and methylation of histone and DNA. We also present other metabolic modifications in bovine embryos, such as lactylation, highlighting the promising epigenetic and metabolic targets to improve conditions for in vitro embryo development.

Changes in Acute-Phase Proteins in Plasma during the Periparturient Period of Dairy Goats

The present study was conducted regarding four acute-phase proteins (APPs) including C-reactive protein (CRP), ceruloplasmin (CP), serum amyloid A (SAA), and haptoglobin (HP) in dairy goats during the periparturient period. The aim of this study was to detect the changes in APPs in plasma during the periparturient period of healthy dairy goats. Guanzhong dairy goats with no other symptoms (n = 15) were selected on the basis of their blood calcium (Ca) and β-hydroxybutyrate (BHBA) concentration. The plasma was collected once a week for ±3 weeks delivery. The concentrations of the four APPs mentioned above were determined using goat-specific ELISA kits. The results showed the CRP level in plasma decreased from 3 weeks to 1 week antepartum and increased later until 1 week postpartum and then decreased to a similar level with antepartum between 1 and 3 weeks postpartum. The content of CP showed a decline in 3 weeks before parturition and an upward trend between 1 week antepartum and 3 weeks postpartum. The SAA concentration decreased from 3 weeks antepartum to 2 weeks postpartum and rebounded later. The level of HP decreased during 3 weeks before parturition and increased until 1 week postpartum, then reached a stable value. Clear variation range and rules of APPs contribute to perinatal health monitoring of dairy goats.

Comparative biochemical profiles, utero-ovarian function, and fertility of the postpartum buffalo with and without subclinical endometritis

In postpartum buffaloes, the process of uterine involution and changes in blood metabolic profile has not been studied in relation to development of subclinical endometritis (SCE). In this study, buffaloes (n = 100) approaching calving were identified. Weekly blood samples were collected on the day of calving up to 6 weeks post-calving. The diameter of uterine horns and onset of ovarian cyclicity (corpus luteum) were recorded through ultrasonography. On the basis of polymorphonuclear cell (PMN) cell count in endometrial cytology at days 45-50 postpartum, buffaloes were divided into two groups, viz., with SCE (> 5% PMN; n = 38) and without SCE (≤ 5% PMN; n = 62). Buffaloes with SCE took longer (P < 0.05) time to complete uterine involution and had larger (P < 0.05) uterine horn diameter between 3rd and 6th weeks postpartum and lower prostaglandin F2α metabolite (PGFM) concentration on the day of calving (P < 0.05) and 1 week (P < 0.001) post-calving than without SCE group. Buffaloes with SCE had lower (P < 0.001) concentration of glucose at weeks 2 and 3, higher (P < 0.001) β-hydroxybutyric acid (BHBA) at week 3, and lower serum albumin concentration throughout the sampling period (P < 0.05 to 0.001) except at 1 week post-calving as compared to without SCE group. The urea concentration was significantly lower (P < 0.05 to 0.001) in buffaloes with SCE from 4 weeks post-calving onwards than without SCE group. The calcium concentration was lower in buffaloes with SCE at weeks 5 (P < 0.001) and 6 (P < 0.05) postpartum, whereas the concentration of magnesium and phosphorus was uniform between the two groups. No significant (P > 0.05) difference in onset of ovarian cyclicity between the 2 groups was observed, whereas buffaloes with SCE had longer (P = 0.001) median days open (141 days) than their counterpart (117 days). The first service conception rate, cumulative pregnancy rate, and pregnancy rate at 150 days postpartum were lower (P < 0.05) in buffaloes with SCE than without SCE group. In summary, higher BHBA and lower serum concentrations of glucose, albumin, urea, and calcium control onset of subclinical endometritis which in turn has negative impact on fertility of buffaloes.