Supplementing N-carbamoylglutamate in late gestation increases newborn calf weight by enhanced placental expression of mTOR and angiogenesis factor genes in dairy cows

The objective of this study was to investigate whether supplementation with N-carbamoylglutamate (NCG) to cows during late gestation alters uteroplacental tissue nutrient transporters, calf metabolism and newborn weight. Thirty multiparous Chinese Holstein cows were used in a randomized complete block design experiment. During the last 28 d of pregnancy, cows were fed a diet without (CON) or with NCG (20 g/d per cow). The body weight of calves was weighed immediately after birth. Placentome samples were collected at parturition and used to assess mRNA expression of genes involved in transport of arginine, glucose, fatty acid and angiogenesis factors, as well as the mammalian target of rapamycin (mTOR) pathway. Blood samples of calves before colostrum consumption were also collected for the detection of plasma parameters, amino acids (AA) and metabolomics analysis. The newborn weight (P = 0.02) and plasma Arg concentration of NCG-calves was significantly higher (P = 0.05) than that of CON-calves, and the plasma concentrations of urea nitrogen tended to be lower (P = 0.10) in the NCG group. The mRNA abundance of genes involved in glucose transport (solute carrier family 2 member 3 [SLC2A3], P < 0.01), angiogenesis (nitric oxide synthase 3 [NOS3], P = 0.02), and mTOR pathway (serine/threonine-protein kinase 1 [AKT1], P = 0.10; eukaryotic translation initiation factor 4B pseudogene 1 [EIF4BP1], P = 0.08; EIF4EBP2, P = 0.04; and E74-like factor 2 [ELF2], P = 0.03) was upregulated in the placentome of NCG-supplemented cows. In addition, 17 metabolites were significantly different in the placentome of NCG-supplemented cows compared to non-supplemented cows, and these metabolites are mainly involved in arginine and proline metabolism, alanine, aspartate and glutamate metabolism, and citrate cycle. In summary, the increased body weight of newborn calves from the NCG supplemented dairy cows may be attributed to the increased angiogenesis and uteroplacental nutrient transport and to the activated mTOR signal pathway, which may result in the increased nutrient supply to the fetus, and improved AA metabolism and urea cycle of the fetus.

Mass-spec-based urinary metabotyping around parturition identifies screening biomarkers for subclinical mastitis in dairy cows

The objective of this study was to determine urinary metabotypes of dairy cows prior to, during, and after diagnosis of subclinical mastitis (SCM). Twenty controls (CON) and 6 cows with SCM were included in the study. DI/LC-MS/MS was used to measure 186 metabolites in the urine at -8 and - 4 wks prepartum, disease diagnosis, and at +4 and + 8 wks postpartum. Results showed a total of 24 and 27 metabolites that differentiated SCM and CON cows at -8 and - 4 wks, respectively, with 5 top metabolites having an accuracy to predict SCM of 1.0, for both time point. Altered metabolites included several acylcarnitines (ACs), phosphatidylcholines (PCs), amino acids (AAs), and biogenic amines (BAs). During SCM diagnosis week there were a total of 22 metabolites that differentiated the SCM and CON cows including 13 ACs, 5 AAs, hexose, and phosphatidylethanolamine ae C44:3. The top 5 metabolites Symmetric dimethylarginine (SDMA), methylglutarylcarnitine, dodecanoylcarnitine, phosphatidylethanolamine ae C42:1, and phosphatidylethanolamine ae C42:0 showed an AUC of 1.0. Metabolite alterations continued at +4 and + 8 wks postpartum with 13 (9 ACs, 3 glycerophospholipids, and 1 BA) and 28 metabolites (14 ACs, 2 glycerophospholipids, hexose, 8 AAs, and 2 BAs) that differentiated the two groups, respectively. The top 5 most important metabolites, for both time points, showed AUCs of 1.0. Results of this study showed that typical urinary metabotypes preceded SCM event starting from -8 and - 4 wks prepartum. Metabotypes typical of SCM continued to be present during the week of SCM and at +4 and + 8 wks postpartum. These data show that the urine of dairy cows can be used with very high accuracy for screening dairy cows for susceptibility to SCM prior to entering into the dry off period and a potential new pen-side test can help dairy producers and veterinarians to make selective treatments.

Urine metabolic fingerprinting can be used to predict the risk of metritis and highlight the pathobiology of the disease in dairy cows

INTRODUCTION

Metritis is an uterine pathology that causes economic losses for the dairy industry. It is associated with lower reproductive efficiency, increased culling rates, decreased milk production and increased veterinary costs.

OBJECTIVES

To gain a more detailed view of the urine metabolome and to detect metabolite signature in cows with metritis. In addition, we aimed to identify early metabolites which can help to detect cows at risk to develop metritis in the future.

METHODS

We used nuclear magnetic resonance spectroscopy starting at 8 and 4 weeks prior to the expected day of parturition, during the week of diagnosis of metritis, and at 4 and 8 weeks after diagnosis of metritis in Holstein dairy cows.

RESULTS

At 8 weeks before parturition, pre-metritic cows had a total of 30 altered metabolites. Interestingly, 28 of them increased in urine when compared with control cows (P < 0.05). At 4 weeks before parturition, 34 metabolites were altered. At the week of diagnosis of metritis a total of 20 metabolites were altered (P < 0.05). The alteration continued at 4 and 8 weeks after diagnosis.

CONCLUSIONS

The metabolic fingerprints in the urine of pre-metritic and metritic cows point toward excretion of multiple amino acids, tricarboxylic acid cycle metabolites and monosaccharides. Combination of galactose, leucine, lysine and panthotenate at 8 weeks before parturition might serve as predictive biomarkers for metritis.

Adipose tissue lipolysis and remodeling during the transition period of dairy cows

Elevated concentrations of plasma fatty acids in transition dairy cows are significantly associated with increased disease susceptibility and poor lactation performance. The main source of plasma fatty acids throughout the transition period is lipolysis from adipose tissue depots. During this time, plasma fatty acids serve as a source of calories mitigating the negative energy balance prompted by copious milk synthesis and limited dry matter intake. Past research has demonstrated that lipolysis in the adipose organ is a complex process that includes not only the activation of lipolytic pathways in response to neural, hormonal, or paracrine stimuli, but also important changes in the structure and cellular distribution of the tissue in a process known as adipose tissue remodeling. This process involves an inflammatory response with immune cell migration, proliferation of the cellular components of the stromal vascular fraction, and changes in the extracellular matrix. This review summarizes current knowledge on lipolysis in dairy cattle, expands on the new field of adipose tissue remodeling, and discusses how these biological processes affect transition cow health and productivity.

Occurrence of retained placenta is preceded by an inflammatory state and alterations of energy metabolism in transition dairy cows

Background

Failure to expel fetal membranes within 24 h of calving is a pathological condition defined as retained placenta (RP). The objective of this investigation was to evaluate whether there are alterations in several selected serum variables related to innate immunity and carbohydrate and lipid metabolism that precede occurrence of RP in transition Holstein dairy cows.

Methods

One hundred multiparous Holstein dairy cows were involved in the study. Blood samples were collected from the coccygeal vein during the −8 to +4 wks around parturition, once per week before the morning feeding. Six healthy control cows (CON) and 6 cows with RP were selected and serum samples at −8, −4, time of diagnosis of disease, and +4 wks relative to parturition were used for analyses. All samples were analyzed for lactate, non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrosis factor (TNF), haptoglobin (Hp), and serum amyloid A (SAA).

Results

Cows with RP had greater concentrations of serum lactate, IL-1, IL-6, TNF, and SAA in comparison with CON cows. Intriguingly, elevated concentrations of all five variables were observed at −8 and −4 wks before the occurrence of RP compared to healthy cows. Cows with RP also had lower DMI and milk production vs CON animals; however milk composition was not affected by RP.

Conclusions

Cows with RP showed an activated innate immunity 8 wks prior to diagnosis of disease. Overall results suggest that serum IL-1, IL- 6, and TNF, and lactate can be used as screening biomarkers to indicate cows that might have health issues during the transition period.