Search

The supply of methionine (Met) in late pregnancy can alter mRNA abundance of genes associated with metabolism and immune response in liver and polymorphonuclear leukocytes (PMN) of the neonatal calf. Whether prenatal supply of Met elicits postnatal effects on systemic inflammation and innate immune response of the calf is not well known. We investigated whether enhancing the maternal supply of Met via feeding ethyl-cellulose rumen-protected Met (RPM) was associated with differences in calf innate immune response mRNA abundance in PMN and systemic indicators of inflammation during the first 50 d of life. Calves (n = 14 per maternal diet) born to cows fed RPM at 0.09% of diet dry matter per day (MET) for the last 28 ± 2 d before calving or fed a control diet with no added Met (CON) were used. Blood for biomarker analysis and isolation of PMN for innate immune function assays and mRNA abundance was harvested at birth (before colostrum feeding) and at 7, 21 and 50 d of age. Whole blood was challenged with enteropathogenic bacteria (Escherichia coli 0118:H8) and phagocytosis and oxidative burst of neutrophils and monocytes were quantified via flow cytometry. Although concentration of haptoglobin and activity of myeloperoxidase among calves from both maternal groups increased markedly between 0 and 7 d of age followed by a decrease to baseline at d 21 the responses were lower in MET compared with CON calves. Nitric oxide concentration decreased markedly between 0 and 7 d regardless of maternal group but MET calves tended to have lower overall concentrations during the study. In vitro phagocytosis in stimulated neutrophils increased markedly over time in both CON and MET calves but responses were overall greater in MET calves. Oxidative burst in both neutrophils and monocytes increased over time regardless of maternal treatment. The mRNA abundance of lactate dehydrogenase (LDHA) signal transducer and activator of transcription 3 (STAT3) and S100 calcium binding protein A8 (S100A8) in PMN was overall greater in MET calves. Overall data suggest that increasing the maternal supply of Met during late pregnancy could affect the neonatal calf inflammatory status and innate immune response. Although changes in mRNA abundance could play a role in coordinating the immune response the exact mechanisms merit further study., (The Authors. Published by FASS Inc. and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

Maternal supply of methyl donors such as methionine (Met) during late pregnancy can affect offspring growth and development. The objective was to investigate the effect of postruminal Met supply during late pregnancy on 1-carbon, Met cycle, and transsulfuration pathways in the calf liver. During the last 28 d of pregnancy, cows were individually fed a control diet or the control diet plus rumen-protected dl-Met (MET; 0.09% dry matter intake). Liver samples obtained from calves (n = 14/group) at 4, 14, 28, and 50 d of age were used for metabolomics, real-time PCR, and enzyme activity analyses. Genes associated with 1-carbon metabolism, DNA methylation, and the cytidine 5'-diphosphocholine-choline pathway were analyzed via real-time PCR. Activity of betaine homocysteine methyltransferase, cystathionine β-synthase, and 5-methyltetrahydrofolate homocysteine methyltransferase (MTR) was analyzed using 14 C isotopes. Data were analyzed using a mixed model that included the fixed effects of maternal treatment, day, and their interaction, and the random effect was calf within maternal diet. Calves born to dams offered MET tended to have greater birth body weight and had overall greater body weight during the first 9 wk of life. However, no differences were detected for daily feed intake and average daily gain between groups. Concentrations of betaine and choline, reflecting Met cycle activity, at d 14 through 28 were greater in MET calves. Transsulfuration pathway intermediates also were altered in MET calves, with concentrations of cysteine sulfinic acid and hypotaurine (d 4 and 14) and taurine being greater (d 4, 14, 28, and 50). Despite the lack of differences in daily feed intake, the greater concentrations of the tricarboxylic acid cycle intermediates fumarate and glutamate along with NAD/NADH in MET calves indicated enhanced rates of energy metabolism. Although activity of betaine homocysteine methyltransferase was greater in MET calves at d 14, cystathionine β-synthase was lower and increased at d 14 and 28, where it was greater compared with the control diet. Activity of MTR was lower at d 4 and 50 in MET calves. Among gene targets measured, MET calves had greater overall expression of MTR, phosphatidylethanolamine N-methyltransferase, and choline kinase α and β. An interaction of maternal diet by time was detected for mRNA abundance of DNA methyltransferase 3α (involved in de novo methylation) due to greater values at d 4 and 14 in MET calves. Overall, the data indicate that enhanced postruminal supply of Met to cows during late pregnancy may program hepatic metabolism of the calf in the context of maintaining Met homeostasis, phosphatidylcholine and taurine synthesis, DNA methylation, and energy metabolism. These alterations potentially result in better efficiency of nutrient use, hence conferring the calf a physiologic advantage during a period of rapid growth and development. The precise biologic mechanisms remain to be established., (The Authors. Published by FASS Inc. and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

The objective of this study was to determine the effects of the amount and chemical form of dietary Se on the distribution of Se among serum proteins. Six growing calves were assigned in a completely randomized design to receive diets containing either adequate (0.41 microgram/g) or excess (0.73 microgram/g) dietary Se. Proteins in serum collected from the calves were separated into albumin, glutathione peroxidase, and selenoprotein P fractions, and the concentration of Se in each was determined. The concentration of Se within serum was elevated by dietary Se supplementation. The selenoprotein P fraction within serum contained the largest percentage of Se among the serum proteins. In a second study, 12 mature cows were assigned to receive one of four experimental salt mixes containing 20, 60, or 120 micrograms of Se as sodium selenite/g of salt mix; the fourth treatment was 60 micrograms of Se as selenized yeast/g of salt mix. Cows given salt with 120 micrograms of Se as selenite or 60 micrograms of Se as selenized yeast had the highest concentrations of Se in whole blood; however, concentrations of Se in serum did not differ among treatments. Concentrations of Se in the protein fractions within serum were not affected by treatment. Within serum, the highest concentration of Se was in the selenoprotein P fraction (31.6 ng/ml), the smallest concentration was in the glutathione peroxidase fraction (4.7 ng/ml), and an intermediate amount of Se was obtained from the albumin fraction (8.5 ng/ml). In conclusion, selenized yeast and selenite as sources of Se for supplementation of cattle resulted in similar patterns of Se distribution among proteins in serum. The greatest concentration of Se was found in the selenoprotein P fraction, which may contribute to Se transportation or function as an antioxidant.

A trial was conducted to determine the effect of maternal supplementation of Se on transfer of Se to the fetus during late gestation. Holstein cows were randomly assigned at dry-off to receive no Se or 3 mg/d of supplemental Se as selenite delivered via an intraruminal bolus. Supplementation significantly increased concentrations of Se in blood of dams at parturition. Similarly, calves of cows that were supplemented with Se had higher Se in blood and liver. Colostral concentrations of Se were increased by maternal Se supplementation; Se increased in the casein fraction. The Se concentrations in blood, plasma, and liver of calves were positively correlated with the Se concentrations in plasma of the dam at parturition. Concentrations of Se in colostrum and in calf liver also were closely correlated. Concentrations of Se in calf liver at d 42 were closely correlated with concentrations of Se in liver at birth. Maternal supplementation of Se increased Se reserves in the liver of the newborn and in colostrum. Carryover effects of Se supplementation of dams were evident in calves at 42 d of age.

Developmental changes of Cu, Mn, Zn, and Se in fetal liver and kidney and the intracellular distributions were determined. Fetuses were obtained from crossbred beef heifers (n = 25) that were slaughtered at different stages of pregnancy. Fetal age was estimated from crown to rump measurements. Selenium concentration of fetal liver increased from d 145 to 195 but decreased from d 195 to 245. Fetal age did not affect Cu, Mn, or Zn in fetal liver and kidney or Se in kidney. Bone Ca significantly decreased with fetal age, but neither bone P nor Ca:P ratio changed. Liver Zn concentrations were correlated negatively with kidney Mn but positively with liver Se. Within fetal liver, the crude nuclear fraction had the largest amount of Cu, and the largest amounts of Zn and Mn were in the cytosolic fractions. The ribosomal fractions contained the least Cu, Zn, and Mn. Results indicate the normal changes that occur in tissue concentrations of minerals in the developing bovine fetus. Storage of minerals in fetal tissue reflects fetal demands for growth and the ability of the dam to transfer minerals.