Effects of restricted dietary phosphorus supply during the dry period on productivity and metabolism in dairy cows.

Phosphorus in bovine nutrition is under ongoing scrutiny because of concerns with excessive amounts of P excreted in manure contributing to environmental pollution. Feeding rations with excessive P content, however, still remains common practice, particularly during the transition period, as limited P supply in late gestation and early lactation is thought to present a risk for health and productivity of high-yielding dairy cows. The objectives of this study were to investigate the effect of restricted P supply during the last 4 wk of pregnancy on Ca and P homeostasis during the transition period in high-yielding dairy cows, and to identify possible effects on metabolism and productivity throughout the following lactation. Thirty late-pregnant multiparous dairy cows were randomly assigned to either a dry cow diet with low (LP) or adequate P (AP) content [0.16 and 0.30% P in dry matter (DM), respectively] to be fed in the 4 wk before calving. After calving all cows received the same ration with adequate P content (0.46% P in DM). Blood, milk, and liver tissue samples were obtained during the dry period and the following lactation, DM intake (DMI), body weight, milk production, and disease occurrence were monitored. Plasma was assayed for the concentrations of P, Ca, Na, and K, metabolic parameters, and liver enzyme activities. Liver tissue was analyzed for mineral, triglyceride, cholesterol, and water contents. Repeated-measures ANOVA was used to identify treatment, time, and treatment × time interaction effects. Cows fed LP had lower plasma P concentrations ([Pi]) than AP cows during restricted P feeding, reaching a nadir of 1.1 mmol/L immediately before calving. After calving, plasma [Pi] of LP cows was at or above the level of AP cows and within the reference range for cattle. Symptoms assumed to be associated with hypophosphatemia were not observed, but plasma Ca was higher from 1 wk before to 1 wk after calving in LP cows, which was associated with a numerically lower incidence of clinical and subclinical hypocalcemia in LP cows. Both treatments had a similar 305-d milk yield (12,112 ± 1,298 kg for LP and 12,229 ± 1,758 kg for AP cows) and similar DMI. Plasma and liver tissue biochemical analysis did not reveal treatment effects on energy, protein, or lipid metabolism. The results reported here indicate that restricted dietary P supply during the dry period positively affected the Ca homeostasis of periparturient dairy cows but did not reveal negative effects on DMI, milk production, or metabolic activity in the following lactation. Restriction of P during the dry period was associated with hypophosphatemia antepartum but neither exacerbated postparturient hypophosphatemia, which is commonly observed in fresh cows, nor was associated with any clinical or subclinical indication of P deficiency in early lactation.

Effects of Escherichia coli strain Nissle 1917 on exercise-induced disruption of gastrointestinal integrity.

PURPOSE: The aim of the current study was to investigate the effects of the probiotic Escherichia coli strain Nissle 1917 (EcN) on the exercise-induced disruption of gastrointestinal (GI) integrity and the associated release of damage and inflammatory markers. METHODS: After a pre-performance test, 19 untrained subjects (aged 18-35 years) passed two identical exhaustive treadmill exercise tests in an intensity corresponding to 60-80% VO2max in a test-retest design. The exercise tests were separated by a time period of 4 weeks. During this period, all subjects ingested 5 ml of an EcN suspension daily. Serum samples were taken before, immediately following and 3 h after both exercise tests. They were analyzed for indicators of GI integrity (zonulin; claudin-3; LPS), various damage and redox markers (I-FABP, GOT; GPT; TBARS) and inflammatory parameters (hsCRP; leucocytes). GI complaints were evaluated by a questionnaire. RESULTS: The intake of EcN resulted in a significantly lower increase in I-FABP and TBARS after exercise (p < 0.05). In contrast, no effect of EcN supplementation was found for hsCRP and leucocyte numbers. Similarly, no differences were found for levels of zonulin and claudin-3. Exercise-associated GI complaints were not affected by the probiotic supplement. CONCLUSION: The probiotic EcN reduced the exercise-associated increase in oxidative stress. This antioxidative mechanism probably leads to a reduction of GI epithelial damage after exhaustive exercise. The lack of EcN effects on other markers of GI permeability and systemic inflammation is most likely due to an inadequate exercise load, with rather small and insignificant exercise effects on these parameters.

Hepatic transcript profiling in early-lactation dairy cows fed rumen-protected niacin during the transition from late pregnancy to lactation.

In dairy cows, administration of high dosages of niacin (nicotinic acid, NA) was found to cause antilipolytic effects, which are mediated by the NA receptor hydroxyl-carboxylic acid receptor 2 (HCAR2) in white adipose tissue (WAT), and thereby an altered hepatic lipid metabolism. However, almost no attention has been paid to possible direct effects of NA in cattle liver, despite evidence that HCAR2 is also expressed in the liver and is even more abundant than in WAT. Because of this, we hypothesized that feeding a high dosage of rumen-protected NA to dairy cows influences critical metabolic or signaling pathways in the liver by inducing changes in the hepatic transcriptome. To identify these pathways, we applied genome-wide transcript profiling in liver biopsies obtained at d 7 postpartum (p.p.) from dairy cows used in our recent study; cows received either no NA (control group, n = 9) or 79 mg of rumen-protected NA/kg of body weight daily (NA group, n = 9) from 21 d before calving until 3 wk p.p. Hepatic transcript profiling revealed that 487 transcripts were differentially expressed (filter criteria: fold change >1.2 or <-1.2 and P < 0.05) in the liver at d 7 p.p. between cows fed NA and control cows. Substantially more transcripts were downregulated (n = 338), whereas only 149 transcripts were upregulated by NA in the liver of cows. Gene set enrichment analysis for the upregulated transcripts revealed that the most-enriched gene ontology biological process terms were exclusively related to immune processes, such as leukocyte differentiation, immune system process, activation of immune response, and acute inflammatory response. Gene set enrichment analysis of the downregulated transcripts showed that the most-enriched biological process terms were related to metabolic processes, such as cellular metabolic process, small molecule metabolic process, lipid catabolic process, organic cyclic compound metabolic process, small molecule biosynthetic process, and cellular lipid catabolic process. In conclusion, hepatic transcriptome analysis showed that rumen-protected NA induces genes that are involved mainly in immune processes, including acute phase response and stress response, in dairy cows at d 7 p.p. Thus, supplementation of a high dosage of rumen-protected NA to dairy cows in the periparturient period may induce or amplify the systemic inflammation-like condition that is typically observed in the liver of high-yielding dairy cows in the p.p. period.

Effects of ad libitum milk replacer feeding and butyrate supplementation on the epithelial growth and development of the gastrointestinal tract in Holstein calves.

Intensive milk feeding and butyrate supplementation in calves stimulate body growth and affect gastrointestinal development. The aim of the present study was to investigate the synergistic effects of ad libitum milk replacer (MR) feeding and butyrate supplementation of MR on rumen and small intestinal growth and on gene expression in the small intestine related to growth and energy metabolism at weaning. Male Holstein calves (n = 32) received colostrum from birth to d 3 of age and MR either ad libitum (Adl) or restrictively (Res; 6 L of MR/d; 12.5% solids) with (AdlB+, ResB+) or without (AdlB-, ResB-) 0.24% butyrate from d 4 until wk 8 of age. From wk 9 to 10, all calves were weaned and were fed 2 L/d until the end of the trial. Concentrate, hay, and water were freely available. At d 80, calves were slaughtered, volatile fatty acids were measured in rumen fluid, and rumen and small intestine samples were taken for histomorphometric measurements. The expression of mRNA associated with the local insulin-like growth factor (IGF) system and glucose metabolism as well as lactase and maltase activities were measured in the intestinal mucosa. The small intestine was 3 m longer in Adl than in Res. In the atrium ruminis, papilla width was greater in Res than in Adl. Villus circumference, cut surface, and height in the duodenum, proximal jejunum, and ileum were greater in Adl than in Res and in the proximal, mid, and distal jejunum and ileum were greater in calves treated with butyrate. Crypt depth in the duodenum and proximal jejunum was greater in Adl than in Res and in the ileum was smaller in calves treated with butyrate. The villus height:crypt depth ratio was greatest in AdlB+ calves. In the proximal and mid jejunum, IGF1 mRNA abundance was lower in calves treated with butyrate. In the proximal jejunum, INSR mRNA abundance was greater in Res than in Adl. The abundance of PCK2 mRNA was greater in Res than in Adl in the duodenum and was greatest in ResB- in the mid jejunum. Lactase activity tended to be greater in Res than in Adl and after butyrate treatment in the proximal jejunum. The results indicated an elevated growth of the small intestinal mucosa at weaning due to intensive milk feeding and butyrate supplementation, and the local IGF system was involved in intestinal growth regulation. Rumen development was not affected by butyrate supplementation of MR and was slightly delayed due to ad libitum MR feeding.

Different milk feeding intensities during the first 4 weeks of rearing dairy calves: Part 3: Plasma metabolomics analysis reveals long-term metabolic imprinting in Holstein heifers.

Adequate nutrition of calves is a fundamental requirement for efficient production in later life. Suboptimal nutrition before weaning could have detrimental long-term effects on metabolic health and could thereby decrease production efficiency. In this study, the metabolomic profiles of German Holstein calves reared on whole milk ad libitum (n = 10), milk replacer ad libitum (n = 9), and milk replacer in restricted amounts (n = 9) were compared. Furthermore, this profiling approach was extended to the first lactation in the same animals for characterizing the long-term effect of quantitative and qualitative dietary manipulations affecting calves during development in a period that is sensitive to metabolic imprinting. Blood plasma samples were collected on d 3, 22, and 52 of life as well as during wk 4 before and wk 3 and 8 after the first calving. Samples were subjected to a targeted metabolomics analysis using the AbsoluteIDQ p180 kit of Biocrates Life Science AG (Innsbruck, Austria). Profiling of metabolomics data was performed by principal component analysis and heatmap visualization of the metabolome, as well as by comparing fold changes and t-test statistics of metabolites. A quantitative identification of 180 plasma metabolites was possible, belonging to the metabolite classes of acyl-carnitines, AA, biogenic amines, phosphatidylcholines, lysophosphatidylcholines, sphingomyelins, and hexoses. Comparing metabolite concentrations between ad libitum-reared and restrictively reared animals revealed significant differences both during calfhood as well as during first lactation. Most dominantly, acylcarnitines of both short- and long-chain length were more abundant in ad libitum reared animals in the long-term, suggesting alterations in mitochondrial function, most likely indicating adaptive mechanisms of energy expenditure. Furthermore, plasma sphingomyelin concentrations were affected by ad libitum versus restricted milk replacer feeding, which can imply long-term modulatory mechanisms affecting insulin sensitivity. The functional characterization of the identified metabolic patterns, particularly the alterations of single lipid species, is required for further improving our understanding of the links between early nutrition shaping metabolic development and a healthy productive life of Holstein dairy cows.

Effects of supplementing rumen-protected niacin on fiber composition and metabolism of skeletal muscle in dairy cows during early lactation.

Nicotinic acid (NA) has been shown to induce muscle fiber switching toward oxidative type I fibers and a muscle metabolic phenotype that favors fatty acid (FA) utilization in growing rats, pigs, and lambs. The hypothesis of the present study was that supplementation of NA in cows during the periparturient phase also induces muscle fiber switching from type II to type I fibers in skeletal muscle and increases the capacity of the muscle to use free FA, which may help to reduce nonesterified fatty acid (NEFA) flow to the liver, liver triglyceride (TG) accumulation, and ketogenesis. Thirty multiparous Holstein dairy cows were allocated to 2 groups and fed a total mixed ration without (control group) or with ∼55 g of rumen-protected NA per cow per day (NA group) from 21 d before expected calving until 3 wk postpartum (p.p.). Blood samples were collected on d -21, -14, -7, 7, 14, 21, 35, and 63 relative to parturition for analysis of TG, NEFA, and ß-hydroxybutyrate. Muscle and liver biopsies were collected on d 7 and 21 for gene expression analysis and to determine muscle fiber composition in the musculus semitendinosus, semimembranosus, and longissimus lumborum by immunohistochemistry, and liver TG concentrations. Supplementation of NA did not affect the proportions of type I (oxidative) or the type II:type I ratio in the 3 muscles considered. A slight shift from glycolytic IIx fibers toward oxidative-glycolytic fast-twitch IIa fibers was found in the semitendinosus, and a tendency in the longissimus lumborum, but not in the semimembranosus. The transcript levels of the genes encoding the muscle fiber type isoforms and involved in FA uptake and oxidation, carnitine transport, tricarboxylic acid cycle, oxidative phosphorylation, and glucose utilization were largely unaffected by NA supplementation in all 3 muscles. Supplementation of NA had no effect on plasma TG and NEFA concentrations, liver TG concentrations, and hepatic expression of genes involved in hepatic FA utilization and lipogenesis. However, it reduced plasma ß-hydroxybutyrate concentrations in wk 2 and 3 p.p. by 18 and 26% and reduced hepatic gene expression of fibroblast growth factor 21, a stress hormone involved in the regulation of ketogenesis, by 74 and 56%. In conclusion, a high dosage of rumen-protected NA reduced plasma ß-hydroxybutyrate concentrations in cows during early lactation, but failed to cause an alteration in muscle fiber composition and muscle metabolic phenotype.

Influence of ad libitum milk replacer feeding and butyrate supplementation on the systemic and hepatic insulin-like growth factor I and its binding proteins in Holstein calves.

Ad libitum milk feeding and butyrate (B) supplementation have the potential to stimulate postnatal growth and development in calves. The somatotropic axis is the main endocrine regulator of postnatal growth and may be affected by both ad libitum milk replacer (MR) feeding and B supplementation in calves. We hypothesized that ad libitum MR feeding and B supplementation stimulate systemic and hepatic insulin-like growth factor (IGF)-I and IGF binding proteins (IGFBP) in preweaning calves. Sixty-four (32 male, 32 female) Holstein calves were examined from birth until wk 11 of life. Calves received MR either ad libitum (Adl) or restrictively (6 L/d; Res). In each feeding group half of the calves received a MR with 0.24% butyrate and the other half received same MR without butyrate. Ad libitum MR feeding was performed from d 4 until wk 8 of age. From wk 9 to 10, Adl and Res calves were gradually weaned and were fed 2 L/d until the end of the trial. Concentrate, hay, and water were freely available. Feed intake was measured daily and body weight weekly. Blood samples for analyzing plasma concentrations of glucose, insulin, IGF-I, and IGFBP-2, -3, and -4 were taken on d 1, 2, 4, and 7, then weekly or every other week (IGFBP) until wk 11 of life. Liver samples were taken on d 50 and at the end of the study (d 80) to measure gene expression of the growth hormone receptor 1A (GHR1A), IGF1, IGFBP1 to 4, and of the IGF Type 1 and insulin receptor in the liver. Intake of MR and body weight were greater, but concentrate intake was lower in Adl than in Res. Plasma concentrations of IGF-I and IGFBP-3 were greater and plasma concentration of IGFBP-2 was lower in Adl than in Res during the ad libitum milk feeding period. After reduction of MR in both groups to 2 L/d plasma concentrations of IGF-I and IGFBP-4 were lower and plasma concentration of IGFBP-2 was higher in Adl than in Res. Supplementation of B depressed plasma IGF-I from wk 1 to 4 and in wk 9. On d 50, mRNA abundance of the GHR1A and IGF1 was greater and of IGFBP2 mRNA was lower in Adl than in Res. At d 80, IGFBP2 mRNA was greater in Adl than in Res, and IGFBP2 mRNA increased with B supplementation. Ad libitum MR feeding stimulated the systemic and hepatic IGF system and mirrored the greater growth rate during the ad libitum MR feeding, whereas butyrate supplementation partly reduced the systemic and hepatic IGF system.

Effects of ad libitum milk replacer feeding and butyrate supplementation on behavior, immune status, and health of Holstein calves in the postnatal period.

Animal welfare in dairy calf husbandry depends on calf rearing and is probably improved by intensive milk feeding programs. In addition, butyrate supplementation in milk replacer (MR) stimulates postnatal growth and may affect the immune system in calves. We have investigated the combined effects of ad libitum MR feeding and butyrate supplementation on feeding behavior, health, and the immune responses in calves. Holstein calves (n = 64) were examined from birth until wk 11 of age. Calves received MR either ad libitum (Adl) or restrictively (Res) with (AdlB+, ResB+) or without (AdlB-, ResB-) 0.24% butyrate supplementation starting on d 4. From wk 9 to 10, all calves were gradually weaned and were fed 2 L/d until the end of the trial. Concentrate, hay, and water were freely available. Calves were housed in straw-bedded group pens with automatic MR feeders, where feed intake and feeding behavior were documented. Blood was drawn on d 1 before the first colostrum intake; on d 2, 4, and 7; and weekly thereafter until the end of the study to measure plasma concentrations of total protein, albumin, the immunoglobulins IgG1, IgG2, and IgM, and the acute phase proteins fibrinogen, serum amyloid A, and haptoglobin. Liver samples were taken on d 50 and 80 to determine gene expression related to acute phase proteins. Body temperature was measured daily for the first 3 wk, and clinical traits were scored daily. Ad libitum MR feeding resulted in greater MR intake, greater MR intake per meal, slower sucking rate, and greater body weight, but in a lower number of unrewarded visits and lower concentrate intake when compared with Res. Butyrate reduced the sucking rate but increased MR intake per meal. Immunoglobulins in the blood plasma increased after colostrum intake in all calves, with only minor differences among groups throughout the study. Plasma fibrinogen and serum amyloid A increased in the first week of life in all calves, and fibrinogen was greater in Res than in Adl on d 21, 49, and 63. Hepatic gene expression of fibrinogen on d 80 was greater in Adl than in Res. Gene expression of SAA2 was greater on d 50 in Adl than in Res and on d 80 was greater in ResB+ than in ResB-. Body temperature was greater in Adl than in Res during the first 2 wk, but neither MR feeding nor butyrate affected the health status. An improved animal welfare in Adl calves is supported by fewer signs of hunger, but intensive milk feeding and butyrate did not affect the health and immune status of the calves in a consistent manner.

Effect of dietary conjugated linoleic acid on vitamin A status of lactating rats and their offspring.

The absorption and metabolism of vitamin A is linked with that of lipids. It is known that conjugated linoleic acid (CLA) affects the lipid metabolism in growing and lactating animals. In the present study, the hypothesis was investigated that dietary CLA influences vitamin A status of lactating rats and their pups during the suckling period. For this purpose, Wistar Han rats were fed either a control diet (control group, n = 14) or a diet containing 0.87% of cis-9, trans-11 and trans-10, cis-12 (1:1) CLA (CLA group, n = 14) during pregnancy and lactation. Vitamin A concentrations in various body tissues were determined 14 days after delivery in dams and 1, 7 and 14 days after birth in pups, and expression of selected genes involved in metabolism of retinoids was determined in dams. Vitamin A concentrations in liver, plasma and muscle were similar in control and CLA-fed dams. Expression of genes involved in retinoid transport, storage and degradation in liver and adipose tissue in dams was also not different between control and CLA-fed dams. Vitamin A concentrations in milk curd, sampled at d 1, 7 and 14 of lactation were not different between control and CLA-fed dams. Vitamin A concentrations in liver, lung and adipose tissue were also not different in pups from control dams and pups from CLA-fed dams. In conclusion, we show for the first time that dietary CLA has little effect on vitamin A concentrations and vitamin A metabolism in lactating rat dams and, moreover, does not influence tissue vitamin A concentrations in their newborn and suckling pups.

Tissue and plasma antioxidant status in response to dietary methionine concentration and source in broilers.

This study hypothesized that plasma and tissue antioxidant status of broilers is positively influenced when dietary Met concentrations exceed, and negatively when they go below NRC recommendations. In addition, different Met sources are hypothesized to affect the antioxidant defence system differently. Day-old male Cobb-500 broilers (n = 336) were allotted to seven groups and phase-fed three wheat-soya bean meal-based basal diets during days 1-10, 11-21 and 22-35. The basal diets (Met- group, Met + Cys concentration 15% below NRC recommendations) were supplemented with 0.10%, 0.25% or 0.40% Met either as DL-Met (DLM) or DL-2-hydroxy-4-(methylthio) butanoic acid (DL-HMTBA) (equimolar comparison). Growth performance and carcass weights were lower in the Met- group compared to the groups whose diets met or exceeded Met requirements. The antioxidant defence system was not influenced by the Met source. However, in the liver, concentrations of glutathione increased with increasing dietary Met concentrations. Tocopherol concentrations in the liver at days 10 and 21 were lower in the Met- group than in the groups supplemented with Met. However, liver concentrations of thiobarbituric acid reactive substances (TBA-RS) and protein carbonyls (PC) were largely not influenced by dietary Met concentration. Plasma tocopherol concentrations at day 35 were lower, and those of TBA-RS and PC at day 35 were higher in Met- group than in the groups fed the Met-supplemented diets. In jejunum, but not in liver, relative mRNA abundances and activities of superoxide dismutase, catalase and glutathione peroxidase were higher in the Met- group than in the groups fed Met-supplemented diets. These data indicate that suboptimum supply of Met results in decreased antioxidant concentrations in plasma and body tissues, and increases oxidative stress in the jejunum mucosa. However, supplementation of Met in excess of the requirements (based on NRC) compared to diets adequate in Met + Cys did not influence the antioxidant defence system.

Influence of conjugated linoleic acids and vitamin E on milk fatty acid composition and concentrations of vitamin A and α-tocopherol in blood and milk of dairy cows.

The objective of this trial was to investigate the influences of conjugated linoleic acid (CLA) and vitamin E (Vit. E) and their interactions on fatty acid composition and vitamins in milk (α-tocopherol, retinol and ß-carotene) as well as on α-tocopherol in blood of pluriparous cows from week 6 ante partum until week 10 post-partum (p.p.). We assigned 59 pluriparous German Holstein cows to four treatment groups with the treatment factors CLA and Vit. E at two levels in a 2 × 2 factorial design. Milk fatty acid composition and milk vitamins were analysed on lactation days 7 and 28. α-tocopherol in blood serum was analysed on days -42, -7, 1, 7, 14, 28 and 70 relative to parturition. Milk concentration of α-tocopherol was influenced by Vit. E (p < .001) and CLA (p = .034). Percentage of cis-9, trans-11 CLA in total milk fat was influenced by treatment with CLA (p < .001), while for percentage of trans-10, cis-12 CLA an interaction between treatment and day (p = .019), driven by an increase in both CLA groups from day 7 to day 28, was found. Serum ratios of α-tocopherol to cholesterol were influenced by Vit. E (p < .001). Results suggest that treatment with CLA during late pregnancy and early lactation is suitable to enhance the proportion of trans-10, cis-12 CLA in milk and thereby influencing nutritional properties. As treatment with Vit. E did not have an impact on milk fatty acid composition, it might be possible to increase the antioxidative capacity of the dairy cow without affecting milk properties. Consequently, combined treatment with CLA and Vit. E might elicit synergistic effects on the cow and milk quality by increasing the proportion of CLA in milk fat as well as the excretion of Vit. E and the Vit. E levels in serum.

Effect of endoplasmic reticulum stress on metabolic and stress signaling and kidney-specific functions in Madin-Darby bovine kidney cells.

Recent studies demonstrated induction of endoplasmic reticulum (ER) stress in tissues of cows after parturition, but knowledge about the effect of ER stress on important cellular processes, such as critical signaling and metabolic pathways, in cattle is scarce. Thus, the present study aimed to investigate the effect of ER stress induction on nuclear factor-κB (NF-κB), nuclear factor E2-related factor 2 (Nrf2), and sterol regulatory element-binding protein (SREBF1) pathway in Madin-Darby bovine kidney (MDBK) cells, a widely used in vitro model in ruminant research. To consider the kidney origin of MDBK cells, the effect on renal distal tubular cell-specific functions, such as transport processes and regulation of 1,25(OH)2D3 levels, was also studied. Treatment of MDBK cells with 2 different ER stress inducers, thapsigargin (TG) and tunicamycin (TM), strongly induced ER stress as evident from induction of ER stress target genes, increased phosphorylation of PKR-like ER kinase, and enhanced splicing of X-box binding protein 1. The TM decreased the protein concentration of NF-κB p50 and the mRNA levels of the NF-κB target genes. Likewise, TG decreased the mRNA concentration of tumor necrosis factor and tended to decrease NF-κB p50 protein and mRNA levels of NF-κB target genes. The mRNA levels of most of the Nrf2 target genes investigated were reduced by TG and TM in MDBK cells. Both ER stress inducers reduced the mRNA levels of SREBF1 and its target genes in MDBK cells. Interestingly, TG decreased, but TM increased the mRNA level of the Ca2+ binding protein calbindin 1, whereas the mRNA level of the plasma membrane Ca2+-transporting ATPase 1 remained unchained. The mRNA level of the cytochrome P450 component 24A1 involved in 1α-hydroxylation of 25(OH)D3 was strongly elevated, whereas the mRNA level of the cytochrome P450 component 27A1 catalyzing the breakdown of 1,25(OH)2D3 was markedly reduced by both ER stress inducers. The concentration of 1,25(OH)2D3 in the supernatant of MDBK cells was increased by approximately 15% by both TG and TM. The present study indicates that under conditions of ER stress, critical signaling pathways, such as NF-κB, Nrf2, and SREBF1, are inhibited, whereas the formation of 1,25(OH)2D3 is stimulated in bovine MDBK cells. Future studies are necessary to clarify the physiological relevance of these findings.

Ad libitum milk replacer feeding, but not butyrate supplementation, affects growth performance as well as metabolic and endocrine traits in Holstein calves.

The enhanced growth performance of calves fed a higher plane of nutrition pre-weaning is well documented, and the effect of butyrate on the development of the gastrointestinal tract in calves has been evaluated. The aim of this study was to examine the synergistic effects of ad libitum milk replacer (MR) feeding and butyrate supplementation on growth performance and energy metabolism in calves. Sixty-four (32 male, 32 female) Holstein calves were examined from birth until wk 11 of life. Calves received MR either ad libitum (Adl) or restrictively (Res) with (AdlB+, ResB+) or without (AdlB-, ResB-) 0.24% butyrate supplementation. Colostrum and transition milk were fed in predefined amounts (Res or Adl) for the first 3 d postpartum. Ad libitum and restrictive MR feeding with or without butyrate was performed from d 4 until wk 8 of age. From wk 9 to 10, all calves were gradually weaned and were fed 2 L/d until the end of the trial. Concentrate (CON), hay, and water were freely available. Intakes of MR and CON were measured daily. Calves were weighed at birth and weekly thereafter. Blood was drawn on d 1 before the first colostrum intake; on d 2, 4, and 7; and weekly thereafter until the end of the study to measure plasma concentrations of metabolites and hormones. Liver samples were taken at d 50 and at the end of the study to determine gene expression related to glucose metabolism. Milk, MR, and total nutrient intake were greater, but CON intake was lower in Adl than in Res calves, resulting in a greater body weight, but partially lower gain to feed ratio in Adl than in Res. Plasma concentrations of glucose and insulin were higher during the ad libitum milk-feeding period, whereas plasma ß-hydroxybutyrate was lower in Adl than in Res. Plasma concentrations of nonesterified fatty acids, lactate, total bilirubin, and cortisol were lower, but triglyceride and cholesterol concentrations were higher in Adl than in Res at specific time points. Feed intake, growth performance, and metabolic and endocrine changes were insignificantly affected by butyrate, and hepatic gene expression of enzymes related to endogenous glucose production was barely influenced by ad libitum MR feeding and butyrate supplementation. Intensive MR feeding indicated greater stimulation of growth and anabolic metabolism, but butyrate supplementation did not further improve postnatal growth or anabolic processes either in intensive or restrictive MR-fed calves.

Different milk feeding intensities during the first 4 weeks of rearing in dairy calves: Part 1: Effects on performance and production from birth over the first lactation.

We aimed to test the effects of ad libitum feeding of whole milk (WM) or milk replacer (MR) versus restrictive feeding of MR during the first 4 wk of life on growth performance and on milk yield in the first lactation. We studied 57 German Holstein calves (29 females, 28 males) from birth until d 110 of life (trial 1). The 28 females from trial 1 were further studied during their first lactation (trial 2). In trial 1, all calves were randomly allocated at birth to 1 of 3 groups: MR-res [n = 20, 6.78 kg MR (11.5% solids)/calf per day], MR-ad lib (n = 17, 13.8% solids) or WM-ad lib (n = 20). All calves received colostrum ad libitum from their dam until d 3 of age. From d 4 to 27, calves were fed according to their group regimen. From d 28 to 55, all calves received MR-res feeding and were then gradually weaned until d 69. We recorded body weight (until d 110) and feed intake (amount, metabolizable energy, and frequency of liquid feed intake until weaning). We estimated the profitability of the different feeding regimens, taking into account income from milk yield (trial 2) and feed costs during rearing. In trial 1, the calves from WM-ad lib and MR-ad lib had total metabolizable energy intakes 2.02- and 1.65-fold greater than the MR-res group during the first 4 wk of life. During this period, concentrate intake did not differ among groups, but tended to be greater in WM-ad lib than in MR-ad lib calves from d 28 to 69. The MR-res calves visited the automatic feeders more often than the ad libitum-fed groups during differential feeding, but 70% of the visits were unrewarded (<10% in the ad libitum-fed calves). When all calves were fed at the MR-res level, the average proportion of unrewarded visits was 65% in all groups. Average daily gain and body weight were greater among MR-ad lib and WM-ad lib calves than among MR-res animals during the first 4 wk of life, but not from d 1 to 110. In trial 2, age at first calving, dry matter intake, and body weight over the first 10 mo of lactation were not different among groups, nor was milk composition. Milk yields (305 d) were numerically but not statistically greater in the ad libitum-fed groups during the first lactation (+765 kg for WM-ad lib vs. MR-res; +612 kg for MR-ad lib vs. MR-res). Feeding WM-ad lib and MR-ad lib was 1.37- and 1.21-fold more costly than MR-res, respectively, but amounted to 18, 15, and 13% of the total estimated feed costs until first calving in WM-ad lib, MR-ad lib, and MR-res, respectively. Our study confirms that ad libitum feeding is an attractive measure for rearing dairy calves, both for animal welfare and-with the caveat of a small sample size in trial 2 that led to insufficient power-economic profit from milk.

Different milk feeding intensities during the first 4 weeks of rearing dairy calves: Part 2: Effects on the metabolic and endocrine status during calfhood and around the first lactation.

Feeding dairy calves at high intensity has been demonstrated to increase milk yield in later life. We investigated the effect of 3 different feeding regimens in the preweaning period on the metabolic and endocrine status during calfhood and in heifers at the onset of the first lactation. In trial 1, 57 German Holstein calves were allocated to 3 different feeding groups: milk replacer restricted to 6.78 kg/calf per day, 11.5% solids (MR-res, n = 20), milk replacer 13.8% solids, ad libitum (MR-ad lib, n = 17), and whole milk ad libitum (WM-ad lib, n = 20). All calves received ad libitum colostrum for 3 d postnatal (p.n.). From d 4 to 27, all calves were fed according to their respective feeding regimen, resulting in average intakes of 6.38, 9.25, and 9.47 kg/d in MR-res, MR-ad lib, and WM-ad lib, respectively. Thereafter, all calves were fed according to the MR-res regimen until weaning at d 55 (gradually until d 69 p.n.). Blood samples were collected on d 0 before colostrum intake and on d 1, 3, 11, 22, 34, 43, 52, 70, 90, and 108 p.n. Liver biopsies were taken on d 19 and 100, and on d 22, 52, and 108 p.n. intravenous glucose tolerance tests were performed. The male calves (n = 8 to 10 per group) underwent also an insulin tolerance test on d 24, 54, and 110 p.n. The females (n = 28) from trial 1 were further reared and bred as common practice, and were enrolled in trial 2 when beginning the last trimester of pregnancy. Blood samples were collected monthly antepartum starting 91 d before calving and weekly (0-70 d) postpartum. Trial 1 was subdivided into 4 phases (P): P0 (d 0-1), P1 (d 2-27), P2 (d 28-69), and P3 (d 70-110 p.n.). In trial 1, the leptin and adiponectin concentrations increased with colostrum intake. Differences in fatty acids, insulin, adiponectin, revised quantitative insulin sensitivity check index (RQUICKI), and variables from the glucose tolerance tests were largely limited to P1. The MR-res group had greater RQUICKI and fatty acid values, and lower insulin and, as a trend, adiponectin concentrations than in 1 or both ad lib groups. These differences were partly sustained in P2 (fatty acids, adiponectin, and RQUICKI) and in P3 (adiponectin). The hepatic mRNA abundance of the gluconeogenic enzymes phosphoenolpyruvate carboxykinase and pyruvatcarboxylase increased from d 19 to 100. None of the blood variables were different between the groups when tested in pregnancy and lactation. Our results do not support a sustained deflection of metabolic regulation by rearing at different feeding intensities; nevertheless, the differences observed during rearing might influence nutrient utilization in later life or the cellular development of organs, such as the mammary gland, and thereby affect milk yield. Further studies involving greater animal numbers and, thus, improved power will help to sort out the mechanisms of programming body function in later life via nutrition in early life.

Effects of body condition, monensin, and essential oils on ruminal lipopolysaccharide concentration, inflammatory markers, and endoplasmatic reticulum stress of transition dairy cows.

Evidence exists that dairy cows experience inflammatory-like phenomena in the transition period. Rumen health and alterations in metabolic processes and gene networks in the liver as the central metabolic organ might be key factors for cows' health and productivity in early lactation. This study made use of an animal model to generate experimental groups with different manifestations of postpartal fat mobilization and ketogenesis. In total, 60 German Holstein cows were allocated 6 wk antepartum to 3 high-body condition score (BCS) groups (BCS 3.95) and 1 low-BCS group (LC; BCS 2.77). High-BCS cows were fed an antepartal forage-to-concentrate ratio of 40:60 on dry matter basis, in contrast to 80:20 in the LC group, and received a monensin controlled-release capsule (HC/MO), a blend of essential oils (HC/EO), or formed a control group (HC). We evaluated serum haptoglobin, kynurenine, tryptophan, ruminal lipopolysaccharide concentration and mRNA abundance of nuclear factor kappa B (NF-κB), nuclear factor E2-related factor 2 (Nrf2), and endoplasmatic reticulum stress-induced unfolded protein response (UPR) target genes in liver biopsy samples from d -42 until +56 relative to calving. Nearly all parameters were highly dependent on time, with greatest variation near calving. The ruminal lipopolysaccharide concentration and evaluated target genes were not generally influenced by antepartal BCS and feeding management. The kynurenine-to-tryptophan ratio was higher in LC than in HC/MO treatment on d 7. Ruminal lipopolysaccharide concentration was higher in HC/MO than in the HC group, but not increased in HC/EO group. Abundance of UPR target gene X-box binding protein 1 was higher in HC/MO than in HC/EO group on d 7. Hepatic mRNA abundance of Nrf2 target gene glutathione peroxidase 3 was higher, whereas expression of NF-κB target gene haptoglobin tended to be higher in LC than in HC/EO cows. The HC/MO cows showed the most prominent increase in the abundance of glutathione peroxidase 3 and haptoglobin after calving in comparison to antepartal values. Results indicate the presence of inflammatory-like phenomena near calving. Simultaneously, alterations in UPR and Nrf2 target genes with antioxidative properties and haptoglobin occurred, being most prominent in LC and HC/MO group.

Correlating Atom Probe Crystallographic Measurements with Transmission Kikuchi Diffraction Data.

Correlative microscopy approaches offer synergistic solutions to many research problems. One such combination, that has been studied in limited detail, is the use of atom probe tomography (APT) and transmission Kikuchi diffraction (TKD) on the same tip specimen. By combining these two powerful microscopy techniques, the microstructure of important engineering alloys can be studied in greater detail. For the first time, the accuracy of crystallographic measurements made using APT will be independently verified using TKD. Experimental data from two atom probe tips, one a nanocrystalline Al-0.5Ag alloy specimen collected on a straight flight-path atom probe and the other a high purity Mo specimen collected on a reflectron-fitted instrument, will be compared. We find that the average minimum misorientation angle, calculated from calibrated atom probe reconstructions with two different pole combinations, deviate 0.7° and 1.4°, respectively, from the TKD results. The type of atom probe and experimental conditions appear to have some impact on this accuracy and the reconstruction and measurement procedures are likely to contribute further to degradation in angular resolution. The challenges and implications of this correlative approach will also be discussed.

Potential of plant polyphenols to combat oxidative stress and inflammatory processes in farm animals.

Polyphenols are secondary plant metabolites which have been shown to exert antioxidative and antiinflamma tory effects in cell culture, rodent and human studies. Based on the fact that conditions of oxidative stress and inflammation are highly relevant in farm animals, polyphenols are considered as promising feed additives in the nutrition of farm animals. However, in contrast to many studies existing with model animals and humans, potential antioxidative and antiinflammatory effects of polyphenols have been less investigated in farm animals so far. This review aims to give an overview about potential antioxidative and antiinflammatory effects in farm animals. The first part of the review highlights the occurrence and the consequences of oxidative stress and inflammation on animal health and performance. The second part of the review deals with bioavailability and metabolism of polyphenols in farm animals. The third and main part of the review presents an overview of the findings from studies which investigated the effects of polyphenols of various plant sources in pigs, poultry and cattle, with particular consideration of effects on the antioxidant system and inflammation.

Antioxidant status and expression of inflammatory genes in gut and liver of piglets fed different dietary methionine concentrations.

This study investigated the hypothesis that dietary concentrations of methionine (Met), as a precursor of cysteine which is a constituent of glutathione (GSH), affect tissue antioxidant concentrations and the antioxidant defence system in pigs. Forty-five piglets (DanZucht × Pietrain) were allotted to three groups of similar mean body weight (11.0 ± 0.9 kg). The basal diet was composed of barley, wheat, corn starch, soybean oil, sucrose, cellulose and a mineral supplement with suboptimal concentrations of Met and was supplemented with dl-Met to reach 0.16%, 0.20% and 0.24% of dietary Met and 0.40%, 0.44% and 0.48% of dietary Met and cysteine in groups 0.16, 0.20 and 0.24 respectively. After 3 weeks, at slaughter, samples of liver, jejunum mucosa and plasma were collected. Feed intake and weight gains increased and feed:gain ratio decreased when dietary Met concentrations increased. The Trolox equivalent antioxidant capacity (TEAC), concentrations of GSH and thiobarbituric acid reactive substances (TBA-RS) and the activity of the glutathione peroxidase (GPx) in liver and jejunum mucosa were similar in all groups (p > 0.05). Relative mRNA concentrations of selected target genes of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2), the master regulator of the antioxidant response, and of the nuclear factor 'kappa-light-chain-enhancer' of activated B-cells (NF-κB), the master regulator of inflammation, were largely unaffected both in jejunum and liver. In conclusion, inflammation- and oxidative stress-related pathways on the molecular level, and concentrations of lipid peroxidation products, of antioxidants and of enzymes involved in the antioxidant defence system were mostly unaffected by dietary Met concentration in gut and liver. These findings suggest that suboptimal dietary Met concentrations did not influence the antioxidant defence system of gut and liver in healthy piglets.

Effects of polyphenol-rich plant products from grape or hop as feed supplements on the expression of inflammatory, antioxidative, cytoprotective and endoplasmic reticulum stress-related genes and the antioxidative status in the liver of piglets.

Recent studies have shown that supplementation of plant products rich in polyphenols exerts anti-inflammatory effects in the small intestine and improves feed conversion in piglets. This study aimed to investigate whether dietary polyphenols have also anti-inflammatory and cytoprotective effects in the liver of piglets. For this end, relative mRNA concentrations of eight genes involved in proinflammatory pathways, eight genes involved in the antioxidative and cytoprotective system, six genes of phase I and phase II metabolism and 15 genes of the unfolded protein response (triggered by stress of the endoplasmic reticulum) in the liver of pigs fed diets supplemented with either 1% of grape seed and grape marc meal extract (GME) or 1% spent hops (SH) as sources of polyphenols were determined. Relative mRNA concentrations of almost all these genes, with few exceptions, in the liver of pigs supplemented with GME or SH did not differ from those in the liver of control piglets. Gene expression data were validated by consideration of concentrations of some selected proteins of these pathways which also did not differ between piglets supplemented with GME or SH and control piglets. Moreover, concentrations of thiobarbituric acid-reactive substances and tocopherols as well as the total antioxidant capacity in liver and plasma did not differ between pigs supplemented with either GME or SH and control piglets. Overall, this study shows that supplementation of GME or SH as sources of polyphenols does not influence hepatic pathways linked to inflammation, the antioxidant and cytoprotective system, stress of the endoplasmic reticulum and the xenobiotic system in healthy piglets.