Early-Life Exposure to Lipopolysaccharide Induces Persistent Changes in Gene Expression Profiles in the Liver and Spleen of Female FVB/N Mice.

The objective of this study was to investigate how subcutaneous (sc) lipopolysaccharide (LPS) administration affects the gene expression profiles of insulin signaling as well as innate and adaptive immunity genes in mouse livers and spleens. FVB/N female mice were randomly assigned to one of two treatment groups at 5 weeks of age: (1) a six-week subcutaneous injection of saline at 11 µL/h (control-CON), or (2) a six-week subcutaneous injection of LPS from Escherichia coli 0111:B4 at 0.1 µg/g body weight at 11 µL/h. At 106 weeks (i.e., 742 days) after the last treatment, mice were euthanized. Following euthanasia, liver and spleen samples were collected, snap frozen, and stored at -80 °C until gene expression profiling. LPS upregulated nine genes in the liver, according to the findings (Pparg, Frs3, Kras, Raf1, Gsk3b, Rras2, Hk2, Pik3r2, and Myd88). With a 4.18-fold increase over the CON group, Pparg was the most up-regulated gene in the liver. Based on the annotation cluster analysis, LPS treatment upregulated liver genes which are involved in pathways associated with hepatic steatosis, B- and T-cell receptor signaling, chemokine signaling, as well as other types of cancers such as endometrial cancer, prostate cancer, and colorectal cancer. LPS increased the spleen expression of Ccl11, Ccl25, Il6, Cxcl5, Pparg, Tlr4, Nos2, Cxcl11, Il1a, Ccl17, and Fcgr3, all of which are involved in innate and adaptive immune responses and the regulation of cytokine production. Furthermore, functional analysis revealed that cytokine-cytokine receptor interaction and chemokine signaling pathways were the most enriched in LPS-treated mice spleen tissue. Our findings support the notion that early-life LPS exposure can result in long-term changes in gene expression profiling in the liver and spleen tissues of FVB/N female mice.

Genome-wide association studies for additive and dominance effects for body composition traits in commercial crossbred Piétrain pigs.

Fat depth (FD) and muscle depth (MD) are economically important traits and used to estimate carcass lean content (LMP), which is one of the main breeding objectives in pig breeding programmes. We assessed the genetic architectures of body composition traits for additive and dominance effects in commercial crossbred Piétrain pigs using both 50 K array and sequence genotypes. We first performed a genome-wide association study (GWAS) using single-marker association analysis with a false discovery rate of 0.1. Then, we estimated the additive and dominance effects of the most significant variant in the quantitative trait loci (QTL) regions. It was investigated whether the use of whole-genome sequence (WGS) will improve the QTL detection (both additive and dominance) with a higher power compared with lower density SNP arrays. Our results showed that more QTL regions were detected by WGS compared with 50 K array (n = 54 vs. n = 17). Of the novel associated regions associated with FD and LMP and detected by WGS, the most pronounced peak was on SSC13, situated at ~116-118, 121-127 and 129-134 Mbp. Additionally, we found that only additive effects contributed to the genetic architecture of the analysed traits and no significant dominance effects were found for the tested SNPs at QTL regions, regardless of panel density. The associated SNPs are located in or near several relevant candidate genes. Of these genes, GABRR2, GALR1, RNGTT, CDH20 and MC4R have been previously reported as being associated with fat deposition traits. However, the genes on SSC1 (ZNF292, ORC3, CNR1, SRSF12, MDN1, TSHZ1, RELCH and RNF152) and SSC18 (TTC26 and KIAA1549) have not been reported previously to our best knowledge. Our current findings provide insights into the genomic regions influencing composition traits in Piétrain pigs.

Exploration of plasma metabolite levels in healthy nursery pigs in response to environmental enrichment and disease resilience.

The purpose of this study was to explore plasma metabolite levels in young healthy pigs and their potential association with disease resilience and estimate genetic and phenotypic correlation with the change in lymphocyte concentration following disease challenge. Plasma samples were collected from 968 healthy nursery pigs over 15 batches at an average of 28 ± 3.23 d of age. Forty-four metabolites were identified and quantified by nuclear magnetic resonance. Pigs were then introduced into a natural disease challenge barn, and were classified into four groups based on the growth rate of each animal in the grow-to-finish phase (GFGR) and treatment rate (TR): resilient (RES), average (MID), susceptible (SUS), and dead (pigs that died before harvest). Blood samples were collected from all pigs before and 2 wk after disease challenge and complete blood count was determined. Environmental enrichment (inedible point source objects) was provided for half of the pigs in seven batches (N = 205) to evaluate its impact on resilience and metabolite concentrations. Concentration of all metabolites was affected by batch, while entry age affected the concentration of 16 metabolites. The concentration of creatinine was significantly lower for pigs classified as "dead" and "susceptible" when compared to "average" (P < 0.05). Pigs that received enrichment had significantly lower concentrations of six metabolites compared with pigs that did not receive enrichment (P ≤ 0.05). Both, group classification and enrichment affected metabolites that are involved in the same pathways of valine, leucine, and isoleucine biosynthesis and degradation. Resilient pigs had higher increase in lymphocyte concentration after disease challenge. The concentration of plasma l-α-aminobutyric acid was significantly negatively genetically correlated with the change in lymphocyte concentration following challenge. In conclusion, creatinine concentration in healthy nursery pigs was lower in pigs classified as susceptible or dead after disease challenge, whilst l-α-aminobutyric may be a genetic biomarker of lymphocyte response after pathogen exposure, and both deserve further investigation. Batch, entry age, and environmental enrichment were important factors affecting the concentration of metabolites and should be taken into consideration in future studies.

The focus of this study was to explore plasma metabolite levels in young healthy pigs and their potential association with health outcome classification following the exposure to a polymicrobial disease challenge. In addition, we explored the effect of the environmental enrichment on metabolite concentrations. Finally, we estimated genetic and phenotypic correlations between metabolites and the magnitude of change in lymphocytes levels following exposure to a polymicrobial disease challenge. We found that concentration of creatinine was lower in pigs that died before marketing, classified as "dead" and susceptible when compared to average group. This indicates that creatinine can be used as an early indicator of death and/or susceptibility of disease in pigs. Providing environmental enrichment affected the concentration of six metabolites and branched chain amino acids index. Such results would be very useful to design environmental enrichment strategies when pigs are challenged by disease in commercial farms. The magnitude of change in lymphocytes level was negatively genetically correlated with l-α-aminobutyric acid. This result indicates that l-αs-aminobutyric acid can be an early indicator of the magnitude of change in lymphocytes level. Such indicator can be collected from nucleus breeding herds in healthy animals and could provide an early biomarker of resilience.

Imputation to whole-genome sequence and its use in genome-wide association studies for pork colour traits in crossbred and purebred pigs.

Imputed whole-genome sequence (WGS) has been proposed to improve genome-wide association studies (GWAS), since all causative mutations responsible for phenotypic variation are expected to be present in the data. This approach was applied on a large number of purebred (PB) and crossbred (CB) pigs for 18 pork color traits to evaluate the impact of using imputed WGS relative to medium-density marker panels. The traits included Minolta A*, B*, and L* for fat (FCOL), quadriceps femoris muscle (QFCOL), thawed loin muscle (TMCOL), fresh ham gluteus medius (GMCOL), ham iliopsoas muscle (ICOL), and longissimus dorsi muscle on the fresh loin (FMCOL). Sequence variants were imputed from a medium-density marker panel (61K for CBs and 50K for PBs) in all genotyped pigs using BeagleV5.0. We obtained high imputation accuracy (average of 0.97 for PBs and 0.91 for CBs). GWAS were conducted for three datasets: 954 CBs and 891 PBs, and the combined CBs and PBs. For most traits, no significant associations were detected, regardless of panel density or population type. However, quantitative trait loci (QTL) regions were only found for a few traits including TMCOL Minolta A* and GMCOL Minolta B* (CBs), FMCOL Minolta B*, FMCOL Minolta L*, and ICOL Minolta B* (PBs) and FMCOL Minolta A*, FMCOL Minolta B*, GMCOL Minolta B*, and ICOL Minolta B* (Combined dataset). More QTL regions were identified with WGS (n = 58) relative to medium-density marker panels (n = 22). Most of the QTL were linked to previously reported QTLs or candidate genes that have been previously reported to be associated with meat quality, pH and pork color; e.g., VIL1, PRKAG3, TTLL4, and SLC11A1, USP37. CTDSP1 gene on SSC15 has not been previously associated with meat color traits in pigs. The findings suggest any added value of WGS was only for detecting novel QTL regions when the sample size is sufficiently large as with the Combined dataset in this study. The percentage of phenotypic variance explained by the most significant SNPs also increased with WGS compared with medium-density panels. The results provide additional insights into identification of a number of candidate regions and genes for pork color traits in different pig populations.

Combination of mouse prion protein with detoxified lipopolysaccharide triggers colon genes related to inflammatory, antibacterial, and apoptotic responses.

Previously we observed that bacterial lipopolysaccharide (LPS) was able to instantly convert recombinant murine prion protein (moPrP) from an alpha-helical to a beta-sheet enriched state. The objectives of this study were to evaluate the effects of a single in vitro administration of recombinant moPrP alone or combined with detoxified lipopolysaccharide (D-LPS) on innate immunity and antibacterial gene expression in the colon of male FVB/N mice, under an Ussing chamber system. Results showed that moPrP alone affected the expression of genes related to both toll-like receptor (TLR)- and nod-like receptor (NLR)-signaling as well as pro- and anti-inflammatory responses. moPrP induced a strong antibacterial response with Slpi mRNA over expression (> 9-fold). Combination of moPrP with D-LPS on the mucosal side of the colon induced genes associated with TLR-signaling, apoptosis, and a very strong antibacterial response (> 35-fold Slpi expression). Administration of moPrP on the mucosal side and D-LPS on the serosal side triggered expression of 12 genes related to TLR signaling, apoptosis, and antibacterial responses, as illustrated by overexpression of Slpi by >30-fold. The over expression of Slpi mRNA was further reaffirmed by ELISA and when moPrP was added to the mucosal side and D-LPS on the serosal side, an increased Slpi protein was observed. Application of combined moPrP and D-LPS on the mucosal side significantly increased the Slpi protein. Results of this study demonstrated that moPrP alone or combined with D-LPS affected the expression of various genes related to inflammation, antibacterial, and apoptotic responses.

Relationship between indirect genetic effects for growth, environmental enrichment, coping style and sex with the serum metabolome profile of pigs.

Including Indirect Genetic Effects (IGE) in breeding programs to reduce aggression in group housed animals has been proposed. However, the effect of selection for IGE for growth on animal metabolism and physiology is unknown. The purpose of this study was twofold: (1) To investigate the effects of this new breeding method along with two housing (barren and straw), coping style (high and low resisters) and sex (female and castrated males) options on the metabolome profile of pigs. (2) To identify and map biological processes associated with a regrouping test at 9 weeks of age. We used Nuclear Magnetic Resonance to quantify 49 serum metabolites at week 8, 9 and 22. Also, we quantified 3 catecholamines (tyramine, epinephrine, phenylethylamine) and serotonin and three water soluble vitamins (B2, B5 and B7). Overall, no significant differences were observed between negative and positive IGE animals. The magnitude of change (delta) of many metabolites as a response to the regrouping test was significantly affected by IGE, especially that of the amino acids (P < 0.05), being greater in positive IGE pigs. The regrouping test was associated with alteration in glycine, serine and threonine metabolism. In conclusion positive and negative IGE animals respond differently to the regrouping test.

Common and specific mineral and metabolic features in dairy cows with clinical metritis, hypocalcaemia or ketosis.

The objectives were to evaluate differences in serum concentration of metabolites, macro minerals and hepatic enzymes at pre and postpartum time-points in dairy cows diagnosed with clinical metritis, hypocalcaemia or ketosis postpartum. A total of 144 Holstein cows from 11 commercial dairy herds in Alberta, (Western Canada) were enrolled in this study. Cows with clinical metritis had lower serum concentrations of glutamate dehydrogenase (GLDH) at pre and postpartum and lower total Ca, albumin, urea, and cholesterol at postpartum when compared to control cows. Cows with hypocalcaemia had greater serum concentrations of Na, Cl, and calculated osmolarity (CalOsmo) at prepartum and lower concentration of total serum Ca, glucose, cholesterol, gamma-glutamyl transpeptidase (GGT), GLDH, total protein and albumin at postpartum. Prepartum serum concentrations of non-esterified fatty acids (NEFA), beta hydroxybutyrate (BHB), Cl, albumin/globulin ratio (A/G), Na, K and sum of Na and K were greater in ketotic cows when compared with control cows. Cows with ketosis had also greater postpartum serum concentrations of NEFA, BHB, GGT and aspartate transaminase (AST) when compared with control cows. Prepartum serum Na and Cl concentrations and CalOsmo were greater in cows diagnosed with hypocalcaemia or ketosis when compared with control cows. Furthermore, postpartum serum concentrations of total Ca, cholesterol, albumin and GLDH were significantly affected by hypocalcaemia or clinical metritis and concentrations of GGT by hypocalcaemia or ketosis. Finally, postpartum serum concentrations of haptoglobin increased in all disease groups when compared with control cows. These results suggest common metabolic features for clinical metritis, hypocalcaemia and ketosis in dairy cows in addition to the specific ones.

Serum metabolic fingerprinting of pre-lameness dairy cows by GC-MS reveals typical profiles that can identify susceptible cows.

The objectives of this study were to identify metabolite fingerprints in the serum related to amino acid (AA), carbohydrate, and lipid metabolism in transition dairy cows at -8 and -4 wks prior to parturition, at +2 wks postpartum during lameness diagnosis as well as at +4 and +8 wks after parturition. All cases of lameness occurred at around +2 wks after parturition. Out of 100 dairy cows included in this nested case-control study only 6 pregnant multiparous (parity: 3.0 ± 0.6, Mean ± SEM) Holstein dairy cows with lameness only and 20 healthy control cows (CON) were selected for serum GC-MS metabolomics analysis. All cows selected were not injured mechanically and had similar parity (3.3 ± 0.6) and body condition score (BCS). A total of 29 metabolites were identified and quantified in the serum. Results showed that 18 and 15 metabolites differentiated pre-lame cows from CON ones at -8 and -4 wks prior to parturition. Ten metabolites were found altered at the week of lameness diagnosis. Of note: pre-lame cows were characterized by greater concentrations of several amino acids including Gly, Leu, Phe, Ser, Val, D-mannose, Myo-inositol, and phosphoric acid (PA) at -8 and -4 wks prior to lameness and at the week of lameness diagnosis. At +4 wks after parturition 11 metabolites were altered in lameness cows, and at +8 wks there were 13 metabolites that differentiated the two groups. The high accuracy of the top 6 metabolites at -8 wks prior to parturition or approximately 9-11 wks before lameness diagnosis (Glu, Orn, Phe, Ser, Val, and PA) and another 5 metabolites at -4 wks before parturition, or approximately 5-7 wks before lameness diagnosis (Leu, Orn, Phe, Ser, and D-mannose) suggest that those metabolites may serve as potential monitoring biomarkers of lameness prior to lameness diagnosis. Data also showed multiple alterations during the week of lameness as well as at +4 and +8 wks postpartum suggesting lame cows are not metabolically healthy several weeks after the incidence of lameness. SIGNIFICANCE: Lameness is one of the top three health issues of dairy cows in Canada that influences early culling of dairy cows. Despite a few efforts, there is scarcity of data regarding metabolic alterations that precede, associate, and follow lameness. We investigated whether alterations in the metabolite signatures prior, during, and after development of lameness can be used to screen cows for susceptibility to lameness, characterize lameness from the metabolic prospective, and predict the outcome of this economically important health issue of dairy cows. The results demonstrate typical metabotypes as shown by increased serum concentrations of Val, Gly, Ser, Leu, Phe, D-mannose, myo-inositol, and phosphoric acid at -8 and -4 wks prior to parturition (or -6 to -10 wks prior to occurrence of lameness) and at the week of lameness diagnosis.

Gene Expression and Fatty Acid Profiling in Longissimus thoracis Muscle, Subcutaneous Fat, and Liver of Light Lambs in Response to Concentrate or Alfalfa Grazing.

A better understanding of gene expression and metabolic pathways in response to a feeding system is critical for identifying key physiological processes and genes associated with polyunsaturated fatty acid (PUFA) content in lamb meat. The main objective of this study was to investigate transcriptional changes in L. thoracis (LT) muscle, liver, and subcutaneous fat (SF) of lambs that grazed alfalfa (ALF) and concentrate-fed (CON) slaughtered at 23 kg and using the Affymetrix Ovine Gene 1.1 ST whole-genome array. The study also evaluated the relationship between meat traits in LT muscle, including color, pigments and lipid oxidation during 7 days of display, α-tocopherol content, intramuscular fat (IMF) content and the fatty acid (FA) profile. Lambs that grazed on alfalfa had a greater α-tocopherol concentration in plasma than CON lambs (P < 0.05). The treatment did not affect the IMF content, meat color or pigments (P > 0.05). Grazing increased the α-tocopherol content (P < 0.001) and decreased lipid oxidation on day 7 of display (P < 0.05) in LT muscle. The ALF group contained a greater amount of conjugated linoleic acid (CLA), C18:3 n-3, C20:5 n-3, C22:5 n-3, and C22:6 n-3 than did the CON group (P < 0.05). We identified 41, 96 and four genes differentially expressed in LT muscle, liver, and subcutaneous fat, respectively. The most enriched biological processes in LT muscle were skeletal muscle tissue development, being the genes related to catabolic and lipid processes downregulated, except for CPT1B, which was upregulated in the ALF lambs. Animals grazing alfalfa had lower expression of desaturase enzymes in the liver (FADS1 and FADS2), which regulate unsaturation of fatty acids and are directly involved in the metabolism of n-3 PUFA series. The results found in the current study showed that ingesting diets richer in n-3 PUFA might have negative effects on the de novo synthesis of n-3 PUFA by downregulating the FADS1 and FADS2 expression. However, feeding diets poorer in n-3 PUFA can promote fatty acid desaturation, which makes these two genes attractive candidates for altering the content of PUFAs in meat.

Reprint of Milk fever in dairy cows is preceded by activation of innate immunity and alterations in carbohydrate metabolism prior to disease occurrence.

The objective of this study was to search for potential alterations in innate immunity reactants and carbohydrate and lipid metabolism in the blood of transition dairy cows before, during, and after clinical occurrence of milk fever (MF) and identify potential predictive biomarkers of disease. One hundred pregnant multiparous Holstein dairy cows were involved in the study starting from -8wks before the expected day of parturition until +8wks postpartum as part of a large retrospective longitudinal study. Health status, DMI, milk yield, and milk composition were monitored during the whole experimental period. Six healthy cows (CON) and 6 cows that showed clinical signs of MF were selected for blood analyses. Serum concentrations of lactate, non-esterified fatty acids (NEFA), ß-hydroxybutyric acid (BHBA), interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrosis factor (TNF), haptoglobin (Hp), and serum amyloid A (SAA) were determined. Results indicated that concentrations of serum lactate, IL-6, TNF, SAA, and Hp were greater in cows with MF than those in the CON group at different time points. Moreover, serum lactate, TNF, SAA, and Hp were greater in cows with MF starting at -8 and -4wks prior to parturition. Both principal component analysis (PCA) and partial least squares - discriminant analysis (PLS-DA) showed separated clusters between MF and CON cows at -8, -4, and disease diagnosis weeks. Overall DMI and milk production were lower in MF-affected cows. Additionally milk fat and fat:protein ratio were greater in MF. In conclusion, cows affected by MF showed alterations in some of the innate immunity reactants and metabolites related to carbohydrate metabolism several weeks prior to appearance of clinical signs of MF. Variable importance in projection plots demonstrated that TNF and SAA in the serum were the strongest discriminators between MF cows and CON ones, which might be useful as predictive biomarkers of the disease.

Milk fever in dairy cows is preceded by activation of innate immunity and alterations in carbohydrate metabolism prior to disease occurrence.

The objective of this study was to search for potential alterations in innate immunity reactants and carbohydrate and lipid metabolism in the blood of transition dairy cows before, during, and after clinical occurrence of milk fever (MF) and identify potential predictive biomarkers of disease. One hundred pregnant multiparous Holstein dairy cows were involved in the study starting from -8wks before the expected day of parturition until +8wks postpartum as part of a large retrospective longitudinal study. Health status, DMI, milk yield, and milk composition were monitored during the whole experimental period. Six healthy cows (CON) and 6 cows that showed clinical signs of MF were selected for blood analyses. Serum concentrations of lactate, non-esterified fatty acids (NEFA), ß-hydroxybutyric acid (BHBA), interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrosis factor (TNF), haptoglobin (Hp), and serum amyloid A (SAA) were determined. Results indicated that concentrations of serum lactate, IL-6, TNF, SAA, and Hp were greater in cows with MF than those in the CON group at different time points. Moreover, serum lactate, TNF, SAA, and Hp were greater in cows with MF starting at -8 and -4wks prior to parturition. Both principal component analysis (PCA) and partial least squares - discriminant analysis (PLS-DA) showed separated clusters between MF and CON cows at -8, -4, and disease diagnosis weeks. Overall DMI and milk production were lower in MF-affected cows. Additionally milk fat and fat:protein ratio were greater in MF. In conclusion, cows affected by MF showed alterations in some of the innate immunity reactants and metabolites related to carbohydrate metabolism several weeks prior to appearance of clinical signs of MF. Variable importance in projection plots demonstrated that TNF and SAA in the serum were the strongest discriminators between MF cows and CON ones, which might be useful as predictive biomarkers of the disease.

GC-MS Metabolomics Identifies Metabolite Alterations That Precede Subclinical Mastitis in the Blood of Transition Dairy Cows.

The objectives of this study were to determine alterations in the serum metabolites related to amino acid (AA), carbohydrate, and lipid metabolism in transition dairy cows before diagnosis of subclinical mastitis (SCM), during, and after diagnosis of disease. A subclinical mastitis case was determined as a cow having somatic cell count (SCC) > 200 000/mL of milk for two or more consecutive reports. Blood samples were collected from 100 Holstein dairy cows at five time points at -8 and -4 weeks before parturition, at the week of SCM diagnosis, and +4 and +8 weeks after parturition. Twenty healthy control cows (CON) and six cows that were diagnosed with SCM were selected for serum analysis with GC-MS. At -8 weeks a total of 13 metabolites were significantly altered in SCM cows. In addition, at the week of SCM diagnosis 17 metabolites were altered in these cows. Four weeks after parturition 10 metabolites were altered in SCM cows and at +8 weeks 11 metabolites were found to be different between the two groups. Valine (Val), serine (Ser), tyrosine (Tyr), and phenylalanine (Phe) had very good predictive abilities for SCM and could be used at -8 weeks and -4 weeks before calving. Combination of Val, isoleucine (Ile), Ser, and proline (Pro) can be used as diagnostic biomarkers of SCM during early stages of lactation at +4 to +8 weeks after parturition. In conclusion, SCM is preceded and followed by alteration in AA metabolism.

Genome-wide expression profiling in muscle and subcutaneous fat of lambs in response to the intake of concentrate supplemented with vitamin E.

BACKGROUND: The objective of this study was to acquire a broader, more comprehensive picture of the transcriptional changes in the L. Thoracis muscle (LT) and subcutaneous fat (SF) of lambs supplemented with vitamin E. Furthermore, we aimed to identify novel genes involved in the metabolism of vitamin E that might also be involved in meat quality. In the first treatment, seven lambs were fed a basal concentrate from weaning to slaughter (CON). In the second treatment, seven lambs received basal concentrate from weaning to 4.71 ± 2.62 days and thereafter concentrate supplemented with 500 mg dl-α-tocopheryl acetate/kg (VE) during the last 33.28 ± 1.07 days before slaughter. RESULTS: The addition of vitamin E to the diet increased the α-tocopherol muscle content and drastically diminished the lipid oxidation of meat. Gene expression profiles for treatments VE and CON were clearly separated from each other in the LT and SF. Vitamin E supplementation had a dramatic effect on subcutaneous fat gene expression, showing general up-regulation of significant genes, compared to CON treatment. In LT, vitamin E supplementation caused down-regulation of genes related to intracellular signaling cascade. Functional analysis of SF showed that vitamin E supplementation caused up-regulation of the lipid biosynthesis process, cholesterol, and sterol and steroid biosynthesis, and it down-regulated genes related to the stress response. CONCLUSIONS: Different gene expression patterns were found between the SF and LT, suggesting tissue specific responses to vitamin E supplementation. Our study enabled us to identify novel genes and metabolic pathways related to vitamin E metabolism that might be implicated in meat quality. Further exploration of these genes and vitamin E could lead to a better understanding of how vitamin E affects the oxidative process that occurs in manufactured meat products.

Dairy cows affected by ketosis show alterations in innate immunity and lipid and carbohydrate metabolism during the dry off period and postpartum.

The objective of this investigation was to search for alterations in blood variables related to innate immunity and carbohydrate and lipid metabolism during the transition period in cows affected by ketosis. One hundred multiparous Holstein dairy cows were involved in the study. Blood samples were collected at -8, -4, week of disease diagnosis (+1 to +3weeks), and +4weeks relative to parturition from 6 healthy cows (CON) and 6 cows with ketosis and were analyzed for serum variables. Results showed that cows with ketosis had greater concentrations of serum ß-hydroxybutyric acid (BHBA), interleukin (IL)-6, tumor necrosis factor (TNF), serum amyloid A (SAA), and lactate in comparison with the CON animals. Serum concentrations of BHBA, IL-6, TNF, and lactate were greater starting at -8 and -4weeks prior to parturition in cows with ketosis vs those of CON group. Cows with ketosis also had lower DMI and milk production vs CON cows. Milk fat also was lower in ketotic cows at diagnosis of disease. Cows affected by ketosis showed an activated innate immunity and altered carbohydrate and lipid metabolism several weeks prior to diagnosis of disease. Serum IL-6 and lactate were the strongest discriminators between ketosis cows and CON ones before the occurrence of ketosis, which might be useful as predictive biomarkers of the disease state.

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), ß-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.

Alterations in innate immunity reactants and carbohydrate and lipid metabolism precede occurrence of metritis in transition dairy cows.

The overall purpose of the present study was to search for early screening biomarkers of disease state. Therefore the objectives of this study were to evaluate metabolites related to carbohydrate metabolism, acute phase proteins, and proinflammatory cytokines in the blood of transition dairy cows starting at -8 weeks before calving. Blood samples were collected from 100 multiparous Holstein dairy cows during -8, -4, disease diagnosis, +4 and +8 weeks relative to parturition. Six healthy cows and 6 cows that showed clinical signs of metritis were selected for serum analysis. Overall the results showed that cows with metritis had greater concentration of lactate, interleukin-6 (IL-6), tumor necrosis factor (TNF), and serum amyloid A (SAA) versus healthy cows throughout the experiment. The disease was associated with decrease in milk production and fat: protein ratio. Cows with metritis showed alteration in metabolites related to carbohydrate metabolism, acute phase proteins, and proinflammatory cytokines starting at -8 weeks prior to parturition and appearance of clinical signs of the disease. This study suggests a possible use of cytokines as early markers of disease in dairy cows.

Innate immunity and carbohydrate metabolism alterations precede occurrence of subclinical mastitis in transition dairy cows.

BACKGROUND: This study examined whether activation of innate immunity and alterations of carbohydrate and lipid metabolism precede development of subclinical mastitis (SCM). METHODS: Blood samples were collected from the coccygeal vein from 100 Holstein dairy cows at -8, -4, disease diagnosis week, and +4 weeks postpartum. Six healthy cows (controls - CON) and six cows that showed clinical signs of SCM were selected for serum analyses. All serum samples were analyzed for acute phase proteins (APP) haptoglobin (Hp) and serum amyloid A (SAA); proinflammatory cytokines including interleukin 1 (IL-1), IL-6, and tumor necrosis factor (TNF) and serum lactate, BHBA, and NEFA concentration. Data of DMI, milk production, and milk composition were recorded and analyzed. RESULTS: The results showed that cows with SCM had greater concentrations of SAA, TNF (P < 0.01), and lactate before expected day of parturition (P < 0.05) compared to CON cows. Cows with SCM showed greater concentrations of lactate starting at -8 weeks (P < 0.05) and TNF starting at -4 weeks prior to the expected day of parturition (P < 0.01). Interestingly, at -4 weeks, concentrations of IL-1 and Hp were lower in cows with SCM compared to healthy cows (P < 0.01) followed by an increase during the week of disease diagnosis (P < 0.05). Subclinical mastitis was associated with lower DMI, at -4 weeks before calving, milk production (P < 0.05) and increased somatic cell counts (SCC) (P < 0.01). CONCLUSIONS: Results of this study suggest that SCM is preceded by activated innate immunity and altered carbohydrate metabolism in transition dairy cows. Moreover the results support the idea that Hp, lactate, and SAA, at -8 weeks, and TNF and IL-1 at -4 weeks can be used as early indicators to screen cows during dry off for disease state.

Alterations of Innate Immunity Reactants in Transition Dairy Cows before Clinical Signs of Lameness.

The objectives of this study were to evaluate metabolic and innate immunity alterations in the blood of transition dairy cows before, during, and after diagnosis of lameness during periparturient period. Blood samples were collected from the coccygeal vain once per week before morning feeding from 100 multiparous Holstein dairy cows during -8, -4, disease diagnosis, and +4 weeks (wks) relative to parturition. Six healthy cows (CON) and six cows that showed clinical signs of lameness were selected for intensive serum analyses. Concentrations of interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrosis factor (TNF), haptoglobin (Hp), serum amyloid A (SAA), lipopolysaccharide binding protein (LBP), lactate, non-esterified fatty acids (NEFA), and ß-hydroxybutyrate (BHBA) were measured in serum by ELISA or colorimetric methods. Health status, DMI, rectal temperature, milk yield, and milk composition also were monitored for each cow during the whole experimental period. Results showed that cows affected by lameness had greater concentrations of lactate, IL-6, and SAA in the serum vs. CON cows. Concentrations of TNF tended to be greater in cows with lameness compared with CON. In addition, there was a health status (Hs) by time (week) interaction for IL-1, TNF, and Hp in lameness cows vs. CON ones. Enhanced serum concentrations of lactate, IL-6, and SAA at -8 and -4 wks before parturition were different in cows with lameness as compared with those of the CON group. The disease was also associated with lowered overall milk production and DMI as well as milk fat and fat-to-protein ratio. In conclusion, cows affected postpartum by lameness had alterations in several serum variables related to innate immunity and carbohydrate metabolism that give insights into the etiopathogenesis of the disease and might serve to monitor health status of transition dairy cows in the near future.

Recombinant mouse prion protein alone or in combination with lipopolysaccharide alters expression of innate immunity genes in the colon of mice.

The objectives of this study were to test whether recombinant mouse (mo)PrP alone or in combination with LPS or under simulated endotoxemia would affect expression of genes related to host inflammatory and antimicrobial responses. To test our hypotheses colon tissues were collected from 16 male mice (FVB/N strain) and mounted in an Ussing chamber. Application of moPrP to the mucosal side of the colon affected genes related to TLR- and NLR- signaling and antimicrobial responses. When LPS was added on the mucosal side of the colon, genes related to TLR, Nlrp3 inflammasome, and iron transport proteins were over-expressed. Addition of LPS to the serosal side of the colon up-regulated genes related to TLR- and NLR-signaling, Nlrp3 inflammasome, and a chemokine. Treatment with both moPrP and LPS to the mucosal side of the colon upregulated genes associated with TLR, downstream signal transduction (DST), inflammatory response, attraction of dendritic cells to the site of inflammation, and the JNK-apoptosis pathway. Administration of moPrP to the mucosal side and LPS to the serosal side of the colon affected genes related to TLR- and NLR-signaling, DST, apoptosis, inflammatory response, cytokines, chemokines, and antimicrobial peptides. Overall this study suggests a potential role for moPrP as an endogenous 'danger signal' associated with activation of colon genes related to innate immunity and antibacterial responses.

Forage preservation (grazing vs. hay) fed to ewes affects the fatty acid profile of milk and CPT1B gene expression in the sheep mammary gland.

BACKGROUND: Alterations in lipid metabolism occur when animals are exposed to different feeding systems. In the last few decades, the characterisation of genes involved in fat metabolism and technological advances have enabled the study of the effect of diet on the milk fatty acid (FA) profile in the mammary gland and aided in the elucidation of the mechanisms of the response to diet. The aim of this study was to evaluate the effect of different forage diets (grazing vs. hay) near the time of ewe parturition on the relationship between the fatty acid profile and gene expression in the mammary gland of the Churra Tensina sheep breed. RESULTS: In this study, the forage type affected the C18:2 cis-9 trans-11 (CLA) and long-chain saturated fatty acid (LCFA) content, with higher percentages during grazing than during hay feeding. This may suggest that these FAs act as regulatory factors for the transcriptional control of the carnitine palmitoyltransferase 1B (CPT1B) gene, which was more highly expressed in the grazing group (GRE). The most highly expressed gene in the mammary gland at the fifth week of lactation is CAAT/ enhancer- binding protein beta (CEBPB), possibly due to its role in milk fat synthesis in the mammary gland. More stable housekeeping genes in the ovine mammary gland that would be appropriate for use in gene expression studies were ribosomal protein L19 (RPL19) and glyceraldehyde- 3- phosphate dehydrogenase (GAPDH). CONCLUSIONS: Small changes in diet, such as the forage preservation (grazing vs. hay), can affect the milk fatty acid profile and the expression of the CPT1B gene, which is associated with the oxidation of fatty acids. When compared to hay fed indoors, grazing fresh low mountain pastures stimulates the milk content of CLA and LCFA via mammary uptake. In this sense, LCFA in milk may be acting as a regulatory factor for transcriptional control of the CPT1B gene, which was more highly expressed in the grazing group.