Altered bile acid and correlations with gut microbiome in transition dairy cows with different glucose and lipid metabolism status.

The transition from pregnancy to lactation is critical in dairy cows. Among others, dairy cows experience a metabolic stress due to a large change in glucose and lipid metabolism. Recent studies revealed that bile acids (BA), besides being involved in both the emulsification and solubilization of fats during intestinal absorption, can also affect the metabolism of glucose and lipids, both directly or indirectly by affecting the gut microbiota. Thus, we used untargeted and targeted metabolomics and 16S rRNA sequencing approaches to investigate the concentration of plasma metabolites and BA, the composition of the rectum microbial community, and assess their interaction in transition dairy cows. In Experiment 1, we investigated BA and other blood parameters and gut microbiota in dairy cows without clinical diseases during the transition period, which can be seen as well adapted to the challenge of changed glucose and lipid metabolism. As expected, we detected an increased plasma concentration of ß-hydroxybutyrate (BHBA) and nonesterified fatty acids (NEFA) but decreased concentration of glucose, cholesterol, and triglycerides (TG). Untargeted metabolomic analysis of the plasma revealed primary BA biosynthesis was one of the affected pathways, and was consistent with the increased concentration of BA in the plasma. A correlation approach revealed a complex association between BA and microbiota with the host plasma concentration of glucose and lipid metabolites. Among BA, chenodeoxycholic acid derivates such as glycolithocholic acid, taurolithocholic acid, lithocholic acid, taurochenodeoxycholic acid, and taurodeoxycholic acid were the main hub nodes connecting microbe and blood metabolites (such as glucose, TG, and NEFA). In Experiment 2, we investigated early postpartum dairy cows with or without hyperketonemia (HPK). As expected, HPK cows had increased concentration of NEFA and decreased concentrations of glucose and triglycerides. The untargeted metabolomic analysis of the plasma revealed that primary BA biosynthesis was also one of the affected pathways. Even though the BA concentration was similar among the 2 groups, the profiles of taurine conjugated BA changed significantly. A correlation analysis also revealed an association between BA and microbiota with the concentration in plasma of glucose and lipid metabolites (such as BHBA). Among BA, cholic acid and its derivates such as taurocholic acid, tauro α-muricholic acid, and taurodeoxycholic acid were the main hub nodes connecting microbe and blood metabolites. Our results indicated an association between BA, intestinal microbe, and glucose and lipid metabolism in transition dairy cows. These findings provide new insight into the adaptation mechanisms of dairy cows during the transition period.

Feeding spent hemp biomass to lactating dairy cows: Effects on performance, milk components and quality, blood parameters, and nitrogen metabolism.

The legalization of industrial hemp by the 2018 Farm Bill in the United States has driven a sharp increase in its cultivation, including for cannabinoid extraction. Spent hemp biomass (SHB), produced from the extraction of cannabinoids, can potentially be used as feed for dairy cows; however, it is still illegal to do so in the United States, according to the US Food and Drug Administration Center for Veterinary Medicine, due to the presence of cannabinoids and the lack of data on the effect on animals. To assess the safety of this byproduct as feed for dairy cows, late-lactation Jersey cows (245 ± 37 d in milk; 483 ± 38 kg body weight; 10 multiparous and 8 primiparous) received a basal total mixed ration (TMR) diet plus 13% alfalfa pellet (CON) or 13% pelleted SHB for 4 wk (intervention period [IP]) followed by 4 wk of withdrawal period (WP), where all cows received only the basal TMR during WP. The dry matter intake (DMI), body weight, body condition score, milk yield, milk components, and fatty acid profile, blood parameters, N metabolism, methane emission, and activity were measured. Results indicated that feeding SHB decreased DMI mainly due to the low palatability of the SHB pellet, as the cows consumed only 7.4% of the total TMR with 13.0% SHB pellet offered in the ration. However, milk yield was not affected during the IP and was higher than CON during the WP, leading to higher milk yield/DMI. Milk components were not affected, except for a tendency in decreased fat percentage. Milk fat produced by cows fed SHB had a higher proportion of oleate and bacteria-derived fatty acids than CON. The activity of the cows was not affected, except for a shorter overall lying time in SHB versus CON cows during the IP. Blood parameters related to immune function were not affected. Compared with CON, cows fed SHB had a lower cholesterol concentration during the whole experiment and higher ß-hydroxybutyric acid during the WP, while a likely low-grade inflammation during the IP was indicated by higher ceruloplasmin and reactive oxidative metabolites. Other parameters related to liver health and inflammatory response were unaffected, except for a tendency for higher activity of alkaline phosphatase during IP and a lower activity of gamma-glutamyl transferase during WP in the SHB group versus CON. The bilirubin concentration was increased in cows fed SHB, suggesting a possible decrease in the clearance ability of the liver. Digestibility of the dry matter and protein and methane emission were not affected by feeding SHB. The urea, purine derivatives, and creatinine concentration in urine was unaffected, but cows fed SHB had higher N use efficiency and lower urine volume. Altogether, our data revealed a relatively low palatability of SHB affecting DMI with minimal biological effects, except for a likely low-grade inflammation, a higher N use efficiency, and a possible decrease in liver clearance. Overall, the data support the use of SHB as a safe feed ingredient for lactating dairy cows.

The Experimental and In Silico-Based Evaluation of NRF2 Modulators, Sulforaphane and Brusatol, on the Transcriptome of Immortalized Bovine Mammary Alveolar Cells.

Changes during the production cycle of dairy cattle can leave these animals susceptible to oxidative stress and reduced antioxidant health. In particular, the periparturient period, when dairy cows must rapidly adapt to the sudden metabolic demands of lactation, is a period when the production of damaging free radicals can overwhelm the natural antioxidant systems, potentially leading to tissue damage and reduced milk production. Central to the protection against free radical damage and antioxidant defense is the transcription factor NRF2, which activates an array of genes associated with antioxidant functions and cell survival. The objective of this study was to evaluate the effect that two natural NRF2 modulators, the NRF2 agonist sulforaphane (SFN) and the antagonist brusatol (BRU), have on the transcriptome of immortalized bovine mammary alveolar cells (MACT) using both the RT-qPCR of putative NRF2 target genes, as well as RNA sequencing approaches. The treatment of cells with SFN resulted in the activation of many putative NRF2 target genes and the upregulation of genes associated with pathways involved in cell survival, metabolism, and antioxidant function while suppressing the expression of genes related to cellular senescence and DNA repair. In contrast, the treatment of cells with BRU resulted in the upregulation of genes associated with inflammation, cellular stress, and apoptosis while suppressing the transcription of genes involved in various metabolic processes. The analysis also revealed several novel putative NRF2 target genes in bovine. In conclusion, these data indicate that the treatment of cells with SFN and BRU may be effective at modulating the NRF2 transcriptional network, but additional effects associated with cellular stress and metabolism may complicate the effectiveness of these compounds to improve antioxidant health in dairy cattle via nutrigenomic approaches.

miRWoods: Enhanced precursor detection and stacked random forests for the sensitive detection of microRNAs.

MicroRNAs are conserved, endogenous small RNAs with critical post-transcriptional regulatory functions throughout eukaryota, including prominent roles in development and disease. Despite much effort, microRNA annotations still contain errors and are incomplete due especially to challenges related to identifying valid miRs that have small numbers of reads, to properly locating hairpin precursors and to balancing precision and recall. Here, we present miRWoods, which solves these challenges using a duplex-focused precursor detection method and stacked random forests with specialized layers to detect mature and precursor microRNAs, and has been tuned to optimize the harmonic mean of precision and recall. We trained and tuned our discovery pipeline on data sets from the well-annotated human genome, and evaluated its performance on data from mouse. Compared to existing approaches, miRWoods better identifies precursor spans, and can balance sensitivity and specificity for an overall greater prediction accuracy, recalling an average of 10% more annotated microRNAs, and correctly predicts substantially more microRNAs with only one read. We apply this method to the under-annotated genomes of Felis catus (domestic cat) and Bos taurus (cow). We identified hundreds of novel microRNAs in small RNA sequencing data sets from muscle and skin from cat, from 10 tissues from cow and also from human and mouse cells. Our novel predictions include a microRNA in an intron of tyrosine kinase 2 (TYK2) that is present in both cat and cow, as well as a family of mirtrons with two instances in the human genome. Our predictions support a more expanded miR-2284 family in the bovine genome, a larger mir-548 family in the human genome, and a larger let-7 family in the feline genome.

Effects of 2,4-thiazolidinedione (TZD) on milk fatty acid profile and serum vitamins in dairy goats challenged with intramammary infusion of Streptococcus uberis.

The study included two experiments. In the first, 24 lactating Saanen dairy goats received low-energy diet without vitamin supplements. Twelve goats received a daily IV injection of 2,4- thiazolidinedione (TZD), others received saline injection. A week later, 6 goats from each treatment were challenged with intramammary infusion (IMI) of saline (CTRL) or Streptococcus uberis. In the second experiment, 12 Saanen lactating dairy goats received supplemental vitamins to reach NRC recommendation level. Six goats in each group were injected with TZD or saline daily, and 14 d later received Streptococcus uberis IMI in the right half of the udder. The hypotheses were (1) TZD does not affect the level of retinol in blood, and (2) the fatty acid profile is affected by the interaction between mammary infection and TZD in dairy goats. In the first experiment blood samples were collected on d -7, -2, 1, 2, 12 and milk samples were collected on d -8, 1, 4, 7, and 12, both relative to IMI. In the second experiment, blood samples were collected on d -15, 0, 1, and 10 relative to IMI. Milk and serum samples were analyzed for retinol, α-tocopherol and fatty acid profile. Serum retinol and ß-carotene concentrations were higher in the second experiment compared to the first. Serum ß-carotene and α-tocopherol were greater in TZD than CTRL and there was a TZD × time interaction in the first experiment. In addition, the TZD × time interaction showed that the milk fatty acid were reduced in C16 : 0 while C18 : 3 n3 while total omega 3 fatty acids were increased, as well as with minor effect on preventing a transient increase in α-tocopherol in milk. Overall, the TZD may affect the lipid-soluble vitamins and fatty acid profile, potentially altering immune responses, during mastitis in dairy goats.

Systems for evaluation of welfare on dairy farms.

Animal welfare is an essential component of dairy production and several systems exist to evaluate the welfare of dairy cows. Here, we review and compare three well-known systems that operate at farm level from around the world (FARM, Welfare Quality®, and The Code of Welfare) and discuss their advantages and limitations. Despite having some commonalities, the programs evaluate different elements. We also briefly review an emerging system (Integrated Diagnostic Welfare System) that might address some of the shortcomings of the existing systems, especially the possibility of automating the evaluation of animal well-being and identifying any cause of poor welfare. None of the aforementioned systems has been fully validated for their ability to assess animal welfare using independent measurements. The future holds increased attention around the well-being of dairy cows and increased use of sensing technologies. There is an urgent need for dairy welfare evaluation systems that are scientifically validated, holistic, and that can take advantage of the use of sensing technologies to continuously monitor animal welfare.

Selenium biofortified alfalfa hay fed in low quantities improves selenium status and glutathione peroxidase activity in transition dairy cows and their calves.

The hypothesis of the study was that feeding a relatively low amount of Se biofortified alfalfa hay during the dry period and early lactation would improve selenium status and glutathione peroxidase activity in dairy cows and their calves. Ten Jersey and 8 Holstein primiparous dairy cows were supplemented with Se biofortified (TRT; n = 9) or non-biofortified (CTR; n = 9) alfalfa hay at a rate of 1 kg/100 kg of BW mixed with the TMR from 40 d prior parturition to 2 weeks post-partum. Se concentration in whole blood, liver, milk, and colostrum, the transfer of Se to calves, and the glutathione peroxidase (GPx) activity were assessed. TRT had 2-fold larger (P < 0.05) Se in blood v. CTR that resulted in larger Se in liver and colostrum but not milk and larger GPx activity in plasma and erythrocytes but not in milk. Compared to CTR, calves from TRT had larger Se in blood but only a numerical (P = 0.09) larger GPx activity in plasma. A positive correlation was detected between Se in the blood and GPx activity in erythrocytes and plasma in cows. Our results demonstrated that feeding pregnant primiparous dairy cows with a relatively low amount of Se-biofortified alfalfa hay is an effective way to increase Se in the blood and liver, leading to greater antioxidant activity via GPx. The same treatment was effective in improving Se concentration in calves but had a modest effect on their GPx activity. Feeding Se biofortified hay increased Se concentration in colostrum but not in milk.

Graduate Student Literature Review: The milk behind the mustache: A review of milk and bone biology.

Exploring the relationship between nutrition, skeletal development, and aging is important in maintaining bone health. Even further, understanding the complexity of skeletal homeostasis may assist in reducing the prevalence of skeletal disease, especially osteoporosis. The skeleton is unique in that it can adapt to various physical pressures, maintain shape, and remodel itself to increase integrity and strength. For decades, it was thought that increasing skeletal health was as simple as drinking three 8-oz. glasses of milk per day due to high levels of bioavailable calcium. New research into the bioactive components of milk have revealed other roles in promoting skeletal health. Milk contains various bioactive peptides, houses genetic information in milk-derived exosomes, and supplies relevant amounts of nutrients important for bone health. In this review, we discuss the basics of skeletal formation and homeostasis, dive into the potential effects of milk on the growing skeleton, and present contrasting findings.

Cow milk does not affect adiposity in growing piglets as a model for children.

The effect of milk consumption on childhood obesity is unclear and a direct demonstration of an association is needed. In the present study, we used piglets as a model for prepubertal children to determine the effect of milk on adipose tissue. Two studies were conducted: study 1 with 5-wk-old male piglets (n = 8) and study 2 with 8- to 9-wk-old male piglets (n = 12). The piglets were fed a normal growing diet and randomly assigned to receive daily either 750 mL of whole cow milk or an isocaloric maltodextrin solution (control). For approximately 12 wk, body weight, feed intake, and subcutaneous back fat thickness were determined ultrasonographically and recorded. At euthanasia, back and neck fat thicknesses were measured and samples of back fat were collected for adipose histology. In study 1, but not study 2, piglets receiving milk grew more and ate more compared with control. In study 1, both back fat and neck fat thickness were greater in the milk-fed piglets and they had a higher frequency of small adipocytes and a lower frequency of intermediate and large adipocytes compared with controls. In study 2, control pigs had a significantly greater frequency of intermediate adipocytes but the milk-fed piglets tended to have a higher frequency of the largest adipocytes. In conclusion, milk has no apparent causal or consistent effect on adipose tissue in growing piglets.

Myogenic potential of mesenchymal stem cells isolated from porcine adipose tissue.

Advances in stem cell biology and materials science have provided a basis for developing tissue engineering methods to repair muscle injury. Among stem cell populations with potential to aid muscle repair, adipose-derived mesenchymal stem cells (ASC) hold great promise. To evaluate the possibility of using porcine ASC for muscle regeneration studies, we co-cultured porcine ASC with murine C2C12 myoblasts. These experiments demonstrated that porcine ASC display significant myogenic potential. Co-culture of ASC expressing green fluorescent protein (GFP) with C2C12 cells resulted in GFP+ myotube formation, indicating fusion of ASC with myoblasts to form myotubes. The presence of porcine lamin A/C positive nuclei in myotubes and RTqPCR analysis of porcine myogenin and desmin expression confirmed that myotube nuclei derived from ASC contribute to muscle gene expression. Co-culturing GFP+ASC with porcine satellite cells demonstrated enhanced myogenic capability of ASC, as the percentage of labeled myotubes increased compared to mouse co-cultures. Enhancing myogenic potential of ASC through soluble factor treatment or expansion of ASC with innate myogenic capacity should allow for their therapeutic use to regenerate muscle tissue lost to disease or injury.

Peroxisome proliferator-activated receptor ß/δ does not regulate glucose uptake and lactose synthesis in bovine mammary epithelial cells cultivated in vitro.

The hypothesis of the study was that inhibition of PPARß/δ increases glucose uptake and lactose synthesis in bovine mammary epithelial cells by reducing the expression of the glucose transporter mRNA destabiliser calreticulin. Three experiments were conducted to test the hypothesis using immortalised bovine mammary alveolar (MACT) and primary bovine mammary (PBMC) cells. In Experiment 1, the most effective dose to inhibit PPARß/δ activity among two synthetic antagonists (GSK-3787 and PT-s58) was assessed using a gene reporter assay. In Experiment 2, the effect on glucose uptake and lactose synthesis was evaluated by measuring glucose and lactose in the media and expression of related key genes upon modulation of PPARß/δ using GSK-3787, the synthetic PPARß/δ agonist GW-501516, or a combination of the two in cells cultivated in plastic. In Experiment 3, the same treatments were applied to cells cultivated in Matrigel and glucose and lactose in media were measured. In Experiment 1 it was determined that a significant inhibition of PPARß/δ in the presence or absence of fetal bovine serum was achieved with ≥ 1000 nm GSK-3787 but no significant inhibition was observed with PT-s58. In Experiment 2, inhibition of PPARß/δ had no effect on glucose uptake and lactose synthesis but they were both increased by GW-501516 in PBMC. The mRNA abundance of PPARß/δ target gene pyruvate dehydrogenase kinase 4 was increased but transcription of calreticulin was decreased (only in MACT cells) by GW-501516. Treatment with GSK-3787 did not affect the transcription of measured genes. No effects on glucose uptake or lactose synthesis were detected by modulation of PPARß/δ activity on cells cultivated in Matrigel. The above data do not provide support for the original hypothesis and suggest that PPARß/δ does not play a major role in glucose uptake and lactose synthesis in bovine mammary epithelial cells.

Use of Pig as a Model for Mesenchymal Stem Cell Therapies for Bone Regeneration.

Bone is a plastic tissue with a large healing capability. However, extensive bone loss due to disease or trauma requires extreme therapy such as bone grafting or tissue-engineering applications. Presently, bone grafting is the gold standard for bone repair, but presents serious limitations including donor site morbidity, rejection, and limited tissue regeneration. The use of stem cells appears to be a means to overcome such limitations. Bone marrow mesenchymal stem cells (BMSC) have been the choice thus far for stem cell therapy for bone regeneration. However, adipose-derived stem cells (ASC) have similar immunophenotype, morphology, multilineage potential, and transcriptome compared to BMSC, and both types have demonstrated extensive osteogenic capacity both in vitro and in vivo in several species. The use of scaffolds in combination with stem cells and growth factors provides a valuable tool for guided bone regeneration, especially for complex anatomic defects. Before translation to human medicine, regenerative strategies must be developed in animal models to improve effectiveness and efficiency. The pig presents as a useful model due to similar macro- and microanatomy and favorable logistics of use. This review examines data that provides strong support for the clinical translation of the pig model for bone regeneration.

Biosynthesis of milk fat, protein, and lactose: roles of transcriptional and posttranscriptional regulation.

The demand for high-quality milk is increasing worldwide. The efficiency of milk synthesis can be improved by taking advantage of the accumulated knowledge of the transcriptional and posttranscriptional regulation of genes coding for proteins involved in the synthesis of fat, protein, and lactose in the mammary gland. Research in this area is relatively new, but data accumulated in the last 10 years provide a relatively clear picture. Milk fat synthesis appears to be regulated, at least in bovines, by an interactive network between SREBP1, PPARγ, and LXRα, with a potential role for other transcription factors, such as Spot14, ChREBP, and Sp1. Milk protein synthesis is highly regulated by insulin, amino acids, and amino acid transporters via transcriptional and posttranscriptional routes, with the insulin-mTOR pathway playing a central role. The transcriptional regulation of lactose synthesis is still poorly understood, but it is clear that glucose transporters play an important role. They can also cooperatively interact with amino acid transporters and the mTOR pathway. Recent data indicate the possibility of nutrigenomic interventions to increase milk fat synthesis by feeding long-chain fatty acids and milk protein synthesis by feeding amino acids. We propose a transcriptional network model to account for all available findings. This model encompasses a complex network of proteins that control milk synthesis with a cross talk between milk fat, protein, and lactose regulation, with mTOR functioning as a central hub.

Liver Transcriptomic Profiles of Ruminant Species Fed Spent Hemp Biomass Containing Cannabinoids.

The inclusion of spent hemp biomass (SHB), an extracted byproduct from industrial cannabidiol (CBD) production, in the diets of dairy cows and lambs appears to be safe with minor effects on the metabolism, including a decrease in circulating cholesterol and increase bilirubinemia, both associated with liver metabolism. Those effects could be consequence of the presence of cannabinoids, particularly Δ9-tetrahydrocannabinol (THC) and CBD in the SHB. This study aimed to study the transcriptional profile of the liver of dairy cows and lambs fed SHB. Dairy cows received SHB or alfalfa pellet for four weeks of intervention (IP) and four weeks of withdrawal periods (WP). Finishing lambs were fed a control diet (CON), 10% (LH2), or 20% (HH2) SHB for 2 months or 1 month followed by 1-month SHB withdrawal (LH1 and HH1, respectively). RNA sequencing was performed, and the mRNA was annotated using the latest reference genomes. The RNAseq data were filtered, normalized for library size and composition, and statistically analyzed by DESeq2. The bioinformatic analysis was performed by using DAVID, Gene Set Enrichment Analysis (GSEA), and the Dynamic Impact Approach. Using a 0.2 FDR cut-off, we identified only ≤24 differentially expressed genes (DEG) in the liver by feeding SHB in dairy cows and a larger number of DEGs in lambs (from 71 in HH1 vs. CON to 552 in LH1 vs. CON). The KEGG analysis demonstrated that feeding SHB in dairy cows and lambs had relatively minor to moderate metabolic alterations in dairy cows and lambs mainly associated with amino acids and lipid metabolism whereas cholesterol synthesis was overall activated in lambs. GSEA identified activation of the PPAR signaling pathway only in dairy cows. We found an opposite effect on activation of metabolism of drug and xenobiotics by cytochrome P450 enzymes in dairy cows and lambs receiving less SHB but an inhibition in HH2 lambs. Immune system-related pathways were inhibited by feeding SHB in lambs, but the impact was minor. Cumulatively, inclusion of SHB containing cannabinoids in dairy and lambs demonstrate very little effects on the alteration of transcriptomic profile of the liver.

Cannabinoid residuals in tissues of lambs fed spent hemp biomass and consumer's exposure assessment.

Spent hemp biomass (SHB) contains trace amounts of cannabinoids, including Δ9-tetrahydrocannabinol (Δ9-THC), that may accumulate in the tissues of animals consuming SHB. We measured cannabinoid residues in the liver, adipose tissue, and muscle of finishing lambs fed either 10% or 20% SHB for 8 weeks, or 4 weeks followed by 4 weeks SHB withdrawal. We detected multiple cannabinoids in the liver at a similar proportion to the SHB. However, CBD and Δ9-THC were enriched >20-fold in the adipose and muscle, compared to their proportion in SHB. The highest concentration of Δ9-THC was detected in adipose tissue and was 7.4-times higher than in muscle. Most cannabinoids were undetectable in tissues after 4 weeks of clearance. The consumers' exposure assessment on Δ9-THC revealed tissue levels of total THC (THCA+Δ9-THC) that exceed the acute reference dose of 1 µg/kg BW across population groups. When consuming meat from the lambs fed 10% and 20% SHB, the maximum total THC exposure was 2.03 and 7.32 µg/kg BW, respectively, equal to or below the Lowest Observed Adverse Effect Level of 36 µg/kg BW, the No Observed Adverse Effect Level of 12 µg/kg BW or a tolerable dose intake of 7 µg/kg BW.

Evaluating the impact of organic chromium on hepatic phospholipid fatty acid molecular species, transcription of genes associated with lipid metabolism and oxidative status in broiler chickens fed flaxseed.

Flaxseed is a rich source of α-linolenic acid (ALA, 18:3 n-3) and can be used to enrich chicken tissues with n-3 fatty acids (FA). However, antinutritional factors in flaxseed compromise the live performance of birds coupled with increased oxidative stress. Chromium (Cr) is a trace element with antioxidant properties. It is hypothesized that Cr supplementation will affect the hepatic total lipid profile, phospholipid n-3 and n-6 FA molecular species, lipid oxidation products, and transcription of genes associated with lipid metabolism in broiler chickens fed flaxseed. Ninety (n = 90), day-old Cornish cross chicks were fed a corn-soybean meal-based diet containing 0% flaxseed (CTR), 10% flaxseed (FLAX), and FLAX + 0.05% organic Cr (FLAXCr) for 42 d. The chicks were kept in 18 pens with 5 chicks per pen. For all response variables, the effect of dietary treatments were compared separately using SAS 9.4. P values were considered significant at ≤0.05. Total lipids, saturated FA, long-chain (≥20C) n-6 FA were reduced while total n-3 FA and long-chain n-3 FA were higher in the liver of FLAX and FLAXCr than CTR (P < 0.05). Hepatic phosphatidylcholine (PC) and phosphatidylethnolamine (PE) n-3 species (36:5, 38:6) were higher in FLAX and FLAXCr compared to CTR (P < 0.05). On the contrary, n-6 species in PC (36:4, 38:4) and PE (38:4) were lower in FLAX and FLAXCr compared to CTR (P < 0.05). Addition of Cr to a flaxseed-containing diet led to an increase in PE 36:4 (P < 0.05). A decrease in the transcription of ELOVL6 gene involved in de novo lipid synthesis was observed in FLAXCr (P = 0.01). An increase in the transcription of genes involved in FA oxidation (ACAA2, ACOX1) was observed in FLAX compared to FLAXCr (P = 0. 05; P = 0.02). A trend for a decrease in the transcription of FADS2 and HMGCS1 was observed in FLAXCr than CTR and FLAX (P = 0.06; 0.08). Transcription of other genes involved in de novo lipid synthesis (FASN, PPARA), FA oxidation (CPT1A, CPT2, ACAA1), and oxidative stress response (GPX1, NQO11, GSTA2, SLC40A1, NFE2L2) were not affected by the diets (P > 0.05). Lipid peroxidation products measured as thiobarbituric acid reactive substances (TBARS) in liver was reduced in FLAXCr than CTR (P < 0.05) and was not different from FLAX (P > 0.05). Serum cholesterol and aspartic aminotransferase were reduced in FLAX and FLAXCr compared to CTR (P < 0.05). The serum glucose level was decreased in FLAX compared to CTR (P < 0.05) and a trend in decrease was noticed in FLAXCr vs. CTR (P = 0.10). Serum TBARS were higher in CTR and FLAXCr compared to FLAX (P < 0.05). In conclusion, flaxseed supplementation enhances total and long-chain n-3 FA while reducing total lipids, saturated, and n-6 FA in the liver. Supplementing Cr along with flaxseed increased n-6 FA species in the hepatic PE and decreased the transcription of genes involved in FA oxidation and lipid synthesis.

Dynamic Profile of the Yak Mammary Transcriptome during the Lactation Cycle.

The objective of this study was to assess the transcriptome of the mammary tissue of four yaks during the whole lactation cycle. For this purpose, biopsies of the mammary gland were performed at -30, -15, 1, 15, 30, 60, 120, 180, and 240 days relative to parturition (d). The transcriptome analysis was performed using a commercial bovine microarray platform and the results were analyzed using several bioinformatic tools. The statistical analysis using an overall false discovery rate ≤ 0.05 for the effect of whole lactation and p < 0.05 for each comparison identified >6000 differentially expressed genes (DEGs) throughout lactation, with a large number of DEGs observed at the onset (1 d vs. -15 d) and at the end of lactation (240 d vs. 180 d). Bioinformatics analysis revealed a major role of genes associated with BTA3, BTA4, BTA6, BTA9, BTA14, and BTA28 in lactation. Functional analysis of DEG underlined an overall induction of lipid metabolism, suggesting an increase in triglycerides synthesis, likely regulated by PPAR signaling. The same analysis revealed an induction of amino acid metabolism and secretion of protein, with a concomitant decrease in proteasome, indicating a major role of amino acid handling and reduced protein degradation in the synthesis and secretion of milk proteins. Glycan biosynthesis was induced for both N-glycan and O-glycan, suggesting increased glycan content in the milk. The cell cycle and immune response, especially antigen processing and presentation, were strongly inhibited during lactation, suggesting that morphological changes are minimized during lactation, while the mammary gland prevents immune hyper-response. Transcripts associated with response to radiation and low oxygen were enriched in the down-regulated DEG affected by the stage of lactation. Except for this last finding, the functions affected by the transcriptomic adaptation to lactation in mammary tissue of yak are very similar to those observed in dairy cows.

Fine metabolic regulation in ruminants via nutrient-gene interactions: saturated long-chain fatty acids increase expression of genes involved in lipid metabolism and immune response partly through PPAR-α activation.

Madin-Darby Bovine Kidney cells cultured with 150 µm of Wy-14 643 (WY, PPARα agonist) or twelve long-chain fatty acids (LCFA; 16 : 0, 18 : 0, cis-9-18 : 1, trans-10-18 : 1, trans-11-18 : 1, 18 : 2n-6, 18 : 3n-3, cis-9, trans-11-18 : 2, trans-10, cis-12-18 : 2, 20 : 0, 20 : 5n-3 and 22 : 6n-3) were used to uncover PPAR-α target genes and determine the effects of LCFA on expression of thirty genes with key functions in lipid metabolism and inflammation. Among fifteen known PPAR-α targets in non-ruminants, ten had greater expression with WY, suggesting that they are bovine PPAR-α targets. The expression of SPP1 and LPIN3 was increased by WY, with no evidence of a similar effect in the published literature, suggesting that both represent bovine-specific PPAR-α targets. We observed the strongest effect on the expression of PPAR-α targets with 16 : 0, 18 : 0 and 20 : 5n-3.When considering the overall effect on expression of the thirty selected genes 20 : 5n-3, 16 : 0 and 18 : 0 had the greatest effect followed by 20 : 0 and c9t11-18 : 2. Gene network analysis indicated an overall increase in lipid metabolism by WY and all LCFA with a central role of PPAR-α but also additional putative transcription factors. A greater increase in the expression of inflammatory genes was observed with 16 : 0 and 18 : 0. Among LCFA, 20 : 5n-3, 16 : 0 and 18 : 0 were the most potent PPAR-α agonists. They also affected the expression of non-PPAR-α targets, eliciting an overall increase in the expression of genes related to lipid metabolism, signalling and inflammatory response. Data appear to highlight a teleological evolutionary adaptation of PPAR in ruminants to cope with the greater availability of saturated rather than unsaturated LCFA.

Adipose-derived mesenchymal stem cells enhance healing of mandibular defects in the ramus of swine.

PURPOSE: This study investigated the effect of adipose-derived mesenchymal stem cells (ASCs) injected locally or systemically on the bone regeneration of a 10-mm-diameter cylindrical noncritical-size defect in the ramus of the pig mandible. MATERIALS AND METHODS: Fifteen Yorkshire pigs, weighing 60 to 80 kg, received bilateral 10-mm-diameter cylindrical surgical defects in each ramus of the mandible. Pigs received 1) a direct injection into the defect of 2.5 million carboxy-fluorescein diacetate succinimidyl ester-labeled ASCs from 1 of 2 pig donors (n = 6); 2) an ear vein injection of 5 million carboxy-fluorescein diacetate succinimidyl ester-labeled ASCs from 1 of 2 pig donors (n = 6); or 3) an ear vein injection of culture Dulbecco's Modified Eagle's Medium without stem cells (control; n = 3). Pigs from each treatment were sacrificed at 1 hour, 2 weeks, or 4 weeks after surgery. Healing of the defect was evaluated by dual-energy x-ray absorptiometry, micro-computed tomography, fluorescent microscopy, and histology. RESULTS: Bone healing was accelerated in the ASC-injected treatment groups at 2 and 4 weeks after surgery compared with the control pigs. CONCLUSIONS: Results from this animal model provide evidence that the injection of ASC locally into a bone defect or systemically can accelerate the healing of bone.

Functional adaptations of the transcriptome to mastitis-causing pathogens: the mammary gland and beyond.

Application of microarrays to the study of intramammary infections in recent years has provided a wealth of fundamental information on the transcriptomics adaptation of tissue/cells to the disease. Due to its heavy toll on productivity and health of the animal, in vivo and in vitro transcriptomics works involving different mastitis-causing pathogens have been conducted on the mammary gland, primarily on livestock species such as cow and sheep, with few studies in non-ruminants. However, the response to an infectious challenge originating in the mammary gland elicits systemic responses in the animal and encompasses tissues such as liver and immune cells in the circulation, with also potential effects on other tissues such as adipose. The susceptibility of the animal to develop mastitis likely is affected by factors beyond the mammary gland, e.g. negative energy balance as it occurs around parturition. Objectives of this review are to discuss the use of systems biology concepts for the holistic study of animal responses to intramammary infection; providing an update of recent work using transcriptomics to study mammary and peripheral tissue (i.e. liver) as well as neutrophils and macrophage responses to mastitis-causing pathogens; discuss the effect of negative energy balance on mastitis predisposition; and analyze the bovine and murine mammary innate-immune responses during lactation and involution using a novel functional analysis approach to uncover potential predisposing factors to mastitis throughout an animal's productive life.