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Circadian disruption increased insulin resistance and decreased mammary development in late gestation, nonlactating (dry) cows. The objective was to measure the effect of circadian disruption on transcriptomes of the liver and mammary gland. At 35 days before expected calving (BEC), multiparous dry cows were assigned to either control (CON) or phase-shifted treatments (PS). CON was exposed to 16-h light and 8-h dark. PS was exposed to 16-h light to 8-h dark, but phase of the light-dark cycle was shifted 6 h every 3 days. On day 21 BEC, liver and mammary were biopsied. RNA was isolated ( n = 6 CON, n = 6 PS per tissue), and libraries were prepared and sequenced using paired-end reads. Reads mapping to bovine genome averaged 27 ± 2 million and aligned to 14,222 protein-coding genes in liver and 15,480 in mammary analysis. In the liver, 834 genes, and in the mammary gland, 862 genes were different (nominal P < 0.05) between PS and CON. In the liver, genes upregulated in PS functioned in cholesterol biosynthesis, endoplasmic reticulum stress, wound healing, and inflammation. Genes downregulated in liver function in cholesterol efflux. In the mammary gland, genes upregulated functioned in mRNA processing and transcription and downregulated genes encoded extracellular matrix proteins and proteases, cathepsins and lysosomal proteases, lipid transporters, and regulated oxidative phosphorylation. Increased cholesterol synthesis and decreased efflux suggest that circadian disruption potentially increases the risk of fatty liver in cows. Decreased remodeling and lipid transport in mammary may decrease milk production capacity during lactation.

Sensors in and around the environment becoming ubiquitous has ushered in the concept of smart animal agriculture which has the potential to greatly improve animal health and productivity using the concepts of remote health monitoring which is a necessity in times when there is a great demand for animal products. The data from in and around animals gathered from sensors dwelling in animal agriculture settings have made farms a part of the Internet of Things space. This has led to active research in developing efficient communication methodologies for farm networks. This study focuses on the first hop of any such farm network where the data from inside the body of the animals is to be communicated to a node dwelling outside the body of the animal. In this paper, we use novel experimental methods to calculate the channel loss of signal at sub-GHz frequencies of 100 - 900 MHz to characterize the in-body to out-of-body communication channel in large animals. A first-of-its-kind 3D bovine modeling is done with computer vision techniques for detailed morphological features of the animal body is used to perform Finite Element Method based Electromagnetic simulations. The results of the simulations are experimentally validated to come up with a complete channel modeling methodology for in-body to out-of-body animal body communication. The experimentally validated 3D bovine model is made available publicly on https://github.com/SparcLab/Bovine-FEM-Model.git GitHub. The results illustrate that an in-body to out-of-body communication channel is realizable from the rumen to the collar of ruminants with ≤ 90 dB path loss at sub-GHz frequencies ( 100-900 MHz) making communication feasible. The developed methodology has been illustrated for ruminants but can also be used for other related in-body to out-of-body studies. Using the developed channel modeling technique, an efficient communication architecture can be formed for in-body to out-of-body communication in animals which paves the way for the design and development of future smart animal agriculture systems.

Cows experience a significant negative protein balance during the first 30 d of lactation. Given the functional effects of AA on health, especially in challenging periods such as calving, higher levels of protein and specific AA in the diet may act to improve health and feed intake. The response of dairy cows to 3 protein supplementation strategies during the transition period and through the first 45 d in milk was evaluated. The final data set had 39 Holstein cows blocked based on parity (primiparous vs. multiparous) and expected calving and randomly assigned within each block to one of 3 dietary treatments: low protein (LP), high protein (HP), or high protein plus rumen-protected methionine (HPM). Treatments were offered from d -18 ± 5 to 45 d relative to parturition. Pre- and postpartum diets were formulated for high metabolizable protein (MP) supply from soybean meal, and HP and HPM provided higher MP balance than LP. Preplanned contrasts were LP versus HP+HPM and HP versus HPM. Significance was declared at P ≤ 0.05 and trends at 0.05

Metabolizable protein supply is a limiting factor for milk production in dairy cows, and the availability of AA is a function of the quantity of the metabolizable protein available and of hepatic AA catabolism. This study aimed to evaluate the effect of postruminal protein infusion on key genes for ureagenesis and AA catabolism. Six multiparous Holstein cows in early lactation were used in a replicated crossover design. Cows were fed a TMR and infused postruminally with either 0 or 600 g/d of milk protein isolate. Periods were 21 d long, consisting of 14 d of adjustment to surroundings, followed by 7 d of protein infusion. On the last day of each infusion, liver samples were collected for mRNA analysis and explant culture, milk samples were collected for mRNA analysis, and blood samples were collected for plasma metabolite analysis. Postruminal infusion of protein increased milk yield by 10.5%, milk fat yield by 12.5%, milk protein yield by 20%, milk lactose yield by 11%, and total solids yield by 15.5%. Postruminal infusion of protein increased milk urea N by 23.5%, blood urea N by 18.6%, and the abundance of hepatic ornithine transcarbamoylase mRNA by 52.8%. Postruminal infusion of protein did not alter the mRNA abundance of hepatic argininosuccinate synthase, α-aminoadipate semialdehyde synthase, cysteine sulfinic acid decarboxylase, or cystathionase. The abundance of RNA for milk proteins was unchanged with postruminal protein infusion. Metabolism of l -[U 14C] Lys to CO2 was increased by 127% (0.143 vs. 0.063 ± 0.04 nmol product·mg tissue−1·h−1), and the metabolism of l -[U 14C] Ala to CO2 increased by 40.5% (0.52 vs. 0.37 ± 0.06 nmol product·mg tissue−1·h−1) with postruminal protein infusion. The rate of l -[1-14C] Met oxidation did not differ. These data indicate increased ureagenesis matched by upregulation of nonessential AA catabolism and a disproportional increase in Lys oxidation in response to increased postruminal protein infusion.

An increase in bovine pyruvate carboxylase (PC; EC 6.4.1.1) at calving and during feed restriction corresponds with increased circulating nonesterified fatty acids as a consequence of negative energy balance. Regulation of PC mRNA and effect of specific combinations of saturated and unsaturated fatty acid profiles has yet to be explored. Our objective was to determine the effects of chain length, degree of saturation, and copresence of saturated and unsaturated fatty acids on activity of bovine PC promoter 1 (PCP1). For these experiments, Madin-Darby bovine kidney cells were transfected with a full-length bovine PCP1 construct from -1002 to +3 bp relative to the bovine PC gene transcription start site (bovine PCP1(-1002_+3)) ligated to a Firefly luciferase reporter, or with one of a series of nested 5' serial truncations (bovine PCP1(-773_+3), bovine PCP1(-494_+3), or bovine PCP1(-222_+3)). Cells were exposed for 23 h to either individual fatty acids (C16:0, C18:0, or C18:3n-3 cis) bound to BSA or to fatty acid mixtures in ratios of 90:10, 75:25, 50:50, or 25:75, corresponding to combinations of C16:0: C18:3n-3 cis or C18:0: C18:3n-3 cis. Total fatty acid concentration was 1.00 mM. Exposure to either C16:0 or C18:3n-3 cis alone elicited a significant increase in capacity to drive bovine PCP1(-1002_+3) activity compared with 1% BSA in Dulbecco's Modified Eagle's Medium control treatment (2.29, 2.89, and 1.00 ± 0.26 fold of promoter induction for C16:0, C18:3n-3 cis, and control, respectively). Treatment with C18:3n-3 cis alone caused a greater increase in promoter activity compared with C16:0 alone, indicating a lesser response to C16:0 alone for bovine PCP1(-1002_+3). Interestingly, inclusion of C18:3n-3 cis, at any level of fatty acid ratios examined, in combination with C16:0 increased promoter activity of bovine PCP1(-773_+3) or bovine PCP1(-222_+3) compared with treatment with C16:0 alone or control. Data from the bovine PCP1 truncation and fatty acid copresence experiments reveal the potential for response elements of unsaturated fatty acids or fatty acid ligands in several bovine PCP1 promoter regions. In silico analysis of bovine PCP1 identified putative peroxisome proliferator-activated receptor α and sterol regulatory element binding protein binding sites which may be implicated in fatty acid signaling to alter bovine PCP1 activity. Pyruvate carboxylase promoter 1 activity that is mediated by unsaturated fatty acids acting through elements within -1002 and -222 bp of bovine PCPI may determine PC response during periods of negative energy balance in dairy cows.

Metabolic fates of fatty acids in tissue may be influenced by extracellular concentration and profile of fatty acids. Previous work has demonstrated the ability of C18:3n-3 cis to ameliorate the effects of C16:0- or C18:0-induced depression of pyruvate carboxylase (PC) mRNA expression. Pyruvate carboxylase catalyzes oxaloacetate synthesis and connects gluconeogenesis from lactate and fatty acid metabolism. Our objective was to determine the effects of co-presence of saturated and unsaturated fatty acids on cellular partitioning of [1-14C]C16:0 metabolism to CO2 or acid-soluble products (ASP) in Madin-Darby bovine kidney cells and the role of PC in this relationship. We hypothesized that the ratio of saturated to unsaturated fatty acid pretreatments regulates [1-14C]C16:0 partitioning to CO2 or ASP. Cells were exposed for 21 h to either individual fatty acids, C16:0, C18:0, C18:1n-9 cis, or C18:3n-3 cis, or to fatty acid combinations in 10:90, 25:75, 50:50, 75:25, or 90:10 ratios for 3 combinations: C16:0/C18:3n-3 cis, C18:0/C18:3n-3 cis, or C18:1n-9 cis/C18:3n-3 cis. Total fatty acid concentration was 1.0 mM during the 21-h pretreatment phase. Following the 21-h incubation phase with fatty acid combinations, cells were incubated in the presence of 1.0 mM [1-14C]C16:0 for 3 h to determine the rate of metabolism to CO2 and ASP collection (per µg DNA-1·h-1). Pretreatment with either C16:0 or C18:0 alone significantly depressed subsequent oxidation of [1-14C]C16:0 to ASP by 62.7 and 41.2%, respectively, compared with C18:3n-3 cis pretreatment. Similar patterns were observed for [1-14C]C16:0 oxidation to CO2. Expression of PC mRNA was significantly decreased with exposure to either C16:0 or C18:0 compared with expression after exposure to either C18:3n-3 cis or control 1% BSA in Dulbecco's modified Eagle's medium. Expression of cytosolic phosphoenolpyruvate carboxykinase (PCK1) mRNA followed a similar pattern. Fatty acid treatments containing C18:1n-9 cis did not alter PC or PCK1 expression from control or C18:3n-3 cis results. Pearson coefficient correlations were determined for PC mRNA expression and rate of [1-14C]C16:0 metabolism to CO2 or ASP, including ketones, and for PCK1 mRNA expression and rate of [1-14C]C16:0 metabolism to CO2 or ASP. Production of CO2 from [1-14C]C16:0 was positively correlated (r = 0.63) with PC expression, whereas ASP production from [1-14C]C16:0 only tended to positively correlate (r = 0.51) with PC mRNA expression. Production of CO2 or ASP from [1-14C]C16:0 were both positively correlated (r = 0.80 and r = 0.69, respectively) with PCK1 expression. Results show a regulation of ketone production by Madin-Darby bovine kidney cells in response to saturated and unsaturated fatty acid pretreatments.

Regions of hypoxia are common in solid tumors and drive changes in gene expression that increase risk of cancer metastasis. Tumor cells must respond to the stress of hypoxia by activating genes to modify cell metabolism and antioxidant response to improve survival. The goal of the current study was to determine the effect of hypoxia on cell metabolism and markers of oxidative stress in metastatic (metM-Wntlung) compared with nonmetastatic (M-Wnt) murine mammary cancer cell lines. We show that hypoxia induced a greater suppression of glutamine to glutamate conversion in metastatic cells (13% in metastatic cells compared to 7% in nonmetastatic cells). We also show that hypoxia increased expression of genes involved in antioxidant response in metastatic compared to nonmetastatic cells, including glutamate cysteine ligase catalytic and modifier subunits and malic enzyme 1. Interestingly, hypoxia increased the mRNA level of the transaminase glutamic pyruvic transaminase 2 (Gpt2, 7.7-fold) only in metM-Wntlung cells. The change in Gpt2 expression was accompanied by transcriptional (4.2-fold) and translational (6.5-fold) induction of the integrated stress response effector protein activating transcription factor 4 (ATF4). Genetic depletion ATF4 demonstrated importance of this molecule for survival of hypoxic metastatic cells in detached conditions. These findings indicate that more aggressive, metastatic cancer cells utilize hypoxia for metabolic reprogramming and induction of antioxidant defense, including activation of ATF4, for survival in detached conditions.

Several cancers, including breast cancers, show dependence on glutamine metabolism. The purpose of the present study was to determine the mechanistic basis and impact of differential glutamine metabolism in nonmetastatic and metastatic murine mammary cancer cells. Universally labeled 13C5-glutamine metabolic tracing, qRT-PCR, measures of reductive–oxidative balance, and exogenous ammonium chloride treatment were used to assess glutamine reprogramming. Results show that 4 mM media concentration of glutamine, compared with 2 mM, reduced viability only in metastatic cells, and that this decrease in viability was accompanied by increased incorporation of glutamine-derived carbon into the tricarboxylic acid (TCA) cycle. While increased glutamine metabolism in metastatic cells occurred in tandem with a decrease in the reduced/oxidized glutathione ratio, treatment with the antioxidant molecule N-acetylcysteine did not rescue cell viability. However, the viability of metastatic cells was more sensitive to ammonium chloride treatment compared with nonmetastatic cells, suggesting a role of metabolic reprogramming in averting nitrogen cytotoxicity in nonmetastatic cells. Overall, these results demonstrate the ability of nonmetastatic cancer cells to reprogram glutamine metabolism and that this ability may be lost in metastatic cells.

Continuous real-time health monitoring in animals is essential for ensuring animal welfare. In ruminants like cows, rumen health is closely intertwined with overall animal health. Therefore, in-situ monitoring of rumen health is critical. However, this demands in-body to out-of-body communication of sensor data. In this paper, we devise a method of channel modeling for a cow using experiments and FEM based simulations at 400 MHz. This technique can be further employed across all frequencies to characterize the communication channel for the development of a channel architecture that efficiently exploits its properties.

An emerging hallmark of cancer is cellular metabolic reprogramming to adapt to varying cellular environments. Throughout the process of metastasis cancer cells gain anchorage independence which confers survival characteristics when detached from the extracellular matrix (ECM). Previous work demonstrates that the bioactive metabolite of vitamin D, 1α,25-dihydroxyvitamin D (1,25[OH]

Obesity and metabolic disorders caused by energy surplus pose an increasing concern within the global population. Brown adipose tissue (BAT) dissipates energy through mitochondrial non-shivering thermogenesis, thus representing a powerful agent against obesity. Here we explore the novel role of a mitochondrial outer membrane protein, LETM1-domain containing 1 (LETMD1), in BAT. We generated a knockout (Letmd1KO ) mouse model and analyzed BAT morphology, function and gene expression under various physiological conditions. While the Letmd1KO mice are born normally and have normal morphology and body weight, they lose multilocular brown adipocytes completely and have diminished mitochondrial abundance, DNA copy number, cristae structure, and thermogenic gene expression in the intrascapular BAT, associated with elevated reactive oxidative stress. In consequence, the Letmd1KO mice fail to maintain body temperature in response to acute cold exposure without food and become hypothermic within 4 h. Although the cold-exposed Letmd1KO mice can maintain body temperature in the presence of food, they cannot upregulate expression of uncoupling protein 1 (UCP1) and convert white to beige adipocytes, nor can they respond to adrenergic stimulation. These results demonstrate that LETMD1 is essential for mitochondrial structure and function, and thermogenesis of brown adipocytes.

Background: Throughout metastatic progression, cancer cells acquire anchorage independence, or the ability to survive detached from the extracellular matrix (ECM). While untransformed epithelial cells reduce energy metabolism when detached, cancer cells display metabolic flexibility to continue important metabolic processes. Glucose and glutamine are predominant nutrients utilized for energy as well as other purposes, and their metabolism is regulated by cancer cells.Methods: The purpose of the current studies was to determine the effects of detachment on glucose and glutamine metabolism in human breast epithelial MCF10A cells transfected with the Harvey-ras oncogene (MCF10A-ras), a model of early-stage cancer. Detachment was simulated with poly-HEMA coated plates, and intracellular metabolic flux was determined using stably labeled 13C5-glutamine and 13C6-glucose tracers.Results: Results show reduced glutamine flux in detached cells as determined by reduced accumulation of label in glutamate (21%), malate (30%), and aspartate (23%) from 13C5-glutamine. Detachment also reduced flux of 13C6-glucose to pyruvate and lactate pools by 51% and 29%, respectively. Similarly, detachment reduced total intracellular pool sizes of pyruvate (51%), lactate (49%), α-ketoglutarate (43%), fumarate (32%), malate (19%), alanine (35%), serine (35%), and glutamate (28%) compared to attached cells, but citrate and aspartate pool sizes were unchanged. Compared to attached cells, detachment increased pyruvate carboxylase (PC) mRNA abundance and protein expression by 131% and 190%, respectively. In detachment, PC activity, determined by 13C6-glucose derived M + 3 isotopomers, was shown to preferentially replenish malate and aspartate, but not citrate pools. In addition, doxycycline-inducible shRNA depletion of PC significantly decreased, while doxycycline-inducible PC overexpression significantly increased, detached cell viability. Further, a switch from glutamine to PC activity for anaplerosis was demonstrated, as supplementation with the cell permeable analog of the tricarboxylic acid cycle intermediate, α-ketoglutarate, a downstream metabolite of glutamine, decreased PC mRNA abundance in detached cells.Conclusion: Collectively, these results suggest that detached breast cancer cells increase PC activity in response to decreased glutamine-derived anaplerosis to promote cell survival.

Pyruvate carboxylase (PC) is a mitochondrial enzyme that catalyzes the ATP-dependent carboxylation of pyruvate to oxaloacetate (OAA), serving to replenish the tricarboxylic acid (TCA) cycle. In nonmalignant tissue, PC plays an essential role in controlling whole-body energetics through regulation of gluconeogenesis in the liver, synthesis of fatty acids in adipocytes, and insulin secretion in pancreatic β cells. In breast cancer, PC activity is linked to pulmonary metastasis, potentially by providing the ability to utilize glucose, fatty acids, and glutamine metabolism as needed under varying conditions as cells metastasize. PC enzymatic activity appears to be of particular importance in cancer cells that are unable to utilize glutamine for anaplerosis. Moreover, PC activity also plays a role in lipid metabolism and protection from oxidative stress in cancer cells. Thus, PC activity may be essential to link energy substrate utilization with cancer progression and to enable the metabolic flexibility necessary for cell resilience to changing and adverse conditions during the metastatic process.

Our objective was to determine the effects of uncouplers of oxidative phosphorylation on the metabolism of propionate in liver tissue of dairy cows in the postpartum period. A total of 8 primiparous dairy cows were biopsied for liver tissue explants in 2 block-design experiments. Cows were 5.9 ± 2.8 (mean ± SD) days in milk, and the 2 experiments were run concurrently. Treatments for experiment 1 were 10 μM 2,4-dinitrophenol methyl ether (DNPME) or propylene carbonate (vehicle control). Treatments for experiment 2 were 5 mM sodium salicylate (SAL) or no treatment (control). Explants were incubated in 2.5 mM [13C3]propionate with treatments and terminated after 0.5, 15, and 60 min of exposure to tracer. Treatment with DNPME had no effects on measured metabolites compared with control. Treatment with SAL increased total 13C% enrichment of succinate (3.03 vs. 2.45%), but tended to decrease total 13C% enrichment of fumarate (2.86 vs. 3.10%) and decreased total 13C% enrichment of malate (3.96 vs. 4.58%) compared with the control. Treatment with DNPME appeared to have no effects on hepatic propionate metabolism, and treatment with SAL may impair the succinate dehydrogenase reaction.

A more complete understanding of the molecular mechanisms that support milk synthesis is needed to develop strategies to efficiently and sustainably meet the growing global demand for dairy products. With the postulate that coding gene transcript abundance reflects relative importance in supporting milk synthesis, we analyzed the global transcriptome of early lactation cows across magnitudes of normalized RNA-Seq read counts. Total RNA was isolated from milk samples collected from early-lactation cows ( n = 6) following two treatment periods of postruminal lysine infusion of 0 or 63 g/day. Twelve libraries were prepared and sequenced on an Illumina NovaSeq6000 platform using paired end reads. Normalized read counts were averaged across both treatments, because EBseq analysis found no significant effect of lysine infusion. Approximately 10% of the total reads corresponded to 12,730 protein coding transcripts with a normalized read count mean ≥5. For functional annotation analysis, the protein coding transcripts were divided into nine categories by magnitude of reads. The 13 most abundant transcripts (≥50K reads) accounted for 67% of the 23M coding reads and included casein and whey proteins, regulators of fat synthesis and secretion, a ubiquitinating protein, and a tRNA transporter. Mammalian target of rapamycin, JAK/STAT, peroxisome proliferator-activated receptor alpha, and ubiquitin proteasome pathways were enriched with normalized reads ≥100 counts. Genes with ≤100 reads regulated tissue homeostasis and immune response. Enrichment in ontologies that reflect maintenance of translation, protein turnover, and amino acid recycling indicated that proteostatic mechanisms are central to supporting mammary function and primary milk component synthesis.

Cytosolic phosphoenolpyruvate carboxykinase (PCK1) is a key enzyme for gluconeogenesis that is positively regulated by propionate in bovines at the transcription level. The specific elements that determine propionate responsiveness within the bovine PCK1 promoter are unknown. In silico promoter analysis of the bovine PCK1 gene revealed several clusters of transcription factor binding sites. In the present study, we determined the essentiality of the putative cyclic AMP response element (CRE) at -94 through -87 bp and the 2 putative hepatic nuclear factor 4α (HNF4α) binding elements at +68 through +72 and -1,078 through -1,074, respectively, in mediating bovine PCK1 promoter responses to propionate and other regulators, including butyrate, cyclic AMP (cAMP), and glucocorticoids. The wild-type bovine PCK1 promoter [PCK1(WT)] was ligated to a luciferase reporter gene and transfected into rat hepatoma (H4IIE) cells. Activities of PCK1(WT) were induced by approximately 2-, 2-, 4-, 8-, 9-, 18-, and 16-fold respectively when exposed to cAMP (as 1.0 mM 8-Br-cAMP), 5.0 μM dexamethasone, cAMP + dexamethasone, 2.5 mM propionate, cAMP + propionate, cAMP + dexamethasone + propionate, and 2.5 mM butyrate. Seven mutants lacking either one single site, 2 of the 3 sites, or all 3 sites, generated by site-directed mutagenesis, were tested. Responses to propionate and all other treatments were completely abolished when CRE at -94 through -87 bp and HNF4α at +68 through +72 bp were both deleted. Our data indicate that these 2 regulatory elements act synergistically to mediate the bovine PCK1 promoter responses to propionate as well as butyrate, cAMP, and dexamethasone. The activation of PCK1 through these regulatory elements serves to activate the metabolic potential of bovine toward gluconeogenesis when the primary substrate for gluconeogenesis, propionate, is also present.

Our objective was to determine the temporal effects of increasing supply of propionate on propionate metabolism in liver tissue of dairy cows in the postpartum (PP) period. A total of 6 dairy cows [primiparous: n = 3, 9.00 ± 1.00 d PP (mean ± SD) and multiparous: n = 3; 4.67 ± 1.15 d PP] were biopsied for liver explants in a block-design experiment. Explants were treated with 3 concentrations of [13C3]sodium propionate of 1, 2, or 4 mM. Explants were incubated in 2 mL of Medium 199 supplemented with 1% BSA, 0.6 mM oleic acid, 2 mM sodium l-lactate, 0.2 mM sodium pyruvate, and 0.5 mMl-glutamine at 38°C and sampled at 0.5, 15, and 60 min. Increasing the concentration of [13C3]propionate increased total 13C% enrichment of propionyl coenzyme A (CoA), succinate, fumarate, malate, and citrate with time. Concentration of propionate did not affect total 13C% enrichment of hepatic glucose or acetyl CoA, but total 13C% enrichment increased with time for hepatic glucose. The 13C labeling from propionate was incorporated into acetyl CoA, but increased concentrations of propionate did not result in greater labeling of acetyl CoA. However, increases in 13C% enrichment of [M+4]citrate and [M+5]citrate concentrations of [13C3]propionate indicate propionate conversion to acetyl CoA and subsequent entry of acetyl CoA into the tricarboxylic acid cycle in dairy cows in the PP period. This research presents evidence that despite an increase in hepatic acetyl CoA concentration and general consensus on the upregulation of gluconeogenesis of dairy cows during the PP period, carbon derived from propionate contributes to the pool of acetyl CoA, which increases as concentration of propionate increases, in addition to stimulating oxidation of acetyl CoA from other sources. Because of the hypophagic effects of propionate, but importance of propionate as a glucose precursor, a balance of propionate supply to dairy cows could lead to improvements in dry matter intake, and subsequently, health and production in dairy cows.

It is well established that adipose tissue can both store and metabolize vitamin D. The active form of vitamin D, 1,25 dihydroxyvitamin D [1,25(OH)2D], regulates adipocyte differentiation and inflammation, highlighting the multifaceted role that vitamin D plays in adipose tissue physiology. However, there is limited evidence regarding vitamin D regulation of mature adipocyte lipid metabolism. We hypothesize that 1,25(OH)2D alters lipid and glucose metabolism in differentiated 3T3-L1 adipocytes to reduce triacylglycerol (TAG) accumulation. In this study, 1,25(OH)2D (10 nmol/L) stimulated a 21% reduction in TAG accumulation in differentiated 3T3-L1 adipocytes after 4 days (P = .01) despite a significant increase in fatty acid uptake (P

The Earth is at a sociotechnical crossroads with humanity hanging in the balance – and high-tech agriculture can help bail us out. Human population growth, increasing urbanization and rising incomes is likely to drastically increase demand for animal agriculture in the coming decades. The US Department of Agriculture (USDA) predicts the need to double global food production by 2050 as the global population increases from 7.3 billion in 2015 to 9.7 billion in 2050 as shown in Fig 1. Much of this growth will be concentrated in the world’s poorest countries where standards of living are set to rise rapidly, increasing the demand for resource-intensive meat and dairy products which has been the historical trend. At the same time, agriculture in the 21st century faces multiple challenges: it must produce more food and fiber to feed a growing population with a smaller rural labor force, produce additional feedstocks for a potentially huge bioenergy market, contribute to overall development in the many agriculture-dependent developing countries, adopt more efficient and sustainable production methods, and adapt to climate change. Additionally, the world’s arable land is already fully employed and shrinking -- the world has lost a third of its arable land due to erosion or pollution in the past 40 years. All these factors put enormous pressure on improving the production efficiency of the world’s supply of food to meet the demand.

Maintaining reductive-oxidative (redox) balance is an essential feature in breast cancer cell survival, with cellular metabolism playing an integral role in maintaining redox balance through its supply of reduced NADPH. In the present studies, the effect of 1,25-dihydroxyvitamin D (1,25(OH)2D) on redox balance was investigated in early stages of breast cancer. Treatment with 1,25(OH)2D promoted oxidative stress in MCF10A-ras and MCF10A-ErbB2 breast epithelial cells, as measured by the decreased ratios of NADPH/NADP+ and reduced to oxidized glutathione (GSH/GSSG). The mRNA and protein expression of the enzyme pyruvate carboxylase (PC) was downregulated with 1,25(OH)2D treatment, suggesting a potential mechanism. Genetic depletion of PC in MCF10A-ras cells resulted in a decreased ratio of NADPH/NADP+ and GSH/GSSG, with 1,25(OH)2D treatment having no further effect. Mutation analysis confirmed the presence and functionality of a vitamin D response element in the PC gene promoter region. Collectively, these results provide evidence that 1,25(OH)2D promotes oxidative stress in early breast cancer progression through transcriptional downregulation of PC.

The objective for this study was to determine the effect of glucose dose and days following peak milk yield on plasma glucose, serum insulin, and plasma nonesterified fatty acids (NEFA) kinetics during an intravenous glucose tolerance test (IVGTT) in lactating dairy cattle. Six lactating Holstein dairy cows (3 primiparous and 3 multiparous) were assigned to 2 squares and received 0.092, 0.15, or 0.3 g of glucose/kg of body weight (BW) during an IVGTT at 74 and 221 d in milk (DIM), representing early (post-peak) lactation and mid lactation, respectively. Treatments were applied in a replicated Latin square design using contiguous 7-d periods within each stage of lactation. Milk production and dry matter intake were determined daily during the first 6 d of each period. The IVGTT was performed on d 7. For the IVGTT, cows were prepared with indwelling catheters in each jugular vein, and blood samples were collected at −15, −10, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min relative to the glucose infusion. Samples were analyzed for plasma glucose, serum insulin, and plasma NEFA concentrations. Increasing the glucose dose during the IVGTT increased plasma glucose area under the curve (AUC), decreased glucose half-life, and increased maximal plasma glucose concentrations in plasma during the IVGTT. Greater glucose dose during the IVGTT elevated serum insulin AUC and increased nadir NEFA concentrations. Maximal plasma glucose concentration during the IVGTT was lower, whereas maximum NEFA concentration, NEFA AUC, and NEFA clearance rate were greater at 74 than at 221 DIM. Only glucose half-life was responsive to stage of lactation × glucose dose effects during the IVGTT, and the decrease in glucose half-life with increasing glucose dose was greater at 74 than at 221 DIM. Glucose AUC was greater and NEFA AUC lower for cows at 74 than at 221 DIM. For the doses tested, a glucose dose greater than 0.092 g/kg of BW resulted in peak blood glucose concentration that exceeded the previously reported renal glucose excretion threshold of 8.3 mM. There is a need for accompanying data to determine if this is the case for the glucose doses evaluated in this experiment. Based on maximal peak glucose concentrations and effects on glucose half-life, we identify 0.092 g of glucose/kg of BW (0.46 g/kg of metabolic body weight) as the preferred dose for the IVGTT for cows at 74 and 221 DIM in this study.

Introduction Meat consumption has been steadily increasing since the 1960s1. As living standards and income levels rise, more people include meat into their diet. Although an important source of nutrients, livestock production has a negative influence on greenhouse gas emissions, water consumption, water pollution, and more, with cattle being the main culprits2. However, while farming practices have improved over the last 60 years resulting in improved efficiencies in water, land, and crop use, studies suggest that cattle farmers can do more to reduce their overall environmental impact towards more sustainable production of animal protein3. The primary value of ruminants in the food chain is their ability to convert non-protein nitrogen, cellulose-rich carbohydrates, and other precursors to a digestible form of protein for human consumption. This is achieved through bacterial fermentation in the rumen that converts nitrogen (ammonia) to bacterial protein, which provides the animal with an essential protein supply to support growth and thereby meat and milk production for human consumption. Too little ammonia in the rumen limits bacterial protein synthesis. However, excess ammonia is converted to urea, which is excreted urine, and is an environmental burden. Excess nitrogen in manure is released to the atmosphere and is part of the issue with nitrogen runoff4. Our group is currently developing robotic technologies, termed RUMENS (Rumen Understanding through Millipede-Engineered Navigation and Sensing), to enable live, in vivo mapping of the ruminal environment, based on a suite of commercial and custom built sensors, of various compounds present in rumen5. Here, we propose a miniature, rapid update zinc oxide (ZnO) film-based sensor for real-time liquid ammonia detection in the rumen. Method Zinc acetate (ZnAc) and 2-methoxyethanol (2ME) were purchased from VWR, ethanolamine and ammonium hydroxide solution (28%) were purchased from Sigma Aldrich. All chemicals were used as received without any purification. Planar electrodes (inset of Figure 1), with dimensions of 1-mm-long and 2.54-mm-wide, were obtained from thermally evaporated Cr and Au on cleaned glass substrate, with the thicknesses of 3 nm and 50 nm, respectively. For ZnO layer deposition, 140 mg of ZnAc was dissolved in 1 mL of 2ME and 45 μL of ethanolamine at 60 °C for about 8 hours. The solution was spin cast at 600 rpm for 60 seconds. After manually patterning between two adjacent devices (to avoid crosstalk), the sample was then placed on a hot plate set to 300 °C in air for 10 minutes. After removal and cooling, the samples were rinsed consecutively in deionized H2O, acetone, ethanol, and IPA for 10 seconds each and then dried on a hotplate in air for 10 minutes at 200 °C6. An impedance measurement, using RLC meter (NF ZM 2372), was used to test the resistance with different ammonium concentrations. Ammonia of 10-1, 10-2, 10-3 and 10-4 M were prepared by diluting a known amount of ammonium hydroxide solution in DI water. A 3 μL of analyte was dropped onto the ZnO layer, directly between two planar gold electrodes. Devices were thoroughly (5 minutes) washed in DI water between measurements. Results and Conclusions Figure 1 shows the relationship between channel impedance (Z’) and concentration of ammonia at different scan frequencies, ranging from 1 to 100 kHz. The measurements reveal that at a fixed frequency, the impedance decreases with increased ammonia concentration. Also, at a single concentration, at low frequencies ( A possible sensing mechanism is the nitrification of NH4 + into nitrate ions, NO3 -, with nitrification reaction: NH4 + + 2O2 → NO3 - + H2O + 2H+. The energy released during oxidation should be sufficient for electrons to jump to the conduction band, resulting in decreasing of resistivity proportional to concentration of ammonia7. These results indicate a suitable device for aqueous ammonia detection in rumen. References Gerten, D.; Heck, V.; Jägermeyr, J.; Bodirsky, B. L.; Fetzer, I.; Jalava, M.; Kummu, M.; Lucht, W.; Rockström, J.; Schaphoff, S.; Schellnhuber, H. J., Feeding ten billion people is possible within four terrestrial planetary boundaries. Nature Sustainability 2020, 3 (3), 200-208. Gerber, P. J.; Steinfeld, H.; Henderson, B.; Mottet, A.; Opio, C.; Dijkman, J.; Falcucci, A.; Tempio, G. Tackling Climate Change Through Livestock - A Global Assessment of Emissions And Mitigation Opportunities; Food and Agriculture Organization of the United Nations: Rome, 2013. González, N.; Marquès, M.; Nadal, M.; Domingo, J. L., Meat consumption: Which are the current global risks? A review of recent (2010–2020) evidences. Food Research International 2020, 137, 109341. Schwab, C. G.; Broderick, G. A., A 100-Year Review: Protein and amino acid nutrition in dairy cows. Journal of Dairy Science 2017, 100 (12), 10094-10112. Balakuntala, M. V.; Ayad, M.; Voyles, R. M.; White, R.; Nawrocki, R.; Sundaram, S.; Priya, S.; Chiu, G.; Donkin, S.; Min, B.-C.; Daniels, K., Global Sustainability through Closed-Loop Precision Animal Agriculture. Mechanical Engineering 2018, 140 (06), S19-S23. Nawrocki, R. A.; Galiger, E. M.; Ostrowski, D. P.; Bailey, B. A.; Jiang, X.; Voyles, R. M.; Kopidakis, N.; Olson, D. C.; Shaheen, S. E., An inverted, organic WORM device based on PEDOT:PSS with very low turn-on voltage. Organic Electronics 2014, 15 (8), 1791-1798. Franco, F. F.; Manjakkal, L.; Shakthivel, D.; Dahiya, R. In ZnO based Screen Printed Aqueous Ammonia Sensor for Water Quality Monitoring, 2019 IEEE Sensors, 2019; pp 1-4. Fig 1. Impedance vs frequency of ammonia sensor as characterized for different concentrations. Figure 1

Both increased de novo fatty acid synthesis and higher neutral lipid accumulation are a common phenotype observed in aggressive breast cancer cells, making lipid metabolism a promising target for breast cancer prevention. In the present studies we demonstrate a novel effect of the active metabolite of vitamin D, 1α,25-dihydroxyvitamin D (1,25(OH)2D) on lipid metabolism in malignant breast epithelial cells. Treatment of MCF10CA1a breast epithelial cells with 1,25(OH)2D (10 nM) for five and seven days decreased the level of triacylglycerol, the most abundant form of neutral lipids, by 20%(±3.9) and 50%(±5.9), respectively. In addition, 1,25(OH)2D treatment for five days decreased palmitate synthesis from glucose, the major fatty acid synthesized de novo (48%±5.5 relative to vehicle). We have further identified the anaplerotic enzyme pyruvate carboxylase (PC) as a target of 1,25(OH)2D mediated regulation and hypothesized that 1,25(OH)2D regulates breast cancer cell lipid metabolism through inhibition of PC. PC mRNA expression was downregulated with 1,25(OH)2D treatment at two (73%±6 relative to vehicle) and five (56%±8 relative to vehicle) days. Decrease in mRNA abundance corresponded with a decrease in PC protein expression at five days of treatment (54%±12 relative to vehicle). Constitutive overexpression of PC in MCF10CA1a cells using a pCMV6-PC plasmid inhibited the effect of 1,25(OH)2D on both TAG accumulation and de novo palmitate synthesis from glucose. Together, these studies demonstrate a novel mechanism through which 1,25(OH)2D regulates lipid metabolism in malignant breast epithelial cells.

Lysine supply is potentially limiting for milk production in dairy cows. The availability of Lys to the mammary gland and other tissues is a function of the quantity of metabolizable Lys supplied and Lys catabolism by the liver. Likewise, Lys catabolism may be influenced by Lys supply. This study evaluated the effect of increased postruminal Lys supply on the expression of aminoadipate semialdehyde synthase (AASS, a committing step in Lys catabolism in the liver) and ornithine transcarbamoylase and argininosuccinate synthase (key urea cycle enzymes that are responsive to protein supply). Eight multiparous peak Holstein cows were used in a replicated 4 × 4 Latin square. Cows were fed a Lys-limiting ration and infused postruminally with 0, 9, 27, or 63 g/d of Lys. The study consisted of 10 d of pretreatment followed by 10 d of Lys infusion. On the last day of each period, liver and milk samples were collected for mRNA analysis, and blood samples were collected for analysis of amino acids and Lys metabolites. Milk protein percent increased by 5.9%, plasma Lys increased by 74%, and α-aminoadipic acid increased by 51% with postruminal infusion of 63 g/d Lys compared with 0 g/d. Expression of AASS, ornithine transcarbamoylase, and argininosuccinate synthase mRNA in liver did not differ with postruminal infusion of Lys. Milk fat globule mRNA for major milk proteins and AASS were not affected by Lys infusion. Postruminal infusion of Lys resulted in an 86% greater increase in AASS mRNA in the liver compared with mammary mRNA. These changes suggest that hepatic Lys metabolism is not responsive to Lys supply at the transcription level, and that the availability of Lys to extrahepatic tissue may be determined by hepatic Lys metabolism.

Breast cancer is the second most common cancer among women in the US. The active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D), is proposed to inhibit cellular processes and to prevent breast cancer. The current studies investigated the effect of 1,25(OH)2D on glutamine metabolism during cancer progression employing Harvey-ras oncogene transformed MCF10A human breast epithelial cells (MCF10A-ras). Treatment with 1,25(OH)2D significantly reduced intracellular glutamine and glutamate levels measured by nuclear magnetic resonance (NMR) by 23 ± 2% each. Further, 1,25(OH)2D treatment reduced glutamine and glutamate flux, determined by [U-13C5] glutamine tracer kinetics, into the TCA cycle by 31 ± 0.2% and 17 ± 0.4%, respectively. The relative levels of mRNA and protein abundance of the major glutamine transporter, solute linked carrier family 1 member A5 (SLC1A5), was significantly decreased by 1,25(OH)2D treatment in both MCF10A-ras cells and MCF10A which overexpress ErbB2 (HER-2/neu). Consistent with these results, glutamine uptake was reduced by 1,25(OH)2D treatment and the impact was eliminated with the SLC1A5 inhibitor L-γ-Glutamyl-p-nitroanilide (GPNA). A consensus sequence to the vitamin D responsive element (VDRE) was identified in silico in the SLC1A5 gene promoter, and site-directed mutagenesis analyses with reporter gene studies demonstrate a functional negative VDRE in the promoter of the SLC1A5 gene. siRNA-SLC1A5 transfection in MCF10A-ras cells significantly reduced SLC1A5 mRNA expression as well as decreased viable cell number similar to 1,25(OH)2D treatment. SLC1A5 knockdown also induced an increase in apoptotic cells in MCF10A-ras cells. These results suggest 1,25(OH)2D alters glutamine metabolism in MCF10A-ras cells by inhibiting glutamine uptake and utilization, in part through down-regulation of SLC1A5 transcript abundance. Thus, 1,25(OH)2D down-regulation of the glutamine transporter, SLC1A5, may facilitate vitamin D prevention of breast cancer.

Cytosolic phosphoenolpyruvate carboxykinase (PCK1) is a critical enzyme within the metabolic networks for gluconeogenesis, hepatic energy metabolism, and tricarboxylic acid cycle function, and is controlled by several transcription factors including hepatic nuclear factor 4α (HNF4α). The primary objective of the present study was to determine whether propionate regulates bovine PCK1 transcription. The second objective was to determine the action of cyclic AMP (cAMP), glucocorticoids, and insulin, hormonal cues known to modulate glucose metabolism, on bovine PCK1 transcriptional activity. The proximal promoter of the bovine PCK1 gene was ligated to a Firefly luciferase reporter and transfected into H4IIE hepatoma cells. Cells were exposed to treatments for 23 h and luciferase activity was determined in cell lysates. Activity of the PCK1 promoter was linearly induced by propionate, and maximally increased 7-fold with 2.5 mM propionate, which was not muted by 100 nM insulin. Activity of the PCK1 promoter was increased 1-fold by either 1.0 mM cAMP or 5.0µM dexamethasone, and 2.2-fold by their combination. Induction by cAMP and dexamethasone was repressed 50% by 100 nM insulin. Propionate, cAMP, and dexamethasone acted synergistically to induce the PCK1 promoter activity. Propionate-responsive regions, identified by 5' deletion analysis, were located between -1,238 and -409 bp and between -85 and +221 bp. Deletions of the core sequences of the 2 putative HNF4α sites decreased the responsiveness to propionate by approximately 40%. These data indicate that propionate regulates its own metabolism through transcriptional stimulation of the bovine PCK1 gene. This induction is mediated, in part, by the 2 putative HNF4α binding sites in the bovine PCK1 promoter.

Mounting evidence indicates that maternal exercise confers protection to adult offspring against various diseases. Here we hypothesized that maternal exercise during gestation would reduce high-fat diet (HFD)-induced hepatic steatosis in adult rat offspring.Following conception, pregnant dams were divided into either voluntary wheel running exercise (GE) or wheel-locked sedentary (GS) groups throughout gestation (days 4-21). Post-weaning, offspring received either normal chow diet (CD; 10% fat, 70% carbohydrate, 20% protein) or HFD (45% fat, 35% carbohydrate, and 20% protein) until sacrificed at 4- or 8-months of age.GE did not affect offspring birth weight or litter size. HFD feeding in offspring increased weight gain, body fat percentage, and glucose tolerance test area under the curve (GTT-AUC). Male offspring from GE dams had reduced body fat percentage across all ages (p0.05). In addition, 8-month male offspring from GE dams were protected against HFD-induced hepatic steatosis, which was associated with increased markers of hepatic mitochondrial biogenesis (PGC-1α and TFAM), autophagic potential (ATG12:ATG5 conjugation) and hepatic triacylglycerol secretion (MTTP).The current study provides the first evidence that gestational exercise can reduce susceptibility to HFD-induced hepatic steatosis in adult male offspring.

Nutritional status and glucose precursors are known regulators of gluconeogenic gene expression. Glycerol can replace corn in diets fed to dairy cows and use of glycerol is linked to increased rumen propionate production. The effect of dietary glycerol on the regulation of gluconeogenic enzymes is unknown. The objective of this study was to examine the effect of glycerol on expression of pyruvate carboxylase (PC), cytosolic and mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-C and PEPCK-M), and glucose-6-phosphatase. Twenty-six multiparous Holstein cows were fed either a control diet or a diet where high-moisture corn was replaced by glycerol from -28 through +56 d relative to calving (DRTC). Liver tissue was collected via percutaneous liver biopsy at -28, -14, +1, +14, +28, and +56 DRTC for RNA analysis. Expression of PC mRNA increased 6-fold at +1 and 4-fold at +14 DRTC relative to precalving levels. Dietary glycerol did not alter expression of PC mRNA expression. Expression of PEPCK-C increased 2.5-fold at +14 and 3-fold at +28 DRTC compared with +1 DRTC. Overall, dietary glycerol increased PEPCK-C expression compared with that of cows fed control diets. The ratio of PC to PEPCK-C was increased 6.3-fold at +1 DRTC compared with precalving and tended to be decreased in cows fed glycerol. We detected no effect of diet or DRTC on PEPCK-M or glucose-6-phosphatase mRNA, and there were no interactions of dietary treatment and DRTC for any transcript measured. Substituting corn with glycerol increased the expression of PEPCK-C mRNA during transition to lactation and suggests that dietary energy source alters hepatic expression. The observed increase in PEPCK-C expression with glycerol feeding may indicate regulation of hepatic gene expression by changes in rumen propionate production.

Elevated needs for glucose in lactating dairy cows are met through a combination of increased capacity for gluconeogenesis and increased supply of gluconeogenic precursors, primarily propionate. This study evaluated the effects of propionate on mRNA expression of cytosolic phosphoenolpyruvate carboxykinase (PCK1), mitochondrial phosphoenolpyruvate carboxykinase (PCK2), pyruvate carboxylase (PC), and glucose-6-phosphatase (G6PC), key gluconeogenic enzymes, and capacity for glucose synthesis in liver of dairy cattle. In experiment 1, six multiparous mid-lactation Holstein cows were used in a replicated 3×3 Latin square design consisting of a 6-d acclimation or washout phase followed by 8h of postruminal infusion of either propionate (1.68mol), glucose (0.84mol), or an equal volume (10mL/min) of water. In experiment 2, twelve male Holstein calves [39±4 kg initial body weight (BW)] were blocked by birth date and assigned to receive, at 7d of age, either propionate [2mmol·h(-1)·(BW(0.75))(-1)], acetate [3.5mmol·h(-1)·(BW(.75))(-1)], or an equal volume (4mL/min) of saline. In both experiments, blood samples were collected at 0, 2, 4, 6, and 8h relative to the start of infusion and liver biopsy samples were collected at the end of the infusion for mRNA analysis. Liver explants from experiment 1 were used to measure tricarboxylic acid cycle flux and gluconeogenesis using (13)C mass isotopomer distribution analysis from (13)C3 propionate. Dry matter intake and milk yield were not altered by infusions in cows. Serum insulin concentration in cows receiving propionate was elevated than cows receiving water, but was not different from cows receiving glucose. Hepatic expression of PCK1 and G6PC mRNA and glucose production in cows receiving propionate were not different from cows receiving water, but tended to be higher compared with cows receiving glucose. Hepatic expression of PCK2 and PC mRNA was not altered by propionate infusion in cows. Blood glucose, insulin, and glucagon in calves receiving propionate were not different than controls. Calves receiving propionate had increased PCK1 mRNA, tended to have increased G6PC mRNA, and had similar PC mRNA compared with saline controls. These data indicate a tendency for in vivo effects of propionate to alter hepatic gene expression in mid-lactation cows and neonatal calves, which are consistent with a feed-forward effect of propionate to regulate its own metabolism toward gluconeogenesis through changes in hepatic PCK1 mRNA.

Heat stress (HS) results from excessive heat load on animals such that all adaptive mechanisms used to dissipate the heat do not return the body to normal body temperature. In pigs, HS results in increased fat deposition compared with pair-fed animals in a thermoneutral environment. Although there is evidence that HS increases activity of lipoprotein lipase (LPL) in adipose tissue of heat stressed pigs, the fundamental causes of the increased adiposity are still unknown. It remains unclear whether HS directly alters metabolism in adipocytes. Therefore, to understand the mechanism of HS effects on porcine adipocytes, we used an in vitro adipocyte differentiation model to characterize cellular responses that occur during differentiation of pig adipocytes. Preadipocytes (stromovascular cells) were differentiated for 9 d at a normal (37°C) or HS (41.5°C) temperature under 5% CO. Expressions of HS genes such as heat shock proteins (HSP; HSP27, HSP60, HSP70, and HSP90), adipogenic markers peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding proteins α (C/EBPα), fatty acid synthase (FAS), adipocyte protein 2 (aP2), fatty acid translocase 36 (CD36), fatty acid transport protein 4 (FATP4), fatty acid transport protein 6 (FATP6), LPL, glucose transporter protein type 4 (GLUT4), phosphoenolpyruvate carboxykinase 1 (PCK1 or PEPCK-C), and glycerol kinase (GK) and adipokines (adiponectin and leptin) were determined by real-time-PCR and immunoblotting or ELISA. Cellular triglyceride (TAG) and ATP concentrations were also determined. As expected, HS increased ( < 0.05) the expressions of HSP genes. There was no HS treatment effect on the level of PPARγ, although C/EBPα was induced ( < 0.05) in HS. So it remains unclear whether HS affects adipocyte differentiation. However, HS leads to increased expressions of genes involved in fatty acid uptake and TAG synthesis (FAS, aP2, CD36, FATP4, FATP6, LPL, GLUT4, PCK1, and GK). This is supported by increased cellular TAG under HS. Therefore, HS promotes increased adipocyte TAG storage, perhaps through upregulation of genes involved in fatty acid uptake and TAG synthesis.

Chemical treatment may improve the nutritional value of corn crop residues, commonly referred to as corn stover, and the potential use of this feed resource for ruminants, including lactating dairy cows. The objective of this study was to determine the effect of prestorage chopping, hydration, and treatment of corn stover with Ca(OH)2 on the feeding value for milk production, milk composition, and dry matter intake (DMI). Multiparous mid-lactation Holstein cows (n = 30) were stratified by parity and milk production and randomly assigned to 1 of 3 diets. Corn stover was chopped, hydrated, and treated with 6% Ca(OH)2 (as-fed basis) and stored in horizontal silo bags. Cows received a control (CON) total mixed ration (TMR) or a TMR in which a mixture of treated corn stover and distillers grains replaced either alfalfa haylage (AHsub) or alfalfa haylage and an additional portion of corn silage (AH+CSsub). Treated corn stover was fed in a TMR at 0, 15, and 30% of the diet DM for the CON, AHsub, and AH+CSsub diets, respectively. Cows were individually fed in tiestalls for 10 wk. Milk production was not altered by treatment. Compared with the CON diet, DMI was reduced when the AHsub diet was fed and tended to be reduced when cows were fed the AH+CSsub diet (25.9, 22.7, and 23.1 ± 0.88 kg/d for CON, AHsub, and AH+CSsub diets, respectively). Energy-corrected milk production per unit of DMI (kg/kg) tended to increase with treated corn stover feeding. Milk composition, energy-corrected milk production, and energy-corrected milk per unit of DMI (kg/kg) were not different among treatments for the 10-wk feeding period. Cows fed the AHsub and AH+CSsub diets had consistent DMI over the 10-wk treatment period, whereas DMI for cows fed the CON diet increased slightly over time. Milk production was not affected by the duration of feeding. These data indicate that corn stover processing, prestorage hydration, and treatment with calcium hydroxide can serve as an alternative to traditional haycrop and corn silage in diets fed to mid-lactation dairy cows.

Plant extracts (PE) are naturally occurring chemicals in plants, and many of these molecules have been reported to influence production efficiency of dairy and beef animals. Two experiments were conducted to determine the effect of a PE additive (CE; an encapsulated blend of cinnamaldehyde and eugenol) on the milk production performance of lactating dairy cows across a range of doses. In experiment 1, 32 Holstein multiand primiparous dairy cows in mid-lactation were assigned to no additive or supplementation with CE (350 mg/d; n = 16 cows/treatment) for 6 wk. In experiment 2, 48 Holstein multi- and primiparous dairy cows were assigned to no additive or supplementation with CE (200, 400, or 600 mg/d; n = 12 animals/treatment) for 8 wk. A 1-wk covariate period was included in both experiments. In both experiments, individual dry matter intake (DMI), milk production, milk composition, and somatic cell count were recorded daily. In experiment 1, CE was associated with an increase in DMI in both parity groups but an increase in milk production of multiparous cows only. In experiment 2, milk yield of multiparous cows was decreased at the 2 highest doses, whereas milk yield of primiparous cows was increased at the low and high doses of CE. These responses were accompanied by similar changes in DMI; therefore, CE did not affect feed efficiency. We observed no effect of CE on SCC or milk composition; however, treatment by parity interactions were detected for each of these variables that have not been described previously. Based on the results of these experiments, we conclude that a blend of cinnamaldehyde and eugenol can increase DMI and milk production in lactating dairy cows. In addition, environmental factors appear to influence the response to CE, including dose and parity, and these should be explored further.

Few data exist on the impact of maternal weight gain on offspring despite evidence demonstrating that early-life environment precipitates risks for metabolic syndrome. We hypothesized that excessive weight gain during pregnancy results in programming that predisposes offspring to obesity and metabolic syndrome. We further hypothesized that early postweaning nutrition alters the effects of maternal weight gain on indications of metabolic syndrome in offspring. Pregnant sows and their offspring were used for these experiments due to similarities with human digestive physiology, metabolism, and neonatal development. First parity sows fed a high-energy (maternal nutrition high energy [MatHE]) diet gained 12.4 kg (42%) more weight during pregnancy than sows fed a normal energy (maternal nutrition normal energy) diet. Birth weight and litter characteristics did not differ, but offspring MatHE gilts weighed more (P < .05) at age of 3 weeks (4.35 vs 5.24 ± 0.35 kg). At age of 12 weeks, offspring from MatHE mothers that were weaned onto a high-energy diet had elevated (P < .05) blood glucose (102 vs 64 mg/dL, confidence interval [CI]: 67-91), insulin (0.21 vs 0.10 ng/mL, CI: 0.011-0.019), and lower nonesterified fatty acid (0.31 vs 0.62 mmol/L, CI: 0.34-0.56) than offspring from the same MatHE sows weaned to the normal energy diet. These effects were not observed for offspring from sows fed a normal energy diet during pregnancy. These data indicate that excessive gestational weight gain during pregnancy in a pig model promotes early indications of metabolic syndrome in offspring that are further promoted by a high-energy postweaning diet.

Recent growth in the ethanol industry has led to increased availability of distillers grains that have undergone various processing methods resulting in differing nutrient composition. A modified dried distillers grains product with reduced fat due to removing oil through a solvent extraction process provides a new feed option for dairy heifers. The objective of this study was to evaluate intake, feed efficiency, and growth of dairy heifers fed diets containing reduced-fat dried distillers grains with solubles (RFDGS). Holstein heifers (n = 27), averaging 161 ± 9 d of age and 157.5 ± 11.4 kg at the start of the study, were blocked according to BW and fed 1 of 3 dietary treatments. Dietary treatments included control, dried distillers grains fed at 20% of the diet DM, and RFDGS fed at 20% of the diet DM for 12 wk. Heifers were weighed every 2 wk to determine ADG. Hip and withers heights were measured on d 0, 42, and 84 of the study, and BCS were determined on d 0 and 84. Blood samples were collected via coccygeal venipuncture at the end of the study for determination of plasma urea nitrogen. In situ DM disappearance and intestinal CP disappearance were determined for feed and diet samples using lactating cows. Dry matter intake, BW gain, and feed efficiency were similar among treatments. In summary, inclusion of either DDGS or RFDGS at 20% of the diet resulted in similar intake, feed efficiency, and gains, and they are viable options for replacement dairy heifers.

This study investigated the effect of phytonutrients (PN) supplied postruminally on nutrient utilization, gut microbial ecology, immune response, and productivity of lactating dairy cows. Eight ruminally cannulated Holstein cows were used in a replicated 4×4 Latin square. Experimental periods lasted 23d, including 14-d washout and 9-d treatment periods. Treatments were control (no PN) and daily doses of 2g/cow of either curcuma oleoresin (curcumin), garlic extract (garlic), or capsicum oleoresin (capsicum). Phytonutrients were pulse-dosed into the abomasum of the cows, through the rumen cannula, 2h after feeding during the last 9d of each experimental period. Dry matter intake was not affected by PN, although it tended to be lower for the garlic treatment compared with the control. Milk yield was decreased (2.2kg/d) by capsicum treatment compared with the control. Feed efficiency, milk composition, milk fat and protein yields, milk N efficiency, and 4.0% fat-corrected milk yield were not affected by treatment. Rumen fermentation variables, apparent total-tract digestibility of nutrients, N excretion with feces and urine, and diversity of fecal bacteria were also not affected by treatment. Phytonutrients had no effect on blood chemistry, but the relative proportion of lymphocytes was increased by the capsicum treatment compared with the control. All PN increased the proportion of total CD4 + cells and total CD4 + cells that co-expressed the activation status signal and CD25 in blood. The percentage of peripheral blood mononuclear cells (PBMC) that proliferated in response to concanavalin A and viability of PBMC were not affected by treatment. Cytokine production by PBMC was not different between control and PN. Expression of mRNA in liver for key enzymes in gluconeogenesis, fatty acid oxidation, and response to reactive oxygen species were not affected by treatment. No difference was observed due to treatment in the oxygen radical absorbance capacity of blood plasma but, compared with the control, garlic treatment increased 8-isoprostane levels. Overall, the PN used in this study had subtle or no effects on blood cells and blood chemistry, nutrient digestibility, and fecal bacterial diversity, but appeared to have an immune-stimulatory effect by activating and inducing the expansion of CD4 cells in dairy cows. Capsicum treatment decreased milk yield, but this and other effects observed in this study should be interpreted with caution because of the short duration of treatment.

Metabolic reprogramming that alters the utilization of glucose including the "Warburg effect" is critical in the development of a tumorigenic phenotype. However, the effects of the Harvey-ras (H-ras) oncogene on cellular energy metabolism during mammary carcinogenesis are not known. The purpose of this study was to determine the effect of H-ras transformation on glucose metabolism using the untransformed MCF10A and H-ras oncogene transfected (MCF10A-ras) human breast epithelial cells, a model for early breast cancer progression. We measured the metabolite fluxes at the cell membrane by a selective micro-biosensor, [(13)C6 ]glucose flux by (13)C-mass isotopomer distribution analysis of media metabolites, intracellular metabolite levels by NMR, and gene expression of glucose metabolism enzymes by quantitative PCR. Results from these studies indicated that MCF10A-ras cells exhibited enhanced glycolytic activity and lactate production, decreased glucose flux through the tricarboxylic acid (TCA) cycle, as well as an increase in the utilization of glucose in the pentose phosphate pathway (PPP). These results provide evidence for a role of H-ras oncogene in the metabolic reprogramming of MCF10A cells during early mammary carcinogenesis.

The greatest risk of metabolic and infectious disease in dairy cows is during the transition from pregnancy to lactating (i.e., the transition period). The objective of this experiment was to determine the effects of extracellular vesicles (microvesicles involved in cell-to-cell signaling) isolated from transition cows on target cell function. We previously identified differences in the protein profiles of exosomes isolated from cows divergent in metabolic health status. Therefore, we hypothesized that these exosomes would affect target tissues differently. To investigate this, 2 groups of cows (n = 5/group) were selected based on the concentration of β-hydroxybutyrate and fatty acids in plasma and triacylglycerol concentration in liver at wk 1 and 2 postcalving. Cows with high concentrations of β-hydroxybutyrate, fatty acids, and triacylglycerol were considered at increased risk of clinical disease during the transition period (high-risk group; n = 5) and were compared with cows that had low concentrations of the selected health indicators (low-risk group; n = 5). At 2 time points during the transition period (postcalving at wk 1 and 4), blood was sampled and plasma exosomes were isolated from the high-risk and low-risk cows. The exosomes were applied at concentrations of 10 and 1 µg/mL to 5 × 103 Madin-Darby bovine kidney cells grown to 50% confluence in 96-well plates. Results indicate a numerical increase in cell proliferation when exosomes from high-risk cows were applied compared with those from low-risk cows. Consistent with an effect on cell proliferation, quantitative reverse transcriptase PCR indicated a trend for upregulation of 3 proinflammatory genes (granulocyte colony-stimulating factor, ciliary neurotrophic factor, and CD27 ligand) with the application of high-risk exosomes, which are involved in cellular growth and survival. Proteomic analysis indicated 2 proteins in the low-risk group that were not identified in the high-risk group (endoplasmin and catalase), which may also be indicative of the metabolic state of origin. It is likely that the metabolic state of the transition cow affects cellular function through exosomal messaging; however, more in-depth research into cross-talk between exosomes and target cells is required to determine whether exosomes influence Madin-Darby bovine kidney cells in this manner.

BACKGROUND: Many pregnancies in the United States are associated with maternal calorie overconsumption. Few data exist that track the impact of maternal and offspring calorie consumption on the risks for obesity development. METHODS: To determine the effects of maternal calorie intake during gestation on programming for adiposity in the offspring, pregnant gilts were fed either a normal (NE) or high (HE) energy diet to induce higher than normal (30 % increase) pregnancy weight gain and the profile of genes related to adipose tissue development was determined in the subcutaneous adipose tissue of the offspring. Gilts were fed the same lactation diet after farrowing and piglets were allowed to suckle from their mothers. Offspring were also fed either a normal energy (NE) or a high energy (HE) diet after weaning (3 weeks of age). Offspring were sacrificed at 48 h, 3 weeks and 3 months of age and the subcutaneous adipose tissue obtained for gene expression analysis by RT-PCR. RESULTS: Gilts on the HE diet had higher pregnancy weight gain and backfat thickness than those on the NE diet. Expression of adipogenic genes, such as peroxisome proliferator activated receptor (PPAR) γ and CCAAT enhancer binding protein (CEBP) α was not different between offspring from NE and HE mothers at 48 h after birth, but they were higher (P

Feed sorting is a natural behavior of dairy cows that can result in inconsistencies in the nutritive value of a total mixed ration (TMR). The objective of this study was to determine the effects of replacing high-moisture corn with glycerol on feed sorting and the feed intake pattern of transition dairy cows. Multiparous Holstein cows (n=26) were paired by expected calving date, housed in individual tie stalls, and fed diets containing either glycerol or high-moisture corn once daily from d -28 to +56 relative to calving. Glycerol was included at 11.5 and 10.8% of the ration dry matter for the pre- and postpartum diets, respectively. The feed consumption pattern was determined by measuring TMR disappearance during the intervals from 0 to 4 h, 4 to 8 h, 8 to 12 h, and 12 to 24 h relative to feed delivery. Feed sorting was determined on d -16, -9, 9, 16, and 51 relative to calving at 4, 8, 12 and 24 h after feeding. The TMR particle size profile was determined at feed delivery and at 4, 8, 12, and 24 after feed delivery by using the Penn State Particle Separator (Nasco, Fort Atkinson, WI) to yield long (19 mm), medium (19 mm,8 mm), short (8 mm,1.18 mm), and fine (1.18 mm) particles. Overall feed intake did not differ between diets and was 14.7±0.4 and 20.2±0.5 kg/d for the pre- and postpartum intervals, respectively. During the prepartum period, glycerol decreased the amount of feed consumed during the first 4h after feed delivery (7.22 vs. 5.59±0.35 kg; control vs. glycerol, respectively) but increased feed consumed from 12 through 24 h after feed delivery (2.22 vs. 3.82±0.35 kg; control vs. glycerol, respectively). Similar effects on the feed consumption pattern were observed after calving. During the prepartum period, cows fed the control diet sorted against long particles, whereas cows fed glycerol did not sort against long particles (77.2 vs. 101.5±3.50% of expected intake for control vs. glycerol; significant treatment effect). The data indicate that addition of glycerol to the TMR alters the feed consumption pattern to increase feed consumption late in the day at the expense of feed consumed immediately after feeding, and it reduces sorting behavior against long particles. Together, these may reduce diurnal variations in the rumen environment to promote greater rumen health in transition cows.

Pyruvate carboxylase (PC) catalyzes the rate-limiting step in gluconeogenesis from lactate and is a determinant of tricarboxylic acid cycle carbon flux. Bovine PC 5' untranslated region (UTR) mRNA variants are the products of a single PC gene containing 3 promoter regions (P3, P2, and P1, 5' to 3') that are responsive to physiological and nutritional stressors. The objective of this study was to determine the direct effects of thermal stress on PC mRNA and gene expression in bovine hepatocyte monolayer cultures, rat hepatoma (H4IIE) cells, and Madin-Darby bovine kidney epithelial (MDBK) cells. Hepatocytes were isolated from 3 Holstein bull calves and used to prepare monolayer cultures. Rat hepatoma cells and MDBK cells were obtained from American Type Culture Collection, Manassas, VA. Beginning 24 h after initial seeding, cells were subjected to either 37°C (control) or 42°C (thermal stress) for 24 h. Treatments were applied in triplicate in a minimum of 3 independent cell preparations. For bovine primary hepatocytes, endogenous expression of bovine PC mRNA increased (P < 0.1) with 24 h of thermal stress (1.31 vs. 2.79 ± 0.49, arbitrary units, control vs. thermal stress, respectively), but there was no change (P ≥ 0.1) in cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) mRNA expression. Similarly, exposure of MDBK cells to thermal stress increased (P < 0.1) expression of bovine PC mRNA without altering (P ≥ 0.1) PEPCK-C mRNA expression. Conversely, there was no effect (P ≥ 0.1) of thermal stress on endogenous rat PC (0.47 vs. 0.30 ± 0.08, control vs. thermal stress) or PEPCK-C (1.61 vs. 1.20 ± 0.48, arbitrary units, control vs. thermal stress, respectively) mRNA expressions in H4IIE cells. To further investigate the regulation of PC, H4IIE cells were transiently transfected with bovine promoter-luciferase constructs containing either P1, P2, or P3, and exposed to thermal stress for 23 h. Activity of P1 was suppressed (P < 0.1) 5-fold, activity of P2 was unchanged (P ≥ 0.1), and activity of P3 was increased (P < 0.1) by 5.4-fold. These data indicate that response of bovine PC gene to thermal stress is through promoter regulation and suggest that there are unique characteristics of bovine PC promoters that may contribute to the physiological response to thermal stress.

Expression of mRNA for pyruvate carboxylase (PC) is elevated at calving and during other physiological states when plasma NEFA concentrations are increased. The objective of this study was to determine the direct effects of fatty acids on expression of PC, cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C), mitochondrial PEPCK (PEPCK-M), and glucose-6-phosphatase (G6Pase) mRNA in Madin-Darby bovine kidney (MDBK) cells. Combinations of C14:0, C16:0, C18:0, C18:1n-6 cis , C18:2n-6 cis , and C18:3n-3 cis were created to mimic the profiles and concentrations in serum from far-off dry cows and late postcalving intervals (PRPT), the profile at calving (CALV), and the profile observed in cows induced to express fatty liver at calving (IFL). The MDBK cells were exposed to fatty acid mixtures for 24h at the following concentrations: 0.25 and 0.5m M for PRPT; 0.25, 0.5, and 1.0m M for CALV; and 0.5 and 1.0m M for IFL. Cells exposed to PRPT had greater PEPCK-C and tended to have greater G6Pase mRNA than control cells. Exposure of cells to 0.25m M PRPT increased expression of PEPCK-C compared with cells exposed to 0.5m M PRPT. Expression of PC and PEPCK-M did not differ with exposure to PRPT. Expression of PEPCK-C was decreased and that of PEPCK-M and G6Pase mRNA increased linearly in response to CALV. The ratio of PC:PEPCK-C mRNA was increased by the IFL mixture and in response to increasing amounts of the CALV fatty acid mixture. Treatment of cells with CALV or IFL increased the sum of PC 5′ untranslated region (UTR) variants A, B, C, and F but did not alter PC 5′ UTR D and E expression. The changes in PEPCK-C, G6Pase, and PC mRNA and the ratio of PC:PEPCK-C observed in MDBK cells in response to fatty acids suggests a role for fatty acid concentration and profile in mediating the expression of key gluconeogenic enzymes.

The purpose of this study was to examine the effects of vitamin D supplementation on inflammatory biomarkers in overweight and obese adults participating in a progressive resistance exercise training program. Twenty-three (26.1 ± 4.7 years) overweight and obese (BMI 31.3 ± 3.2 kg/m2) adults were randomized into a double-blind vitamin D supplementation (Vit D 4,000 IU/day; female 5, male 5) or placebo (PL, female 7; male 6) intervention trial. Both groups performed 12 weeks (3 days/week) of progressive resistance exercise training (three sets of eight exercises) at 70-80% of one repetition maximum. Whole-blood lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNF) α production as well as circulating C-reactive protein (CRP), TNFα, interleukin 6 (IL-6), and alanine aminotransferase (ALT) were assessed at baseline and after the 12-week intervention. No main effects of group or time were detected for circulating CRP, TNFα, IL-6, and ALT. As expected, when PL and Vit D groups were combined, there was a significant correlation between percent body fat and CRP at baseline (r = 0.45, P = 0.04), and between serum 25OHD and CRP at 12 weeks (r = 0.49, P = 0.03). The PL group had a significant increase in 25 μg/ml LPS + polymixin B-stimulated TNFα production (P = 0.04), and both groups had a significant reduction in unstimulated TNFα production (P < 0.05) after the 12-week intervention. Vitamin D supplementation in healthy, overweight, and obese adults participating in a resistance training intervention did not augment exercise-induced changes in inflammatory biomarkers.

The consumption of soy protein lowers blood cholesterol in humans and animals. Breeding may alter the physiological effects of soybeans, such as its cholesterol-lowering property. Our hypothesis is that breeding affects the hypocholesterolemic effect of soy by modulating the expression of key hepatic enzymes related to cholesterol and bile acid biosynthesis, as well as altering fecal neutral and acidic steroid excretion. Therefore the aim of this study was to evaluate the effect of a new Brazilian soybean cultivar (UFV-116), lacking lipoxygenases 2 and 3, compared with a commercial cultivar (OCEPAR-19), on 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) and cholesterol 7α-hydroxylase (CYP7A) mRNA expression and fecal steroid output in rats. Thirty-six male rats were fed UFV-116, OCEPAR-19, or casein as the protein source, with or without addition of dietary cholesterol (0.25%). Blood and liver cholesterol, HMGR and CYP7A mRNA abundance, and fecal excretion of steroids were measured. Blood and liver cholesterol levels were lowered by both soybean cultivars, with and without cholesterol, but UFV-116 was more effective when included in the cholesterol-free diet. Both soy diets promoted lower levels of HMGR mRNA, higher levels of CYP7A mRNA, and higher excretion of fecal secondary bile acids. There was higher fecal neutral steroid output when cholesterol was added to all diets. These data show that both soybean cultivars acted similarly in lowering serum and hepatic cholesterol; therefore, breeding did not affect the hypocholesterolemic effect of the new cultivar.

Pyruvate carboxylase (PC; EC 6.4.1.1) is critical in gluconeogenesis from lactate and maintenance of tricarboxylic acid cycle intermediates. Whereas increases in PC mRNA have been observed during feed restriction, the mechanism of regulation is unknown; however, coinciding increases in circulating NEFA concentrations suggests that fatty acids may contribute to regulation of gene expression during feed restriction. The objective of this study was to examine the direct effect of exposure to serum from full-fed control cows with serum from cows that were restricted to 50% of ad libitum intake for 5 d on PC expression in vitro. Rat hepatoma (H4IIE) cells were transiently transfected with bovine promoter-luciferase constructs containing bovine PC promoter 1 and treated with serum from control cows, serum from feed-restricted cows, or modified serum. Modified serum pools were generated by supplemented serum from control cows with C14:0, C16:0, C18:0, C18:1n-9 cis, C18:2n-6 cis, and C18:3n-3 cis to match the total NEFA in serum from feed-restricted cows (1.3 mM) in the relative proportion found in serum from control or feed-restricted cows. Exposure of cells to serum from feed-restricted cows increased (P < 0.05) PC promoter 1 activity 2.2-fold compared with cells exposed to control cow serum. Exposure to serum from control cows with fatty acids added to a NEFA concentration of 1.3 mM to reflect the fatty acid profile of control and feed-restricted cows increased (P < 0.05) promoter 1 activity 2.1- and 2.5-fold, respectively, compared with cells incubated with control cow serum. There was no difference (P ≥ 0.05) in promoter 1 activity in cells treated with modified serum compared with serum from feed-restricted cows. These data indicate that promoter 1 is activated by fatty acids found in serum of feed-restricted cows. These data suggest a role of NEFA to regulate expression of bovine PC mRNA through specific activation of PC promoter 1.

Pyruvate carboxylase (PC; EC 6.4.1.1) is a critical enzyme for gluconeogenesis and maintenance of tricarboxylic acid (TCA) cycle intermediates, and expression of PC mRNA is increased at calving and during feed restriction. The bovine PC gene contains 3 promoters (3, 2, and 1 from 5' to 3') that produce 6 mRNA 5' variants (A through F). Products of promoter 1, untranslated region (UTR) variants A, B, C, and F are specifically expressed in glucogenic and lipogenic tissues. The objective of this study was to develop a quantitative PCR-based assay for bovine PC 5' UTR variants that would permit simultaneous characterization of PC variant expression and to determine the pattern of PC variant expression during the transition to lactation and during feed restriction. Primer combinations specific to the coding region of PC and the 5' UTR for variants D, E, and F were used with Taqman probes in a real-time PCR multiplex assay to simultaneously determine total PC mRNA and expression of each UTR variant. The intraassay and interassay CV were less than 2 and 10%, respectively. Total PC mRNA and PC 5' UTR variant profile was determined for liver biopsy samples collected from Holstein cows (n = 8) at -28, +1, and +28 d relative to calving (DRTC) and from mid-lactation Holstein cows subjected to either feed restriction (n = 8) or fed for ad libitum intake (n = 8). The expression of PC mRNA corresponding to the coding region of PC and PC 5' UTR variant regions A, B, C, and F increased (P < 0.05) 4-fold with feed restriction and 6-fold at calving. Nuclei isolated from liver biopsy samples and used to determine the rates of PC gene transcription indicate changes in the abundance of PC 5' mRNA variants A, B, C, and F that are due to corresponding changes in the rate of transcription of the bovine PC gene. The data support the use of the multiplex assay described here as a proxy measure of the activity of bovine PC promoter 1. The increased PC mRNA expression observed at calving and during feed restriction is the result of specific increases in 5' UTR variants A, B, C, and F due to increased transcriptional activity of promoter 1 of the PC gene.

Gluconeogenesis is a crucial process to support glucose homeostasis when nutritional supply with glucose is insufficient. Because ingested carbohydrates are efficiently fermented to short-chain fatty acids in the rumen, ruminants are required to meet the largest part of their glucose demand by de novo genesis after weaning. The qualitative difference to nonruminant species is that propionate originating from ruminal metabolism is the major substrate for gluconeogenesis. Disposal of propionate into gluconeogenesis via propionyl-CoA carboxylase, methylmalonyl-CoA mutase, and the cytosolic form of phosphoenolpyruvate carboxykinase (PEPCK) has a high metabolic priority and continues even if glucose is exogenously supplied. Gluconeogenesis is regulated at the transcriptional and several posttranscriptional levels and is under hormonal control (primarily insulin, glucagon, and growth hormone). Transcriptional regulation is relevant for regulating precursor entry into gluconeogenesis (propionate, alanine and other amino acids, lactate, and glycerol). Promoters of the bovine pyruvate carboxylase (PC) and PEPCK genes are directly controlled by metabolic products. The final steps decisive for glucose release (fructose 1,6-bisphosphatase and glucose 6-phosphatase) appear to be highly dependent on posttranscriptional regulation according to actual glucose status. Glucogenic precursor entry, together with hepatic glycogen dynamics, is mostly sufficient to meet the needs for hepatic glucose output except in high-producing dairy cows during the transition from the dry period to peak lactation. Lactating cows adapt to the increased glucose requirement for lactose production by mobilization of endogenous glucogenic substrates and increased hepatic PC expression. If these adaptations fail, lipid metabolism may be altered leading to fatty liver and ketosis. Increasing feed intake and provision of glucogenic precursors from the diet are important to ameliorate these disturbances. An improved understanding of the complex mechanisms underlying gluconeogenesis may further improve our options to enhance the postpartum health status of dairy cows.

Growth of the corn ethanol industry has created a need for alternatives to corn for lactating dairy cows. Concurrent expansion in soydiesel production is expected to increase availability and promote favorable pricing for glycerol, a primary co-product material. The objective of this study was to determine the feeding value of glycerol as a replacement for corn in diets fed to lactating dairy cattle. Sixty lactating Holstein cows housed in individual tie stalls were fed a base diet consisting of corn silage, legume forages, corn grain, soyhulls, roasted soybeans, and protein supplements. After a 2-wk acclimation period, cows were fed diets containing 0, 5, 10, or 15% refined glycerol for 56 d. Cows were milked twice daily and weekly milk samples were collected. Milk production was 36.3, 37.2, 37.9, and 36.2 +/- 1.6 kg/d and feed intake was 23.8, 24.6, 24.8, and 24.0 +/- 0.7 kg/d for 0, 5, 10, and 15% glycerol treatments, respectively, and did not differ except for a modest reduction in feed intake during the first 7 d of the trial for 15% glycerol (treatment x time effect). Milk composition was not altered by glycerol feeding except that milk urea nitrogen was decreased from 12.5 +/- 0.4 to 10.2 +/- 0.4 mg/dL with glycerol addition. Cows fed diets containing 10 and 15% glycerol gained more weight than those fed rations containing 0 or 5% glycerol but body condition scores did not differ with glycerol feeding. The data indicate that glycerol is a suitable replacement for corn grain in diets for lactating dairy cattle and that it may be included in rations to a level of at least 15% of dry matter without adverse effects on milk production or milk composition.