Project description:The liver of dairy cows naturally displays a series of metabolic adaptation during the periparturient period in response to the increasing nutrient requirement of lactation. The hepatic adaptation is partly regulated by insulin resistance and it is affected by the prepartal energy intake level of cows. We aimed to investigate the metabolic changes in the liver of dairy cows during the periparturient at gene expression level and to study the effect of prepartal energy level on the metabolic adaptation at gene expression level.B13:N13
Project description:The ruminant liver has multiple roles in the dairy cow and many of these are crucial in nutrient supply during lactation. Reduced feed intake alters the expression of many genes and pathways in the liver, inducing a period of negative energy balance. Once-daily milking is a management strategy to reduce the effects of periods of negative energy balance so the objective of this study was to determine if once-daily milking altered hepatic gene transcription during a period of negative energy balance induce by caloric restriction. Multiparous Holstein-Friesian and Holstein-Friesian x Jersey cows (n = 120) were grazed on pasture and milked twice daily (2X) from calving until 34 ± 6 days in milk (mean ± standard deviation). Cows were then allocated to one of four treatments in a 2 x 2 factorial arrangement. Treatments consisted of two milking frequencies (2X or once daily; 1X) and two feeding levels for three weeks: adequately fed (AF), consuming 14.3 kg dry matter intake/cow per d, or underfed (UF) consuming 8.3 kg dry matter intake /cow per d. After the treatment period, all cows were fed to target grazing residuals ? 1600 kg DM/cow per d and milked 2X for 20 wk. Liver tissue was collected from 12 cows per treatment by subcutaneous biopsy at 3 wk relative to treatment start, RNA extracted and transcript abundance of genes quantified.
Project description:The ruminant liver has multiple roles in the dairy cow and many of these are crucial in nutrient supply during lactation. Reduced feed intake alters the expression of many genes and pathways in the liver, inducing a period of negative energy balance. Once-daily milking is a management strategy to reduce the effects of periods of negative energy balance so the objective of this study was to determine if once-daily milking altered hepatic gene transcription during a period of negative energy balance induce by caloric restriction. Multiparous Holstein-Friesian and Holstein-Friesian x Jersey cows (n = 120) were grazed on pasture and milked twice daily (2X) from calving until 34 ± 6 days in milk (mean ± standard deviation). Cows were then allocated to one of four treatments in a 2 x 2 factorial arrangement. Treatments consisted of two milking frequencies (2X or once daily; 1X) and two feeding levels for three weeks: adequately fed (AF), consuming 14.3 kg dry matter intake/cow per d, or underfed (UF) consuming 8.3 kg dry matter intake /cow per d. After the treatment period, all cows were fed to target grazing residuals ? 1600 kg DM/cow per d and milked 2X for 20 wk. Liver tissue was collected from 12 cows per treatment by subcutaneous biopsy at 3 wk relative to treatment start, RNA extracted and transcript abundance of genes quantified. 48 animals were enrolled in this study, a liver sample from 45 animals was used for microarray analysis. A reference design was used for hybridisation, whereby each of the 46 samples were hybridised to individual microarrays along with a pooled reference sample. The reference sample was generated by taking equal concentrations of each of the experimental samples.
Project description:Cows were selected from two groups of 12 cows enrolled in a large experiment to assess the effects of ad libitum or restricted intake of moderate-energy diets during the entire dry period on pre-partum metabolism and post-partum metabolism and performance. A corn silage-based diet (26% of diet dry matter) providing 1.59 Mcal/kg during the far-off dry period (first 5 wk of an 8-wk dry period) or providing 1.61 Mcal/kg during the close-up dry period (last 3 wk of the dry period) was fed for ad libitum or restricted intake. Four multiparous Holstein cows were randomly selected from the ad libitum and restricted intake groups. Keywords: time course, ad libitum or restricted feeding prepartum
Project description:Using an Agilent microarray platform, the present study examined changes in the transcriptome of bovine polymorphonuclear leukocytes (PMNL) due to prepartal dietary intake. Twelve Holstein cows were fed a high-straw, control diet (CON; NEL = 1.34 Mcal/kg) or overfed a moderate-energy diet (OVE; NEL = 1.62 Mcal/kg) during the dry period. Blood for PMNL isolation and metabolite analysis was collected at -14 and +7 d relative to parturition. At an ANOVA false discovery rate (FDR) <0.05, energy intake (OVE vs. CON) influenced 1806 genes. Dynamic Impact Approach (DIA) bioinformatics analysis classified treatment effects on KEGG pathways, including: activated Oxidative Phosphorylation and Biosynthesis of Unsaturated Fatty Acids, and inhibited RNA Polymerase, Proteasome, and Toll-like Receptor Signaling Pathway. This analysis indicates that processes critical for energy metabolism and cellular and immune function were impacted with mixed results. However, overall interpretation of the transcriptome data agreed in part with literature documenting a potentially detrimental, chronic activation of PMNL in response to overfeeding. The widespread, transcriptome-level changes captured here confirm the importance of dietary energy adjustments around calving on the immune system.
Project description:Negative energy balance and hepatic gene expression patterns in high yielding dairy cows during the early postpartum period [liver]
Project description:Negative energy balance and splenic gene expression patterns in high yielding dairy cows during the early postpartum period [spleen]