Glucose and Fatty Acid Metabolism of Dairy Cows in a Total Mixed Ration or Pasture-Based System During Lactation

Abstract

In this study, we explored mechanisms related to glucose and fatty acid metabolism in Holstein–Friesian multiparous dairy cows during lactation under two feeding strategies. From 0 to 180 days postpartum, cows were fed total mixed ration (TMR) ad libitum (non-grazing group, G0) or grazed Festuca arundinacea or Medicago sativa and were supplemented with 5.4 kg DM/d of an energy-protein concentrate (grazing group, G1). From 180 to 250 days postpartum, all cows grazed F. arundinacea and were supplemented with TMR. Plasma samples and liver biopsies were collected at −14, 35, 60, 110, 180, and 250 days in milk (DIM) for metabolite, hormone, gene expression, and western blot analysis. Our results showed increased levels of negative energy balance markers: plasma non-esterified fatty acids (NEFA), liver triglyceride and plasma β-hydroxybutyrate (BHB) (P < 0.01), triglyceride and β-hydroxybutyrate concentration were especially elevated for G1 cows. Also, hepatic mRNA expression of gluconeogenic enzymes was upregulated during early lactation (P < 0.05). In particular, methymalonyl-CoA mutase expression was increased for G0 cows (P < 0.05) while pyruvate carboxylase (PC) expression was increased for G1 cows (P < 0.05), suggesting differential gluconeogenic precursors for different feeding strategies. Phosphorylation of AMP-activated protein kinase was increased in early lactation vs. late lactation (P < 0.01) and negatively correlated with PC mRNA levels. The positive association of gluconeogenic genes with proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) hepatic expression supported the importance of this transcription factor in glucose metabolism. The peroxisome proliferator-activated receptor alpha (PPARA) mRNA was increased during early lactation (P < 0.05), and was positively associated to PPARGC1A, carnitine palmitoyl-transferase 1, and hydroxymethylglutaryl-CoA synthase 2 (HMGCS2) mRNA expression. Alongside, hepatic mRNA expression of FABP was decreased for G1 vs. G0 cows (P < 0.05), possibly linked to impaired fatty acid transport and related to accumulation of liver triglycerides, evidencing G1 cows fail to adapt to the demands of early lactation. In sum, our results showed that metabolic adaptations related to early lactation negative energy balance can be affected by feeding strategy and might be regulated by the metabolic sensors AMPK, SIRT1, and coordinated by transcription factors PPARGC1A and PPARA.

Differential hepatic mitochondrial function and gluconeogenic gene expression in 2 Holstein strains in a pasture-based system

“…Negative energy balance markers such as plasma NEFA, plasma BHB, and liver triglyceride did not indicate subclinical ketosis (>1.0 mmol/L of plasma BHB) or clinical fatty liver (>10% liver triglyceride wet weight; Bobe et al, 2004;Meikle et al, 2004) and were similar to previously reported values for mid-to late lactation in grazing conditions (García-Roche et al, 2021). However, the NZH cows had greater plasma glucose concentrations than the NAH cows, probably due to greater glucose uptake by the mammary gland (Bell and Bauman, 1997), as milk yield in NAH cows was greater.…”

“…Plasma glucose, urea, BHB, and nonesterified fatty acids (NEFA) were determined spectrophotometrically with commercial kits from Biosystems S.A. for glucose and urea and from Randox Laboratories Ltd. for BHB and NEFA, at λ = 505 nm, 600 nm, 340 nm, and 560 nm, respectively (Astessiano et al, 2015;García-Roche et al, 2021).…”

“…Also, intrinsic to pasture-based systems is the greater energy expenditure due to walking and grazing activities (Jasinsky et al, 2019). Previous authors have shown that when nutrient concentration is insufficient, cows may show a poor metabolic status, as negative energy balance markers such as plasma nonesterified fatty acids and BHB and liver triglyceride concentrations are exacerbated (Meikle et al, 2013;García-Roche et al, 2021). Furthermore, hepatic energy metabolism has also been reported to be compromised in cows managed under a pasture-based system, as mitochondrial function is impaired during early lactation (García-Roche et al, 2019).…”

Effects of dietary butyrate supplementation and oral nonsteroidal anti-inflammatory drug administration on serum inflammatory markers and productivity of dairy cows during the calving transition

“…This may be explained by the difference in physiological state; from a few days before calving to the fresh period, plasma BHB increases from incomplete oxidation of FA in the liver (Grummer, 2008), reducing the relative contribution of supplemental butyrate to overall plasma BHB. In the studies reporting that butyrate supplementation increased plasma BHB, cows were approximately 60 (Izumi et al, 2019), 150 (Halfen et al, 2021) or 180 DIM (Urrutia et al, 2019), when excessive FA mobilization likely did not occur (Grum et al, 1996;Nogalski et al, 2012;García-Roche et al, 2021) and BHB production in the liver was reduced, which increased the relative contribution of supplemental butyrate to plasma BHB.…”

What to feed or what not to feed-that is still the question

“…The authors used various analytical methods to decipher intermediary flux via metabolite measurements that reflected on biochemical reaction architectures. The diverse mitochondrial adaptation to TMR and pasture-based feeding was recently strengthened by genetic and protein expression experiments (García-Roche et al, 2021). These are clearly substantial advancements for the field to understand the significance of biochemical reactions required for the production of milk and other biosynthetic products in cattle fed either by grain or grass.…”