Dry period plane of energy: Effects on glucose tolerance in transition dairy cows

Abstract

Overfeeding energy in the dry period can affect glucose metabolism and the energy balance of transition dairy cows with potential detrimental effects on the ability to successfully adapt to early lactation. The objectives of this study were to investigate the effect of different dry cow feeding strategies on glucose tolerance and on resting concentrations of blood glucose, glucagon, insulin, nonesterified fatty acids (NEFA), and β-hydroxybutyrate (BHB) in the peripartum period. Cows entering second or greater lactation were enrolled at dry-off (57 d before expected parturition) into 1 of 3 treatment groups following a randomized block design: cows that received a total mixed ration (TMR) formulated to meet but not exceed energy requirements during the dry period (n=28, controlled energy); cows that received a TMR supplying approximately 150% of energy requirements during the dry period (n=28, high energy); and cows that were fed the same diet as the controlled energy group for the first 28 d, after which the TMR was formulated to supply approximately 125% of energy requirements until calving (n=28, intermediate energy). Intravenous glucose tolerance tests (IVGTT) with rapid administration of 0.25 g of glucose/kg of body weight were performed 28 and 10d before expected parturition, as well as at 4 and 21 d after calving. Area under the curve for insulin and glucose, maximal concentration and time to half-maximal concentration of insulin and glucose, and clearance rates were calculated. Insulin resistance (IR) indices were calculated from baseline samples obtained during IVGTT and Spearman rank correlations determined between IVGTT parameters and IR indices. Treatment did not affect IVGTT parameters at any of the 4 time points. Correlation between IR indices and IVGTT parameters was generally poor. Overfeeding cows energy in excess of predicted requirements by approximately 50% during the entire dry period resulted in decreased postpartum basal plasma glucose and insulin, as well as increased glucagon, BHB, and NEFA concentrations after calving compared with cows fed a controlled energy diet during the dry period. In conclusion, overfeeding energy during the entire dry period or close-up period alone did not affect glucose tolerance as assessed by IVGTT but energy uptake during the dry period was associated with changes in peripartal resting concentrations of glucose, as well as postpartum insulin, glucagon, NEFA, and BHB concentrations.

Hyperglycaemia in transition dairy cows: Effects of lactational stage and conjugated linoleic acid supplementation on glucose metabolism and turnover

“…() and Sano et al. () found a lower insulin response to glucose infusion in lactating cows compared with non‐lactating animals, which indicates the necessity of maintenance of nutrient direction towards the mammary gland during lactation (Mann et al., ). Furthermore, Thompson, Weiser, Seto, and Black () and Lomax, Baird, Symonds, Mallinson, and Shaw () reported a decreased hepatic glucose production and reduced uptake of gluconeogenic precursors in cows following glucose infusion.…”

Temporal changes in sphingolipids and systemic insulin sensitivity during the transition from gestation to lactation

“…Two important metabolic adaptations that facilitate glucose partitioning toward the fetus and the mammary gland include a progressive reduction of insulin secretion by the pancreas, and impaired insulin responsiveness in adipose and skeletal muscle tissues [4, 5]. The progressive development of insulin resistance during peripartum has been validated through direct measurements of insulin secretion and responsiveness, such as glucose tolerance testing and insulin tolerance testing [6, 7, 8]. Because insulin is an anti-lipolytic hormone, the excessive mobilization of fatty acids from adipose tissue is an unfavorable outcome of reduced insulin action.…”

Production‐related metabolic disorders of cattle: ketosis, milk fever and grass staggers

“…Cows with postpartum ketosis have lower circulating concentrations of glucose than herdmates (Mann and others 2016b). More recently, we showed that intravenous glucose administration (Fig 2) in addition to oral propylene glycol was able to lower BHB concentrations to a greater extent and duration in hyperketonaemic postpartum cows (Mann and others 2017).…”