Effects of niacin supplementation on the insulin resistance in Holstein cows during early lactation

Talija Hristovska,Radojica Đoković,Marko R Cincović,Branislava Belić,Bojan Toholj,Dragica Stojanović,Milanka Jezdimirović

doi:10.2754/avb201786030231

Abstract

Insulin resistance in early lactation includes low glucose concentration, low insulin release and responsiveness and high lipolysis. Niacin is important antilipolytic agent and leads to increase glucose and insulin concentration. The objectives of this study were to determine the influence of niacin on the insulin resistance in cows during early lactation using the difference of value and regression analysis between blood non-esterified fatty acid (NEFA), glucose and insulin concentrations, revised quantitative insulin sensitivity check index and glucose-to-insulin ratio. Niacin supplementation led to a decrease of NEFA concentration and an increase of glucose and insulin concentrations during the first three weeks after calving. Cows in the niacin group which were more resistant to insulin showed higher concentrations of non-esterified fatty acid in comparison with more sensitive cows from the same group, but still lower than the control. The regression analyses suggest the following characteristics of cows supplemented with niacin in comparison with the control group: the insulin response to glucose was more intense; the antilipolytic effect of insulin was lower; insulin efficiency expressed as glucose-to-insulin ratio increase with a decrease in NEFA. The metabolic changes due to niacin supplementation showed a dual influence on the insulin resistance in dairy cows during early lactation: decreased NEFA concentrations led to a decrease in the insulin resistance (due to an increase in insulin efficiency and insulin sensitivity index), but increased concentrations of insulin and glucose possibly caused an increase in the insulin resistance in dairy cows (due to lower insulin sensitivity index and possibly lower antilipolytic effects of insulin).

Highlights

The transitional period, from 3 weeks before to 3 weeks after parturition, is critically important to health, production, and profitability of dairy cows (Butler 2000)
The objectives of this study were to determine the influence of niacin on the insulin resistance in cows during early lactation using the difference of value and regression analysis between blood non-esterified fatty acid (NEFA), glucose and insulin concentrations, revised quantitative insulin sensitivity check index and glucose-to-insulin ratio
The metabolic changes due to niacin supplementation showed a dual influence on the insulin resistance in dairy cows during early lactation: decreased NEFA concentrations led to a decrease in the insulin resistance, but increased concentrations of insulin and glucose possibly caused an increase in the insulin resistance in dairy cows

Summary

Introduction

The transitional period, from 3 weeks before to 3 weeks after parturition, is critically important to health, production, and profitability of dairy cows (Butler 2000). Elevated plasma NEFA concentrations are correlated with postpartum disorders (Dyk et al 1995), depressed feed intake and increased triglyceride accumulation in the liver (Grummer 1993) Another important change during this period is the development of insulin resistance in peripheral tissues. Pires et al (2007) showed that the induction of hyperlipidaemia causes insulin resistance in Holstein cows by impairing both the sensitivity and maximum responsiveness to insulin They suggest that elevated NEFA concentrations during the periparturient period may potentially interrupt adipose tissue functions and that NEFAs may be a key factor triggering insulin resistance in Holstein cows. We hypothesize that niacin administration to dairy cows in the transition period can influence the insulin responsiveness and resistance in adipose tissue by virtue of niacin-induced changes in NEFA, glucose and insulin concentrations

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Conclusion