Effects of abomasal infusion of nicotinic acid on responses to glucose and β-agonist challenges in underfed lactating cows.

The objectives were to assess the use of nicotinic acid (NA) to chronically (i.e., 74 h) manipulate plasma nonesterified fatty acid (NEFA) concentrations in partially feed-restricted lactating cows, determine whether the reduction of plasma NEFA altered responses to i.

Antilipolytic and lipolytic effects of administering free or ruminally protected nicotinic acid to feed-restricted Holstein cows.

The objectives were to determine effects of 12 hourly infusions of different quantities of nicotinic acid (NA) on plasma nonesterified fatty acid (NEFA; experiment 1) and whether longer (108 h) continuous infusions of NA could induce sustained reductions of plasma NEFA (experiment 2) in nonlactating, nongestating Holstein cows that were feed restricted. Experiment 1 was a 5×5 Latin square with 6-d periods and 9 recovery days between each period. Each period consisted of 5 d of partial feed restriction to increase plasma NEFA concentration.

Effects of abomasal infusion of linseed oil on responses to glucose and insulin in holstein cows.

The objective was to study the effects of abomasal infusion of linseed oil, a source rich in n-3 C18:3, on whole-body response to insulin (experiment 1) and on insulin antilipolytic effects during feed restriction (experiment 2). In experiment 1, eight nonlactating, non-gestating cows were assigned to a crossover design, fed to meet maintenance requirements, and infused abomasally with either linseed oil (LIN) or tallow (TAL) at a rate of 0.54 g/kg of body weight per d for 5.

Reduction of plasma NEFA concentration by nicotinic acid enhances the response to insulin in feed-restricted Holstein cows.

The objective was to investigate the relationship between elevated plasma nonesterified fatty acid (NEFA) concentration and insulin resistance in Holstein cows. Six nonlactating, nongestating, ruminally cannulated Holstein cows were blocked by body condition score and randomly assigned to a sequence of 2 treatments in a crossover design. Cows were offered legume and grass hay ad libitum supplemented with minerals and vitamins and were allowed free access to water and a trace mineralized salt block.