Effects of Niacin Source on Epinephrine Stimulation of Plasma Nonesterified Fatty Acid and Glucose Concentrations, on Diet Digestibility and on Rumen Protozoal Numbers in Lactating Dairy Cows

• Published in: The Journal of nutrition Vol. 120; no. 12; pp. 1648 - 1653
• Main Authors: Erickson, Peter S., Trusk, Ann M., Murphy, Michael R.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01.12.1990; American Society for Nutritional Sciences
• Subjects: ACIDE GRAS; ACIDOS GRASOS; ADRENALINE; Animals; Biological and medical sciences; Blood Glucose - metabolism; Cattle - physiology; cows; Diet; DIETA; DIGESTIBILIDAD; DIGESTIBILITE; Digestion - drug effects; EPINEFRINA; epinephrine; Epinephrine - pharmacology; Eukaryota - isolation & purification; Fatty Acids, Nonesterified - blood; Female; Fundamental and applied biological sciences. Psychology; GLUCOSA; GLUCOSE; LACTACION; LACTATION; Lipolysis - drug effects; Mother. Fetoplacental unit. Mammary gland. Milk; niacin; Niacin - administration & dosage; Niacin - pharmacology; Niacinamide - administration & dosage; Niacinamide - pharmacology; NICOTINAMIDA; NICOTINAMIDE; PLASMA SANGUIN; PLASMA SANGUINEO; Pregnancy. Parturition. Lactation; PROTOZOA; REGIME ALIMENTAIRE; RUMEN; Rumen - parasitology; VACAS LECHERAS; VACHE LAITIERE; Vertebrates: reproduction; niacin; epinephrine; cows; protozoa; Lactation; Ruminant animal; Free form; Vitamin; Nicotinic acid; Lipids; Ox; Stimulation; Supplemented diet; Glucose; Blood plasma; Female; Ungulata; Digestibility; Epinephrine; Protozoa; Rumen; Digestion; Metabolism; Fatty acids; Lipolysis; Feeding; Vertebrata; Mammalia; Artiodactyla
• ISSN: 0022-3166; 1541-6100
• DOI: 10.1093/jn/120.12.1648

Effects of niacin (nicotinic acid or nicotinamide) supplementation of dairy cow diets on apparent total tract nutrient digestibility, milk yield and milk composition were determined using six mid-lactation Holstein cows in a replicated 3 × 3 Latin square design arranged to test for residual treatment effects. Treatments were control, 12 g/d of nicotinic acid or 12 g/d of nicotinamide. Periods were 14 d long; d 1 to 4 served as an adaptation period before treatment administration commenced (d 5 to 14). Effects of supplemental niacin on plasma nonesterified fatty acid (NEFA) concentrations and plasma glucose concentrations were tested following saline injection on d 10. Blood was then sampled for 5.5 h at 15-min intervals. On d 13, cows were treated similarly except that epinephrine replaced saline. The area below d-10 curves was subtracted from the area below d-13 curves to serve as an indicator of niacin's effect on plasma NEFA and glucose concentration responses to epinephrine injection. Niacin treatments did not change the area differences for plasma glucose compared to the control treatment; however, there was a trend for niacin to reduce the area difference compared to the control treatment for plasma NEFA. Niacin treatments did not alter dry matter intake, nutrient digestibility, milk yield or composition. Niacin supplementation increased the number of entodinia protozoa in rumen fluid.