Oral administration of lysine restores food intake and ventromedial hypothalamic dopamine in chicken on a lysine-free diet

Abstract

1. This study was conducted to examine whether oral administration of lysine solution affect food intake and the ventromedial hypothalamic (VMH) monoamines in chickens fed on a lysine-free diet. 2. Chickens were assigned to four treatment groups. Two groups of chickens were given two different doses of lysine solution (0.1 g and 0.07 g in 1 ml of saline) exogenously (orally) while being fed on a lysine-free diet, and these results were compared with a control diet plus saline group. Another group of chickens was fed on a lysine-free diet without lysine supplementation, and their results were compared with the lysine treated groups. The extracellular dopamine (DA), norepinephrine (NE) and serotonin (5-HT) in the VMH of freely moving chicken were measured by in vivo microdialysis. 3. There was no significant difference in food intake between the control diet and the lysine supplemented groups during the time-course of the experiments. Food intake significantly decreased at 4, 5 and 6 h in the lysine-free diet plus saline group compared with the lysine supplemented groups. Of the VMH monoamines, the DA concentration remained close to the baseline in the lysine supplemented groups. This DA concentration was significantly lower than the baseline in the lysine-free diet plus saline group at 3.5 h and thereafter. 4. No significant difference from the baseline was observed for NE in the lysine-free diet plus saline group. The 5-HT concentrations were close to the baseline for all groups throughout the experiments. 5. The findings suggest that oral administration of lysine solution to chickens fed on a lysine-free diet restored food intake which was associated with the variations of VMH DA concentration.

Adrenergic and noradrenergic regulation of poultry behavior and production

“…A recent study of lysine in poultry diets showed that both feed intake and central NE were reduced in a lysine-free diet [67]. These data suggest a role for diet in manipulation of NE-regulated feeding behaviors.…”

Digestible Lysine Requirements the Performance, Carcass Traits and Breast Meat Quality of Slow-Growing Broilers

“…Several studies have been carried out to evaluate the responses of broilers to different lysine concentrations in the diet and to determine broiler lysine requirements for efficiency, performance, and carcass composition (Alam et al, 2012). However, the formulation of diets for slow-growing broilers are typically based on the nutritional requirements established for geneticallyimproved broilers with high growth potential, as there is little information regarding the growth requirements for slow-growing broilers, which may limit the efficiency of feed utilization and compromise the final profitability.…”