The central effects of silymarin on feeding behavior in broiler chickens and relationship with serotonergic system

Silymarin is the effective substance of thistle plant, which causes some physiological effects and improves nutritional behavior. This research was conducted to determine the central effects of silymarin on feeding behavior in broiler chickens and to find the mechanism of feed intake and to investigate its relationship with the serotonergic system.

In this research, 30 pieces of broiler chickens cannulated in the brain were used. In the first stage of the research (28 days old), silymarin was injected in the amount of 20 micrograms per kilogram of body weight. After injection, feed and water intake was measured in 30 to 180 minutes. In the second stage of the experiment (34 days), the relationship between silymarin and the serotonergic system was investigated. The treatments included 1- control, 2- methysergide, 3- ketanserin, 4- methysergide + silymarin, and 5- ketanserin + silymarin.

In the first stage, in 60 and 180 minutes, silimarin caused a significant decrease in feed intake (P<0.05). In the second stage, the central injection of the combination of silymarin with methysergide caused a significant decrease in feed consumption, while the central injection of the combination of silymarin with ketanserin had no significant effect on feed consumption. Central injection of silymarin had no effect on water intake in broilers.

The results showed that although central injection of silymarin decreased feed intake in broilers, it did not affect water consumption. Also, the central injection of the combination of silymarin with methysergide decreased feed intake in broilers.