Animal physiology
Nabiallah Salari; Yadollah Badakhshan; Rohallah Mirmahmoudi; Jamil Bahrampour; Arsalan Barazandeh
Abstract
Tryptophan is 3 th essential amino acid for the body. Also an important substrate for essential hormones such as serotonin and melatonin. This amino acid is metabolized in two ways in the body 1- Kynurunine pathway and 2- serotonin pathway. Tryptophan entry to These metabolizing pathways is five percent ...
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Tryptophan is 3 th essential amino acid for the body. Also an important substrate for essential hormones such as serotonin and melatonin. This amino acid is metabolized in two ways in the body 1- Kynurunine pathway and 2- serotonin pathway. Tryptophan entry to These metabolizing pathways is five percent for serotonin production and ninety and five percent for kynurenine production. This experiment was performed to evaluate the Effect of intraperitoneal injection of the L-tryptophan on feed intake, rectal temperature, and some blood biochemical metabolites of the Kermani sheep breed. 20 eight-month-old lambs grouped in 10 males and 10 females in a factorial design. Lambs were divided into control groups (saline intraperitoneal injection) and treatment groups (intraperitoneal injection with 50 mg tryptophan amino acid/kg body weight ). The Control group of each gender was injected only with physiological serum intraperitoneally .immediately after injection, the feed was offered to them and cumulative feed intake was measured in 2 hours intervals for a four-hour duration. Feed was a total mixed ration consisting of 40 % concentrated and 60 % roughage. Heartbeat, respiration rate, and rectal temperature were measured every hour after amino acid or saline injection. This experiment showed that feed intake in tryptophan treatment was reduced compared to the control group, also female lambs had significantly lower cumulative feed intake (P<0.05). Heart rate decreased in males and tryptophan treatment (P<0.05). Tryptophan injection significantly reduced rectal temperature (P<0.05). Tryptophan injection did not show a significant effect on the serum concentrations of T3 and T4 hormones of lambs (P>0.05) but reduced the ratio of T3 to T4 (P<0.05). this means thyroxin converted to triiodothyronine more effectively in the group that received tryptophan amino acid. Levels of cortisol, total protein, cholesterol, triglyceride, creatine, and urea were not significantly different in the tryptophan-receiving lamb compared to the control group (P>0.05). Serum albumin concentration decreased in tryptophan-receiving lambs compared to the control group (P<0.05).blood Albumin level was decreased in tryptophan-injected lamb compared with the control group (P<0.05). According to the results of this experiment, reduction of heart rate and rectal temperature in tryptophan treatment, it could be concluded that tryptophan improves the condition of livestock under heat stress by affecting the mechanisms of coping with high ambient temperature. These mechanisms are related to heartbeat and respiration rate control centers that were affected by intraperitoneal injection of tryptophan amino acid. Tryptophan in route of intraperitoneal injection significantly reduced cumulative feed intake but this was compensated for some hours of post-injection.
