[XIV-29-19_21] 畜産物利用（XIV-午後）

[XIV29-21E] L-Leucine stimulates growth in heat-exposed broilers

^○Chowdhury Vishwajit Sur¹, Han Guofeng¹, Bungo Takashi², Tashiro Kosuke¹, Furuse Mitsuhiro¹ (1.Kyushu Univ., 2.Hiroshima Univ.)

[Background and purpose] L-Leucine (L-Leu) in ovo injection afforded thermotolerance in broiler chicks. The purpose of this study was to investigate the effects of L-Leu in ovo injection on the growth, rectal temperature (RT) and plasma parameters in broilers under high ambient temperature. [Materials and methods] Fertilized broiler eggs (Chunky) were in ovo injected with sterile water (500 μl/egg) or L-Leu (35 μmol/500 μl/egg) on embryonic day 7. The chicks were kept under control thermoneutral temperature followed by exposing them to a natural summer temperature (14–29 days old), and chronic heat stress (30°C, 24 h/ day, 30–44 days old). The body weight and RT were measured once in a week until 44 days old. The blood sample was collected for further analysis. [Results] L-Leu injection significantly increased body weight gain and RT in heat-exposed broilers. There were no changes in liver and heart weight between the treatment and control groups. Plasma glucose, triacylglycerol and aspartate amino transferase showed no significant changes between the groups. [Conclusion] L-Leu in ovo administration stimulated the growth and RT in heat-exposed broilers.