Immunization against cholecystokinin decreases appetite in lambs

Area of Science:

• Animal Science
• Immunology
• Physiology

Background:

• Cholecystokinin (CCK) is a key gut hormone regulating appetite and satiety.
• Understanding CCK's role is crucial for managing feed intake and growth in livestock.

Purpose of the Study:

• To investigate the impact of active immunization against CCK on feed intake, body weight gain, and carcass traits in sheep.
• To determine if CCK immunization can be used as a tool to modulate growth performance.

Main Methods:

• Nine wether lambs were immunized with a CCK-human serum globulin conjugate or a control conjugate.
• Antibody titers were measured to confirm immune response to CCK.
• Feed intake, body weight, and carcass characteristics were monitored throughout the study.

Main Results:

• CCK-immunized lambs developed antibodies capable of binding circulating CCK.
• A significant decrease in feed intake, appetite, and body weight gain was observed in CCK-immunized lambs compared to controls.
• No significant alterations in carcass composition or organ growth relative to body growth were detected.

Conclusions:

• Active immunization against CCK in sheep led to reduced feed intake and growth.
• The immunization strategy may have potentiated CCK's physiological actions rather than neutralizing its appetite-regulating effects.
• Further research is needed to elucidate the precise mechanisms by which CCK immunization influences appetite regulation.