Changes in food intake and forestomach motility of dwarf goats by recombinant bovine cytokines (IL-1 beta, IL-2) and IFN-gamma.

The present study was carried out to investigate the effects of rboIL-1 beta, rboIL-2, and rboIFN-gamma on food intake and forestomach motility in conscious dwarf goats. The intravenous injection of rboIL-1 beta (1 micrograms kg-1) resulted in tachycardia and an immediate fever that reached peak values 45 and 180 min after injection. At 9 to 13 min after rboIL-1 beta administration, both frequency and amplitude of rumen contractions rapidly diminished, being minimal at 30 min; during the fever, all goats refused to eat. Compared with the fever induced by rboIL-1 beta, that caused by rboIFN-gamma (2 micrograms kg-1 IV) was delayed in onset. Although the biphasic fever after rboIFN-gamma was more pronounced than after rboIL-1 beta, the changes in forestomach motility, food intake, and heart rate were less than after rboIL-1 beta. No changes in rectal temperature, heart rate, forestomach motility, and food intake were observed after rboIL-2 (1 micrograms kg-1 IV) injection. These results strongly indicate that the effects of cytokines on body temperature can be dissociated from their effects on food intake. Furthermore, these data suggest a possible relationship between forestomach motility and food intake.