ASTROVIRUS INFECTION IN HATCHLING TURKEYS - ALTERATIONS IN INTESTINALMALTASE ACTIVITY

Two experiments were conducted to determine intestinal disaccharidase activity in 1-day-old commercial turkey poults inoculated with astrovi rus. Small intestinal samples were collected on days 0.5, 1, 3, and 7 postinoculation (PI) in Expt. 1 and on days 7, 10, and 14 PI in Expt. 2 and evaluated for specific maltase activity (SMA). Astrovirus infect ion was verified on day 7 PI by immune electron microscopy of intestin al contents. Inoculated poults developed diarrhea and a transient, sig nificant decrease in intestinal SMA. SMA was significantly (P < 0.05) lower In astrovirus-inoculated poults than in control poults throughou t the entire small intestine from day 3 through day 7 PI. However, SMA had returned to normal in inoculated poults by day 10 PI and was sign ificantly higher than control values (P < 0.05) in all sections of the small intestine, except in the proximal jejunum, by day 14 PI. Decrea sed SMA caused by astrovirus infection resulted in disaccharide maldig estion, malabsorption, and subsequent osmotic diarrhea. As astrovirus was cleared from the intestinal tract, SMA was restored and diarrhea w as resolved.