Alkaline phosphatase activities in intestinal mucosa from calves infected with Cooperia punctata and Eimeria bovis

Thirty calves 12 weeks of age raised under essentially parasite-free conditions were used to determine the effects of Cooperia punctata and Eimeria bovis (in single and combination infections) on mucosal alkaline phosphatase activities at 8 locations in the small intestine. In experiment 1, 5 calves infected with C punctata 3 weeks previously had highly significant (P less than 0.01) reductions in mucosal alkaline phosphatase activities compared with those in 5 noninfected control calves. These reductions were greatest in the 2 locations of the intestine closest to the pylorus. Infected calves had a mean of 44,356 C punctata adults present. In experiment 2, 5 calves infected with E bovis 2 weeks previously had significant (P less than 0.05) reductions in mucosal alkaline phosphatase activities compared with those in 5 noninfected control calves. These reductions were present in the caudal half of the intestine. Numerous 1st-generation E bovis schizonts were present in the caudal third of the intestine. In experiment 3, 5 calves infected with C punctata and E bovis of the same durations as in experiments 1 and 2 had highly significant (P less than 0.01) reductions in mucosal alkaline phosphatase activities in the cranial half of the intestine compared with those in the controls. These reductions were much larger than in either of the monospecific infections (experiments 1 and 2). A mean of 31,968 adult C punctata were recovered from the infected calves, and numerous E bovis schizonts were observed in the caudal third of the intestine.