Effects of wheat structure and viscosity on coccidiosis in broiler chickens

In an experiment with broiler chickens to investigate the effects of physical form of wheat and viscosity of digesta on an Eimeria acervulina infection given on day 21, balanced feeds containing 400 g whole wheat/kg (WW) were compared with those with 400 g ground wheat/kg (GW), with or without addition of carboxymethyl cellulose (CMC− vs. CMC+). Neither treatment significantly affected healthy bird performance from days 15 to 21, or bird performance during recovery from the infection, from days 29 to 42. Neither treatment significantly affected total faecal oocyst yields. During the acute phase of the infection (days 22–28), birds fed on WW had significantly lower weight gains (WW=39.2 g per day, GW=51.8 g per day) and lower food conversion efficiency (FCE; GW=0.50; WW=0.43), and tended to have lower feed intakes (p=0.052), than those fed on GW. Birds fed on the CMC+ feeds had significantly inferior FCE than the birds fed the CMC− feeds (days 22–28) (0.44 vs. 0.49). Over the course of the whole infection (days 22–42), birds given feeds containing WW, and those fed on the CMC+ feeds, had significantly inferior FCE than those fed on the GW, and CMC− feeds (WW=0.49, GW=0.52, CMC+=0.50, and CMC−=0.52). Birds fed on the CMC+ feeds had significantly higher water:feed ratios than those fed on the CMC− feeds throughout the experiment.