THE EFFECT OF MYCOCURB(R), PROPIONIC-ACID, AND CALCIUM PROPIONATE ON THE INTESTINAL STRENGTH OF BROILER-CHICKENS

Field observations suggest that propionic acid-based mold inhibitors r educe the severity of proventriculitis and consequent fragile intestin es. Therefore, two studies were conducted to determine the effects of a propionic acid-based mold inhibitor (Mycocurb(R)), calcium propionat e, and propionic acid on intestinal strength. Cobb x Cobb male broiler chicks were placed in an experimental design that consisted of six di etary treatments with four replicate floor pens of 40 (Experiment 1) a nd 30 (Experiment 2) broilers per pen. The dietary treatments in Exper iment 1 consisted of control, 2.27, 4.54, and 9.07 kg/ton Mycocurb(R) and 4.54 and 9.07 kg/ton calcium propionate. The dietary treatments in Experiment 2 consisted of control, 2.27, 4.54, and 9.07 kg/ton Mycocu rb(R), and 4.54 and 9.07 kg/ton propionic acid. Water and the dietary treatments were made available to the broilers for ad libitum consumpt ion from 1 d to 6 wk of age. In Experiment 1, five broilers from each pen were killed each week, a 10-cm section of intestine was removed an terior to the cecal junction, and its strength was measured. The conte nts of this section of intestine were collected and pH determinations were made on this material. In Experiment 2, five broilers were killed from each pen starting when the broilers were 3 wk of age, and every week thereafter a 10-cm section of intestine was removed posterior to the duodenal loop and its strength measured. The contents of this sect ion of intestine were collected and pH determinations were performed o n this material. Intestinal strength at both of these locations increa sed with age, and the upper intestinal section was not as strong as th e lower intestinal section. Mycocurb(R), calcium propionate, and propi onic acid did not show any consistent effects on body weight, pH of in testinal contents, or intestinal strength.