Effect of gamma irradiation, penicillin, and/or pectic enzyme on chick growth depression and fecal stickiness caused by rye, citrus pectin, and guar gum.

The effects of gamma irradiation of rye, corn, pectin, and guar gum and supplementation of procaine penicillin and/or pectic enzyme (Irgazyme-100) were studied. Addition of 62.5% rye, 4% pectin, or 2% guar gum in place of corn significantly reduced chick growth (P < .05). Exposure to gamma irradiation, procaine penicillin, or pectic enzyme supplementation improved the growth of chicks fed rye. Growth response on the rye diet to one or more combinations of gamma irradiation, procaine penicillin, and pectic enzyme was greater than that of gamma irradiation, procaine penicillin, or pectic enzyme alone. Gamma irradiation or pectic enzyme supplementatin of pectin or guar gum improved chick growth and almost eliminated their growth depressing properties. A combination of gamma irradiation and pectic enzyme failed to give a further significant increase in growth over that of either alone. Addition of procaine penicillin to diets containing rye, irradiated pectin, or guar gum elicited a significant growth response, but the response was greatly reduced when diets contained irradiated guar gum or irradiated pectin. Feces of chicks fed diets containing rye, pectin, or guar gum adhered to screen floors in much greater amounts than for corn-fed chicks. Gamma irradiation, procaine penicillin, or pectic enzyme had no significant effect on fecal condition of birds fed diets containing rye or guar gum. In contrast, fecal condition of birds fed guar gum was significantly improved by a combination of gamma irradiation and pectic enzyme supplement. Gamma irradiation almost eliminated and pectic enzyme supplementation completely eliminated properties of pectin causing sticky feces. Results indicate that the component of rye that causes sticky feces was not changed by gamma irradiation and/or pectic enzyme, and, therefore, is different from the growth depressing factor and from citrus pectin.