An Early Detection Method for Gizzerosine Contained in Fish Meal using Chick Assay

Abstract

Five experiments were conducted to establish a detection method for gizzerosine contained in fish meal by assay using commercial male broiler chicks.
1) Gizzard Erosion (GE) of day-old chicks before feeding was considerably high. It did not depend on the body weight of the chicks. It was also observed that GE score of the chicks rapidly decreased for three days after feeding.
2) Day-old chicks or two-day-old chicks, which were fed commercial diet during one day, were fed the experimental diet containing 7.5, 15, 30 or 60% fish meal that caused severe GE to five-day-old. In these experiments, it was difficult to detect the GE positive fish meal by measuring GE scores.
3) Four-day-old chicks, which were fed commercial diet during three days, were fed the same experimental diet. It showed a trend that the GE score were increased by higher fish meal rations from two days to five days. This result seemed to be due to the disappearance of GE in day-old chicks by feeding commercial diet for three days.
4) If the assay using four-day-old chicks was carried out, the fish meal which caused severe GE could be detected by two days feeding. It is suggested, if the term of the assay is extended to seven days, that fish meal of a lower GE positiveness may be detected.