200 Dokki-4- laying pullets commencing laying for about three months were used to study the effect of oxytetracycline supplemeni tation on egg production and hatchability under Upper Egypt con ditinos the results obtained could be summerized as follow:
1-The inconporation of oxytetracycline in the breeder rations under
Upper Egypt conditions resulted in an increase in both laying rate and egg weight. This increase represent about 10% of total egg production of the control pullets. The increase was more pronounced during hot months.
2--The antibiotic seems not to affect the fertility or the percentages
of both pipped eggs and dead chicks at hatch. However, it lowered the embryonic mortality and abnormal chicks at hatch. In general, the use of oxytetracycline imporved hatchability by
about 9% 3_-The chick weight at hacth was superior in the group supplemented
with oxytetracycline.