Two new cases of BSE have been discovered in the past week, bringing the total for April to 13, the lowest monthly total since July 2001.
It brings the total number of BSE cases for 2003 to 82, compared to 133 cases for the same period last year.
The recent cases, both in eight-year-old cattle, were reported in counties Wicklow and Limerick.
The two cases were identified under the increased active surveillance programme, which tests all cattle over 30 months destined for human consumption and all dead animals. Over 1.54 million tests have been carried out to date under the active surveillance programme.
The Department said that the underlying trend "remains positive".
It said the increasing age profile of animals confirmed with the disease indicates the enhanced controls introduced in 1996 and early 1997 are proving effective.