Last week, the beef heifer price differential between Northern Ireland and the Republic was 33.9p/kg (46.3c/kg), the Livestock and Meat Commission (LMC) said.
This has narrowed on the price paid for the same time last month which was 40p/kg (54.6c/kg).
It said that an improvement in the value of euro against Sterling last week helped increase both R3 steer and heifer prices in the Republic in Sterling terms.
The R3 heifer price for the week ending August 29 was up the equivalent of 5.1c/kg to 297.7p/kg, it said.
In terms of EU heifer prices, Ireland continues to pay the fifth highest price in the EU for heifers.
For the week ending August 23, 2015 the average R3 heifer price in the Republic was 409.4c/kg; back 22.6c/kg from the 431.9c/kg paid in the week ending July 26, 2015.
This latest price was 10.8c/kg above the EU average.
Northern Ireland throughput
The plants in the North have reported a tightening in supplies of prime cattle with throughput last week similar to the previous week at 5,094 head, the LMC said.
It said this was a 14% reduction from the corresponding week in 2014 when 5,904 prime cattle were slaughtered in Northern Ireland plants.
Strong supplies of cows continue to come forward for slaughter with 2,024 cows killed in Northern Ireland plants last week, it said.
This takes cow throughput for August 2015 to 7,964 head compared to 6,916 cows killed in August 2014.
A further 1,228 cows were exported from the North to the Republic for direct slaughter during August 2015, a notable increase from the 375 that were exported during August 2014.
Exports of prime cattle from NI for direct slaughter in the rest of the UK last week totalled 201 head, the LMC said the highest weekly export during 2015 to date and is similar to year earlier levels.
Meanwhile imports of prime cattle from Republic for direct slaughter in the North last week totalled 470 head taking imports for August 2015 to 1,340 head, it said.
This is markedly lower than August 2014 levels when 2,993 prime cattle were imported from the Republic for direct slaughter.