* Growth in Q1 farm output slows from same period in 2013
* Q1 rice output below govt forecasts
* April-Sept rice output seen up 4.5 pct
* Q1 GDP data to be released on May 29 (Adds rice output forecasts)
MANILA, May 15 (Reuters) - Growth in agricultural output in the Philippines slowed in the first quarter from the same period a year ago after strong typhoons hit the country.
The Philippine Statistics Authority said in a report on Thursday that agricultural production in the first quarter expanded by 0.67 percent from a year ago versus 3.11 percent in the same period of 2013.
Typhoon Haiyan, one of the strongest storms to make landfall anywhere, devastated the central Philippines on Nov. 8, killing more than 6,000 people, leaving thousands missing and homeless, and destroying billion of pesos worth of infrastructure and crops.
Unmilled rice output grew 3.28 percent to 4.3 million tonnes in the first quarter, below the government forecast of 4.53 million tonnes for the period, according to PSA figures.
Rice exporters in the region are looking out for any sign the Southeast Asian nation could need to import more of the staple grain.
It has bought a total of 1.3 million tonnes of rice from Vietnam, the world's No. 2 exporter after India, in the last six months to boost state stockpiles.
Some rice traders, however, have predicted the Philippines would need to import 2 million tonnes of rice this year after the government failed to meet its end-2013 rice self-sufficiency and inventory targets.
Unmilled rice output in the Philippines between April and September is forecast to grow 4.5 percent from a year ago to 7.5 million tonnes, based on the latest government estimates.
The rice harvest in the second quarter is seen up by 4.56 percent at 4 million tonnes, based on standing crops, the statistics agency said.
For the third quarter, rice output is predicted to grow 4.51 percent to 3.5 million tonnes, based on farmers' planting intentions.
The PSA said poultry production grew by 1.33 percent in the first quarter from 2013, while livestock output increased by 1.2 percent. Fisheries output contracted 3.25 percent, the agency said.
The report comes ahead of first quarter GDP data on May 29.
(Reporting by Erik dela Cruz; Editing by Eric Meijer and Joseph Radford)