4790
In Trial 1 , eight sows were allowed to farrow naturally ( d 114 , NF sows ) and eight sows were induced to farrow ( IF sows ) prematurely by injection of prostaglandin F2 alpha on d 112 of gestation .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
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