Portland-based biotech firm ImmuCell Corp. completed a $9 million public offering Friday, selling over 1.6 million additional shares to investors.

The publicly traded company, which develops animal health products for the dairy and beef industries, said it will use the money for expansion and to reduce debt. ImmuCell said it netted about $8.3 million from the offering after deducting fees and expenses.

The company intends to use a portion of the offering’s proceeds to expand production capacity for First Defense, a natural product that prevents scours, or diarrhea, in newborn calves. A production bottleneck that caused a backlog of customer orders to accrue affected the company’s bottom line in the first quarter of 2018, but ImmuCell said the sales value of the backlog has been greatly reduced from about $1.25 million a year ago to just $185,000.

ImmuCell said it also is likely to use a portion of the offering’s proceeds to expand facilities to manufacture a new product called Re-Tain that has been submitted to the U.S. Food and Drug Administration for approval. In November 2017, ImmuCell completed construction of a new $20 million manufacturing facility to produce Re-Tain, a natural alternative to antibiotics for treating mastitis, a disease that afflicts lactating dairy cows.

Any remaining proceeds from the offering would be used to reduce the company’s debt or for working capital, the company said. ImmuCell shares trade on the Nasdaq Stock Market under the symbol ICCC.