Portland biotech firm ImmuCell Corp. on Monday reported a significant revenue increase for the third quarter, with sales up 38 percent from a year earlier to $3 million.

The company, which develops and manufactures bovine health products for the dairy and beef industries, said the revenue boost was the result of eliminating a production bottleneck that had restricted sales in 2018 despite increased customer demand.

ImmuCell reported a net loss of $503,000, or 7 cents per share, for the third quarter as it continued to absorb the costs of a $20 million manufacturing facility completed in late 2017 for a new product called Re-Tain that must receive regulatory approval before sales can commence.

The product, which treats mastitis, or inflammation of the udders in lactating cows, is undergoing a lengthy U.S. Food and Drug Administration approval process, which includes inspection of the manufacturing operation and evaluation of product samples.

Re-Tain is expected to receive FDA approval sometime in 2021. Once available, it would have a market advantage over competing products because it would not require farmers to discard any milk from cows undergoing treatment, the company has said.

The third-quarter sales increase reflects ImmuCell’s growing production capacity for its flagship product, First Defense, a natural alternative to antibiotics that provides immunity in newborn calves to scours, or diarrhea. The company said it has leased a 14,300-square-foot facility adjacent to its existing operations to boost First Defense production capacity even further, which should be up and running by mid-2020.

“We continue to see favorable sales results during 2019 from investments in the First Defense product line,” ImmuCell President and CEO Michael Brigham said in a news release. “We are growing and investing in infrastructure to fuel future growth.”

ImmuCell is the smallest of Maine’s four non-bank publicly traded companies, with 52 employees and 2018 revenue of $11 million. The company’s shares trade on the Nasdaq Stock Market under the symbol ICCC.

The quarterly earnings report was released shortly after the stock market closed on Monday. The value of ImmuCell shares fell by 2 percent in trading Monday to end the day at $5 per share.