7. Other Intangible Assets

The following table summarizes the components of gross and net acquired intangible assets:

Other intangible assets acquired include contract-based and technology-based intangible assets.

As part of its acquisition of the remaining majority interest in FourStar Microbial during the first quarter of fiscal 2013, the Company acquired approximately $0.1 million of marketing-related intangible assets, $0.1 million of customer-related intangible assets and $6.9 million of other intangible assets.

The Company evaluates long-lived assets, including amortizable and indefinite-lived intangible assets, for impairment whenever events or changes in circumstances indicate the carrying value may not be recoverable. The Company evaluates indefinite-lived intangible assets on an annual basis. In fiscal 2013, the Company tested its indefinite-lived intangible assets and no impairment was indicated. Other factors indicating the carrying value of the Company’s amortizable intangible assets may not be recoverable were not present in fiscal 2013 or during the three months ended December 28, 2013, and accordingly, no impairment testing was performed on these assets.

The Company is currently amortizing its acquired intangible assets with definite lives over periods ranging from 1 to 25 years; over weighted average remaining lives of six years for marketing-related intangibles, 15 years for customer-related intangibles and 15 years for other acquired intangibles. Amortization expense for intangibles subject to amortization was approximately $1.0 million and $1.1 million for the three months ended December 28, 2013 and December 29, 2012, respectively, and is classified within operating expenses in the condensed consolidated statements of operations. Estimated annual amortization expense related to acquired intangible assets in each of the succeeding five years is estimated to be approximately $5 million per year from fiscal 2014 through fiscal 2018.