Viacom Inc., owner of Nickelodeon, MTV and other cable networks, said second-quarter profit climbed 53 percent as shows such as “Jersey Shore” added viewers. Net income increased to $376 million, or 63 cents a share, from $245 million, or 40 cents, a year earlier, New York-based Viacom said today in a statement distributed by PR Newswire. Excluding some items, earnings per share of 72 cents exceeded the 62-cent average of 22 analysts’ estimates. A strong advertising market helped boost Viacom’s TV channels, including MTV, Comedy Central and Nickelodeon, with ad buyers paying big premiums for ads sold close to when they air. U.S. ad revenue grew 11% compared to a year earlier, up from 10% growth in the fourth calendar quarter of 2010.