sealPurdue News

August 22, 1997

Purdue study: One vitamin A shot does nothing for hogs

WEST LAFAYETTE, Ind. -- Hog farmers who hope to boost pig production by giving each of their healthy sows a single, massive shot of vitamin A are probably wasting their money, according to Purdue University research.

The research, partially funded by the Indiana Pork Producers and the National Pork Producers councils, was reported this summer in the national council's 1996 Research Investment Report.

"If a producer's hogs are already healthy and not vitamin A deficient, a single shot of the vitamin per hog isn't going to do anything for them," said Purdue animal scientist Mark Diekman. "Especially if a hog already produces pretty good-sized litters, an injection of vitamin A probably won't bring any improvement. It largely depends on the genetics of the pig."

Diekman and Purdue animal scientist Wayne Singleton gave each of 977 sows a single injection of 1,000,000 International Units of vitamin A, then monitored the size and weight of their litters. The researchers gave the injection at different points in a sow's life, from weaning until 110 days after she'd been bred.

Timing didn't matter. When compared to a control group of pigs that received placebos, there was no difference in total litter size or weight, no matter when a sow was given the shot of vitamin A. Also, a single injection did not increase the chances that piglets would live after birth, nor did it decrease the number of runts born per litter.

Other researchers had found that litter size increased when they gave vitamin A, but the hogs they tested were already deficient in the vitamin, Diekman said. Another group found that litter size increased when hogs received a series of vitamin A shots. The Purdue researchers were the first to test single vitamin A shots and to show no effect.

For more information on hog production, join Diekman and other Purdue researchers at the 1997 Purdue Swine Day on Thursday (8/28). Registration begins at 8 a.m. at the Purdue Animal Sciences Research Center on U.S. 52 in Montmorenci. There is no cost for registration. Lunch will be available for $6 from the Purdue Block and Bridle Club, a student animal sciences organization.

Source: Mark Diekman (765) 494-4829
Writer: Rebecca Goetz (7650 494-0461, e-mail
Purdue News Service: (765) 494-2096; e-mail,

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