Evaluation of Conjugated Linoleic Acid (CLA) and Dietary Antibiotics as Growth Promotants in Weanling Pigs

Purdue University 2000 Swine Research Report. There has been considerable pressure placed on pig producers worldwide to decrease the use of antibiotic growth promotants. This makes it necessary to search for viable alternatives to feeding antibiotics. One alternative may be the incorporation of conjugated linoleic acid (CLA) into swine diets. CLA is a fatty acid that is a positional and geometrical isomer of the n-6 fatty acid linoleic acid. CLA has been shown to modulate immune system function in chickens, rats, and mice by decreasing the amount of body weight lost due to an experimental immune system challenge with E. coli lipopolysaccharide (Cook et al., 1993; Miller et al., 1994). Preliminary research indicates that CLA can modify the immune system of weanling pigs by increasing immune system activation (Bassaganya et al., 1999). Research has shown that finishing pigs fed diets containing added CLA have increased feed efficiency and carcass leanness (Dugan et al., 1997; Eggert et al., 1999). However, limited research has been conducted on the effectiveness of dietary CLA on growth performance characteristics of pigs during the nursery stage of production. Our objective was to examine the effectiveness of CLA and a dietary sequence of antibiotics consisting of carbadox, tilmicosin, and tylosin/sulfamethazine as growth promotants and immune system modulators in weanling pigs reared under a one-site, continuous flow management scheme.