Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2001
Publication Date: N/A
Interpretive Summary: This experiment determined whether dietary conjugated linoleic acid (CLA) can be used to alter fatty acid composition of edible tissues in pigs. Secondly some animals were treated with porcine somatotropin (pST), a potent partitioning agent that reduces fat accumulation and enhances muscle growth. Swine were fed the diet from a body weight of 20 kg to 55 kg. Blood samples were collected at 55 kg. Half of the carcass was analyzed for chemical composition. Samples of fat and muscle were analyzed for their fatty acid composition. Dietary CLA did not affect animal performance as pigs grew. Dietary CLA did not affect hormones or metabolites in the blood. Dietary CLA altered fatty acid composition of both muscle and fat. Dietary CLA increased the saturated fatty acid content of muscle and fat. Treatment with pST reduced the saturated fat content and increased the polyunsaturated fatty acid content of both muscle and fat in CLA fed pigs. These data indicate that pST functions to enhance the percentage of polyunsaturated fatty acids in muscle and fat.
Technical Abstract: This experiment examined the dietary dose responsive to CLA addition with respect to the fatty acid profile of edible and trimmed lean tissue in pigs treated with porcine somatotropin (pST), a potent partitioning agent. Conjugated linoleic was fed at doses from 0 to 2.0% to gilts and barrows from 20 to 55 kg BW. Additional groups were treated with sterile 50 mM bicarbonate buffer + 0% CLA, pST (100 mg/kg BW) + 0.5% CLA or pST (100 mg/kg BW) + 2.0% CLA. Animals were fed a diet containing 18% CP, 1.2% lysine, and 3.5 Mcal of DE/kg at 110% of ad libitum. Blood samples were obtained on the day before slaughter at 55 kg BW. The fatty acid profile in dorsal subcutaneous adipose tissue (SQ) and latissimus dorsi (LD) samples was determined by gas chromatography. Dietary CLA supplementation did not affect ADG, total gain, feed intake, feed efficiency or carcass composition. Dietary CLA did not affect serum BUN, insulin, glucose or IGF-I levels. Dietary CLA increased the percentage of stearic acid while the percentages as oleic and linolenic acid were reduced in LD. Treatment with CLA + pST increased the percentage of linoleic and arachidonic acids that comprised the LD fatty acids while reducing the percentage of palmitate and oleic acids. Dietary CLA increased the percentage of palmitic and stearic acids in SQ while reducing the percentage of oleic, linoleic, linolenic and arachidonic acids. The percentage of palmitate was reduced in SQ while linoleic was increased with CLA + pST administration. These data indicate that pST functions to enhance the percentage of polyunsaturated fatty acids in LD and SQ in animals fed CLA while reducing the percentage of saturated and monounsaturated fatty acids.