The effect of adding copper and various fat sources to the diets of weanling swine on growth performance and serum fatty acid profiles.

An experiment involving 540 weanling pigs was conducted to determine the effect of the addition of Cu (5, 125, or 250 ppm) on the growth performance and serum fatty acid profiles of pigs fed diets that contained no added fat (NO FAT), 5% added soybean oil (SBO), 5% added animal fat (ANI), or 5% added medium-chain triglycerides (MCT). Pigs had ad libitum access to corn-soybean meal-based diets that contained 10% whey and 5% fish meal during the 28-d trial. Pigs were weighed and pen feed intakes were recorded weekly. Blood samples were collected for serum fatty acid analysis on d 1, 14, and 28 of the trial. The addition of all sources of fat to the diet increased (P < .001) ADG and gain:feed ratios during the 28-d trial. Increasing levels of dietary Cu linearly increased (P < .001) ADG and quadratically increased (P < .05) ADFI during the 28-d experiment. A Cu x fat source interaction was observed d 14 to 28 for ADG. The ADG of pigs fed NO FAT or SBO linearly increased with increasing levels of Cu, and pigs fed MCT or ANI had quadratic increases in ADG as Cu levels increased. Compared with the NO FAT diet, d-28 serum saturated fatty acid concentrations were decreased (P < .01) by the addition of SBO or ANI, monounsaturated fatty acid concentrations were decreased (P < .001) by the addition of SBO, and polyunsaturated fatty acid concentrations were increased by the addition of SBO (P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)