Effect of feeding high oleic soybean oil to finishing pigs on growth performance, carcass characteristics, and meat quality

This study aimed to evaluate the effects of dietary fat source and feeding duration on growth performance, carcass characteristics, and meat quality of finishing pigs. A total of 450 twenty-one-week-old finishing pigs with an average body weight of 113.7 ± 8 kg were housed in 90 pens assigned to one of five dietary treatments in a 2×2 + 1 factorial design. Dietary treatments consisted of two fat sources (CWG: 4% inclusion of choice white grease and HOSO: 4% inclusion of high oleic soybean oil) each provided 2 or 4 weeks before marketing. The "+1" diet was corn-based without fat inclusion (CON). Observations included growth performance, carcass characteristics, fatty acid (FA) profile, and sensory evaluation. Data was analyzed using PROC MIXED in SAS considering dietary treatment as a main effect, feeding duration, and their interactions. Pre-planned contrasts were used to compare dietary treatments with the control. From d14 to 28 and the overall experimental period (d0-28), pigs fed fat-supplemented diets had a greater (P<0.05) average daily gain and gain-to-feed ratio than CON-fed pigs. There was no significant difference (P>0.05) in growth performance when comparing fat sources or feeding periods. Pigs supplemented with either CWG or HOSO showed a tendency to have a greater (P<0.10) belly weight and belly yield and a lesser (P<0.10) loin yield and loin muscle area when compared with CON pigs. The loin from pigs fed fat sources had greater (P<0.05) oleic acid and eicosenoic acid concentration when compared with CON. When CWG was compared with HOSO, pigs fed CWG had a higher (P<0.05) concentration of palmitic acid and stearic acid while the HOSO pigs had a higher concentration of oleic acid and linolenic acid in the loin. In the belly, CON had a higher (P<0.05) concentration of palmitic acid and stearic acid compared to HOSO, while pigs fed fat sources had a higher concentration of oleic acid and eicosenoic acid. Bellies from HOSO had higher (P<0.05) oleic acid and α-linolenic acid methyl ester concentrations, while CWG had higher concentrations of g-linolenic acid. For the sensory evaluation, the palatability and acceptability of pork were not affected (P>0.05) by dietary treatments. In conclusion, supplementation with HOSO not only improved performance but tended to improve some carcass characteristics and increased the concentration of oleic acid and some other unsaturated FA with a concomitant decrease in the concentration of some saturated FA in pork.