Effects of increasing choice white grease in corn- and sorghum-based diets on growth performance, carcass characteristics, and fat quality characteristics of finishing pigs1

Abstract

A total of 120 pigs (60 barrows and 60 gilts; TR4 × PIC 1050; 54.4 kg initial BW) were used in an 83-d study to evaluate the effects of added fat in corn- and sorghum-based diets on growth performance, carcass characteristics, and carcass fat quality. Treatments were arranged in a 2 × 3 factorial with grain source (corn or sorghum) and added fat (0, 2.5, or 5% choice white grease; CWG) as factors. There were 2 pigs (1 barrow and 1 gilt) per pen and 10 replicate pens per treatment. Pigs and feeders were weighed on d 14, 22, 39, 53, 67, and 83 to calculate ADG, ADFI, and G:F. At the end of the trial, pigs were slaughtered and jowl fat and backfat samples were collected and analyzed for fatty acid profile. No interactions were observed for growth performance. Pigs fed sorghum-based diets had greater (P < 0.01) ADG than pigs fed corn-based diets. Adding CWG improved (linear, P < 0.01) ADG. Pigs fed corn-based diets tended to have greater (P < 0.09) carcass yield, 10th-rib backfat, and percentage lean than pigs fed sorghum-based diets. Adding CWG increased (linear, P = 0.02) 10th-rib backfat, tended to increase (linear, P = 0.08) HCW, and tended to decrease (linear, P = 0.07) percentage lean. There was no grain source × fat level interaction for iodine value (IV) in backfat, but an interaction (P = 0.03) was observed for IV in jowl fat. Adding CWG increased (P < 0.01) IV in jowl fat for pigs fed sorghum- and corn-based diets; however, the greatest increase was between 0 and 2.5% CWG in sorghum-based diets and between 2.5 and 5% CWG in corn-based diets. Pigs fed corn-based diets had less (P = 0.01) C18:1 cis-9 and MUFA but greater (P = 0.01) C18:2n-6, PUFA, and backfat IV than pigs fed sorghum-based diets. Increasing CWG in the diet increased (linear, P = 0.01) backfat IV. Of the 2 fat depots, backfat generally had a reduced IV than jowl fat. In summary, feeding sorghum-based diets reduced carcass fat IV and unsaturated fats compared with corn-based diets. As expected, adding CWG increased carcass fat IV regardless of the cereal grain in the diet.

Influence of dietary fat source and feeding duration on finishing pig growth performance, carcass composition, and fat quality1,2

“…However, add ed fat did increase backfat depth. Similarly, Apple et al (2009b) and Benz et al (2011b) reported that carcasses from pigs fed added dietary fat, regardless of source, had greater average backfat depths than carcasses from pigs fed a diet without added fat. This would be expected as the pig is consuming a high energy diet and once the pig has reached the break point of protein accretion, they will rapidly fatten (Pettigrew and Esnaola, 2001).…”

Effects of distillers dried grains with solubles and added fat fed immediately before slaughter on growth performance and carcass characteristics of finishing pigs1

“…Added fat has been shown in some cases to improve HCW and carcass yield (Smith et al, 1999;Jackson et al, 2009) while others have reported no improvements in carcass yield (Engel et al, 2001;Benz et al, 2011). Beaulieu et al (2009) reported that for every 0.10 increase in Mcal/kg of DE, carcass yield improved by 0.20% units.…”

“…Increased carcass backfat depth is the 1 carcass trait most consistently increased with added dietary fat, due to high energy intake (Beaulieu et al, 2009;Benz et al, 2011;Salyer et al, 2012). Because most pork producers are paid on a carcass basis in the U.S., another measurement of response to observe is carcass performance.…”

Composition and quality characteristics of carcasses from pigs divergently selected for residual feed intake on high- or low-energy diets1

“…Additionally, weak correlations were found between the various depots' iodine values, suggesting that one depot's iodine value may not be a good predictor of the iodine value of another depot . Backfat generally had a reduced iodine value when compared to jowl adipose tissue (Benz et al, 2011). In research focused on diet differences (linoleic acid inclusion level, fat inclusion level, and fat source), it was recorded that overall gilts have adipose tissue with higher iodine values than adipose tissue from barrows (Averette Gatlin et al, 2002), possibly due to having a lesser percent of 14:0 (myristic acid) and 16:0 (palmitic acid) and greater percent of 18:2 n-6 (linoleic acid) in their adipose tissue (Martin et al, 1972).…”