Fat-free Lean Index Research Articles

Dietary Valine/Isoleucine Ratio Impact Carcass Characteristics, Meat Edible Quality and Nutritional Values in Finishing Crossbred Duroc × Landrace × Yorkshire Pigs With Different Slaughter Weights.

The aim of this study was to investigate effects of dietary ratio of valine to isoleucine [R(V/I)] on carcass characteristics and meat quality of finishing pigs and whether slaughter weight influence the effect. We carried out a 2 × 3 factorial trial with two slaughter weight (105 vs. 130 kg) and three R(V/I) (0.58, 1.23, and 2.60 at 75–100 kg body weight, and 0.70, 1.24, and 2.39 at 100–135 kg body weight for L-, N- and H-R (V/I), respectively). Data show that increasing slaughter weight significantly increased meat color (a*45 min and b*45 min), drip loss and shear force (P < 0.05). Meanwhile, increasing slaughter weight reduced sarcomere length, the proportion of protein-bound water, and most kinds of muscular total amino acid contents except for tryptophan and arginine, while increased contents of muscular free lysine, tryptophan, leucine, isoleucine, valine, alanine, and arginine in the M. longissimus thoracis (P < 0.05). Health lipid indices based on fatty acid composition of intramuscular lipid were improved as the slaughter weight increased (P < 0.05). Notably, pigs received N-R (V/I) diet improved carcass traits in terms of thinner backfat thickness and higher fat-free lean index, as well as increased meat flavor-contributing amino acids at the cost of reduced intramuscular fat content and increased shear force of cooked meat compared with the pigs fed L-R (V/I) and H-R(V/I) diets (P < 0.05). H-R (V/I) diet decreased ultimate pH value and sarcomere length of the skeletal muscle but increased the proportion of free water (T23), consequently, increased drip loss and cooking loss of fresh meat in pigs (P < 0.05). In conclusion, both slaughter weight and dietary ratio of valine to isoleucine exerted significant impacts on carcass characteristics, meat quality and nutrition values. In particular, carcass traits and meat color of lighter pigs were more susceptible to the influence of dietary R (V/I) relative to heavier pigs.

Different dietary starch sources alter the carcass traits, meat quality, and the profile of muscle amino acid and fatty acid in finishing pigs

BackgroundWith increasing health awareness among consumers, the demand for healthier, tastier, higher quality and nutritional value pork is increasing. It has been shown that different dietary starch sources can alter the carcass traits and meat quality. However, research on the effects of different starch sources with clear different amylose/amylopectin ratio on the amino acid and fatty acid composition in Longissimus thoracis (L. thoracis) muscle of pigs is limited. This study aimed to investigate the effects of different dietary starch sources on carcass traits, meat quality, muscle amino acid and fatty acid composition, and the mRNA expression levels of genes involved in lipid metabolism and muscle fiber characteristics in finishing pigs. A total of 72 Duroc × Landrace × Large White barrows were randomly allocated to 3 different dietary treatment groups with 8 replicate pens/group and 3 pigs per pen. Tapioca starch (TS), corn starch (CS), and pea starch (PS), with amylose/amylopectin ratio of 0.11, 0.25, and 0.44, respectively, were used as their dietary starch sources for 40 days.ResultsResults showed that the PS diet significantly increased (P < 0.05) the final body weight, average daily gain, loin-eye area, and fat-free lean index compared with the TS diet, but significantly decreased (P < 0.05) the feed to gain ratio and backfat thickness. Compared with the TS diet, PS diet also increased (P < 0.05) the pH45 min, marbling scores, the content of intramuscular fat and inosine monophosphate in the L. thoracis, and decreased (P < 0.05) the drip loss and shear force. In addition, compared with the TS diet, PS diet increased (P < 0.05) the proportions of flavor amino acids, DHA, EPA, and n-3 polyunsaturated fatty acid (PUFA) in the L. thoracis compared with TS diet, but decreased (P < 0.05) the ratio of n-6/n-3 PUFA. Furthermore, compared with the TS diet, PS diet also upregulated (P < 0.05) the lipogenic genes (FAS, LPL, SCD, ACCα) and myosin heavy-chain (MyHC)-IIa mRNA expression levels compared with the TS diet, but downregulated (P < 0.05) the CPT1B and MyHC-IIb mRNA levels.ConclusionsIn conclusion, these results provided compelling evidence that the different dietary starch source altered the carcass traits, meat flavor and quality in finishing pigs, and consumption of a diet with higher amylose/amylopectin ratio results in the production of a healthy, higher quality, and nutritional value pork.

The effects of dietary soybean hulls particle size and diet form on nursery and finishing pig performance.

Two experiments were conducted to investigate increasing unground and finely ground soybean hulls fed in meal or pelleted form on nursery and finishing pig performance. In experiment 1, 1,100 nursery pigs (initially 6.8 ± 0.1 kg and 28 d of age) were used in a 42-d study with 11 replicates per treatment. Treatments were arranged in a 2 × 2 × 2 factorial with main effects of soybean hulls (10% vs. 20%), grind type (unground, 617 µ vs. ground, 398 µ), and diet type (pelleted vs. meal form). No three-way or soybean hull level × grind type interactions were observed. Overall, average daily gain (ADG) was increased (P < 0.05) by pelleting, decreased (P < 0.05) by grinding, but unaffected by soybean hull levels. Grind type × diet form interactions were observed (P < 0.05) for gain:feed ratio (G:F) and a tendency for average daily feed intake (ADFI; P < 0.10). This was because grinding soybean hulls decreased (P < 0.05) ADFI and increased (P < 0.05) G:F when fed in meal form; however, grinding did not affect ADFI and decreased (P < 0.05) G:F when diets were pelleted. Increasing soybean hulls increased (P < 0.05) ADFI and decreased (P < 0.05) G:F when diets were fed in meal form, but these effects were not observed when diets were pelleted (diet form × soybean hull level interaction, P < 0.06). In experiment 2, 1,215 pigs (initially 21.1 ± 0.1 kg) were used in a 118-d study with nine replications per treatment. Treatments were a corn–soybean meal–based control diet and four diets arranged in a 2 × 2 factorial with the main effects of soybean hulls (7.5% vs. 15%) and grind type (unground, 787 µ vs. ground, 370 µ). All diets were fed in meal form. No soybean hull level × grind type interactions were observed for any growth or carcass responses. Increasing dietary soybean hulls from 0% to 15%, regardless of particle size, did not affect ADG or ADFI, but decreased (linear, P < 0.02) G:F. Carcass yield, hot carcass weight, and backfat depth decreased (linear, P < 0.03) whereas percentage lean increased (linear, P < 0.01) with increasing soybean hulls. Pigs fed ground soybean hulls had increased backfat depth (P < 0.01) and decreased (P < 0.01) percentage lean and fat-free lean index. In summary, increasing soybean hulls up to 20% decreased G:F in nursery and finishing pigs, whereas pelleting nursery diets improved ADG and eliminated the negative effect of increasing soybean hulls on G:F. Grinding soybean hulls reduced growth performance in nursery and finishing pigs.

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

A total of 160 finishing pigs (PIC 327 × 1050; initially 45.6 kg) were used in an 84-d experiment to evaluate the effects of dietary fat source and feeding duration on growth performance, carcass characteristics, and carcass fat quality. There were 2 pigs per pen with 8 pens per treatment. The 10 dietary treatments were a corn-soybean meal control diet with no added fat and a 3 × 3 factorial with main effects of fat source (4% tallow, 4% soybean oil, or a blend of 2% tallow and 2% soybean oil) and feeding duration (d 0 to 42, 42 to 84, or 0 to 84). The control corn-soybean meal diet was fed in place of added fat diets when needed for duration treatment purposes. On d 0, 1 pig was identified in each pen and fat biopsy samples of the back, belly, and jowl were collected on d 0, 41, and 81 for fatty acid analysis. At the conclusion of the study, all pigs were harvested, carcass characteristics were determined, and back, belly, and jowl fat samples were collected for analysis. Overall (d 0 to 84), there were no differences among pigs fed the different fat sources for growth and carcass characteristics; however, pigs fed diets with added fat for the entire study had improved ( = 0.036) G:F compared with pigs fed the control diet without added fat. Pigs fed supplemental fat throughout the entire study also had improved ( < 0.05) ADG and G:F as well as heavier d-84 BW ( = 0.006) compared with pigs fed additional fat during only 1 period. Adding fat for the entire study increased ( = 0.032) backfat and tended to reduce ( = 0.079) the fat free lean index compared with pigs fed the control diet without added fat. Added fat also increased ( < 0.05) the iodine value (IV) when compared with pigs fed the control diet. Increasing the feeding duration of soybean oil lowered MUFA and increased PUFA concentrations for all fat depots, whereas these values remained relatively unchanged by the addition of tallow (duration × fat source interactions, < 0.05). Our study failed to show any feeding period × fat source interactions ( < 0.05) in fatty acid composition or IV for jowl fat, whereas this interaction occurred for belly fat and backfat, which would indicate a longer turnover rate for jowl fat. In conclusion, feeding additional fat improved ADG and G:F; however, feeding soybean oil for an increased duration, either alone or in combination with tallow, negatively affected the fatty acid composition and IV of different fat depots.

Effects of an abrupt change between diet form on growth performance of finishing pigs

A total of 200 finishing pigs (PIC TR4×1050; initially 60±4.7kg) were used in a 58 days growth assay to determine the effects of an abrupt change in diet form from meal to pelleted and pelleted to meal diets on growth performance and carcass measurements. The experiment was designed as a randomized complete block design with 5 pigs per pen and 10 pens per treatment. Diets were fed in 2 phases, day 0–36 and day 36–58 for phase 1 and 2, respectively. Treatments were meal to meal, meal to pelleted, pelleted to meal, and pelleted to pelleted diets for Phases 1 and 2 of the experiment, respectively. For Phase 1 (day 0–36), pigs fed the mean of the pelleted diet had increased (P<0.01) ADG and G:F compared to pigs fed the mean of the meal diet. For Phase 2 (day 36–58), pigs fed the pelleted diet had increased (P<0.01) ADG and G:F compared to pigs fed the meal diets. Pigs fed the pelleted diet from day 0 to 58 had increased (P<0.01) ADG and G:F compared to pigs fed the meal diet from day 0 to 58. For day 0–58, pigs fed the pelleted diet for either Phase 1 or 2, but not both, tended to have decreased (P<0.11) ADG and G:F compared to those fed the pelleted diet for the entire experiment. Pigs fed the meal then pelleted diet did not differ (P>0.27) in performance compared to those fed the pelleted then meal diet. No differences (P>0.19) were observed in dressing percentage, fat thickness, loin depth, or percentage fat free lean index. In conclusion, pigs fed the pelleted diet the entire experiment had increased ADG compared to pigs fed the meal diet. Pigs fed the pelleted diet had the greatest G:F, pigs fed meal the worst, and pigs fed pellets for only part of the grow-finish phase fell between the other treatments.

Effects of sorghum particle size on milling characteristics and growth performance in finishing pigs

A total of 200 finishing pigs (PIC TR4×1050; initially 46.8±1.24kg) were used in a 69-day growth assay to determine the effects of sorghum particle size on growth performance and carcass characteristics. Pigs were sorted by sex, ancestry, and BW with 5 pigs per pen and 10 pens per treatment. Treatments were a corn–soybean meal-based control with the corn milled to a target particle size of 600μm and sorghum milled to target particle sizes of 800, 600, and 400μm. Actual mean particle sizes were 555μm for corn and 724, 573, and 319μm for sorghum. All diets were pelleted. Pigs were slaughtered (average final BW of 123kg) at a commercial abattoir. Pigs fed the sorghum-based treatments were not different in growth performance, hot carcass weight, backfat thickness, loin depth, or fat free lean index compared to those fed the corn control; however, there was a tendency for pigs fed sorghum-based treatments to have increased (P<0.09) ADG, ADFI, and dressing percentage. As particle size of sorghum was reduced from 724 to 319μm, ADG was not affected but G:F increased (linear, P<0.01). Reducing particle size of sorghum had no effect (P>0.23) on hot carcass weight, backfat thickness, loin depth, or fat free lean index, but dressing percentage tended to improve (P<0.06). In conclusion, linear improvements in G:F were demonstrated with reduction of sorghum particle size from 724 to 319μm. Moreover, our data suggest that the performance of pigs fed corn-based diets were within the range of the responses to those fed sorghum-based diets with varying sorghum particle sizes.

The effects of feeder design and dietary dried distillers' grains with solubles on the performance and carcass characteristics of finishing pigs1,2

Three experiments were conducted to compare the effects of a conventional dry (five 30.5-cm spaces 152.4 cm wide; Staco Inc., Schaefferstown, PA) vs. a wet-dry (double sided; each side = 38.1-cm space; Crystal Spring; GroMaster Inc., Omaha, NE) finishing feeder (Exp. 1 and 2) and to evaluate the effects of feeder design and dietary level of dried distillers' grains with solubles (DDGS; >10% oil; Exp. 3) on performance and carcass characteristics of finishing pigs. In Exp. 1, 1,186 pigs (32.1 kg BW) were used in a 69-d experiment. There were 26 to 28 pigs per pen and 22 pens per feeder design, and all pigs received the same diets in 4 phases. In Exp. 2, 1,236 pigs (28.7 kg BW) were used in a 104-d experiment, with 25 to 28 pigs per pen and 23 pens per feeder design, and all pigs received the same diets in 5 phases. Carcass measurements were obtained from 11 pens of each feeder design after harvest. In Exp. 3, 1,080 pigs (35.1 kg BW) were used in a 99-d 2 × 2 factorial with main effects of feeder design (dry vs. wet-dry feeders) and DDGS (20 vs. 60%) with 10 pens of 27 pigs per treatment and all diets fed in 4 phases. Jowl fat samples were collected from 2 pigs per pen for fatty acid analysis and iodine value (IV) determination. In all experiments, pigs fed with the wet-dry feeder had greater (P < 0.05) ADG, ADFI, and final BW. In Exp. 2 and 3, HCW and backfat depth were increased (P < 0.05) for pigs fed with a wet-dry feeder, but G:F and fat-free lean index (FFLI) were reduced. Jowl IV was also reduced (P < 0.05) with a wet-dry feeder in Exp. 3. Pigs fed 60% DDGS in Exp. 3 had decreased (P < 0.05) ADG, G:F, final BW, HCW, and backfat but increased jowl IV and a tendency (P < 0.07) toward greater FFLI regardless of feeder type. In conclusion, pigs fed with this specific type of wet-dry feeder had improved ADG and ADFI, poorer G:F, and increased backfat depth compared to pigs fed with a conventional dry feeder. The poorer growth performance and increased jowl IV of pigs fed diets with 60% DDGS was similarly exhibited for pigs fed on both feeders.

Effects of preslaughter feed withdrawal time on finishing pig carcass, body weight gain, and food safety characteristics in a commercial environment.

The effects of feed withdrawal time before slaughter on finishing pig carcass composition were evaluated in 2 studies. In Exp. 1, 728 pigs (BW = 128.9 ± 1.2 kg) were allotted to 1 of 4 treatments in a randomized design with number of pigs per pen and location within barn balanced across treatment. The 4 treatments were feed withdrawal times of 8, 24, 36, or 48 h and there were 12 replicate pens per treatment. Before feed withdrawal, pigs were fed a standard corn-soybean meal diet containing dried distillers grains with solubles (DDGS), bakery coproducts, and 5.0 mg/kg ractopamine HCl. Feed withdrawal time decreased (linear; P < 0.02) live weight, HCW, and backfat while increasing percentage yield (quadratic; P < 0.01) and fat-free lean index (FFLI; linear; P < 0.001). In Exp. 2, 843 pigs (BW = 125.4 ± 1.6 kg) were used to determine the impact of feed withdrawal on growth, carcass, blood lactate, and meat quality. There were 4 treatments: withholding feed for 8, 12, 24, or 36 h, with 10 replicates per treatment. Pigs were fed a common corn-soybean meal-based diet containing 20% DDGS and 5.0 mg/kg ractopamine HCl. Withholding feed decreased (linear; P < 0.001) live weight, ultimately resulting in decreased (P < 0.01) HCW. There were no differences in FFLI or backfat, but percentage yield (linear; P < 0.001) increased with longer withdrawal times. Carcass contaminations by stomach contents escaping from the oral cavity after shackling (leaking ingesta) or visible fecal contamination of the exterior of the carcass (runny bung) were also measured. Although withholding feed did not affect runny bung, it increased (linear; P < 0.001) the incidence of leaking ingesta, whereas blood lactate, visual color score, and purge loss were unaffected. Withholding feed increased 45-min pH (quadratic; P > 0.02) and ultimate pH (linear; P < 0.01) and increased (quadratic; P < 0.03) visual marbling score. Withholding feed decreased (linear; P < 0.001) feed intake, resulting in feed savings of up to 3 kg/pig. Although several heavyweight pigs were removed before trial commencement and the variable number of remaining pigs per pen may have influenced the response to feed withdrawal, the present data indicates that finishing pigs can experience between 24 and 36 h of feed withdrawal without negatively affecting carcass composition. However, the increased incidence of leaking ingesta beyond 12 h of feed withdrawal is concerning.

Influence of dietary fat source and feeding duration on pig growth performance, carcass composition, and fat quality (2014)

A total of 160 finishing pigs (PIC 327 × 1050; initially 100.5 lb) were used in an 84-d experiment to evaluate the effects of dietary fat source and feeding duration on growth performance, carcass characteristics, and fat quality. Dietary treatments included a corn-soybean meal control diet with no added fat or a 3 × 3 factorial with main effects of fat source (4% tallow, 4% soybean oil, or a blend of 2% tallow and 2% soybean oil) and feeding duration (d 0 to 42, 42 to 84, or 0 to 84). One pig was identified in each pen on d 0, and biopsy samples of the back, belly, and jowl fat were collected on d 0, 41, and 81. At the conclusion of the study, all pigs were harvested, carcass characteristics were measured, and back, belly, and jowl fat samples were collected. Overall (d 0 to 84), there were no differences between fat sources for growth and carcass characteristics; however, pigs fed diets with added fat from d 0 to 84 had improved (P < 0.036) F/G compared with pigs fed a control diet without added fat. Pigs fed added fat throughout the entire study also had improved (P < 0.042) ADG and F/G and heavier d-84 BW (P < 0.006) compared with pigs fed additional fat for only period 1 or 2. Adding fat for the entire study increased (P < 0.032) backfat and tended to reduce (P < 0.083) fat-free lean index compared with pigs fed the control diet without added fat. Added fat also increased (P < 0.05) iodine value (IV) compared with pigs fed the control diet. Increasing the feeding duration of soybean oil or a blend of soybean oil and tallow decreased monounsaturated and increased polyunsaturated fatty acids relative to feeding tallow (duration × fat source interaction, P < 0.05), with the greatest changes in C18:1 and C18:2, respectively. In conclusion, feeding added fat improved ADG and F/G; however, feeding soybean oil for increasing duration, either alone or in a blend with tallow, negatively affected the fatty acid composition and IV of finishing pigs.; Swine Day, Manhattan, KS, November 20, 2014

Effects of standardized ileal digestible tryptophan:lysine in diets containing 30% dried distillers grains with solubles on finishing pig performance and carcass traits1,2

Two experiments were conducted to determine the effects of standardized ileal digestible (SID) Trp:Lys in grow-finish swine diets containing 30% dried distillers grains with solubles (DDGS). Within each experiment, crystalline Lys and Trp replaced soybean meal to alter the dietary SID Trp:Lys concentration but maintain minimum ratios of other AA to Lys. In Exp. 1, 638 pigs (36.3 kg initial BW) were used in a 105-d trial (6 pens per treatment). Pens of pigs were randomly allotted to 1 of 4 dietary treatments with SID Trp:Lys of 14.0, 15.0, 16.5, and 18.0%. From d 0 to 42, as Trp:Lys increased, ADG increased (quadratic; P = 0.05) and ADFI tended to increase (quadratic; P = 0.07) with no changes in G:F. Both ADG and ADFI were maximized at Trp:Lys of 16.5%. From d 42 to 105, increasing SID Trp:Lys increased (linear; P < 0.001) ADG and ADFI. Unlike data from d 0 to 42, the response was linear through the greatest SID Trp:Lys of 18.0%. Overall (d 0 to 105), increasing SID Trp:Lys increased (linear; P < 0.001) final BW, ADG, ADFI, and HCW. In Exp. 2, 1,214 pigs (66.3 kg initial BW) were used in a 73-d finishing trial (9 pens per treatment). Pens of pigs were randomly allotted to 1 of 5 dietary treatments with SID Trp:Lys of 15.0, 16.5, 18.0, and 19.5 and the 15.0% Trp:Lys diet with l-Trp added to achieve 18.0% SID Trp:Lys. Overall (d 0 to 73), ADG, ADFI, G:F, and final BW improved (linear; P < 0.03) as dietary SID Trp:Lys increased through 19.5%. No differences were found in growth performance between the 2 diets containing 18.0% SID Trp:Lys. For carcass traits, increasing SID Trp:Lys resulted in increased HCW (linear; P = 0.01) and a tendency toward a decreased (quadratic; P = 0.09) backfat depth and fat-free lean index (FFLI), with pigs fed diets containing 16.5 and 18.0% SID Trp:Lys having increased FFLI and lower backfat depth compared with pigs fed 15.0 and 19.5% SID Trp:Lys. Pigs fed the diet with added crystalline Trp tended to have increased (P = 0.08) backfat depth and decreased FFLI (P = 0.10) compared with pigs fed the same SID Trp:Lys without crystalline Trp. The results indicated that the optimal SID Trp:Lys was 16.5% from 36.3 to 72.6 kg but at least 19.5% from 72.6 to 120.2 kg in corn-soybean meal diets containing 30% DDGS.

Effects of two feeder designs and adjustment strategies on the growth performance and carcass characteristics of growing–finishing pigs1,2

Our objective was to compare effects of a conventional dry (CD, 152.4-cm-wide, 5-space, Staco Inc., Schaefferstown, PA) and a wet-dry (WD, double-sided, each side = 38.1-cm-space, Crystal Springs, GroMaster Inc., Omaha, NE) feeder using various feeder adjustment openings on the growth performance and carcass characteristics of growing-finishing pigs (Sus scrofa). In Exp. 1, 1,296 pigs (BW 19 kg) were used in a 27-d study to evaluate 3 feeder openings nested within each feeder design. From d 0 to 27, pigs fed with a WD feeder had similar ADG, but lower (P < 0.02) ADFI and greater G:F than pigs fed with a CD feeder. Increased adjustment opening increased (linear, P < 0.01) ADG and ADFI by pigs fed with a WD feeder, and increased (linear, P < 0.01) ADFI by pigs fed with a CD feeder. In Exp. 2, 1,248 pigs (BW 33 kg) were used to evaluate 3 feeder openings nested within each feeder design in a 93-d study. Pigs fed with a WD feeder had greater (P < 0.05) ADG, ADFI, final BW, HCW, and backfat, but decreased fat-free lean index (FFLI) than those fed with a CD feeder. Increased opening of the WD feeder resulted in greater (linear, P < 0.05) ADG, ADFI, HCW, and backfat, but lower FFLI. No differences among CD feeder openings were observed, and G:F did not differ among all feeder treatments. In Exp. 3, 1,287 pigs (BW 38 kg) were used in a 92-d factorial experiment with 4 feeder treatments and 2 diet types (low and high byproduct diets). Feeder treatments were CD at approximately a 2.4-cm opening, WD at a 3.2-cm opening, WD changed to a 2.5-cm opening on d 56, and WD changed to a 2.5-cm opening on d 28 and a 1.9-cm opening on d 56. Pigs fed with a WD feeder had greater (P < 0.01) ADG, ADFI, HCW, and backfat, but decreased FFLI than pigs fed with a CD feeder. Decreasing the WD feeder opening during the study decreased (P < 0.05) ADG. Pigs with the WD feeder opening decreased to 1.9 cm had reduced (P < 0.05) ADFI and backfat, but increased FFLI compared with pigs with a WD feeder opening of 3.2 cm. Feed efficiency did not differ among treatments. In conclusion, ADG, ADFI, HCW, and backfat were increased with the WD feeder evaluated in this experiment, but the growth of pigs fed with a WD feeder was more sensitive to differences in feeder adjustment than that of pigs fed with a CD feeder.

Effects of dietary wheat middlings, distillers dried grains with solubles, and choice white grease on growth performance, carcass characteristics, and carcass fat quality of finishing pigs1

Two experiments were conducted to evaluate the effects of adding combinations of wheat middlings (midds), distillers dried grains with solubles (DDGS), and choice white grease (CWG) to growing-finishing pig diets on growth, carcass traits, and carcass fat quality. In Exp. 1, 288 pigs (average initial BW = 46.6 kg) were used in an 84-d experiment with pens of pigs randomly allotted to 1 of 4 treatments with 8 pigs per pen and 9 pens per treatment. Treatments included a corn-soybean meal-based control, the control with 30% DDGS, the DDGS diet with 10% midds, or the DDGS diet with 20% midds. Diets were fed in 4 phases and formulated to constant standardized ileal digestible (SID) Lys:ME ratios within each phase. Overall (d 0 to 84), pigs fed diets containing increasing midds had decreased (linear, P ≤ 0.02) ADG and G:F, but ADFI was not affected. Feeding 30% DDGS did not influence growth. For carcass traits, increasing midds decreased (linear, P < 0.01) carcass yield and HCW but also decreased (quadratic, P = 0.02) backfat depth and increased (quadratic, P < 0.01) fat-free lean index (FFLI). Feeding 30% DDGS decreased (P = 0.03) carcass yield and backfat depth (P < 0.01) but increased FFLI (P = 0.02) and jowl fat iodine value (P < 0.01). In Exp. 2, 288 pigs (initial BW = 42.3 kg) were used in an 87-d experiment with pens of pigs randomly allotted to 1 of 6 dietary treatments with 8 pigs per pen and 6 pens per treatment. Treatments were arranged in a 2 × 3 factorial with 2 amounts of midds (0 or 20%) and 3 amounts of CWG (0, 2.5, or 5.0%). All diets contained 15% DDGS. Diets were fed in 4 phases and formulated to constant SID Lys:ME ratios in each phase. No CWG × midds interactions were observed. Overall (d 0 to 87), feeding 20% midds decreased (P < 0.01) ADG and G:F. Pigs increasing CWG had improved ADG (quadratic, P = 0.03) and G:F (linear, P < 0.01). Dietary midds or CWG did not affect ADFI. For carcass traits, feeding 20% midds decreased (P < 0.05) carcass yield, HCW, backfat depth, and loin depth but increased (P < 0.01) jowl fat iodine value. Pigs fed CWG had decreased (linear, P < 0.05) FFLI and increased (linear, P < 0.01) jowl fat iodine value. In conclusion, feeding midds reduced pig growth performance, carcass yield, and increased jowl fat iodine value. Although increasing diet energy with CWG can help mitigate negative effects on live performance, CWG did not eliminate negative impacts of midds on carcass yield, HCW, and jowl fat iodine value.

Amino acid digestibility and energy content of deoiled (solvent-extracted) corn distillers dried grains with solubles for swine and effects on growth performance and carcass characteristics1,2

A study with 3 experiments was conducted to determine the AA digestibility and energy concentration of deoiled (solvent-extracted) corn distillers dried grains with solubles (dDGS) and to evaluate its effect on nursery pig growth performance, finishing pig growth performance, and carcass traits. In Exp. 1, a total of 5 growing barrows (initial BW = 30.8 kg) were fitted with a T-cannula in the distal ileum and allotted to 1 of 2 treatments: 1) a diet with dDGS as the sole protein source, or 2) a N-free diet for determining basal endogenous AA losses in a crossover design at 68.0 kg of BW. Apparent and standardized (SID) ileal digestibility of AA and energy concentration of dDGS were determined. In Exp. 2, a total of 210 pigs (initial BW = 9.9 kg) were used in a 28-d experiment to evaluate the effect of dDGS on nursery pig performance. Pigs were allotted to 5 dietary treatments (0, 5, 10, 20, or 30% dDGS) formulated to contain equal ME (increased added fat with increasing dDGS) and SID Lys concentrations based on the values obtained from Exp. 1. In Exp. 3, a total of 1,215 pigs (initial BW = 29.6 kg) were used in a 99-d experiment to determine the effect of dDGS on growth and carcass characteristics of finishing pigs. Pigs were allotted to dietary treatments similar to those used in Exp. 2 and were fed in 4 phases. The analyzed chemical composition of dDGS in Exp. 1 was 35.6% CP, 5.29% ash, 4.6% fat, 18.4% ADF, and 39.5% NDF on a DM basis. Apparent ileal digestibility values of Lys, Met, and Thr in dDGS were 47.2, 79.4, and 64.1%, respectively, and SID values were 50.4, 80.4, and 68.9%, respectively. The determined GE and DE and the calculated ME and NE values of dDGS were 5,098, 3,100, 2,858, and 2,045 kcal/kg of DM, respectively. In Exp. 2, nursery pig ADG, ADFI, and G:F were similar among treatments. In Exp. 3, increasing dDGS reduced (linear; P < 0.01) ADG and ADFI but tended to improve (linear; P = 0.07) G:F. Carcass weight and yield were reduced (linear; P < 0.01), loin depth tended to decrease (linear; P = 0.09), and carcass fat iodine values increased (linear; P < 0.01) as dDGS increased. No difference was observed in backfat, percentage of lean, or fat-free lean index among treatments. In conclusion, dDGS had greater CP and AA but less energy content than traditional distillers dried grains with solubles. In addition, when dietary fat was added to diets to offset the reduced ME content, feeding up to 30% dDGS did not affect the growth performance of nursery pigs but did negatively affect the ADG, ADFI, and carcass fat quality of finishing pigs.

The effects of sorghum dried distillers grains with solubles on finishing pig growth performance, carcass characteristics, and fat quality (2011)

A total of 288 finishing pigs (PIC TR4 × 1050, initially 129.6 lb) were used in a 73-d study to determine the effects of increasing sorghum dried distillers grains with solubles (DDGS) in sorghum- or corn-based diets on finishing pig growth performance, carcass characteristics, and fat quality. Pigs were allotted to 1 of 6 dietary treatments in a completely randomized design based on initial pen weight. The dietary treatments included sorghum-based diets with sorghum DDGS included at 0, 15, 30, or 45%; a sorghum-based diet with 30% corn DDGS; and a corn-based diet with 30% corn DDGS. Overall (d 0 to 73), increasing sorghum DDGS from 0 to 45% reduced (linear, P < 0.04) ADG and ADFI. Increasing sorghum DDGS increased (linear, P < 0.01) backfat iodine value (IV), and fat color became less red (a*; linear, P < 0.01) and tended to be less yellow (b*; linear, P < 0.06). No differences were observed in growth performance among pigs fed corn- or sorghum-based diets with 30% corn DDGS along with similar carcass characteristics, backfat, loin depth, fat-free lean index (FFLI), HCW, carcass yield, and backfat IV. Pigs fed sorghum-based diets with either 30% sorghum or corn DDGS had similar ADG, ADFI, and F/G, as well as similar carcass characteristics; however, pigs fed 30% sorghum DDGS had decreased (P < 0.01) backfat IV and fat color that was more white (L*) and less yellow (b*) in color than pigs fed 30% corn DDGS. We observed similar ADG, ADFI, and F/G, as well as carcass characteristics, for pigs fed corn- or sorghum-based diets with 30% DDGS. Backfat IV was greater in pigs fed increasing DDGS, with a notable increase in pigs fed corn DDGS compared with those fed sorghum DDGS. Feeding sorghum DDGS produces pork fat that is lighter in color and less yellow than those fed corn DDGS, which may have an important role in pork export markets.; Swine Day, Manhattan, KS, November 17, 2011

Effects of abrupt changes between mash and pellet diets on growth performance in finishing pigs (2011)

A total of 200 finishing pigs (average initial BW of 132.3 lb) were used in a 58-d growth assay to determine the effects of an abrupt change from mash to pellets and pellets to mash on growth performance and carcass measurements. The experiment was designed as a randomized complete block with 5 pigs per pen and 10 pens per treatment. There were 4 treatments with 2 phases of diets utilized. Treatments were mash to mash, mash to pellets, pellets to mash, and pellets to pellets for Phases 1 and 2 of the experiment. For Phase 1 (d 0 to 36), pigs fed the pelleted diet had 4% greater (P 0.15) were observed in dressing percentage, fat thickness, loin depth, or percentage fat-free lean index (FFLI). Pigs fed pellets tended to have the greatest growth performance, pigs fed mash the worst, with pigs fed pellets for only part of the grow-finish phase rating intermediate.

Effects of sorghum particle size on milling characteristics, growth performance, and carcass characteristics in finishing pigs (2011)

A total of 200 finishing pigs (PIC TR4 × 1050; average initial BW of 103.2 lb) were used in a 69-d growth assay to determine the effects of sorghum particle size on growth performance. Pigs were sorted by sex and ancestry and balanced by BW, with 5 pigs per pen and 10 pens per treatment. Treatments were a corn-soybean meal-based control with the corn milled to a target mean particle size of 600 μm, and sorghum diets milled to a target mean particle size of 800, 600, or 400 μm. Actual mean particle sizes were 555 μm for corn, and 724, 573, and 319 μm for sorghum, respectively. Feed and water were offered on an ad libitum basis until the pigs were slaughtered (average final BW of 271 lb) at a commercial abattoir. Reducing sorghum particle size improved (linear, P < 0.01) F/G, and we observed a tendency for decreased (P < 0.06) ADFI. Reducing sorghum particle size from 724 to 319 μm had no effects on HCW, backfat thickness, loin depth, or percentage fat-free lean index (FFLI), but tended to increase (P < 0.06) carcass yield. Pigs fed the sorghum-based diets had no difference in growth performance or carcass characteristics compared with those fed the control diet, except carcass yield, which was numerically greater (P < 0.07) for pigs fed the sorghum-based diets. When using a regression equation, we determined that sorghum must be ground to 513 μm to achieve a F/G equal to that of a corn-based diet, with corn ground to 550 μm. In conclusion, linear improvements in F/G and carcass yield were demonstrated with the reduction of sorghum particle size to 319 μm. In this experiment, sorghum should be ground 42 μm finer than corn to achieve a similar feeding value.

Effects of feeder design, wet-dry feeder adjustment strategy, and diet type on the growth performance and carcass characteristics of growing-finishing pigs (2010)

A total of 1,287 pigs (PIC 337 × 1050, initially 82.7 lb) were used to compare the effects of a conventional dry feeder, 3 wet-dry feeder adjustment strategies, and 2 diet types on growing-finishing pig performance. There were 27 pigs per pen and 6 pens per treatment. The first wet-dry strategy consisted of maintaining a setting of 18 throughout the study (WD18). The second wet-dry strategy consisted of an initial setting of 18 until d 56 followed by a reduced setting of 14 for the remainder of the experiment (WD14). The third wet-dry strategy consisted of an initial setting of 18 until d 28, a setting of 14 until d 56, and a setting of 10 for the remainder of the experiment (WD10). The conventional dry feeder remained at a setting of 8 throughout the study. The 2 diet types evaluated in this study were a corn-soybean meal-15% DDGS diet and a corn-25% DDGS-20% bakery by-product-soybean meal diet; both diets were fed over 4 dietary phases. Overall (d 0 to 92), all pigs fed using the wet-dry feeder had greater (P < 0.001) ADG, ADFI, and final BW than pigs fed with the conventional dry feeder. However, within the wet-dry treatments, pigs fed with WD14 and WD10 had a reduced (P < 0.05) ADG compared with pigs fed with WD18. Additionally, ADFI of pigs fed using WD10 was lower (P < 0.05) than that of pigs fed with WD18, and ADFI of pigs fed with WD14 was intermediate. There were no differences in F/G among feeder treatments, and growth performance was similar between the 2 diet types. Pigs fed using the wet-dry feeder had greater (P < 0.02) HCW, yield, backfat depth, revenue per pig, and feed cost per pig than pigs fed with the conventional dry feeder. The loin depth of pigs fed using the wet-dry feeder was less (P < 0.04) than that of pigs fed with the conventional dry feeder. Differences in backfat and loin depth resulted in pigs using the wet-dry feeder having a lower (P < 0.001) fat-free lean index (FFLI) than pigs fed with the conventional dry feeder. However, within the wet-dry feeder treatments, pigs fed with WD10 had a reduced (P < 0.05) backfat depth and increased (P < 0.05) FFLI compared with pigs fed with WD18. The backfat depth and FFLI of pigs fed with WD14 were intermediate. Although not significantly different, income over feed cost was numerically greatest for pigs fed using WD10, followed by conventional dry, WD18, and WD14. In conclusion, reducing the wet-dry feeder setting in later growth periods may improve carcass leanness while maintaining the advantages in growth rate.

Effects of feeder design and feeder adjustment on the growth performance of growing-finishing pigs (2010)

Two experiments were performed to evaluate the effects of feeder design (conventional dry feeder vs. wet-dry feeder) and adjustment on growing-finishing pig performance. In both experiments, all pigs (PIC 337 × 1050) were fed the same corn-soybean meal diets with 15% dried distillers grains with solubles (DDGS). In Exp. 1, 1,296 pigs (initially 43 lb) were used in a 69-d study. From d 0 to 27, 3 feeder settings were evaluated for each feeder type. Numbered settings (located in each feeder) were 6, 8, and 10 for the conventional dry feeder and 6, 10, and 14 for the wet-dry feeder. An increased setting number corresponded to a greater opening. From d 27 to 69, all feeders were adjusted to an opening of approximately 1 in. (conventional dry feeder setting 8; wet-dry feeder setting 14). From d 0 to 27, pigs using a wet-dry feeder had lower (P < 0.02) ADFI and better F/G than pigs using a conventional dry feeder. Increasing the feeder setting improved (linear, P < 0.01) ADG, ADFI, and d-27 BW of pigs using a wet-dry feeder and increased (linear, P < 0.01) ADFI of pigs using a conventional dry feeder. From d 27 to 69, ADG and ADFI of pigs using a wet-dry feeder were greater (P < 0.01) than those of pigs using a conventional dry feeder, and increasing the feeder setting from d 0 to 27 resulted in greater (linear, P < 0.01) ADFI and poorer F/G for pigs using a wet-dry feeder. Overall (d 0 to 69), pigs using a wet-dry feeder had greater (P < 0.05) ADG, ADFI, final BW, and better F/G than pigs that used a conventional dry feeder. Increasing the feeder setting of a wet-dry feeder from d 0 to 27 resulted in greater (linear, P < 0.01) ADG and ADFI, poorer (linear, P < 0.03) F/G, and heavier (linear, P < 0.01) final BW. Feeder setting of a conventional dry feeder from d 0 to 27 did not affect overall performance. In Exp. 2, 1,248 pigs (initially 73 lb) were used in a 93-d study. Three feeder settings were evaluated throughout the study for each feeder type (conventional dry feeder set at 6, 8, and 10; wet-dry feeder set at 10, 14, and 18). Overall, pigs using a wet-dry feeder had greater (P < 0.05) ADG, ADFI, final BW, HCW, backfat depth, and feed cost but reduced (P < 0.04) fat-free lean index (FFLI) compared with pigs using a conventional dry feeder. Increasing the feeder setting of a wet-dry feeder resulted in greater (linear, P < 0.05) ADG, ADFI, final BW, HCW, backfat depth, and feed cost. When HCW was used as a covariate, FFLI of pigs using a wet-dry feeder decreased (linear, P < 0.02) with increased feeder opening. Increasing the feeder setting of a conventional dry feeder had no effect on growth performance and carcass characteristics. In conclusion, the growth rate of pigs improved with a wet-dry feeder compared with a conventional dry feeder; however, the growth of pigs using a wet-dry feeder was more sensitive to differences in feeder adjustment.

Meta-analyses describing the variables that influence the backfat, belly fat, and jowl fat iodine value of pork carcasses (2010)

Concern about the quality of pork fat has increased in the United States over the last decade, largely because of the increased availability and use of dried distillers grains with solubles (DDGS) in swine diets. The iodine value (IV) of pork fat is commonly used as an indicator of quality. To identify the factors associated with carcass fat IV, meta-analyses were conducted to describe the relevant variables and to develop prediction equations to assist swine nutritionists and producers in producing pork fat with an acceptable IV. Data from 21 experiments were used to develop prediction equations for carcass fat IV of pigs fed a relatively constant dietary iodine value product (IVP) throughout the feeding period, and 6 experiments were used to develop prediction equations for carcass fat IV of pigs fed a dietary IVP-reduction strategy before marketing. Backfat, belly fat, and jowl fat IV were all highly correlated among the experiments that measured the IV of the multiple fat depots (r ≥ 0.880; P < 0.001). As expected, the dietary concentrations of unsaturated (primarily polyunsaturated) fatty acids were the most important in predicting carcass fat IV. However, improved prediction models were achieved by including variables to describe the pigs’ initial and final BW, ADG, and carcass leanness. Increased ADG, final BW, BW range over course of the diet, and backfat depth resulted in reduced backfat IV (P < 0.02). Belly fat IV was also reduced with increasing final BW, BW range over course of the diet, and backfat depth (P < 0.03). A reduced jowl fat IV was associated with an increase in backfat depth and a lower fat-free lean index (FFLI, P < 0.02). Data analyzed to develop equations for predicting carcass fat IV using a dietary IVP-reduction strategy indicated that the concentrations of dietary polyunsaturated fatty acids in the initial diet were the most important. The concentrations of dietary polyunsaturated fatty acids in the reducedIVP diet fed before marketing were also important in predicting the IV of carcass fat. However, the IV of backfat was the most amenable to change using an IVP-reduction strategy. Feeding the pigs for a longer period and to a heavier final BW resulted in a reduced backfat IV (P ≤ 0.05). These results indicate that, although primarily determined by dietary factors, an understanding of the other variables that influence the IV of pork fat is necessary to reduce the likelihood of concerns with pork fat quality.

Effect of constant or step-up ractopamine hcl (paylean) feeding programs on growth performance and carcass characteristics of late-finishing pigs (2009)

A total of 1,099 pigs (PIC 337 × C22; initial BW = 208 lb) were used to evaluate the effect of ractopamine HCl (RAC) feeding programs on growth and carcass traits of late-finishing pigs. Pigs were randomly assigned to 1 of 3 treatments balanced by average BW within gender. There were 14 pens per treatment and 26 pigs per pen. Treatments were a basal diet with: (1) 0 g/ton RAC for 28 d (control), (2) 0 g/ton RAC from d 0 to 7 and 4.5 g/ton RAC from d 7 to 28 (constant), and (3) 4.5 g/ton from d 0 to 14 and 6.75 g/ton from d 14 to 28 (step-up). Pig ADG, ADFI, and F/G were determined weekly, and carcass data were collected at the end of experiment. From d 0 to 7, step-up pigs had improved (P < 0.04) ADG, ADFI, and F/G compared with pigs in all other treatments. From d 0 to 14, RAC-fed pigs, regardless of the feeding program, had greater (P < 0.01) ADG and better (P < 0.01) F/G than control pigs. From d 14 to 28, although pigs in both RAC-fed treatments had greater (P < 0.01) ADG than control pigs, the step-up pigs had lower (P < 0.05) ADG and ADFI than the constant-fed pigs. Regardless of the RAC feeding program, all RAC-fed pigs exhibited better (P < 0.01) F/G than control pigs. From d 7 to 28, pigs fed the constant and step-up treatments exhibited greater (P < 0.01) ADG and better (P < 0.05) F/G than control pigs. However, when pigs fed the RAC-fed treatments were compared, step-up pigs had lower (P < 0.01) ADG and ADFI but similar (P > 0.27) F/G. Overall (d 0 to 28), ADFI (P = 0.15) was similar between treatments, but RAC-fed pigs had greater (P < 0.01) ADG than control pigs, which led to improved (P < 0.01) F/G. Pigs fed either RAC feeding strategy had similar performance overall. RAC-fed pigs had heavier (P < 0.05) carcass weights and tended (P < 0.10) to have greater yield than control pigs. Among the 3 groups, step-up pigs had the greatest (P < 0.05) percentage lean, loin depth, and fat-free lean index as well as the lowest (P < 0.01) backfat depth. The pigs fed either RAC program had greater (P < 0.05) revenue than control pigs. Although feed cost was higher (P < 0.01) in the RAC-fed pigs than in the control, income over feed cost tended (P < 0.07) to be higher for RAC-fed pigs than for control pigs. In conclusion, feeding a constant level of 4.5 g/ton RAC for 21 d improved growth similarly to feeding the 28-d step-up program. However, the 28-d RAC step-up program resulted in additional improvement in carcass traits of late-finishing pigs.; Swine Day, Manhattan, KS, November 19, 2009