Late Finishing Pigs Research Articles

53 Evaluation of the impact of high doses of phytase and marketing strategy on performance and carcass characteristics of late finishing pigs in commercial settings

Abstract As late finishing pigs reach market weight, space allowance per unit of body weight (BW) is reduced, which negatively impacts growth performance. Supplementing high doses of phytase results in the near complete destruction of phytic acid resulting in increased levels of lower inositol esters and inositol, which have been associated with a decreased stress response as well as having insulin-like effects. This study evaluated the impacts of high doses of phytase and two marketing strategies on growth performance and carcass characteristics of late finishing pigs. Pigs (n = 2,200; initial BW = 89.64 ± 3.08 kg) were randomly distributed to 96 pens using two commercial research barns, with 18 to 24 pigs per pen, balanced for gilts and barrows. Two phytase supplementation doses (super-dosing control of 2,250 FTU/kg and hyper-dosing at 4,500 FTU/kg) and two marketing strategies (Standard or Late) were combined to create 4 treatments in a 2×2 factorial arrangement. The first marketing event occurred at an average BW of 123.3 kg on d 22 for the Standard group and at 145.3 kg on d 44 for the Late group, marketing the heaviest 1 to 5 pigs per pen (13.2% of pigs). The second group (15.4% of pigs; BW of 147.3 and 144.8 kg for Standard and Late marketing) was marketed on d 50 and marketing of all remaining pigs occurred on d 63 for both treatments. Finisher diets contained 0.74% SID lysine, 0.60% Ca, and 0.37% available P. Regardless of the dose, phytase was given the same matrix values for nutrients and metabolizable energy. No interactions were observed between marketing strategy and phytase supplementation (P > 0.22), and no effect of phytase was observed (P > 0.09). Average BW of all pigs marketed was greater (P < 0.001) for the Late compared with the Standard marketing strategy (143.8 vs. 141.7 kg/d). Days to market was greater for Late marketing (59.7 vs. 56.8 d) as a result of the extra 22 d before the first marketing compared with the Standard strategy. Thus, average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio were not impacted (P ≥ 0.486) by marketing treatments. Hot carcass weight (103.83 vs. 101.44 kg) and yield (78.10 vs. 77.73%) were greater (P < 0.001) for Late marketing. Fat cover was greater and percent lean was less (P < 0.05) for the Late marketing treatment, but loin depth and marbling were not different (P > 0.09). All primal cuts were heavier (P < 0.001), resulting in a total primal weight of 89.44 and 87.54 kg (P < 0.001) for Late and Standard marketing, respectively. Results suggest that delaying the first marketing improved final BW, yield, and weight of primal cuts and that supplementing phytase above super-dosing levels in late finishing pigs did not improve growth performance or carcass value, regardless of marketing strategy.

26 Effects of increasing net energy or standardized ileal digestible lysine in soybean meal-based diets on early and late finishing pig performance

Abstract A total of 2,265 finishing pigs [337×1050, PIC; initial body weight (BW) = 50.2 kg) were used in two 28-d trials to determine the effect of increasing net energy (NE) or standardized ileal digestible Lys in soybean meal (SBM) based diets on early and late finishing pig performance. There were 27 pigs/pen and 21 pens/treatment. Soybean meal NE value used in diet formulation was either 78% (2,087 kcal/kg) or 100% (2,672 kcal/kg) of corn NE. Four treatment diets were assigned to pens in a completely randomized design and consisted of: 1) high level of SBM estimated at 100% NE of corn (High SBM); 2) low level of SBM estimated at 100% NE of corn with added feed-grade AA (Low SBM); 3) low level of SBM estimated at 78% NE of corn with added fat (Low SBM w/fat) to equal the NE in diets 1 and 2; and 4) low level of SBM estimated at 100% NE of corn with increased feed-grade AA and increased Lys:NE (Low SBM w/AA). Following the early finishing 28-d growth trial (initial BW = 50.2 kg), pigs were fed a common diet for 30-d and pens were randomly reallotted to 1 of the same 4 treatments for the late finishing trial (initial BW 114.1 kg). In early finishing, there were no differences (P > 0.10) in average daily gain (ADG), but pigs fed Low SBM w/AA had increased (P < 0.05) average daily feed intake (ADFI) compared with pigs fed High SBM (Table). The increased ADFI without increased ADG resulted in decreased (P < 0.05) gain to feed ratio (G:F) in pigs fed Low SBM w/AA compared with pigs fed Low SBM w/fat. Pigs fed Low SBM w/fat had improved (P < 0.05) caloric efficiency (CE) compared with pigs fed Low SBM w/AA. In late finishing, there was a tendency (P = 0.099) for a treatment effect on G:F where pigs fed High SBM had the greatest G:F, but there was not a significant difference (P > 0.05) between any two treatments when using a Tukey multiple comparison adjustment. There was no evidence (P > 0.10) for a difference between treatments on ADG, ADFI, or CE. Based on the performance of pigs fed the Low SBM w/AA diet, the decreased growth performance of low SBM diets is not due to a low Lys:Calorie ratio that results when NE is underestimated. Using caloric efficiency, an estimate of the NE of SBM was calculated by adjusting NE of SBM used in formulation until CE for the High SBM and Low SBM treatments were equal. These results showed SBM was estimated to contain 94% the NE of corn in the early finishing period and 125% the NE of corn in the late finishing period.

An Evaluation of Paddy Rice as an Alternative Energy Source in Protein-Restricted Diets for Growing, Early-Finishing, and Late-Finishing Pigs

Three experiments were conducted to evaluate paddy rice as an alternative energy feedstuff in low-protein diets for pigs. In Experiment 1, a total of 400 growing pigs (20.68 ± 0.29 kg initial bodyweight), were randomly allocated four dietary treatments with 0, 10, 15, and 20% paddy rice for 30 days. Feeding 10% or 15% paddy rice had no adverse impacts on average daily gain (ADG) and feed to gain ratio (F:G), while the inclusion of 20% rice in diets significantly influenced the growth performance of pigs. In Experiment 2, 364 early-finishing pigs (42.25 ± 0.47 kg) were divided into four treatments with 0, 15, 20, and 25% paddy rice for 35 days. Feeding 15% or 20% paddy rice had no negative consequences on growth performance, while pigs fed with 25% rice had the lowest ADG and the greatest F:G. In Experiment 3, 364 late-finishing pigs (79.52 ± 1.28 kg) were divided into four treatments with 0, 20, 25, and 30% paddy rice for 60 days. Paddy rice can be included at up to 30% in diets without compromising growth performance, while feeding with 25% rice significantly improved the performance for pigs compared with the corn-fed control.

PSIV-13 Evaluation of Floor Space Restriction and Hyper-Dosing of Phytase on Growth Performance, Carcass Characteristics and Serum Chemistry of Late Finishing Pigs

Abstract This study was conducted to evaluate the impact of strategically applied hyper-dosing of phytase on growth performance, carcass characteristics and serum chemistry profile of late finishing pigs housed under space-restricted conditions. A total of 375 finishing pigs (94.63 ± 0.61 kg) were randomly assigned to 48 pens, with 7 to 8 pigs per pen equally balanced for gilts and barrows. Two phytase supplementation doses (control of 2,500 FTU/kg or hyper-dose of 5,000 FTU/kg) and two space allocation dimensions (adequate with 0.85 m2/pig or restricted with 0.66 m2/pig) were combined to create 4 treatments in a 2 x 2 factorial arrangement. Pigs were fed a finishing diet formulated to contain 0.68% standardized ileal digestible (SID) lysine, 0.55% Ca, and 0.24% available P and phytase was given equal matrix values for Ca, P, SID amino acids, and net energy for both supplementation levels. Analyzed dietary phytase concentrations were 2,970 and 6,560 FTU/kg for the 2,500 and 5,000 FTU/kg treatments, respectively. The 3 heaviest pigs per pen (2 barrows and 1 gilt) were marketed on d 28 and the remaining pigs were marketed on d 42. No interactions; P > 0.10) were observed between floor space allowance and phytase supplementation. Pig body weight was determined weekly and was reduced (P < 0.008) by restriction of space on week 3 (116.7 vs. 118.4 kg), and 4 (time of first marketing; 123.6 vs. 125.4 kg) and tended to be reduced (P < 0.08) on week 5 (125.5 vs. 127.8 kg), and 6 (second marketing; 133.0 vs. 135.3 kg). Body weight considering all pigs marketed (d 28 and d 42) was reduced (P = 0.009; 133.9 vs. 135.4) by space restriction. Space restriction reduced ADG during week 1, 3, the first marketing period, and for all pigs marketed (P < 0.05). Similarly, ADFI was reduced in space restricted pigs for all periods (P ≤ 0.001), but gain:feed was not impacted (P > 0.08). Back fat depth and loin eye area measured using ultrasound was not impacted by space restriction. Hyper-dosing with phytase did not impact (P > 0.06) growth performance or carcass characteristics, regardless of space allowance. Space restriction and phytase supplementation did not impact serum chemistry except for increased serum total protein and decreased urea N (P < 0.05) due to space restriction and decreased aspartate transaminase with hyper-dosing phytase. Results indicate that restricted floor space allowance reduced growth rate, feed intake and body weight of late finishing pigs and that hyper-dosing phytase was not an effective strategy in improving growth performance regardless of space allowance.

Effect of reducing dietary crude protein level on growth performance, blood profiles, nutrient digestibility, carcass traits, and odor emissions in growing-finishing pigs.

This study was conducted to evaluate the effect of a low-protein (LP) diet on growth performance, carcass traits, nutrient digestibility, blood profiles, and odor emissions in growing-finishing pigs. A total of 126 crossbred pigs ([Yorkshire × Landrace] × Duroc) with an average body weight (BW) of 38.56 ± 0.53 kg were used for a 14-week feeding trial. Experimental pigs were allotted to one of 6 treatments in 3 replicates of 7 pigs per pen in a randomized complete block design. Pigs were fed each treatment diet with different levels of crude protein (CP). Phase 1 (early growing): 14%, 15%, 16%, 17%, 18%, 19%; phase 2 (late growing): 13%, 14%, 15%, 16%, 17%, 18%; phase 3 (early finishing): 12%, 13%, 14%, 15%, 16%, 17%; phase 4 (late finishing): 11%, 12%, 13%, 14%, 15%, 16%. All experimental diets in each phase were contained the same concentration of lysine (Lys), methionine (Met), threonine (Thr), and tryptophan (Trp). Over the entire experimental period, there was no significant difference in body weight (BW), average daily feed intake (ADFI), and gain-to-feed ratio (G:F ratio) among all treatments (p>0.05), but a quadratic effect (p = 0.04) was observed in average daily gain (ADG) during the late finishing phase with higher ADG in Group D. Blood urea nitrogen concentration linearly increased with an increase in dietary CP levels (p<0.01). Regarding nutrient digestibility, excreted nitrogen in urine and feces and nitrogen retention linearly increased as the CP level increased (p<0.01). A linear effect was observed with increasing CP levels in amines, ammonia, and hydrogen sulfide in odor emissions (p<0.01). No significant effects were observed in the measurements of carcass traits and meat characteristics (p>0.05). In phase feeding, reducing the CP level to 14% in early-growing pigs, 13% in late-growing pigs, 12% in early-finishing pigs, and 11% in late-finishing pigs is recommended.

Multiple amino acid supplementations to reduce dietary protein for pigs during early and late finisher periods under commercial conditions.

With the easy availability and competitive prices of crystalline amino acids (AAs), the reduction of dietary crude protein (CP) for pigs during early and late finisher periods is possible under commercial conditions. Two experiments were conducted to assess the growth efficiency of early and late-finishing pigs fed with protein-restricted diets supplemented with Lys, Met, Thr, Trp, Val, Ile and His. In Experiment 1, 840 early finishing pigs were allocated to four dietary treatments with CP levels designed at 150, 142, 134, and 126 g kg-1 diet. In Experiment 2, 768 late-finishing pigs were allotted to four dietary treatments providing CP levels at 140, 130, 120, and 110 g kg-1 diet. In Experiment 1, the data showed that CP levels could be decreased from 150 to 126 g kg-1 without adversely affecting performance of early finishing pigs as no significant difference was observed for final bodyweight, average daily gain (ADG), feed to gain ratio (F:G), or average daily feed intake (ADFI). In Experiment 2, late-finishing pigs consuming 120 g kg-1 CP tended to have the highest ADG and lowest F:G whereas those fed the 110 g kg-1 CP diet showed the opposite trend. Based on quadratic analysis, the optimum CP levels to maximize ADG and minimize F:G were 126 and 127 g kg-1 , respectively. These findings showed that dietary CP levels could be decreased to 126 g kg-1 for early finishing pigs while improved performance was noted in late-finishing pigs consuming 120 g kg-1 CP. © 2023 Society of Chemical Industry.

Effects of increasing soybean meal in corn-based diets on the growth performance of late finishing pigs.

Three experiments were conducted to determine the effects of increasing soybean meal (SBM) levels by replacing feed-grade amino acids (AA) in corn, corn dried distillers grains with solubles (DDGS), and corn-wheat midds-based diets on growth performance of late finishing pigs (n = 4,406) raised in commercial facilities. Across all experiments, pens of pigs were blocked by initial bodyweight (BW) and randomly assigned to 1 of 5 dietary treatments. All diets were formulated to contain 0.70% standardized ileal digestible (SID) Lys and varying amounts of feed-grade AA. All diets were formulated to meet or exceed minimum essential AA requirement estimates as a ratio to Lys. In Exp. 1, 1,793 pigs (initially 104.9 ± 4.9 kg) were fed corn-based diets and pens of pigs were assigned treatments with increasing SBM from 5% to 20%. Overall, average daily gain (ADG) and feed efficiency (G:F) improved (linear and cubic, P ≤ 0.02) as dietary SBM increased, with the greatest improvement observed as SBM increased from 5% to 8.75% and little improvement thereafter. In Exp. 2, 1,827 pigs (initially 97.9 ± 4.3 kg) were fed diets containing 25% DDGS with SBM levels increasing from 0% to 16%. Overall, feed efficiency marginally improved (linear, P ≤ 0.10) as SBM increased, with the greatest performance observed when diets contained 8% SBM and similar performance thereafter with 12 or 16% dietary SBM. In Exp. 3, 786 pigs (initially 96.7 ± 3.2 kg) were fed diets that contained 30% wheat midds and dietary SBM from 0% to 16%. Final BW of pigs increased (linear, P < 0.05) and overall ADG and G:F improved (linear and cubic, P < 0.05) as SBM increased. The combined results of the three experiments suggest that inclusion of at least 4% to 8% dietary SBM at the expense of feed-grade amino acids in corn-based diets with or without grain coproducts can improve growth performance of late-finishing (greater than 100 kg) pigs.

Strategies to manage barn feed supply to prolong and hold late finishing pigs during a supply chain disruption.

The U.S. pork production system is sensitive to supply chain disruptions, including those that can create challenges of feed delivery and feed management during the event of a foreign animal disease outbreak. Therefore, the objective was to evaluate feeding strategies during a prolonged feed availability shortage in group-housed finishing pigs and assess the impacts on pig performance. A total of 1,407 mixed-sex pigs (92 ± 11 kg BW) were randomly allocated to one of five treatments across 60 pens (N = 12 pens per treatment, 22 pigs per pen) and were blocked by initial body weight (BW) within the replicate, over a 21-d test period. Treatments were fed for 14 d (P1), and thereafter all pens returned to ad libitum access to a standard commercial diet for 7 d (P2). Treatments included: 1) Pens fed ad libitum (CON); 2) Pens fed at 1.45X ME maintenance requirement daily of CON diet (1.45X); 3) Pens fed 2X ME maintenance requirement daily of CON diet (2X); 4) Tightened feeders to the lowest setting, fed ad libitum of CON diet (CF); and 5) whole corn kernels, fed ad libitum (WC). P1 and P2 BW and feed disappearance were recorded to calculate ADG, ADFI, and G:F. Data were analyzed with pen as the experimental unit and least-squares means values reported by treatment. Compared to CON, pens fed 1.45X, 2X, CF, and WC treatments had significantly reduced P1 ADG (1.09 vs. 0.02, 0.34, 0.72, 0.41 kg/d, respectively), ADFI (3.21 vs. 1.42, 1.90, 2.49, 2.40 kg/d, respectively) and G:F (P < 0.05). During P2, ADG and G:F were increased (P < 0.05) compared to CON across all treatments. However, ADFI increased only in the 2X, CF, and WC diet from the CON (P < 0.05). Overall (days 0 to 21), all strategies attenuated BW, ADG, and ADFI (P < 0.01) compared to CON. However, G:F was only reduced (P < 0.01) in 1.45X and WC, but not 2X and CF (P > 0.05) compared to CON. In conclusion, all strategies explored could extend feed budgets. Even though these strategies were successful, increased BW variability was reported with more restrictive strategies. Further, adverse pig behaviors and welfare implications needs to be considered in adopting any restrictive feeding strategy.

PSIII-18 Effect of Increasing L-Lysine-HCl and Amino Acid Ratios on Performance of Finishing Pigs from 109 to 129 Kg

Abstract A total of 1,789 pigs (PIC; 337×1050; initial BW 108.9 ± 1.14 kg) were used to determine the effects of increasing L-Lys-HCl and AA ratios on performance of late finishing pigs fed corn-soybean meal diets without DDGS. The study used 2 groups of pigs and each study lasted 18 and 27 d, respectively. Pigs were housed in mixed gender pens with 20 to 25 pigs/pen and 19 replications/treatment (10 and 9 replications/group, respectively). Pens of pigs were blocked by BW and randomly allotted to 1 of 4 dietary treatments. Treatment diets were formulated to 0.70% digestible Lys and consisted of low, medium, or high levels of feed-grade AA and moderate or high AA ratios relative to Lys. Low, medium and high feed-grade AA treatments had increased L-Lys-HCl (0.15, 0.30 and 0.39%) replacing soybean meal to achieve CP levels of 13.6, 12.0, and 11.0. Minimum AA:Lys ratios were 53% Ile, 128% Leu, 58% Met&amp;Cys, 66% Thr, 18.5% Trp, 68% Val, and 34% His in Moderate AA ratio diets and 60% Ile, 128% Leu, 60% Met&amp;Cys, 70% Thr, 21.2% Trp, 72% Val, and 33% His for the high AA ratio treatment. Overall, there was a marginally significant increase in ADFI (quadratic, P = 0.097) observed in pigs fed medium feed-grade AA and moderate AA ratios. Treatment diets had no effect on ADG or G:F. At the end of group 2, carcass data was collected with no differences (P &amp;gt; 0.10) observed for HCW, carcass yield, backfat depth, loin depth or percentage lean. In summary, differing levels of feed-grade AA and AA ratios used in this study did not impact growth performance or carcass characteristics of late finishing pigs with the exception of a marginally significant increase in ADFI.

Effects of standardized ileal digestible lysine on growth performance and economic return in duroc-sired finishing pigs.

In the United States, emphasis has shifted toward improved pork quality and has resulted in greater use of Duroc-based terminal sires. Duroc sires have differences in ADG, ADFI, G:F, and carcass leanness compared to other sires. Therefore, our objective was to determine the standardized ileal digestible (SID) Lys estimates for Duroc-based sired finishing pigs. In Exp. 1, 2,124 pigs (DNA 600 ×PIC 1050, initially 48.9 kg) were used with 24–27 pigs per pen and 16 pens per treatment. Corn-soybean meal-based diets were fed in three phases (49–59, 59–71, and 71–81 kg). Pens were randomly allotted to 1 of 5 treatments based as a percentage of PIC (2016) SID Lys estimates for gilts (85%, 95%, 103%, 110%, and 120%). Phase 1 diets were formulated to 0.90%, 1.01%, 1.09%, 1.17%, and 1.27%, phase 2 to 0.79%, 0.87%, 0.94%, 1.03%, and 1.10%, and phase 3 to 0.71%, 0.78%, 0.85%, 0.92%, and 0.99% SID Lys. Increasing SID Lys increased (linear, P < 0.001) ADG and Lys intake/kg of gain. A marginally significant improvement (quadratic, P = 0.071) in G:F was observed as SID Lys increased. Feed cost, feed cost/kg of gain, revenue (linear, P < 0.01) and income over feed cost (IOFC) increased (quadratic, P = 0.045) with increasing SID Lys. In Exp. 2, 2,099 pigs (DNA 600 ×PIC 1050, initially 90.1 kg) were used with 24–27 pigs per pen and 20 pens per treatment. Corn-soybean meal-based diets were fed in 2 phases (90–106 and 106–136 kg). Pens were randomly allotted to 1 of 4 treatments based as a percentage of PIC (2016) SID Lys estimates for gilts (85%, 93%, 100%, and 110%). Phase 1 diets were formulated to 0.65%, 0.71%, 0.77%, and 0.84% and phase 2 to 0.60%, 0.66%, 0.71%, and 0.78% SID Lys. Overall, increasing SID Lys increased (linear, P < 0.05) G:F, Lys intake/kg of gain, live weight and HCW, and increased (quadratic, P = 0.020) ADG. Feed cost (linear, P < 0.01), revenue, and IOFC increased (quadratic, P ≤ 0.053) with increasing SID Lys. In conclusion, the SID Lys estimate for growth and IOFC was 1.19% or 4.63 g SID Lys/Mcal of NE, 1.05% or 4.04 g SID Lys/Mcal of NE, and 0.94% or 3.58 g SID Lys/Mcal of NE for pigs weighing 49–59 kg, 59–71 kg, and 71–81 kg, respectively. The SID Lys estimate for late finishing pigs was 0.74%–0.81% or 2.85–3.10 g SID Lys/Mcal of NE, and 0.69%–0.75% or 2.61–2.84 g SID Lys/Mcal of NE, for 90–106 kg and 106–136 kg pigs, respectively. These data provide SID Lys estimates for current Duroc-sired genetic lines raised in a commercial environment.

224 Amino Acid Imbalance with Excess Methionine in Late-finishing Pigs: Effects on Performance and Carcass Quality

Abstract Limitations in harvest facility capacity can necessitate feeding programs to slow growth rate in late-finishing pigs. In Trial 1, six dietary regimens were used with 423 pigs (initial weight, 109 kg) randomly allotted in a 35 d study. The regimens consisted of: 1) Con (11.7% CP diet), 2) Low Protein (LP 8.8% CP), 3) Methionine (Met) 1% (LP plus 1% added Met for 35 d), 4) Met 1–1.8% (LP plus 1, 1.2, 1.4, 1.6 and 1.8% added Met for d 0–7, 7–14, 14–21, 21–28 and 28–35 d, respectively), 5) Met 2% (LP plus 2% added Met for 35 d) and 6) Met 1.5–2.3% (LP plus 1.5, 1.7, 1.9, 2.1 and 2.3%, added Met for d 0–7, 7–14, 14–21, 21–28 and 28–35 d, respectively). Pigs on Met 1% had reduced overall ADG and ADFI (P &amp;lt; 0.05) with similar G:F vs. pigs on LP. Compared to pigs on Met 1%, pigs on Met 1–1.8%, Met 2%, and Met 1.5–2.3% had reduced (P &amp;lt; 0.05) ADG of 28, 54 and 53%, respectively; and decreased (P &amp;lt; 0.05) ADFI of 12, 26 and 26%, respectively. In Trial 2, three regimens were used with 393 pigs (initial weight, 109 kg) in a 35 d study. The regimens consisted of 1) Met 2%, 2) Met 1.5–2.3% and 3) Met 2.0–2.8% (LP plus 2.0, 2.2, 2.4, 2.6 and 2.8% added Met for d 0–7, 7–14, 14–21, 21–28 and 28–35 d, respectively). Regimens 1 and 2 were identical to Trial 1. Overall, pigs on Met 1.5–2.3% had ADG and ADFI which were greater (P &amp;lt; 0.001) compared to pigs on Met 2%. Pigs on Met 2–2.8% had an overall ADG and ADFI which were less (P &amp;lt; 0.05) than those pigs on Met 2%. These data suggest that growth can be manipulated with excess Met.

Amino acid imbalance with excess methionine in late-finishing pigs: effects on performance and carcass quality

Abstract Limitations in harvest facility capacity can necessitate feeding strategies to slow growth rate in late-finishing pigs. In Exp. 1, six dietary treatments were used with 423 late-finishing pigs (initial weight of 109.5 kg) randomly allotted (mixed-sex) across 24 pens in a 35 d study. The treatments consisted of: 1) Positive Control (PC, 11.7% CP (Crude Protein) diet with added amino acids (AA), 2) Methionine (Met) 0% (8.8% CP with added AA), 3) Met 1% (8.8% CP with added AA plus 1% added Met for 35 d), 4) Met 1-1.8% (8.8% CP with added AA plus 1, 1.2, 1.4, 1.6 and 1.8% added Met for d 0-7, 7-14, 14-21, 21-28 and 28-35 d, respectively), 5) Met 2% (8.8% CP with added AA plus 2% added Met for 35 d) and 6) Met 1.5-2.3% (8.8% CP with added AA plus 1.5, 1.7, 1.9, 2.1 and 2.3% added Met for d 0-7, 7-14, 14-21, 21-28 and 28-35 d, respectively). Overall, pigs on the PC had improved ADG and G:F (P &amp;lt; 0.05) compared to the other five treatments. Pigs on Met 1% had reduced overall ADG and ADFI (P &amp;lt; 0.05) with similar G:F compared to pigs on Met 0%. Compared to pigs on Met 1%, pigs on Met 1-1.8%, Met 2%, and Met 1.5-2.3% had reduced (P &amp;lt; 0.05) ADG of 28, 54 and 53%, respectively; and decreased (P &amp;lt; 0.05) ADFI of 12, 26 and 26%, respectively. Dressing percent was similar among all six treatments. In Exp. 2, three dietary treatments were used with 393 late-finishing pigs (average initial weight was 108.8 kg) randomly allotted (mixed-sex) across 24 pens in a 35-d study. The treatments consisted of 1) Met 2%, 2) Met 1.5-2.3% and 3) Met 2.0-2.8% (8.8% CP with added AA plus 2.0, 2.2, 2.4, 2.6 and 2.8% added Met for d 0-7, 7-14, 14-21, 21-28 and 28-35 d, respectively). Treatments 1 and 2 were identical to Exp. 1. Overall, pigs on Met 1.5-2.3% had ADG of 241 g and ADFI of 2,040 g which were greater (P &amp;lt; 0.001) compared to pigs on Met 2% with ADG of 57 g and ADFI of 1,515 g. Furthermore, pigs on Met 2-2.8% had an overall ADG of -62 g and ADFI of 1,254 g which were less (P &amp;lt; 0.05) than those pigs on Met 2%. Percent lean and dressing percent were similar among the three treatments. These data suggest that late-finishing growth can be manipulated in a concise and effective manner by creating amino acid imbalances with varying levels of excess Met.

138 Effects of Increasing Soybean Meal in Corn-based Diets on Growth Performance of Late-finishing Pigs

Abstract Two experiments were conducted to determine the effects of increasing levels of soybean meal (SBM) replacing feed grade amino acids in corn or corn-dried distillers grains with solubles (DDGS)-based diets on growth performance of late finishing pigs. In both experiments, there were 22 to 27 pigs per pen and 14 pens per treatment. Average length of the experiments was 35 (Exp. 1) and 29 days (Exp. 2). Diets were balanced to contain 0.70% SID Lys and 2,667 or 2,610 kcal NE/kg for Exp. 1 and 2, respectively. Minimum amino acid ratios relative to Lys were: Ile, 55; Met&amp;Cys, 60; Thr, 65; Trp, 19.5, and Val, 70. Dietary crude protein ranged from 10.1 to 15.2 for Exp. 1 and 13.6 to 19.4 for Exp. 2. The statistical model considered fixed effects of treatment, linear and quadratic contrasts, and random effect of block. In Exp.1, 1,793 pigs (L337×1050, PIC; initially 104.9 ± 1.4 kg) were fed corn-based diets and pens of pigs were assigned to 1 of 5 dietary treatments with increasing SBM from 5 to 20%. Overall, average daily gain (ADG) and gain-to-feed (G:F) increased (linear; P &amp;lt; 0.05) as SBM increased with the greatest improvement observed as SBM increased from 5 to 8.75%, with little improvement thereafter. In Exp. 2, 1,827 pigs (L337×1050, PIC; initially 97.9 ± 1.1 kg) were used in a similar study as Exp. 1, but all diets contained 25% DDGS and SBM levels increased from 0 to 16%. Overall, G:F and final bodyweight of pigs marginally improved (linear and quadratic, respectively; P &amp;lt; 0.10) as SBM increased, with the greatest performance observed when diets contained 8% SBM. These results suggest that increasing SBM up to 8% at the expense of feed grade amino acids in corn or corn-DDGS-based diets improved ADG or G:F in late-finishing pigs.

205 Dietary Strategies to Limit Average Daily Gain of Late Finishing Pigs

Abstract A total of 2,164 pigs [DNA610 x DNA241; initially 100.7 ± 2.14 kg body weight (BW)] were used in a 54.1 ± 3.85-day study to determine dietary strategies to limit average daily gain (ADG) in late finishing pigs raised in a commercial environment. Mixed-sex pens (20.0 ± 0.85 pigs/pen) balanced by initial BW and gender ratio were randomly assigned to 1 of 4 dietary treatments fed ad libitum with 27 replications each: (1) Nutritionally replete corn soybean-meal control (CTRL), (2) Treatment 1 with 21% reduced lysine and other amino acids (AAR), (3) Corn/vitamin/mineral diet (CVM), and (4) Treatment 3 fed for 21 days then switched to CTRL. Data were analyzed as a randomized complete block design using a linear mixed model. Relative to CTRL, feeding AAR or CVM for 21 days reduced ADG (P &amp;lt; 0.001), average daily feed intake (ADFI; P = 0.005), and gain-to-feed (G:F, P &amp;lt; 0.001). Over 55-days, AAR and CVM diets reduced (P &amp;lt; 0.001) cumulative ADG, ADFI, G:F, and final BW compared to CTRL. Transitioning to CTRL diet from CVM diet after 21-days increased ADG (P &amp;lt; 0.001) and improved G:F (P &amp;lt; 0.001) from day 21 to marketing compared to 55-day CTRL, AAR, and CVM; nevertheless, the compensatory CTRL period was insufficient for the 21-day CVM fed pigs to fully compensate resulting in reduced cumulative BW, ADG (P &amp;lt; 0.001) and poorer G:F (P &amp;lt; 0.001) than the 55-day CTRL. All holding strategies decreased (P &amp;lt; 0.001) carcass yield, hot carcass weight (HCW), and loin depth compared to CTRL. Utilizing a CVM diet for 21 or 55 days increased (P &amp;lt; 0.001) backfat compared to CTRL or AAR. In summary, utilizing lysine deficient or corn/vitamin/mineral diets can limit ADG along with poorer G:F. Transitioning to a non-holding diet after feeding a corn/vitamin/mineral diet for 21-days resulted in compensatory gain, but reductions in growth performance and carcass traits remained evident.

169 The Effect of Standardized Ileal Digestible isoleucine:lysine in Diets Containing 20% Dried Distillers Grains with Solubles on Finishing Pig Performance and Carcass Characteristics

Abstract Previous research suggests an increase of the isoleucine (Ile) requirement for late finishing pigs. Diets containing dried distillers grains with solubles (DDGS) provide excess leucine which can lead to changes in available Ile due to the antagonistic relationship of branched chain amino acids. Therefore, the Ile requirement in finishing diets containing DDGS deserve to be re-evaluated. A finishing study was conducted to determine the standardized ileal digestible (SID) Ile:Lysine (Lys) requirement in diets containing 20% DDGS. Pigs (n = 2,268; 82.3 ± 0.39 kgs) were used in a 56-d trial (14 replicates per treatment). Pens were assigned to one of six dietary treatments balancing for previous treatment. Treatments consisted of a corn-soybean meal diet (CS) or diets containing 20% DDGS with a SID Ile:lys ratio of 55, 60, 65, 70, or 75%. Data was analyzed as a randomized complete block, pair-wise comparisons and single degree of freedom orthogonal polynomials (DDGS diets only) were used to evaluate treatment responses, and pen was the experimental unit. Increasing the SID Ile:Lys did not impact cumulative performance of pigs fed diets containing 20% DDGS (P &amp;gt; 0.175). Pigs fed CS had improved (P &amp;lt; 0.010) ADFI compared to pigs fed SID Ile:Lys of 65 and 75% and tended (P = 0.084) to have greater ADG than 55 and 75% Ile:Lys treatments. Feed efficiency did not differ due to treatment (P = 0.427). Increasing the SID Ile:Lys to 65% in 20% DDGS diets decreased back fat and increased loin depth (quadratic; P &amp;lt; 0.029) and tended to increase percent lean (quadratic; P = 0.076), but did not alter hot carcass weight (P &amp;gt; 0.428). Pigs fed CS diets had greater hot carcass weights (P &amp;lt; 0.031) compared to pigs fed DDGS diets except for pigs fed 60% Ile:Lys diets. These data suggest a SID Ile:Lys of 60% is required to maximize growth performance and SID Ile:Lys of 65% increases carcass traits in diets containing 20% DDGS.

Nutritional approaches to slow late finishing pig growth.

Nutritional approaches to slow late finishing pig growth.

Nutritional approaches to slow late finishing pig growth: implications on carcass composition and pork quality.

Although pork producers typically aim to optimize growth rates, occasionally it is necessary to slow growth, such as when harvest facility capacity is limited. In finishing pigs, numerous dietary strategies can be used to slow growth so pigs are at optimal slaughter body weights when harvest facility capacity and/or access is restored. However, the impact of these diets on pork carcass quality is largely unknown. Thus, this study aimed to evaluate the efficacy of dietary strategies to slow growth in late finishing pigs and evaluate their effects on carcass composition and pork quality. Mixed-sex pigs (n = 897; 125 ± 2 kg BW) were randomly allotted across 48 pens and assigned to 1 of 6 dietary treatments (n = 8 pens/treatment): (1) Control diet representative of a typical finisher diet (CON); (2) diet containing 3% calcium chloride (CaCl2); (3) diet containing 97% corn and no soybean meal (Corn); (4) diet deficient in isoleucine (LowIle); (5) diet containing 15% neutral detergent fiber (NDF) from soybean hulls (15% NDF); and (6) diet containing 20% NDF from soybean hulls (20% NDF). Over 42 d, pen body weights and feed disappearance were collected. Pigs were harvested in 3 groups (14, 28, and 42 d on feed) and carcass data collected. From the harvest group, 1 loin was collected from 120 randomly selected carcasses (20 loins/treatment) to evaluate pork quality traits. Overall, ADG was reduced in CaCl2, Corn, and 20% NDF pigs compared with CON pigs (P < 0.001). However, ADFI was only reduced in CaCl2 and 20% NDF pigs compared with CON (P < 0.001). Feed efficiency was reduced in CaCl2 and Corn pigs compared with CON (P < 0.001). Hot carcass weights were reduced in CaCl2 pigs at all harvest dates (P < 0.001) and were reduced in Corn and 20% NDF pigs at days 28 and 42 compared with CON pigs (P < 0.001). In general, CaCl2 and 20% NDF diets resulted in leaner carcasses, whereas the Corn diet increased backfat by 42 d on test (P < 0.05). Loin pH was reduced and star probe increased in CaCl2 pigs compared with CON pigs (P < 0.05); no treatments differed from CON pigs regarding drip loss, cook loss, color, firmness, or marbling (P ≥ 0.117). Overall, these data indicate that several dietary strategies can slow finishing pig growth without evidence of behavioral vices. However, changes to carcass composition and quality were also observed, indicating quality should be taken into consideration when choosing diets to slow growth.

Fermented Feed Modulates Meat Quality and Promotes the Growth of Longissimus Thoracis of Late-Finishing Pigs.

Simple SummaryLittle is known about the effect of fermented feed on lean mass production of finishing pigs and the underlying mechanism. This study aimed to investigate the effect of fermented diet on growth performance, carcass traits, meat quality and growth of longissimus thoracis (LT) of finishing pigs. Our results found that fermented diet significantly increased loin eye area and lean mass percentage, decreased backfat thickness and improved meat quality of LT by decreasing shear force and drip loss at 48 h post slaughter and improving meat sensory characteristics compared with control diet. Fermented diet also increased the abundance of insulin, insulin receptor, myoblast determination protein (MyoD) and myosin heavy chain-I (MyHC-I) transcripts, and the phosphorylation levels of protein kinase B (AKT), mammalian target of rapamycin (mTORC1), initiation factor 4E-binding protein 1 (4EBP1) and S6 kinase 1 (S6K1) in LT, while decreasing the expression of muscle atrophy F-box (MAFbx) and forkhead Box O1 (Foxo1) mRNA transcripts. Our results indicated that fermented diet improved meat quality and enhanced LT growth of finishing pigs by increasing insulin/AKT/mTORC1 protein synthesis cascade and activating Foxo1/MAFbx pathway, along with the regulation of ribosomal protein and proteins involved in muscle contraction and muscle hypertrophy. This study investigated the effect of fermented diet on growth performance, carcass traits, meat quality and growth of longissimus thoracis (LT) of finishing pigs. A total of 48 finishing pigs [Duroc × (Landrace × Large White), male, 126 ± 5-d-old] weighing 98.76 ± 1.27 kg were randomly assigned to two treatments (eight pens per treatment and three pigs per pen) for a 28-d feeding trial, including control diet and fermented diet. Fermented diet significantly increased the loin eye area and lean mass percentage, decreased backfat thickness and improved meat quality of LT by decreasing the shear force and drip loss at 48 h post slaughter and improving meat sensory characteristics compared with control diet. A fermented diet also significantly increased the abundance of insulin, insulin receptor (IR), myoblast determination protein (MyoD) and myosin heavy chain-I (MyHC-I) transcripts, and the phosphorylation levels of AKT, mTORC1, 4EBP1 and S6K1 in LT, while decreasing the expression of muscle atrophy F-box (MAFbx) and forkhead Box O1 (Foxo1) mRNA transcripts. Moreover, proteomic analysis revealed that differentially expressed proteins predominantly involved in protein synthesis and muscle development were modulated by fermented diet. Our results indicated that a fermented diet improved meat quality and enhanced LT growth of finishing pigs by increasing insulin/AKT/mTORC1 protein synthesis cascade and activating the Foxo1/MAFbx pathway, along with the regulation of ribosomal protein and proteins involved in muscle contraction and muscle hypertrophy.

The ideal protein profile for late-finishing pigs in precision feeding systems: Threonine

Optimal amino acid ratios for pigs have been established for conventional phase feeding systems, but these ratios may differ for precision feeding systems. Our objective was to assess the impact of different dietary Thr inclusion levels (70, 85, 100, 115, or 130% of the estimated ideal 0.65 Thr:Lys ratio) on growth performance, plasma biochemical parameters, and splanchnic and muscle AA composition in pigs raised in a conventional group phase feeding (GPF) system and in an individual precision feeding (IPF) system. A total of 110 finishing pigs (110 ± 7.02 kg initial body weight; 11 pigs per treatment) were housed in the same room for 21 d. Pigs were randomly assigned to a 2 × 5 factorial arrangement and fed using automatic feeders. Individual pigs were considered the experimental units. Five pigs per treatment were slaughtered at the end of the trial. The gain:feed ratio was not affected by feeding system, but there was a quadratic effect of Thr inclusion rate (P < 0.05). Lysine intake was 16% greater and Thr intake was 15% greater for the GPF pigs than for the IPF pigs (P < 0.05). Protein deposition (g/d) was not affected by any treatment. Protein deposition in daily gain was affected by the interaction between Thr inclusion rate and feeding system, with a quadratic (P < 0.05) effect for the GPF pigs and a cubic (P < 0.10) effect for the IPF pigs. The pigs in IPF consumed 14% less (P < 0.05) crude protein and excreted 17% less (P < 0.05) N than the GPF pigs did. The pigs in IPF retained 9% more (P < 0.05) N than the GPF pigs. Plasma urea values were 9% higher (P < 0.05) in GPF than those in IPF. The gamma-glutamyl transferase enzyme decreased (P < 0.05) in a quadratic manner within IPF but increased (P < 0.05) in a quadratic manner within GPF. In the IPF systems, the average concentration of albumin and C-reactive protein tended (P < 0.10) to be 2 and 22% lower, respectively, than in GPF. Changes in amino acid concentrations occurred mainly in the liver of the IPF pigs. The pigs in IPF had higher (P < 0.05) concentrations of collagen in the longissimus dorsi than the pigs in GPF. Lastly, IPF allowed standardized ileal digestible Lys and Thr intakes to decrease by 16 and 15%, respectively, without differences in average daily gain and gain:feed ratio in comparison with GPF.

Effect of ractopamine and conjugated linoleic acid on performance of late finishing pigs

The dietary inclusion of feed additives to improve the carcass characteristics of the final product is of great importance for the pork production chain. The aim of our study was to evaluate the effects of the association of ractopamine (RAC) and conjugated linoleic acid (CLA) on the performance traits of finishing pigs during the last 26 days prior to slaughter. In total, 810 commercial hybrid barrows were used. Animals were distributed among treatments according to a randomised block design in a 3 × 3 factorial arrangement, with three RAC levels (0, 5 or 10 ppm) and three CLA levels (0, 0.3 or 0.6%). Pigs fed the diet with 5 ppm RAC had higher average daily feed intake (ADFI) (2.83 kg; P < 0.05) when compared with those fed 10 ppm RAC and the control diet (2.75 and 2.74 kg, respectively). Lower ADFI values (P < 0.01) were observed with the diets containing CLA compared with the control diet with no CLA (2.73 and 2.75 v. 2.85 kg/day, respectively). The average daily weight gain of pigs fed 5 and 10 ppm RAC was +148 and +173 g/dayhigher (P < 0.001), respectively, than those fed the control diet. Dietary RAC levels influenced (P < 0.001) feed conversion ratio (FCR), which was reduced as RAC levels increased, with the pigs fed 10, 5 and 0 ppm RAC presenting FCR values of 2.57, 2.71 and 3.05, respectively. FCR also improved (P < 0.05) with the inclusion of 0.6% CLA relative to the control diet (2.70 v. 2.84, respectively). There was a significant interaction between CLA × RAC levels (P < 0.01) for final BW, loin eye area (LEA) (P < 0.05) and backfat thickness (BT) (P < 0.05). The treatments containing 10 ppm RAC + 0.6% or 0.3% CLA increased LEA and reduced BT. In conclusion, the level of 10 ppm inclusion of RAC increased the overall performance parameters of pigs and therefore improved production efficiency. The combined use of RAC and CLA promoted a lower feed conversion ratio as well as better quantitative carcass traits, as demonstrated by the higher LEA and lower BT. The dietary inclusion of CLA at 0.3% improved feed efficiency, however, without affecting LEA or BT yields.