Effects of the standardized ileal digestible lysine to metabolizable energy ratio on performance and carcass characteristics of growing-finishing pigs

A total of 2,121 growing-finishing pigs (Duroc × Landrace × Large White) were utilized in six experiments conducted to determine the effects of different ratios of standardized ileal digestible lysine (SID-Lys) to metabolizable energy (ME) on the performance and carcass characteristics of growing-finishing pigs. Exps. 1 (30 to 50 kg), 2 (52 to 70 kg) and 3 (81 to 104 kg) were conducted to find an optimum ME level and then this level was used in Exps. 4 (29 to 47 kg), 5 (54 to 76 kg) and 6 (84 to 109 kg) to test the response of pigs to different ratios of SID-Lys:ME. In Exps.1 to 3, four treatments were used consisting of diets with a formulated ME content of 3.1, 3.2, 3.3 or 3.4 in Exps. 1 and 2 while Exp. 3 used 3.05, 3.15, 3.25 or 3.35 Mcal/kg. A constant SID-Lys:ME ratio of 2.6, 2.3 or 2.0 g/Mcal was used in Exps. 1, 2 and 3, respectively. Weight gain was significantly increased with increasing energy level in Exp.1 while weight gain was unaltered in Exps. 2 and 3. For all three experiments, feed intake was decreased (P < 0.05) and feed efficiency was improved (P < 0.05) with increasing energy level. Tenth rib back fat thickness linearly increased (P < 0.05) with increasing energy level. In Exps. 4 to 6, five treatments were used consisting of diets with a SID-Lys:ME ratio of 2.4, 2.6, 2.8, 3.0 or 3.2 in Exp. 1, 2.1, 2.3, 2.5, 2.7, 2.9 or 3.2 in Exp. 2 and 1.8, 2.0, 2.2, 2.4, or 2.6 in Exp. 3. A constant ME level 3.2, 3.2 and 3.05 Mcal/kg was used in Exps. 1, 2 and 3, respectively (selected based on the results of weight gain). For all three experiments, weight gain increased (P < 0.05) and feed efficiency improved linearly (P < 0.05) as the SID-Lys:ME ratio increased. Tenth rib back fat thickness linearly decreased (P < 0.05) as the SID-Lys:ME ratio increased. Based on a straight broken-line model, the estimated SID-Lys:ME ratio to maximize weight gain was 3.0, 2.43 and 2.2 for 29 to 47, 54 to76 and 84 to 109 kg of pigs, respectively.     

Effects of dietary lysine and energy density on performance and carcass characteristics of finishing pigs fed ractopamine

Two hundred sixteen crossbred barrows and gilts (84.3 kg BW) were used to test the effects of dietary energy density and lysine:energy ratio (Lys:ME) on the performance, carcass characteristics, and pork quality of finishing pigs fed 10 ppm ractopamine. Pigs were blocked by BW and gender, allotted to 36 pens (six pigs per pen), and pens were assigned randomly within blocks to dietary treatments (as-fed basis) arranged in a 2 x 3 factorial design, with two levels of energy (3.30 or 3.48 Mcal/kg) and three Lys:ME (1.7, 2.4, or 3.1 g lysine/Mcal) levels. Pigs were fed experimental diets for 28 d, and weights and feed disappearance were recorded weekly to calculate ADG, ADFI, and G:F. Upon completion of the feeding trial, pigs were slaughtered and carcass data were collected before fabrication. During carcass fabrication, hams were analyzed for lean composition using a ham electrical conductivity (TOBEC) unit, and loins were collected, vacuum-packaged, and boxed for pork quality data collection. Energy density had no (P > 0.22) effect on ADG or ADFI across the entire 28-d feeding trial; however, pigs fed 3.48 Mcal of ME were more (P < 0.02) efficient than pigs fed 3.30 Mcal of ME. In addition, ADG and G:F increased linearly (P < 0.01) as Lys:ME increased from 1.7 to 3.1 g/Mcal. Carcasses of pigs fed 3.48 Mcal of ME were fatter at the last lumbar vertebrae (P < 0.08) and 10th rib (P < 0.04), resulting in a lower (P < 0.03) predicted fat-free lean yield (FFLY). Conversely, 10th-rib fat thickness decreased linearly (P = 0.02), and LM depth (P < 0.01) and area (P < 0.01) increased linearly, with increasing Lys:ME. Moreover, FFLY (P < 0.01) and actual ham lean yield (P < 0.01) increased as Lys:ME increased in the diet. Dietary energy density had no (P > 0.19) effect on pork quality, and Lys:ME did not (P > 0.20) affect muscle pH, drip loss, color, and firmness scores. Marbling scores, as well as LM lipid content, decreased linearly (P < 0.01) as Lys:ME increased from 1.7 to 3.1 g/Mcal. There was a linear (P < 0.01) increase in shear force of cooked LM chops as Lys:ME increased in the finishing diet. Results indicate that 3.30 Mcal of ME/kg (as-fed basis) is sufficient for optimal performance and carcass leanness in pigs fed ractopamine. The Lys:ME for optimal performance and carcass composition seems higher than that currently used in the swine industry; however, feeding very high Lys:ME (> 3.0 g/Mcal, as-fed basis) to ractopamine-fed pigs may result in decreased marbling and cooked pork tenderness.     

Effects of dietary fat on growth performance and carcass characteristics of growing-finishing pigs reared in a commercial environment.

We conducted two experiments to evaluate the effects of added choice white grease on performance and carcass merit of barrows and gilts reared under commercial conditions. Pigs were housed either 20 (Exp. 1) or 25 (Exp. 2) per pen and were provided 0.67 m2 of pen space per pig. Diets were based on corn and soybean meal and fed in a meal form. The proportion of soybean meal was increased in diets with added fat to maintain the same calorie:lysine ratio in all diets within a weight phase. In Exp. 1, 480 pigs were fed diets with 0, 2, 4, or 6% fat. Total lysine contents of the control diets were 1.21, 0.88, and 0.66% during the weight phases 36 to 59, 59 to 93, and 93 to 120 kg, respectively. Gain:feed was increased linearly (P < 0.01) due to fat addition in all weight intervals and over the total experiment. The effect of added fat on ADG was not consistent among the weight phases; a linear (P < 0.01) improvement was found from 36 to 59 kg, but no effect was found during the heavier weight phases. Over the total experiment, however, ADG was improved (P < 0.01) linearly. Carcass traits were not affected by treatment. Experiment 2 used 900 pigs to evaluate possible carryover effects on performance and carcass merit from feeding 6% fat. The experiment was divided into four phases: 25 to 45, 45 to 70, 70 to 90, and 90 to 115 kg; lysine contents of the control diets fed in each phase were 1.23, 1.05, 0.81, and 0.63%, respectively. The six treatments consisted of no added fat throughout the experiment or 6% added fat fed from 25 to 45 kg, 25 to 70 kg, 25 to 90 kg, 25 to 115 kg, or 45 to 70 and 90 to 115 kg. Carryover effects for ADG and G:F (P < 0.07) were found for the 90- to 115-kg interval and for ADFI and ME intake (P < 0.05) for the 45- to 70- and 70-to 90-kg intervals. When fat was added in the previous weight interval, ADG and G:F were improved and ADFI and ME intake were decreased in the subsequent weight interval. Pigs fed fat from 25 to 115 kg had more (P < 0.05) backfat and lower (P < 0.05) carcass leanness than pigs on the other treatments. These data suggest that fat can be added or removed from diets of growing-finishing pigs without any detrimental carryover effects. In fact, the positive carryover effect on ADG and G:F from 95 to 115 kg suggests that feeding fat from 25 to 95 kg will maximize performance over the total growing-finishing period but minimize any detrimental effects of added fat on carcass leanness.     

Effects of lysine:calorie ratio on growth performance of 10- to 25-kilogram pigs

Crossbred barrows (n = 336 Newsham Hybrids) initially 9.9 kg and 31+/-2 d of age were used to evaluate the effects of energy density and lysine:calorie ratio on growth performance. Pigs were allotted by initial weight in a 3 x 4 factorial arrangement of treatments in a randomized complete block design with six replicate pens per treatment. Each pen had four or five pigs with an equal number of pigs per pen within replicate. Pigs were fed increasing dietary energy densities (3.25, 3.38, and 3.51 Mcal ME/kg) and lysine:calorie ratios (3.00, 3.45, 3.90, and 4.35 g lysine/Mcal ME). Energy density was changed by levels of choice white grease (0, 3, and 6%), and lysine:calorie ratio was changed by altering the corn:soybean meal ratio. Over the 21-d trial, an energy density x lysine:calorie ratio interaction was observed for ADG (P < .05). Pigs fed diets containing 3.25 or 3.51 Mcal ME/kg had increasing ADG with increasing lysine:calorie ratio, whereas ADG of pigs fed 3.38 Mcal ME/kg was not affected by lysine:calorie ratio. Feed efficiency (gain:feed ratio) increased and ADFI decreased as lysine:calorie ratio increased (linear, P < .01) and as energy density increased (quadratic, P < .01 and .10, respectively). On d 21, two pigs per pen were scanned ultrasonically for backfat depth. An energy density x lysine:calorie ratio interaction (P < .06) was observed. Pigs fed diets containing 3.25 and 3.38 Mcal ME/kg had decreasing fat depth as lysine:calorie ratio increased; however, backfat depth was not affected by lysine:calorie ratio and was greatest for pigs fed 3.51 Mcal ME/kg. These results suggest that 10- to 25-kg pigs fed diets containing 3.38 Mcal ME/kg had maximum feed efficiency and that they required at least 4.35 g lysine/Mcal ME. However, pigs fed 3.51 Mcal ME/kg had increased fat depth regardless of calorie:lysine ratio.     

不同能量水平下三种有机铬对生长肥育猪生长性能及胴体品质的影响

将吡啶羧酸铬、烟酸铬、酵母铬分别以0.2mg/kg的浓度添加到两种不同能量水平的饲料中,探讨在两种能量水平下,3种有机铬对生长育肥猪的生长性能和肉品质的影响。结果显示,这6种饲料对生长肥育猪的日增重、料重比的差异显著(P<0.05);对45minpH值、滴水损失、背膘厚的影响差异不显著(P>0.05),对24hpH值、嫩度、眼肌面积、肉色的影响差异显著(P<0.05)。     

日粮消化能与可消化赖氨酸水平对断奶仔猪生产性能的影响

本文旨在研究日粮不同消化能与可消化赖氨酸水平对断奶仔猪生产性能的影响.采用2×3因子设计,以消化能(3500 kcal/kg 与3400 kcal/kg)与可消化赖氨酸水平(1.10%、1.25%和1.40%)为两个主效应.选用288头23日龄断奶健康的杜X长X大三元杂交仔猪[初始体重(6.64±0.39)kg],公母各半,随机分为6个处理,每个处理6个重复,每个重复8头猪,试验期14 d.结果表明:在本试验条件下,与低消化能水平相比,高消化能组显著提高了仔猪日增重(4.6%)和饲料转化率(8.9%)(P＜0.01),降低了日采食量(5%)(P＜0.01).日粮消化能水平对腹泻率无显著影响(P＞0.05).随着日粮赖氨酸水平的提高.断奶仔猪日增重也相应提高(P=0.04).高赖氨酸比低赖氨酸组日增重提高12.4%,饲料转化率也提高5.3%(P＜0.01).日粮赖氨酸水平对日采食量和腹泻率影响并不显著.消化能与赖氨酸互作对试验猪日增重、日采食量、饲料转化率及腹泻率交互作用不明显.综合考虑,日粮消化能水平为3500 kcal/kg,可消化赖氨酸水平为1.25%时,断奶仔猪发挥最大的生长性能,日增重最大,饲料转化率最佳.     

能量和蛋白来源对生长育肥猪生长性能、胴体性状和肉质的影响

试验旨在探讨饲粮能量和蛋白来源对育肥猪生长性能、养分消化率、血清生化指标、胴体性状以及肉质的影响。试验采用2×2因子试验设计,选取DLY育肥猪60头[平均体重(81±7.89) kg],随机分为4个处理,每个处理5个重复,每个重复3头猪。饲粮能量来源包括玉米和小麦,饲粮蛋白来源包括豆粕和菜粕。4个处理分别饲喂玉米-豆粕型、玉米-菜粕型、小麦-豆粕型、小麦-菜粕型饲粮,试验期28 d。结果表明:①4种饲粮对猪平均日采食量和平均日增重无显著影响(P0.05),但玉米豆粕组的料重比显著低于其余3组(P0.05)。②能量和蛋白来源显著影响养分的消化率。与小麦饲粮相比,玉米饲粮极显著提高了粗脂肪、干物质、灰分、钙和磷的消化率以及能量的利用率(P0.01);与豆粕饲粮相比,菜粕饲粮极显著提高了钙、磷的消化率和能量的利用率(P0.01),显著提高了干物质的消化率(P0.05)。③与豆粕饲粮相比,菜粕饲粮极显著提高了猪血清尿素氮的含量(P0.01);与小麦饲粮相比,玉米饲粮显著提高了猪血清总蛋白水平,显著降低了胰岛素样生长因子Ⅰ水平。④玉米豆粕组的眼肌面积显著高于玉米菜粕组(P0.05);与玉米菜粕组相比,小麦菜粕组显著降低了肌肉的蒸煮损失(P0.05),显著提高了肌内脂肪含量(P0.05)。由此可见,4种饲粮对育肥猪的生长性能无显著影响,但显著影响猪养分的表观消化率,且对育肥猪胴体性状、肉质有一定的影响。     

DDGS对生长育成猪的生产性能及胴体品质的影响

本试验旨在研究DDGS对生长育成猪的生产性能和胴体品质的影响。432头体重为29.8±0.2kg的育成猪被随机分成1-9个日粮组,分别为对照组（D0）,D15-0wk,D15-3wk,D15-6wk,D15-9wk,D30-0wk,D30-3wk,D30-6wk和D30-9wk,其中D0、D15和D30分别代表DDGS在猪日粮中的百分含量;0wk、3wk、6wk和9wk代表在屠宰0、3、6和9周前分别取消DDGS在猪日粮的添加时间。结果显示,当生长育成猪日粮中的DDGS含量为15%或30%时,不管屠宰前是否取消DDGS的添加,除了D30-0wk处理组的猪的ADG比对照组（D0）稍降外（0.87：0.92kg/d;P〈0.05）,其他处理组猪的ADG、ADFI和G：F均没有显著差异（P=0.76）。DDGS的不同含量或屠宰前取消DDGS的添加时间（0周、3周、6周和9周）对猪胴体质量、背最长肌（LM）猪肉品质、背脂和腹脂颜色评分分数没有显著影响（背脂,P=0.47;腹脂,P=0.17）。相对对照组,D30-0wk组的腹部猪肉嫩度稍低（P=0.04）,其他处理组猪的腹部猪肉嫩度与对照组的差别均不大（P=0.26）。当增加猪日粮中的DDGS含量时,腹脂的亚油酸含量（C18：2;P〈0.001）和碘值（IV;P〈0.001）有所增加。当猪日粮中含有15%DDGS时,在屠宰前的0～9周取消DDGS添加可以线性的降低猪腹脂的C18：2含量和腹脂碘值（屠宰前的第0-、3-、6-和9周的腹脂C18：2含量分别为：14.6%、13.3%、12.6%、10.9%;P=0.001;碘值分别为：67.3、64.4、64.1和62.7）;而当猪的日粮中含有30%DDGS时,在屠宰前0～9周取消DDGS的添加也可以线性的降低猪腹脂的C18：2含量和腹脂碘值（屠宰前的第0-、3-、6-和9周的腹脂C18：2含量分别为：17.3%、16.1%、14.2%和12.4%;P〈0.001;碘值分别为：71.2、68.2、64.5和62.7）。总体来看,当在生长育肥猪中添加高达30%DDGS对猪的生产性能有极小影响,且在屠宰前的3周取消在猪日粮中的DDGS的添加可以降低猪腹脂的C18：2含量和碘值。     

Effects of choice white grease and soybean oil on growth performance, carcass characteristics, and carcass fat quality of growing-finishing pigs

A total of 144 barrows and gilts (initial BW = 44 kg) were used in an 82-d experiment to evaluate the effects of dietary fat source and duration of feeding fat on growth performance, carcass characteristics, and carcass fat quality. Dietary treatments were a corn-soybean meal control diet with no added fat and a 2 × 4 factorial arrangement of treatments with 5% choice white grease (CWG) or soybean oil (SBO) fed from d 0 to 26, 54, 68, or 82. At the conclusion of the study (d 82), pigs were slaughtered, carcass characteristics were measured, and backfat and jowl fat samples were collected. Fatty acid analysis was performed, and iodine value (IV) was calculated for all backfat and jowl fat samples. Pigs fed SBO tended to have increased (P = 0.07) ADG compared with pigs fed CWG. For pigs fed SBO, increasing feeding duration increased (quadratic, P < 0.01) ADG and G:F. For pigs fed CWG, increasing feeding duration improved (quadratic, P < 0.01) G:F. For pigs fed SBO or CWG, increasing feeding duration increased carcass yield (quadratic, P < 0.04) and HCW (quadratic, P < 0.02). Dietary fat source and feeding duration did not affect backfat depth, loin depth, or lean percentage. As expected, barrows had greater ADG and ADFI (P < 0.01) and poorer G:F (P = 0.03) than gilts. Barrows also had greater last-rib (P = 0.04) and 10th-rib backfat (P < 0.01) and reduced loin depth and lean percentage (P < 0.01) compared with gilts. Increasing feeding duration of CWG or SBO increased (P < 0.10) C18:2n-6, PUFA, PUFA:SFA ratio, and IV in jowl fat and backfat. Pigs fed SBO had greater (P < 0.01) C18:2n-6, PUFA, PUFA:SFA ratio, and IV but decreased (P < 0.01) C18:1 cis-9, C16:0, SFA, and MUFA concentrations compared with pigs fed CWG in jowl fat and backfat. Barrows had decreased (P = 0.03) IV in jowl fat and backfat compared with gilts. In summary, adding SBO or CWG increased the amount of unsaturated fat deposited. Increasing feeding duration of dietary fat increases the amount of unsaturated fatty acids, which leads to softer carcass fat.     

Effect of dietary protein source and lysine:DE ratio on growth performance, meat quality, and body composition of growing-finishing pigs.

The effects of four protein sources (soybean meal, sunflower meal, pea, and fish meal as the main protein source) and three apparent ileally digestible Lys:DE ratios (0.50, 0.43, 0.36 and 0.42, 0.36, 0.30 g Lys/MJ DE for 30 to 60 kg BW and 60 to 105 kg BW, respectively) in pig diets on growing-finishing performance, and carcass and meat quality traits were investigated. Eight individually housed animals per treatment received the diets from 30 to 105 kg BW at a level of 3.0 times maintenance requirements of energy. The ileal digestibility of protein sources was determined in a previous digestibility experiment. Protein sources showed no differences in growth performance from 30 to 105 kg BW. From 30 to 60 kg BW soybean treatment had lowest performance. The protein sources had no effect on lean meat percentage, liver weight, or meat quality (intramuscular fat content, pH at 45 min and 24 h after slaughter, drip loss, and meat color measured 24 h and 4 d after slaughter). The experimental diets formulated on the basis of similar apparent ileal digestible lysine content resulted in similar body composition regardless of the protein source used (P > 0.05). Reducing the Lys:DE ratio from 0.50/0.43 to 0.36/0.30 (by about 28%) reduced BW gain by 119 g/d from 30 to 60 kg and by 151 g/d from 60 to 105 kg BW. The gain:feed ratio increased by 82 g/kg in the first phase and by 47 g/kg in the second phase for the highest Lys:DE treatment compared with the lowest. Reducing Lys:DE ratio did not modify meat quality traits. A high Lys:DE ratio was associated with a high lean meat percentage. Differences between the medium- and low-Lys:DE groups were not significant. Lowering the Lys:DE ratio increased (P < 0.05) crude fat and fatty tissue content and decreased (P < 0.05) protein and muscle content in the body. Ash content and bone volume were not affected by Lys:DE ratio (P > 0.05). The chemical composition of the carcass can be predicted with moderate accuracy (R2 = 0.39 to 0.58) using volumetric composition data of previously frozen carcasses. In conclusion, similar growth performance, carcass and meat quality, and body composition can be expected if diet formulation is based on the apparent ileally digestible amino acid contents of feedstuffs, independent of dietary protein sources. Diminishing Lys:DE ratios reduce growth performance but do not modify meat quality traits. The chemical composition of the carcass can be predicted with moderate accuracy using the volumetric composition of thawed carcasses.     

Effects of dietary soy isoflavones on growth, carcass traits, and meat quality in growing-finishing pigs

Two experiments were conducted to determine the effect of soy isoflavones on growth, meat quality, and carcass traits of growing-finishing pigs. In Exp. 1, 36 barrows (initial and final BW, 26 and 113 kg, respectively) were used and each treatment was replicated four times with three pigs each. The dietary treatments were 1) corn-soybean meal (C-SBM), 2) corn-soy protein concentrate (low isoflavones, C-SPC), or 3) C-SPC + isoflavones (isoflavone levels equal to those in C-SBM). Daily gain and ADFI were increased (P < 0.10) in pigs fed the C-SPC relative to pigs fed the C-SPC + isoflavone diet in the late finishing period; otherwise, growth performance was not affected (P > 0.10) by diet. Longissimus muscle area, 10th-rib fat depth, percentage muscling (National Pork Producers Council), 24-h pH and temperature, color, firmness-wetness, marbling, drip loss, and CIE L*, a*, and b* color values were not affected (P > 0.10) by diet. Dressing percentage, carcass length, weight and percentage of fat-free lean in ham and carcass, lean gain per day, lean:fat, and ham weight were increased (P < 0.10), and ham fat and percentage fat in ham and carcass were decreased (P < 0.10) in pigs fed the C-SPC + isoflavone diet compared with pigs fed the C-SPC diet. Pigs fed the C-SPC + isoflavone diet had similar (P > 0.10) carcass traits as pigs fed the C-SBM diet, except carcass length, percentage ham lean and thaw loss were greater (P < 0.10), and total ham fat was less (P < 0.10) in pigs fed the C-SPC + isoflavone diet. In Exp. 2, 60 gilts (initial and final BW, 31 and 116 kg, respectively) were used, and each treatment was replicated five times with four pigs per replicate. The treatments were 1) C-SBM, 2) C-SBM + isoflavone levels two times those in C-SBM, and 3) C-SBM + isoflavone levels five times those in C-SBM. Daily feed intake was linearly decreased (P < 0.10) in the growing phase and increased (P < 0.10) in the late finishing phases as isoflavone levels increased; otherwise, growth performance was not affected (P > 0.10) by diet. Diet did not affect (P > 0.10) carcass traits; however, CIE a* and b* color scores and drip loss were decreased (P < 0.06) as isoflavone levels increased. Soy isoflavones decreased fat and increased lean in barrows when fed within the dietary concentrations found in typical C-SBM diets but not when fed to gilts at concentrations above those present in C-SBM diets.     

Effects of pantothenic acid on growth performance and carcass characteristics of growing-finishing pigs fed diets with or without ractopamine hydrochloride

Two experiments evaluated effects of added pantothenic acid on performance of growing-finishing pigs. In Exp. 1, 156 pigs (PIC, initial BW = 25.7 kg) were used in a 3 x 2 x 2 factorial to evaluate the effects of added pantothenic acid (PA; 0, 22.5, or 45 ppm), ractopamine.HCl (RAC; 0 or 10 mg/kg), and sex on growth performance and carcass traits. Pigs were fed increasing PA from 25.7 to 123.6 kg (d 0 to 98) and RAC for the last 28 d before slaughter. Increasing the amount of added PA had no effect (P > 0.40) on ADG, ADFI, or G:F from d 0 to 70. A PA x sex interaction (P < 0.03) was observed for ADG and G:F from d 71 to 98. Increasing the amount of added PA increased ADG and G:F in gilts, but not in barrows. Increasing the amount of added PA had no effect (P > 0.38) on carcass traits. Added RAC increased (P < 0.01) ADG and G:F for d 71 to 98 and d 0 to 98 and increased (P < 0.01) LM area and percentage lean. In Exp. 2, 1,080 pigs (PIC, initial BW = 40.4 kg, final BW = 123.6 kg) were used to determine the effects of increasing PA on growth performance and carcass characteristics of growing-finishing pigs reared in a commercial finishing facility. Pigs were fed 0, 22.5, 45.0, or 90 mg/kg of added PA. Increasing the amount of added PA had no effect (P > 0.45) on ADG, ADFI, or G:F, and no differences were observed (P > 0.07) for carcass traits. In summary, adding dietary PA to diets during the growing-finishing phase did not provide any advantages in growth performance or carcass composition of growing-finishing pigs. Furthermore, it appears that the pantothenic acid in corn and soybean meal may be sufficient to meet the requirements of 25- to 120-kg pigs.     

Effects of increasing L-lysine HCl in corn- or sorghum-soybean meal-based diets on growth performance and carcass characteristics of growing-finishing pigs

We conducted three experiments to determine the effects of increasing L-lysine HCl in growing-finishing pig diets. Experiments 1 and 2, conducted at the Kansas State University research center, each used 360 growing-finishing pigs with initial BW of 56 and 63 kg, respectively. Dietary treatments were sorghum- (Exp. 1) or corn- (Exp. 2) soybean meal-based and consisted of a control (no L-lysine HCl) or 0.15, 0.225, and 0.30% L-lysine HCl replacing lysine provided by soybean meal. Experiment 3 was conducted in a commercial research facility using a total of 1,200 gilts with an initial BW of 29 kg. Pigs were allotted to one of eight dietary treatments fed in four phases. These consisted of a positive control diet with no added L-lysine HCl and the control diet with 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30% L-lysine HCl replacing the lysine provided by soybean meal. The eighth dietary treatment was a negative control diet with no added L-lysine HCl and formulated to contain 0.10% less total lysine than the other treatments to ensure that dietary lysine was not above required levels. In Exp. 1, increasing L-lysine HCl decreased (linear, P < 0.01) ADG, feed efficiency (G:F), and percentage lean and increased (linear, P < 0.01) backfat depth. In Exp. 2, increasing L-lysine HCl decreased (quadratic, P < 0.03) ADG, G:F, and ADFI, but carcass characteristics were not affected. In Exp. 3, increasing L-lysine HCl decreased ADG (linear, P < 0.01) and G:F (quadratic P < 0.03). In all three experiments, the greatest negative responses were observed when more than 0.15% L-lysine HCl was added to the diet. Therefore, unless other synthetic amino acids are added to the diet, no more than 0.15% L-lysine HCl should replace lysine from soybean meal in a corn- or sorghum-soybean meal-based diet to avoid deficiencies of other amino acids. Based on the content of diets containing 0.15% Lysine-HCl, it appears the requirements for methionine plus cystine expressed as ratios relative to lysine are not greater than 50% during the early growing-finishing period (30 to 45 kg) and 62% during the late finishing period (90 to 120 kg) on a true digestible basis. For similar periods, the ratio requirements for threonine are not greater than 59% and 64% on a true digestible basis.     

Effect of dietary energy concentration and apparent ileal digestible lysine:metabolizable energy ratio on nitrogen balance and growth performance of young pigs

Two experiments were conducted to determine the optimal apparent ileal digestible lysine:ME (Lys:ME) ratio and the effects of lysine and ME levels on N balance (Exp. 1) and growth performance (Exp. 2) in growing pigs. Diets were designed to contain Lys:ME ratios of 0.6, 0.7, 0.8, and 0.9 g/MJ at 13.5 and 14.5 MJ of ME/kg of diet in a 4 x 2 factorial arrangement. In Exp. 1, conventional N balances were determined on 48 crossbred barrows (synthetic line 990, initial BW = 13.1 +/- 0.7 kg) at approximately 15, 20, and 25 kg of BW with six pigs per diet. At 15 kg of BW, an energy density x Lys:ME ratio interaction on daily N retention was observed (P < 0.05). At each BW, N retention improved with an increase in N intake associated with increasing ME concentration. In 15-kg BW pigs, increasing the Lys:ME ratio increased daily N retention at the 13.5 (linear, P < 0.001) and 14.5 MJ of ME level (linear, P < 0.01; quadratic, P < 0.05). In 20-kg BW pigs, N retention (g/d) increased (linear, P < 0.001; quadratic, P < 0.01) and N retention (percentage) increased (linear, P < 0.001) as the Lys:ME ratio increased. At 25 kg of BW, N retention (g/d) increased quadratically (P < 0.05) with an increase in Lys:ME ratio. The Lys:ME ratios that maximized daily N retention at 15 kg of BW were 0.88 and 0.85 g/MJ at the 13.5 and 14.5 MJ of ME levels, respectively and 0.81 and 0.77 g/MJ (for both ME levels) at 20 and 25 kg of BW, respectively. Over the 28-d trial, an energy density x Lys:ME ratio interaction on ADG was observed (P < 0.05). Increasing energy density increased growth performance, whereas increasing the Lys:ME ratio in high-energy diets increased ADG (linear, P < 0.05; quadratic, P < 0.01) and gain:feed ratio (G/F) quadratically (P < 0.01). Average daily gain and G/F ratio were greatest in pigs fed the 14.5 MJ of ME diet and the Lys:ME ratio of 0.82 g/MJ. In Exp. 2, 128 individually housed crossbred barrows and gilts (initial BW = 12.8 +/- 1.6 kg) were used to determine the effect of diets used in Exp. 1 on growth performance in a 4 x 2 x 2 factorial arrangement. The ME level increased ADG and G/F from d 0 to 14 and from d 0 to 28. Increasing the Lys:ME ratio increased ADG from d 0 to 14, whereas growth performance was maximized in pigs fed Lys:ME ratio of 0.82 g/MJ. These results suggest that pigs from 13 to 20 and from 20 to 30 kg of BW fed diets containing 14.5 MJ of ME/kg had maximum N retention and ADG at 0.85 and 0.77 g of apparent ileal digestible lysine/MJ of ME, respectively.     

Effects of modified tall oil and creatine monohydrate on growth performance, carcass characteristics, and meat quality of growing-finishing pigs

The effects of feeding modified tall oil (MTO) and creatine monohydrate (CMH) on growing-finishing pig growth performance, carcass characteristics, and meat quality were determined. Eighty cross-bred barrows (initially 45.4 kg) were allotted randomly to one of four dietary treatments by weight and ancestry. The experiment was arranged as a 2 x 2 factorial with two levels of MTO (0 or 0.50%), which were fed throughout the growing-finishing period, and two levels of CMH (0 or 25 g/d), which were fed for the final 10 d before slaughter. The corn-soybean meal diets were fed in two phases (45.4 to 78.9 kg and 78.9 to 117.5 kg BW). When CMH was added to the diet in place of corn, average BW was 107.5 kg. Feeding MTO increased (P < 0.05) ADG and gain:feed ratio (G/F) during the 45.4- to 78.9-kg growth interval and tended to improve (P = 0.10) G/F during the 45.4- to 107.5-kg growth interval. Dietary treatment did not affect (P > 0.15) growth performance during the 78.9- to 107.5-kg growth interval. Modified tall oil increased (P = 0.02) G/F during the 10-d CMH supplementation period, and CMH numerically (P = 0.11) increased ADG and G/F. Supplementation of CMH did not affect (P > 0.20) any measured carcass characteristic or measures of meat quality at 24 h or 14 d postmortem. Feeding MTO reduced average back-fat (P = 0.05) and 10th rib backfat (P = 0.01) but did not affect (P > 0.10) other measured carcass characteristics or measures of meat quality at 24 h postmortem. Modified tall oil increased (P = 0.02) L* values (lightness) and tended to increase (P < 0.10) thawing and cooking losses of longissimus muscle chops at 14 d postmortem. These data demonstrate that MTO improves growth performance and reduces backfat in growing-finishing pigs, but supplementation of CMH, under the conditions of this experiment, was not beneficial for growing-finishing pigs.     

Effect of different dietary protein levels and amino acids supplementation patterns on growth performance,carcass characteristics and nitrogen excretion in growing-finishing pigs

Background: This study was conducted to determine the effects of different dietary protein levels and amino acids supplementation patterns in low protein diets on the growth performance, carcass characteristics and nitrogen excretion in growing-finishing pigs.Forty-two barrows(25.00 ± 0.39 kg) were randomly assigned to 7 diets. Diet 1: the high crude protein diet with balanced for 10 essential amino acids(EAAs). Diet 2: the medium crude protein diet with 2%(approx) decreased protein level of Diet 1 and balanced 10 EAAs. Diet 3: the low crude protein diet with 4% decreased protein level of Diet 1 and balanced 10 EAAs. The protein levels of Diet 4, 5, 6 and 7 were the same as that of Diet 3. Diet 4 was only balanced for lysine(Lys), methionine(Met), threonine(Thr) and tryptophan(Trp); Diet 5 and 6 were further supplemented with extra isoleucine(Ile) or valine(Val), respectively; Diet 7 was further supplemented with extra Ile + Val.Results: Over the 112 days trial, the reduction of dietary protein by 2% or 4% with balanced10 EAAs significantly decreased nitrogen excretion(P 0.05), but had no effects on growth performance and carcass characteristics(P 0.05). In low protein diet, Val supplementation significantly increased body weight gain at 25–50 kg phase(P 0.05), while Ile supplementation at 75–100 kg phase and 100–125 kg phase significantly reduced the ratio of feed to gain(P 0.05). No effect of different dietary protein levels and amino acids supplementation patterns in low protein diets on carcass characteristics was observed(P 0.05). The total N excretion of pigs supplemented with only Lys, Met, Thr and Trp was numerically higher than that of pigs fed with extra Ile, or Val, or Ile + Val diets.Conclusion: In low protein diet, Val is more required than Ile in the early growing phage(25–50 kg), while Ile becomes more required in the late growing and finishing phage(75–125 kg).     

非淀粉多糖酶对生长育肥猪生长性能、胴体性状和肉品质的影响

本研究主要通过生长育肥猪的饲养试验,观察日粮中添加非淀粉多糖酶(Non-Starch Polysaccharide Enzyme,NSP酶)对生长育肥猪生长性能、胴体性状和肉品质的影响。试验选择体质量约为40kg的杜长大三元杂交猪48头,公母各半。本试验随机分为2个处理,每个处理3个重复,每个重复8头猪,对照组饲喂基础日粮,NSP酶组饲喂基础日粮+0.6%NSP酶。结果表明:(1)生长性能方面,NSP酶组的平均日增重和平均日采食量均显著高于对照组(P<0.05),分别提高了9.8%和4.7%;NSP酶组的料重比显著低于对照组(P<0.05),降低了5.0%;(2)在胴体性状和背最长肌化学组成方面,NSP酶组眼肌面积比对照组显著提高(P<0.05),提高了9.8%;与对照组相比,滴水损失和剪切力2个指标分别降低了2.0%和14.6%,但在统计学上未达到显著水平(P>0.05)。结果显示,基础饲粮中添加NSP酶能有效提高生长育肥猪生长性能,并在一定程度上改善肉品质。     

Influence of the dietary ratio between sulphur containing amino acids and lysine on performance of growing-finishing pigs fed diets with various lysine concentrations.

This study was conducted to determine the optimal ratio between sulphur containing amino acids and lysine in diets for growing-finishing pigs. Therefore, a total of five trials was carried out in which growing-finishing pigs (live weight range between 53 and 105 kg) were fed diets with various concentrations of lysine (0.62, 0.70 and 0.78%) and various ratios between sulphur containing amino acids to lysine. The diets contained 12.9 MJ ME per kg and 13.5% CP; the ratio between sulphur containing amino acids to lysine was adjusted by individual supplementation of the diets with DL-methionine. Increasing dietary levels of lysine from 0.62 to 0.78% continuously increased daily body weight gains and improved feed conversion efficiency as well as carcass characteristics. There was no significant interaction between the dietary lysine supply and the ratio between sulphur containing amino acids to lysine on animal performance parameters. This means that the effect of the ratio of sulphur containing amino acids to lysine was similar for various dietary lysine concentrations. The optimum ratio between sulphur containing amino acids to lysine according to quadratic regression analysis was 0.60, for both, growth and feed conversion. Reducing the ratio between sulphur containing amino acids to lysine from 0.59 to 0.53 and 0.47 reduced body weight by 3 and 12%, resp., and elevated the feed conversion ratio by 2 and 12%, resp. An increase of the ratio between sulphur containing amino acids to lysine from 0.59 to 0.65 failed to increase the animal performance. In contrast to animal performance parameters, optimum carcass characteristics (eye muscle area, fat area above eye muscle, meat-fat ratio and lean percentage) were achieved already at a ratio of sulphur containing amino acids to lysine of 0.53.     

Effects of modified tall oil and vitamin E on growth performance,carcass characteristics,and meat quality of growing-finishing pigs

Crossbred barrows (n = 72) were used to evaluate effects of diet supplementation with modified tall oil (MTO; 0.0 or 0.50%) and vitamin E (0, 22, or 110 IU/kg) on growth performance, carcass traits, and longissimus muscle (LM) quality traits of finishing pigs. Pigs were blocked by ancestry and initial BW and allotted randomly to treatments in a 2 x 3 factorial. Corn-soybean meal-based diets were fed in two phases: 45.5 to 81.6 (1.00% lysine) and 81.6 to 114.6 (0.75% lysine) kg BW with no added fat. From 45.5 to 81.6 kg, pigs fed MTO had greater ADG (P = 0.03) regardless of added vitamin E; otherwise, treatment did not affect growth performance. Carcasses from pigs fed MTO had reduced (P < 0.05) average backfat (2.76 vs 2.92 cm) and firmer bellies compared to those fed no MTO. Boneless loins were cut into 2.54-cm chops at 7 d postmortem and evaluated for display color, thiobarbituric acid-reactive substance (TBARS), Warner-Bratzler shear force (WBSF), and sensory panel ratings. Visual color was similar (P > 0.05) among treatments at 0 and 1 d of display. At 4 and 6 d of display chops from pigs fed MTO with 110 IU vitamin E/kg had less deterioration (P < 0.05) than chops from pigs fed MTO with 0 IU vitamin E/kg and 0.0% MTO with 22 or 110 IU vitamin E/kg. The CIE L*, a*, b* and spectral values also suggested a delay in color deterioration for chops from pigs fed MTO with 110 IU vitamin E/kg. At 6 and 8 d of display, chops from pigs fed 110 IU vitamin E/kg had lower (P < 0.05) L* values than those from pigs fed 0 or 22 IU vitamin E/kg, and higher (P < 0.05) a* values than those from pigs fed 0 IU vitamin E/kg feed. A higher (P < 0.05) %R630/%R580 (indicator of more oxymyoglobin) was observed for chops from pigs fed MTO with 110 IU vitamin E/kg than those from pigs fed 0.0% MTO with 22 or 110 IU vitamin E/kg and MTO with 0 IU vitamin E/kg. Chops from pigs fed MTO with 110 IU vitamin E/kg had lower (P < 0.05) TBARS values than those from pigs fed MTO with 0 IU vitamin E/kg. No differences (P > 0.05) were detected among treatments for WBSF or sensory evaluations. The addition of MTO in swine diets improved belly firmness and reduced backfat, and feeding MTO with high levels of vitamin E extended display life without affecting palatability of LM chops.