低聚木糖对生长肥育猪血浆生化参数和肌肉脂肪酸组成的影响

本试验旨在研究低聚木糖(XOS)对生长肥育猪血浆生化参数和肌肉脂肪酸组成的影响。选取70日龄、平均体重约为30kg的杜×长×大三元杂交猪110头,随机分为11组,每组10头(公母各占1/2),单栏饲养。试验设对照组(饲喂基础饲粮),抗生素组(饲喂在基础饲粮中添加0.04kg/t速大肥、0.2kg/t抗敌素的饲粮),30~65kg阶段100、250和500g/t XOS添加组(在30~65kg阶段分别饲喂在基础饲粮中添加100、250和500g/t XOS的饲粮,在66~100kg阶段均饲喂基础饲粮),66~100kg阶段100、250和500g/t XOS添加组(在30~65kg阶段均饲喂基础饲粮,在66~100kg阶段分别饲喂在基础饲粮中添加100、250和500g/t XOS的饲粮)以及30~100kg阶段100、250和500g/t XOS添加组(分别饲喂在基础饲粮中添加100、250和500g/t XOS的饲粮)。于试猪平均体重达100kg(约170日龄)时,前腔静脉采血,离心分离血浆,测定生化参数;屠宰后取背最长肌和股二头肌样品,测定其脂肪酸组成。结果表明:与对照组相比,30~65kg阶段,饲粮添加100或500g/t XOS可显著降低股二头肌中十七烷酸(C17∶0)含量(P0.05);66~100kg阶段,饲粮添加250g/t XOS可显著增加股二头肌中饱和脂肪酸(SFA)+单不饱和脂肪酸(MUFA)含量(P0.05),添加100或500g/t XOS可显著增加股二头肌中花生烯酸(C20∶1)含量(P0.05);30~100kg阶段,饲粮添加100g/t XOS可显著增加背最长肌中油酸/亚油酸以及股二头肌中C20∶1、MUFA和SFA+MUFA含量(P0.05),添加100或250g/t XOS可显著降低血浆总胆固醇浓度(P0.05),添加500g/t XOS可显著增加血浆高密度脂蛋白-胆固醇浓度(P0.05)。综上所述,饲粮添加一定剂量的XOS可通过调控与脂代谢相关的血浆生化参数、增加肌肉中MUFA和SFA+MUFA含量而改善猪肉的风味和营养价值,且以30~100kg阶段添加100g/t XOS为最佳。     

低聚木糖对断奶仔猪生长性能、腹泻率和血浆生化参数的影响

本文旨在评价不同剂量的低聚木糖(XOS)同时替代抗生素与氧化锌对断奶仔猪生长性能、腹泻率和血浆生化参数的影响,并筛选出其最佳添加剂量。试验选取21日龄的"杜×长×大"断奶仔猪150头,随机分为5组,每组6重复,每重复5头猪。试验各组分别为空白对照组(不添加抗生素、氧化锌)、阳性对照组(添加抗生素、氧化锌)及100、250和500 g/t XOS添加组。记录每栏仔猪的日采食量和腹泻情况,于试验第1、7、21和56天,记录每栏仔猪的体重,计算平均日采食量(ADFI)、平均日增重(ADG)和料重比;前腔静脉采血,分离血浆,检测其生化参数。试验期56 d。结果表明:1)试验第8~21天和第1~56天时,100 g/t XOS组的ADG显著高于空白对照组(P0.05);试验第8~21天、第22~56天和第1~56天时,100 g/t XOS组的ADFI显著高于空白对照组(P0.05)。2)试验第1~7天时100和250 g/t XOS组以及试验第8~21天时3个XOS添加组的腹泻率均显著低于空白对照组(P0.05),且与阳性对照组无显著差异(P0.05)。3)试验第7天时,500 g/t XOS组血浆天冬氨酸转氨酶(AST)和乳酸脱氢酶(LDH)活性显著高于阳性对照组(P0.05);试验第21天时,100和500 g/t XOS组血浆丙氨酸转氨酶(ALT)活性显著高于空白对照组(P0.05);试验第56天时,100 g/t XOS组血浆ALT活性、500 g/t XOS组血浆AST活性、250和500 g/t XOS组血浆碱性磷酸酶活性均显著高于空白对照组和阳性对照组(P0.05),100 g/t XOS组血浆LDH活性显著高于空白对照组(P0.05),500 g/t XOS组血浆α-淀粉酶活性显著高于阳性对照组(P0.05)。上述结果表明,饲粮中添加100~250 g/t的XOS可通过调控断奶仔猪营养素代谢增强肠道健康、减少腹泻,从而促进生长;随着仔猪日龄的增加,可适当增加XOS的添加量。     

发酵乳酸杆菌对生长肥育猪生长性能和肉品质的影响

本试验旨在研究日粮中添加发酵乳酸杆菌(Lactobacillus fermentum)对生长肥育猪生长性能和肉品质的影响.试验选择144头日龄、胎次相近,体晕在20 kg左右的杜×长×大三元仔猪,公母各占1/2,随机分成对照组、抗生素组和发酵乳酸杆菌组,每组6个重复,每个重复8头猪.试验分2个阶段:生长阶段(体重20～50 kg)和肥育阶段(体重50～90 kg).对照组饲喂基础日粮,抗生素组饲喂基础日粮+150 mg/kg会霉素,发酵乳酸杆菌组饲喂基础日粮+0.1%发酵乳酸杆菌.结果表明:(1)生长性能方面,在生长阶段,发酵乳酸杆菌组的平均日增蕈(ADG)比对照组提高了5.8%,料重比(F/G)降低了2.7%;在肥育阶段,发酵乳酸杆菌组的ADG比对照组提高了6.7%,F/G降低了4.6%;在整个试验期,发酵乳酸杆菌组的ADG比对照组提高了6.3%,F/G降低了3.9%.日粮中添加0.1%单一的发酵乳酸杆菌代替抗生素(金霉素),试验猪生长性能略优于抗生素(P>0.05).在生长阶段,发酵乳酸杆菌组的ADG比抗生素组提高了0.1%,F/G降低了2.3%;在肥育阶段,发酵乳酸杆菌组的ADG比抗生素组提高了9.2%,F/G降低了3.7%;在整个试验期,发酵乳酸杆菌组的ADG比抗生素组提高了5.1%,F/G降低了2.5%;(2)发酵乳酸杆菌组滴水损失比对照组和抗生索组分别降低2.3%和5.0%,剪切力比对照组和抗生素组分别降低26.1%和18.2%;(3)与对照组相比,发酵乳酸杆菌组显著提高了C18:2、C20:2、C20:4和总多不饱和脂肪酸(PUFA)的含量(P<0.05);与抗生素组相比,显著降低了C20:2的含量(P<0.05).以上研究结果表明,发酵乳酸杆菌能不同程度地改善生长肥育猪生长性能、胴体品质和肌肉质量.     

复合酶对生长肥育猪生长性能、胴体性状及部分肉品质的影响

试验旨在研究日粮中添加复合酶对生长肥育猪生长、胴体性状及部分肉品质的影响。试验选择60头日龄、胎次相近,体重在60 kg左右的杜×大×长三元肉猪,随机分成对照组、复合酶Ⅰ组、复合酶Ⅱ组及阳性对照组,每组15头。试验期为58 d,在相同饲养管理条件下,对照组饲喂基础日粮,复合酶Ⅰ组饲喂基础日粮+1.0‰复合酶,复合酶Ⅱ组饲喂基础日粮+2.0‰复合酶,阳性对照组饲喂基础日粮+0.2‰酶制剂。试验表明:①生长性能方面,复合酶Ⅰ组试末均重(BW)、平均日增重(ADG)显著高于其它各组(P<0.05),料重比(F/G)显著低于其它各组(P<0.05),BW、ADG比对照组分别提高了4.9%、12.45%,F/G降低了11.2%;②胴体性状方面,各组间屠宰率、胴体重、胴体长、皮率及骨率差异不显著(P>0.05);复合酶Ⅰ组的背膘厚显著低于对照组(P<0.05)、瘦肉率显著高于对照组和阳性对照组(P<0.05),皮厚、板油重及肥肉率略低于对照组(P>0.05)),眼肌面积略高于对照组(P>0.05);③肉品质方面,各组间肉的pH值、L*值及a*值差异不显著(P>0.05),但与对照组相比,复合酶Ⅰ组有提高的趋势;复合酶Ⅰ组肉的失水率显著低于对照组(P<0.05),大理石纹评分显著高于对照组(P<0.05)。结果表明,日粮中添加复合酶可改善生长肥育猪的生长性能、胴体性状和肉品质,以1.0‰添加效果最好。     

低聚木糖对生长肥育猪血浆生化参数、肌肉氨基酸含量和肌纤维类型组成的影响

本试验旨在研究低聚木糖(XOS)对生长肥育猪血浆生化参数、肌肉氨基酸含量和肌纤维类型组成的影响。试验选取70日龄、平均体重约为30 kg的杜×长×大三元杂交猪80头,随机分为8组,每组10个重复(公母各占1/2),每个重复1头猪。试验设对照组、抗生素组、30~65 kg阶段100、250和500 g/t XOS组以及30~100 kg阶段100、250和500 g/t XOS组。于试猪平均体重达100 kg时,前腔静脉采血,离心分离血浆,测定生化参数;屠宰后取背最长肌样品,测定其氨基酸含量及肌纤维类型和肌肉生长相关基因mRNA表达量。结果表明:1)与对照组或抗生素组相比,饲粮添加不同剂量XOS可显著提高血浆球蛋白含量(P0.05),显著降低白蛋白/球蛋白值(P0.05);2)与对照组或抗生素组相比,30~65 kg阶段饲粮添加250 g/t XOS可显著降低背最长肌中苏氨酸(Thr)、亮氨酸(Leu)、苯丙氨酸和丝氨酸(Ser)含量(P0.05),30~65 kg阶段饲粮添加500 g/t XOS可显著增加背最长肌肌球蛋白重链Ⅱx(My HCⅡx)、生肌决定因子(Myo D)、肌细胞生成素(Myo G)和生肌增强因子2A(MEF2A)mRNA表达量(P0.05);3)与对照组或抗生素组相比,30~100 kg阶段饲粮添加100或500 g/t XOS可显著增加背最长肌中Thr、Leu、Ser、总氨基酸、必需氨基酸和鲜味氨基酸含量以及My HCⅡx、Myo D、Myo G、MEF2A和肌肉生长抑制素mRNA表达量(P0.05)。综上所述,饲粮添加一定剂量的XOS可调控机体氮代谢,上调肌纤维类型和肌肉生长相关基因的表达,且以30~100 kg阶段添加100 g/t XOS的效果较佳。     

牛至提取物对生长育肥猪生长性能、胴体性状及肉品质的影响

本试验旨在研究牛至提取物对生长育肥猪生长性能、胴体性状及肉品质的影响。将126头体重为(41.64±1.63)kg的杜×长×大生长育肥猪随机分为3组,对照组饲喂基础日粮,试验组分别在基础日粮中添加300、500 mg/kg牛至提取物。每组设3个重复,每个重复14头。预试期5 d,正试期92 d。试验结束时,测定生长育肥猪生长性能、胴体性状和肉品质。结果表明:与对照组相比,300、500 mg/kg牛至提取物组平均日增重、平均日采食量显著提高,耗料增重比显著降低,肌肉中肌苷酸含量显著提高;500 mg/kg牛至提取物组肉色、屠宰后pH45min显著高于对照组和300 mg/kg牛至提取物组,滴水损失则显著降低;各组屠宰率、瘦肉率、平均背膘厚、眼肌面积以及肌肉的水分、粗脂肪、粗蛋白质和粗灰分含量差异不显著。以上结果表明,日粮添加500 mg/kg牛至提取物可提高生长育肥猪生长性能,改善肉品质和风味。     

甜菜碱对金华猪生长性能及胴体肉品质的影响

试验研究了甜菜碱对金华猪生长肥育性能及胴体肉品质的影响。结果表明,金华猪饲粮中添加甜菜碱可提高金华猪日增重,其中以1 250 mg/kg组最佳,比对照组提高8.77%,但差异不显著(P0.05);与对照组相比,添加1 250 mg/kg甜菜碱金华猪胴体瘦肉率提高4.84%(P0.05),3点平均背膘厚降低17.23%(P0.05);甜菜碱对金华猪胴体肉品质没有影响。试验结果表明,饲粮中甜菜碱以1 250 mg/kg的添加量对提高金华猪日增重及改善胴体品质较为理想。     

苜蓿加工粉尘对育肥猪生长性能、胴体性状、肉品质及经济效益的影响

本试验旨在研究饲粮中添加苜蓿加工粉尘对育肥猪生长性能、胴体性状、肉品质及经济效益的影响，探讨其在育肥猪上的应用效果。选取平均体重为(30.32±1.46) kg的“杜×长×大”三元杂交猪48头，按性别、体重基本一致的原则随机分为4组，每组3个重复，每个重复4头。对照组饲喂基础饲粮，试验组饲喂在基础饲粮中分别添加2%、4%、6%苜蓿加工粉尘的饲粮。试验期82 d，分为育肥前期(1～41 d)和育肥后期(42～82 d)2个阶段。结果表明：1)与对照组相比，2%苜蓿加工粉尘组育肥后期和育肥全期平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G)差异不显著(P>0.05)，育肥前期ADFI显著降低了10.13%(P<0.05)，育肥前期ADG和F/G分别降低了6.85%和3.53%(P>0.05);4%、6%苜蓿加工粉尘组育肥前期、育肥后期和育肥全期ADG、ADFI和F/G差异不显著(P>0.05)。2)与对照组相比，2%、4%、6%苜蓿加工粉尘组瘦肉率分别增加了0.60%、1.50%和2.45%(P>0.05)；各组之间宰前活重、胴体重、屠宰率、眼...     

稀土元素螯合物与有机硒协同作用对生长猪生产性能的影响

试验研究稀土元素螯合物(rare earth-amino acid chelate)与有机硒(organic selenium)对生长猪生长性能的影响。选择85日龄,体重35 kg左右、体重相近、健康的杜×长×大生长猪176头,按照体重相近、遗传背景一致、公母各半的原则随机分为4组,每组2个重复,每个重复22头猪。Ⅰ组为对照组,饲喂玉米-豆粕型基础日粮,Ⅱ、Ⅲ、Ⅳ组在基础日粮的基础上均添加300 g/t的稀土超微螯合包并分别添加0.3 mg/kg的酵母硒、高硒预混料和蛋白硒,试验期31 d。结果表明:在日粮中添加300 g/t的稀土超微螯合包和0.3 mg/kg的酵母硒可明显提高生长猪的平均日增重(ADG)、平均日采食量(ADFI),降低料重比(F/G),有效降低生长猪的腹泻率与死亡率。结果显示,日粮中添加300 g/t的稀土超微螯合包和0.3 mg/kg的酵母硒可显著改善生长猪的生长性能,提高机体的抗病能力。     

半胱胺和酵母铬对生长肥育猪生产性能和胴体品质的影响

试验选择25 kg左右的"杜长大"三元杂交猪96头,采用2×2析因设计分成4组,每组6个重复,每个重复4头。对照组喂基础饲粮,酵母铬(Cr)组在基础饲粮中添加酵母铬(生长期和肥育期分别添加Gr 200、300μg/kg),半胱胺(CS)组在基础饲粮中添加半胱胺(生长期和肥育期分别添加CS 120、170 mg/kg),复合组在基础饲粮中同时添加酵母铬和半胱胺(生长期和肥育期分别添加Gr 200μg+CS 120 mg/kg、Gr300μg+CS 170 mg/kg)。试验分生长期和肥育期两阶段进行,研究半胱胺和酵母铬对生长肥育猪生长性能、胴体和肌肉品质的影响。结果表明,生长肥育猪饲粮中分别添加半胱胺和酵母铬,一定程度上可改善生产性能,提高日增重、降低饲料/增重比;二者同时添加时有提高日增重的趋势,但统计分析差异不显著(P>0.05)。饲粮中分别或同时添加半胱胺和酵母铬对胴体肌肉品质也有一定的改善作用,但统计分析差异不显著(P>0.05)。     

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.     

Effect of wean-to-finish management on pig performance

In each of three trials, 240 crossbred barrows weaned at 17 d of age (5.1 kg BW) were assigned to one of three experimental treatments based on light and heavy weight outcome groups. Experimental treatments were 1) wean-to-finish at 0.69 m2/pig and 15 pigs/pen; 2) wean-to-finish double-stocked at 0.35 m2/pig, 30 pigs per pen for 8 wk and then randomly split into two pens (either stayed in same pen or moved to new pen) for growth to slaughter at 0.69 m2/pig; and 3) nursery facility for 8 wk at 0.35 m2/pig and 15 pigs/pen followed by move to the same grow-finish facility housing wean-to-finish and double-stocked pigs and maintaining pen integrity. Beginning at 38 kg BW, diets were supplemented with either bacitracin methylenedisalicylate at 33 mg/kg to slaughter or tylosin at 44 mg/kg to 59 kg BW and 22 mg/kg thereafter. There were no trial x treatment interactions, even though there was considerable variation in health status among trials. At the end of the 56-d nursery period, wean-to-finish pigs weighed more than nursery (28.7 vs 27.7 kg; P = 0.071) and double-stocked pigs (28.7 vs 26.9 kg; P = 0.002), due to greater ADG (wean-to-finish vs nursery; P = 0.062; wean-to-finish vs double-stocked; P = 0.002) and greater ADFI (wean-to-finish vs nursery; P = 0.024; wean-to-finish vs double-stocked, P = 0.002). There was no effect of treatments (P > 0.1) on ADG, feed conversion, carcass lean percentage, or lean gain during the growing-finishing period. There was also no effect of treatment (P > 0.1) on ADG or ADFI from weaning to slaughter. There was no difference (P > 0.1) between bacitracin methylenedisalicylate and tylosin for ADG, feed conversion, carcass lean percentage, or daily lean gain. These data suggest that housing 5-kg weaned pigs in fully slatted growing-finishing facilities from weaning to slaughter was not detrimental to overall performance. In this experiment, dietary additions of bacitracin methylenedisalicylate or tylosin from 38 kg BW to slaughter weight resulted in similar growth performance.     

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.     

Effects of increasing crude glycerol and dried distillers grains with solubles on growth performance, carcass characteristics, and carcass fat quality of finishing pigs

This study was conducted to determine the effects of dietary crude glycerol and dried distillers grains with solubles (DDGS) on growing-finishing pig performance, carcass characteristics, and carcass fat quality. We hypothesized that because dietary crude glycerol has been observed to increase carcass SFA, it might ameliorate the negative effects of DDGS on fat quality. The 97-d study was conducted at a commercial swine research facility in southwestern Minnesota with 1,160 barrows (initial BW = 31.0 ± 1.1 kg). Pigs were blocked by initial BW, and pens were randomly allotted to 1 of 6 dietary treatments with 7 replications per treatment. Treatments were arranged in a 2 × 3 factorial with main effects of crude glycerol (0, 2.5, or 5%) and DDGS (0 or 20%). All corn-soybean meal-based diets contained 3% added fat (choice white grease). There were no glycerol × DDGS interactions for any response criteria evaluated. Increasing dietary glycerol did not affect finishing pig growth performance. Adding 20% DDGS to the diet did not affect ADG; however, finishing pigs fed diets with added DDGS had greater (2.47 vs. 2.41 kg/d; P = 0.02) ADFI and poorer (0.39 vs. 0.40; P = 0.01) G:F than pigs not fed DDGS. Feeding increasing dietary glycerol or 20% DDGS did not affect carcass characteristics. For carcass fat quality, feeding 20% DDGS resulted in decreased (P < 0.01) palmitic and oleic acids, total SFA and total MUFA, and increased (P < 0.01) linoleic, total PUFA, total unsaturated fatty acids, and iodine value in jowl fat, belly fat, and backfat. Increasing dietary crude glycerol increased myristic acid (linear, P < 0.05) and MUFA (quadratic, P < 0.05) in jowl fat and increased (quadratic, P < 0.05) oleic acid and MUFA in backfat. In conclusion, feeding 20% DDGS to finishing pigs increased ADFI, reduced G:F, and increased carcass fat iodine value, whereas feeding crude glycerol did not influence growth performance, carcass characteristics, and had a minor influence on fatty acids of carcass fat. Both of these biofuel coproducts can be used in combination without affecting finishing pig performance or carcass traits; however, feeding crude glycerol did not fully mitigate the increased unsaturation of carcass fat observed when feeding DDGS.     

Effect of dietary formates on growth performance, carcass traits, sensory quality, intestinal microflora, and stomach alterations in growing-finishing pigs

Three experiments were conducted to evaluate the effect of adding salts of formic acid to diets for growing-finishing pigs. In Exp. 1, 72 pigs (23.1 kg and 104.5 kg initial and final BW) were used to evaluate the effect of Ca/Na-formate and K-diformate on performance and carcass traits. Treatments were organized in a 2 x 3 factorial arrangement with two feeding regimens (limit and semi-ad libitum feeding) and three diets (control, .85% Ca/Na-formate, and .8% K-diformate). No significant feeding regime x diet interaction was found. The K-diformate diet increased overall ADG of pigs compared with the control and Ca/Na-formate diets, but had no effect on ADFI or gain/feed (G/F) ratio. Neither K-diformate nor Ca/Na-formate had any effect on carcass lean or fat content. In Exp. 2, 10 limit-fed pigs (24.3 kg and 85.1 kg initial and final BW) were used to study the effect of K-diformate on performance and sensory quality of pork. Adding .8% K-diformate to diets increased ADG (P < .13) and G/F (P < .04), but had no effect on sensory quality of the pork or content of formate in liver, kidney, or muscle tissue of pigs. In Exp. 3, 96 limit-fed pigs (27.1 kg and 105 kg initial and final BW) were used to determine the effect of adding K-diformate to diets on performance, carcass traits, and stomach keratinization and(or) lesions. Adding K-diformate (0, .6, or 1.2%) to diets increased ADG and ADFI (linear P < .01). The K-diformate reduced the percentage of carcass fat (linear P < .03) and fat area in the cutlet (linear P < .09) and increased percentage lean in the ham (linear P < .01), flank (linear P < .02), loin (linear P < .09), and neck and shoulder (linear P < .09). The K-diformate had no negative effect on stomach alterations. In Exp. 3, the concentration of coliform bacteria in the gastrointestinal tract was evaluated in eight control and eight 1.2% K-diformate-fed pigs. The K-diformate reduced the number of coliforms in the duodenum (P < .03), jejunum (P < .02), and rectum (P < .10) of pigs. In conclusion, K-diformate improved growth performance and carcass quality of growing-finishing pigs, whereas Ca/Na-formate had no effect. K-diformate had no adverse effect on sensory quality of pork or on stomach alteration scores.     

Performance of growing-finishing pigs fed diets containing Roundup Ready corn (event nk603), a nontransgenic genetically similar corn, or conventional corn lines

Two studies were conducted at two locations to evaluate growth performance and carcass characteristics of growing-finishing pigs fed diets containing either glyphosate-tolerant Roundup Ready (event nk603) corn, a nontransgenic genetically similar control corn (RX670), or two conventional sources of nontransgenic corn (RX740 and DK647). A randomized complete block design (three and four blocks in Studies 1 and 2, respectively) with a 2 x 4 factorial arrangement of treatments (two genders and four corn lines) was used. Study 1 used 72 barrows and 72 gilts (housed in single-gender groups of six; six pens per dietary treatment) with initial and final BW of approximately 22 and 116 kg, respectively. Study 2 used 80 barrows and 80 gilts (housed in single-gender groups of five; eight pens per dietary treatment) with initial and final BW of approximately 30 and 120 kg, respectively. Pigs were housed in a modified open-front building in Study 1 and in an environmentally controlled finishing building in Study 2. The test corns were included at a fixed proportion of the diet in both studies. Animals had ad libitum access to feed and water. Pigs were slaughtered using standard procedures and carcass measurements were taken. In Study 1, overall ADG, ADFI (as-fed basis), and gain:feed (G:F) were not affected (P > 0.05) by corn line. In Study 2, there was no effect of corn line on overall ADFI (as-fed basis) or G:F ratio. In addition, overall ADG of barrows fed the four corn lines did not differ (P > 0.05); however, overall ADG of gilts fed corn DK647 was greater (P < 0.05) than that of pigs fed the other corn lines. There was no effect (P > 0.05) of corn line on carcass yield or fatness measurements in either study. Differences between barrows and gilts for growth and carcass traits were generally similar for both studies and in line with previous research. Overall, these results indicate that Roundup Ready corn (nk603) gives equivalent animal performance to conventional corn for growing pigs.     

Effects of graded levels of xylo-oligosaccharides on growth performance,serum parameters,intestinal morphology,and intestinal barrier function in weaned piglets

The objective of this study was to investigate the effects of xylo-oligosaccharides (XOSs) supplementation on growth performance, serum parameters, small intestinal morphology, intestinal mucosal integrity, and immune function in weaned piglets. A total of 240 weaned piglets with an average body weight (BW) of 8.82 ± 0.05 kg (28 d of age) were assigned randomly to four dietary treatments in a 28-d trial, including a control (CON) diet and three diets with XOS supplementation at the concentration of 100 (XOS100), 500 (XOS500), and 1,000 (XOS1000) mg/kg. There were four replicates per treatment with 15 pigs per pen. From day 1 to 14, there were no differences (P > 0.05) in average daily gain (ADG), average daily feed intake, and gain to feed ratio (G:F) during the different treatments. The different doses of XOSs showed a quadratic effect on BW on day 28, ADG, and G:F on day 1 to 28 of piglets (P < 0.05). From day 15 to 28, ADG of pigs fed the XOS500 diet was higher (P < 0.05) than pigs fed the CON diet. During the overall period (day 1 to 28), pigs fed the XOS500 diet had a higher BW, ADG, and G:F than pigs fed the CON diet (P < 0.05). In addition, compared with the CON group, the XOS500 group had significantly higher serum total antioxidant capacity, total superoxide dismutase and catalase levels, and lower malondialdehyde levels on days 14 and 28 (P < 0.05). The serum immunoglobulin G (IgG) concentration in the XOS500 group was also significantly higher compared with the CON group on days 14 and 28 (P < 0.05). However, serum immunoglobulin A and immunoglobulin M were not affected by the dietary treatments. Supplementation of XOS500 to the feed significantly increased the villus height (VH) and VH to crypt depth ratio in the jejunum and ileum in comparison with the CON and XOS1000 groups. Moreover, the XOS500 group significantly elevated the expression levels of occludin and zonula occludens protein-1 in the ileum compared with the CON group. The ileal interleukin (IL)-1β, IL-8, and interferon (IFN)-γ mRNA expression levels in the XOS100 and XOS500 groups were markedly lower than in the CON group. In contrast, the ileal IL-10 mRNA expression levels were remarkably higher in the XOS500 than in the CON group. In conclusion, XOSs have a beneficial effect on growth performance by improving serum antioxidant defense system, serum IgG, small intestinal structure, and intestinal barrier function in weaned piglets.     

Compensatory growth response in pigs: effects on growth performance, composition of weight gain at carcass and muscle levels, and meat quality

A restriction/realimentation feeding strategy was applied to pigs to increase the age at market weight and final ADG, modify protein and lipid deposition rates at carcass and muscle levels, and thereby improve eating quality of the pork. A total of 126 Duroc x (Large White x Landrace) pigs (females and castrated males) were used. At the average BW of 30 kg, within litter and sex, pairs of littermates (blocked by BW) were randomly assigned to ad libitum (AL) feeding during growing (30 to 70 kg of BW) and finishing (70 to 110 kg of BW) periods (AL, n = 56), or restricted feeding at 65% of the ADFI of the AL pigs, on a BW basis, during the growing period and AL feeding during finishing (compensatory growth, CG; n = 56). In each feeding regimen, 15 pigs were slaughtered at 70 kg of BW, and 41 pigs were slaughtered at 110 kg of BW. Additionally, 14 pigs were slaughtered at 30 kg of BW to calculate tissue deposition rates. The CG pigs showed decreased ADG (-35%, P = 0.001) during growing but increased ADG (+13%, P = 0.001) during finishing (i.e., compensatory growth) due to greater (P = 0.001) ADFI and G:F. Hence, CG pigs were 19 d older at 110 kg of BW than AL pigs. The CG pigs were leaner at 70 kg of BW than AL (e.g., 11.7 vs. 13.5 mm of average backfat thickness for CG and AL pigs, respectively, P = 0.023), whereas the differences were reduced at 110 kg of BW (20.6 vs. 21.0 mm of average backfat thickness for CG and AL pigs, respectively, P = 0.536). At 70 kg of BW, intramuscular fat (IMF) content of LM did not differ between CG and AL pigs (1.25 vs. 1.49%, respectively, P = 0.118), whereas CG pigs had less IMF in LM at 110 kg of BW (2.19 vs. 2.53% for CG and AL pigs, respectively, P = 0.034). Feeding regimen influenced the composition of weight gain. From 30 to 70 kg of BW, feed restriction reduced (P = 0.001) lean and adipose tissue deposition at the carcass level and protein and lipid deposition at the muscle level. From 70 to 110 kg of BW, the CG feeding strategy increased (P = 0.016) deposition of adipose but not of lean tissue at the carcass level. However, lipid and protein deposition at the muscle level were not affected. Thus, realimentation promoted deposition of subcutaneous fat over IMF. Feeding regimen hardly affected technological meat quality at 110 kg of BW. The CG feeding strategy decreased (P = 0.014) the meat juiciness score in relation to the decreased IMF but did not influence other sensory traits. Elevated IMF content and improved pork quality might be achieved by modifying the onset or duration of the restriction and realimentation periods.     

Performance of growing-finishing pigs fed diets containing YieldGard Rootworm corn (MON 863), a nontransgenic genetically similar corn, or conventional corn hybrids

Two studies were conducted at two locations to evaluate growth performance and carcass characteristics of growing-finishing pigs fed diets containing either YieldGard Rootworm corn (MON 863), a non-transgenic genetically similar corn (RX670), or two conventional nontransgenic corn hybrids (DK647 and RX740). A randomized complete block design with a 2 x 4 factorial arrangement of treatments (two genders and four corn hybrids) was used. Study 1 used 72 barrows and 72 gilts (progeny of Danbred sires x [Danbred x NE White line] dams grown from 22.7 to 117.0 kg BW). Pigs were housed in a modified open-front building in single-gender groups of six (six pens per dietary treatment). Study 2 used 80 barrows and 80 gilts (progeny of PIC 337 sires x C22 dams) grown from 29.5 to 114.9 kg BW. Pigs were housed in an environmentally controlled finishing building in single-gender groups of five (eight pens per dietary treatment). The test corns were included at a fixed proportion of the diet in both studies. Animals had ad libitum access to feed and water. Pigs were slaughtered at the end of the growth period using standard procedures, and carcass measurements were taken. There were no diet x gender interactions for growth performance or carcass measurements in either study. In both studies, overall ADG, ADFI, and G:F were not affected by corn hybrid. There was no effect of corn hybrid on carcass or LM quality measurements in Study 1. In Study 2, LM protein content was less (P< 0.05) for pigs fed RX740 compared with those fed either MON 863 or RX670; however, there was no effect of corn hybrid on other LM composition measures or on quality traits. In both studies, differences between barrows and gilts for growth and carcass traits were similar to previous research. These results suggest that the YieldGard Rootworm corn (MON 863) results in equivalent growth performance and carcass quality to nontransgenic corn hybrids in growing-finishing pigs.