Identification of serum stress biomarkers in pigs housed at different stocking densities

Eight Duroc×(Landrace×Large White) male pigs housed at a stocking rate of 0.50m(2)/pig were subjected to a higher stocking rate of 0.25m(2)/pig (higher density, HD) for two 4-day periods over 26 days. Using biochemical and proteomic techniques serum and plasma samples were examined to identify potential biomarkers for monitoring stress due to HD housing. HD housed pigs showed significant differences (P<0.001) in total cholesterol and low density lipoprotein-associated cholesterol, as well as in concentrations of the pig-major acute phase protein (Pig-MAP) (P=0.002). No differences were observed in serum cortisol or other acute phase proteins such as haptoglobin, C-reactive protein or apolipoprotein A-I. HD-individuals also showed an imbalance in redox homeostasis, detected as an increase in the level of oxidized proteins measured as the total plasma carbonyl protein content (P<0.001) with a compensatory increase in the activity of the antioxidant enzyme glutathione peroxidase (P=0.012). Comparison of the serum proteome yielded a new potential stress biomarker, identified as actin by mass spectrometry. Cluster analysis of the results indicated that individuals segregated into two groups, with different response patterns, suggesting that the stress response depended on individual susceptibility.     

二氢吡啶对猪生长发育和肉质性能影响的研究

二氢吡啶 (Diludin)的化学名称为 2、6 -二甲基 - 3、5 -二乙酯基 - 1、4 -二氢吡啶 ,具有抗氧化、提高畜禽生产性能等多种作用 ,是一种良好的饲料添加剂 ,目前已广泛应用到畜禽生产中。我国利用二氢吡啶的研究主要集中在家禽上 ,二氢吡啶对猪生长发育的研究较少 ,对猪肉质影响的报道更少 ,为进一步探讨猪饲料中二氢吡啶的最佳添加浓度和对肉质的影响 ,进行了本次试验。1　材料和方法1 1　二氢吡啶　由北京桑普生物化学技术有限公司提供。1 2　地点和试验期　本研究在江西某猪场进行 ,试验期为 1 0 0d。1 3　试猪及分组　试验选择体重、…     

Effect of sow history features on growth and feed intake in grow-finish pigs

The sow provides a specific environment to her offspring during gestation and lactation. Certain features in the early life of the sow (sow history features) may affect her ability to deliver and feed a healthy litter. In genetic analyses of grow-finish traits, these effects are estimated as common litter or permanent sow effects. The objective of this research was to identify sow history features that affect the growth rate (GR) and feed intake (FI) of her offspring during the grow-finish stage. Data from 17,743 grow-finish pigs, coming from 604 sires and 681 crossbred sows, were recorded between May 2001 and February 2010 at the experimental farm of the Institute for Pig Genetics (Beilen, the Netherlands). The grow-finish stage was divided into 2 phases (phase 1: 26 to 75 kg; phase 2: 75 to 115 kg). The sow history features were birth litter size, birth year and season, birth farm, weaning age, age of transfer to the experimental farm, and age at first insemination. The sow features were added to the basic model one at a time to study their effect on the grow-finish traits of the pigs. Subsequently, significant sow features (P < 0.1) were fitted simultaneously in an animal model. With every extra piglet in the birth litter of the sow, the GR of her offspring decreased by 1 g/d and the FI decreased by 4 g/d. Every extra day to the first insemination increased the GR of grow-finish pigs by 0.1 g/d. The heritability estimates for GR and FI (only in phase 2 of the grow-finish stage) decreased after adding the sow features to the model. No differences were found in estimates of the common litter effects between the basic model and the model with all significant sow features. The estimates of the permanent sow effect changed for FI from 0.03 (basic model) to 0.00 (model with sow features), and for FI in phase 1, the permanent sow effect decreased from 0.03 (basic model) to 0.01 (model with sow features). In conclusion, selected sow features do affect the grow-finish traits of the pigs, but their estimates are small and explain only a small proportion of the differences in the GR and FI of grow-finish pigs. The sow features partially explained the permanent sow effect of FI-related traits and did not explain the common litter effect. Although the sow early life features can affect piglet traits, they do not predict which sows produce better performing offspring in the grow-finish stage.     

Effects of increasing dietary niacin on growth performance and meat quality in finishing pigs reared in two different environments

We conducted two experiments to determine the effects of added dietary niacin on growth performance and meat quality in finishing pigs. Pigs were blocked by weight and assigned to one of six dietary treatments in both experiments. Dietary treatments consisted of a corn-soybean meal-based control diet (no added niacin) or the control diet with 13, 28, 55, 110, or 550 mg/kg of added niacin. In Exp. 1, pigs were housed at the Kansas State University research from with two pigs per pen (six pens per treatment per sex). In Exp. 2, pigs were housed with 26 pigs per pen (four pens per treatment per sex) in a commercial research barn. In Exp. 1, 144 pigs (initially 51.2 kg) were fed diets in two phases (d 0 to 25 and 25 to 62) that were formulated to 1.00 and 0.75% lysine, respectively. In Exp. 2, 1,248 pigs (initially 35.9 kg) were fed diets in four phases (d 0 to 28, 29 to 56, 57 to 84, and 85 to 117), with corresponding total lysine concentrations of 1.25, 1.10, 0.90, and 0.65% lysine, respectively. Added fat (6.0%) was included in the first three phases. In Exp. 1, average daily feed intake tended (quadratic, P < 0.07) to increase then return to values similar to control pigs as dietary niacin increased. Longissimus muscle (LM) 24-h pH (longissimus of pigs fed added niacin) tended to increase (control vs niacin, P < 0.06) for pigs fed added niacin. In the commercial facility (Exp. 2), increasing added niacin improved gain:feed (quadratic, P < 0.01) and subjective color score, and ultimate pH (linear, P < 0.01). Added niacin also decreased (linear, P < 0.04) carcass shrink, L* values, and drip loss percentage. Results from these two studies show that 13 to 55 mg/kg added dietary niacin can be fed to pigs in a commercial environment to improve gain:feed. It also appears that pork quality, as measured by drip loss, pH, and color, may be improved by higher concentrations of added dietary niacin.     

微生物发酵饲料对育肥猪生长性能及肉质的影响

为了研究乳酸菌发酵饲料对育肥猪生长性能、肉品质的影响及其机理,选择体重约80 kg的杜×长×大三元杂交生长育肥猪320头,随机分为对照组和试验组,每组8个重复,每个重复20头猪,对照组饲喂基础饲粮,试验组饲粮中5%的原料经乳酸菌发酵处理后再与其他原料混合;试验预试期3 d,正试期4周,在第4周结束时,每组随机抽取6头猪进行屠宰,测定屠宰性能和肉质。结果显示:与对照组相比,饲喂发酵饲料对肥育猪的干物质采食量、平均日增重和料重影响差异不显著(P0.05),猪血清中的生长激素和胰岛素样生长因子-I水平组间差异也不显著(P=0.11);试验组育肥猪的背最长肌pH_(45 min)和肉色评分显著增加(P0.05),背最长肌肉剪切力显著降低(P0.05);试验组血清谷胱甘肽还原酶活性有升高趋势(P=0.08)。结果表明:肥育猪饲料中添加5%发酵饲料原料可改善猪肉品质。     

饲料中添加紫花苜蓿多糖对育肥猪生长性能和胴体品质的影响

为研究紫花苜蓿多糖对育肥猪生长性能及胴体品质的影响,选择体重相近的健康三元杂交育肥猪180头,随机分成3组,每个组3个重复,每个重复20头,1组饲喂基础日粮为对照组,2、3组分别在基础日粮中添加5.0%、10.0%紫花苜蓿多糖,预试验10 d,试验期60 d。在试验1 d和60 d测定生长性能指标,试验结束测定胴体品质。结果表明:(1)试验2、3组试验末重和平均日增重分别较对照组提高5.8%、6.2%、14.0%、14.9%(P <0.05),试验2、3组料重比分别较对照组降低4.6%、5.0%(P <0.05)。(2)试验2、3组屠宰率和瘦肉率分别较对照组提高4.2%、4.0%、5.8%、6.9%(P <0.05);试验2、3组胴体率均高于对照组(P> 0.05),试验2、3组背膘厚和眼肌面积分别较对照组降低7.8%、10.0%、8.9%、8.7%(P <0.05)。(3)试验2、3组肉质评价指标大理石评分、肉色、剪切力、p H24 h较对照组相比,均差异性不显著(P> 0.05)。综述所述,日粮中10.0%紫花苜蓿多糖可以提高育肥猪的生长性能和胴体品质。     

不同能量水平日粮添加抗氧化剂对生长猪生长性能及肉质的影响

文章旨在研究不同能量水平日粮添加抗氧化剂对仔猪生长性能和肉质的影响。试验选择360头体重一致的仔猪(杜洛克和长白各半),随机分为6组,每组3个重复,每个重复20头猪。试验共设计6种日粮,其中对照组饲喂基础日粮,处理组分别在日粮中添加100、0、200、200和200 g/kg草粉,其中最后两个处理组分别添加200 mg/kgα-生育酚和儿茶素。试验由断奶开展到出栏。杜洛克猪肌肉pH45min显著高于长白猪(P <0.05),与对照组相比,处理1组和处理3组显著降低背膘深度(P <0.05)。杜洛克猪较长白猪显著提高了肌间脂肪和灰分含量(P <0.05),而长白猪较杜洛克猪显著提高了肌肉水分含量(P <0.05),处理5组较处理2组显著提高了肌肉灰分含量(P <0.05)。杜洛克猪较长白猪显著提高了肌肉C16:1和C18:1含量(P <0.05)。饲喂处理2和5组日粮的长白猪较对照组显著降低了肌肉MDA含量(P <0.05)。综上所述:日粮添加抗氧化及限饲提高长白猪肌肉瘦肉率和多不饱和脂肪酸含量。低能日粮可以改善背膘厚度和肌间脂肪水平,同时增加肌肉的氧化稳定性。     

Effects of dietary iodine value product on growth performance and carcass fat quality of finishing pigs

A total of 120 barrows (initial BW = 47.9 ± 3.6 kg; PIC 1050) were used in an 83-d study to determine the effects of dietary iodine value (IV) product (IVP) on growth performance and fat quality. Pigs were blocked by BW and randomly allotted to 1 of 6 treatments with 2 pigs per pen and 10 pens per treatment. Dietary treatments were fed in 3 phases and formulated to 3 IVP concentrations (low, medium, and high) in each phase. Treatments were 1) corn-soybean meal control diet with no added fat (low IVP), 2) corn-extruded expelled soybean meal (EESM) diet with no added fat (medium IVP), 3) corn-soybean meal diet with 15% distillers dried grains with solubles and choice white grease (DDGS + CWG; medium IVP), 4) corn-soybean meal diet with low CWG (medium IVP), 5) corn-EESM diet with 15% DDGS (high IVP), and 6) corn-soybean meal diet with high CWG (high IVP). On d 83, pigs were slaughtered and backfat and jowl fat samples were collected and analyzed. The calculated and analyzed dietary IVP values were highly correlated (r(2) = 0.86, P < 0.01). Pigs fed the control diet, EESM, or high CWG had greater (P < 0.05) ADG than pigs fed EESM + DDGS. Pigs fed the control diet had greater (P < 0.05) ADFI than pigs fed all other diets. Pigs fed EESM + DDGS and high CWG had improved (P < 0.05) G:F compared with pigs fed the control diet or DDGS + CWG. Pigs fed diets with DDGS had greater (P < 0.05) backfat and jowl fat IV, C18:2n-6, and PUFA and less SFA than pigs fed all other treatments. Pigs fed EESM had greater (P < 0.05) backfat and jowl fat IV, C18:2n-6, and PUFA than pigs fed the control diet, low CWG, or high CWG. Pigs fed low CWG or high CWG had greater (P < 0.05) jowl fat IV than control pigs. Feeding ingredients high in unsaturated fatty acids, such as DDGS and EESM, had a greater impact on fat IV than CWG, even when diet IVP was similar. Therefore, IVP was a poor predictor of carcass fat IV in pigs fed diets with different fat sources and amounts of unsaturated fats formulated with similar IVP. Dietary C18:2n-6 content was a better predictor of carcass fat IV than diet IVP.     

牛至油对育肥猪生长性能和肉品质的影响

文章旨在研究不同浓度的牛至油对肥育猪生长性能和肉质特性的影响。试验选择32头阉割公猪和32头后备母猪随机分成4个组,对照组饲喂基础日粮,试验组分别在基础日粮中添加0.2、0.4和0.8mg/kg牛至油,试验共开展5周。试验结束后禁食12h,称重后屠宰。经过一夜的冷却,从屠体上取50cm的腰肌(每组8头,4头公猪、4头母猪)。日粮中添加牛至精油对生长猪末重、日增重、屠宰率均无显著差异(P>0.05),同时各组最长肌嫩度、屠宰后45min和24h后的pH、肉色及感官特性也无显著差异(P>0.05)。此外,脂质氧化试验结果显示,日粮添加牛至油对肌肉无明显的抗氧化作用(P>0.05)。综上所述,由于胴体和肉质属性均无显著变化,说明本试验中日粮添加不同水平牛至油对猪的肉质参数没有影响。     

Effects of supplemental humic substances on growth performance, blood characteristics and meat quality in finishing pigs

A total of forty-eight finishing pigs were used to determine the effects of humic substances (HS) on growth performance, blood characteristics, and meat quality. The finishing pigs were assigned randomly by weight to three treatments. The dietary treatments included: 1) Control (CON; basal diet), 2) HS1 (basal diet + 5% humic substances) and 3) HS2 (basal diet + 10% humic substances). Results of the whole experimental period showed that addition of 10% HS to the diet, significantly increased average daily gain (ADG) and gain/feed (G:F) (P < 0.05). At the end of the experiment, the relative lymphocyte counts (% of total white blood cells) of pigs fed HS2 diet were higher (P < 0.05) than that of pigs fed CON diet. The Minolta color parameter a of pigs fed HS2 was similar to that of pigs fed HS1, however, it was higher (P < 0.05) than that of pigs fed CON diet. The inclusion of either 5% or 10% HS significantly decreased backfat thickness (P < 0.05). The marbling score was increased significantly (P < 0.05) when diets were supplemented with HS at a level of 10%. The results of this study suggest that HS might be utilized as a feed additive in the diet. It could improve growth performance, relative lymphocyte counts and meat quality.     

半胱胺对育肥猪生产性能的影响

动物的生长发育受神经内分泌系统的调节，而其中最重要的是由下丘脑-垂体-靶腺构成的神经内分泌生长轴（the somatotropic axis）。生长激素（Growth Hormone，GH）是该调控的核心，它能够促进肌肉组织蛋白质的合成，抑制脂肪组织葡萄糖的摄入和脂肪的合成。生长抑素（Somatostatin，SS）是由神经系统和胃肠道产生的，     

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。     

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。     

复合维生素添加剂对肉猪肥育性能、胴体性状和肌肉品质的影响

<正>国内外先进养猪技术的应用,使猪胴体瘦肉率、生长速度和饲料报酬有了较大幅度的提高,这种提高却是以猪肌肉品质下降为代价的,因此如何利用营养     

超微茶粉对生长猪生长性能、胴体品质及脂肪代谢的影响

为了研究超微茶粉对生长猪生长性能、胴体品质及脂肪代谢的影响,将64头50 kg左右的杜长大阉公猪随机分为4组,每组4栏(重复),每栏4头,对照组采食基础日粮,试验组分别添加0.5%、1.0%和1.5%的超微茶粉,试验期70 d,试验结束时计算日增重、料重比,然后屠宰测定分析肌肉胴体品质及脂肪沉积性能。结果表明,超微茶粉对生长猪生长性能没显著影响,并且能显著降低肌内脂肪(IMF)含量,可以显著提高生长猪的瘦肉率和眼肌面积、猪肉肉色以及降低滴水损失和剪切力(P<0.05)。同时,利用前体脂肪细胞研究表没食子儿茶素没食子酸酯(EGCG)对脂肪代谢关键基因表达的影响,结果表明,前体脂肪细胞在EGCG作用下,p-AMPKα蛋白和LPL基因表达显著增加,同时C/EBPβ、SREBP-1、PPARγ基因表达显著降低(P<0.05)。我们的结果提示,超微茶粉对生长猪生长性能没有影响,但可以显著改善肌肉品质,其作用机理可能与对脂肪代谢的调控有关。     

SSTR和IGFBP对生长猪生产性能的影响

选用 9周龄 1 9kg左右约·杜·长·宁四元杂种猪 60头 ,随机分为 3组 ,试验组I、试验组II和对照组各 2 0头。试验组I在 1 0、 1 3和 1 5周龄颈部皮下注射生长激素抑制激素受体 (SSTR)疫苗 ;试验组II在 1 0周龄颈部皮下注射SSTR +IGFBP (胰岛素样生长因子结合蛋白 )疫苗 ,1 3及 1 5周龄注射SSTR疫苗 ;对照组注射相同剂量的生理盐水。结果表明 :SSTR组平均日增重较对照组提高 5 73% ,采食量提高 3 88%。SSTR +IGFBP组平均日增重较对照组提高 9 74% ,采食量提高 1 1 1 6%。     

液态饲喂在育肥猪上的使用效果

为研究饲料液态饲喂对育肥猪生长性能和经济效益的影响,试验选用体重为(82.93±3.35) kg的"杜×长×大"(Duroc×Landrace×Yorkshire)三元杂交猪300头,随机分为3组,每组5个重复,每个重复20头猪,试验期为31 d,对照组饲喂固体颗粒饲料,试验A组用对照组日粮加水饲喂,试验B组日粮由干料、过期酸奶、水按比例配制而成,干基营养水平与对照组相当。试验结果表明:相比对照组,试验A组的平均日增重、平均日采食量分别提高了6.9%和2.1%,料重比降低了4.3%,但两组之间差异不显著;试验B组的平均日增重与对照组相当,平均日采食量、料重比分别降低了6.3%(P<0.05)和6.4%(P>0.05);同时,饲喂液态料的两个试验组经济效益均有不同程度提高。     

Interaction of swine nursery and grow-finish space allocations on performance

Two experiments were conducted to evaluate the possible interaction of nursery space allocations and grow-finish space allocations in swine. In Exp. 1, crowding was achieved by varying the number of pigs per pen. During the nursery phase, decreasing the space allocation (0.16 m2/pig vs 0.25 m2/pig; 8 and 12 pens per treatment, respectively) by increasing the number of pigs per pen (18 vs 12) resulted in a decrease in daily feed intake (0.609 vs 0.683 kg/d; P < 0.001) and daily gain (0.364 vs 0.408 kg/d; P < 0.001). Pigs were mixed within nursery treatment groups and reassigned to grow-finish pens (6 pens per treatment) at the end of the 35-d nursery period providing either 0.56 m2/pig (14 pigs/pen) or 0.78 m2/pig (10 pigs/pen). Crowding during the grow-finish phase decreased daily feed intake (P < 0.003) and daily gain (P < 0.001). In Exp. 2, space allocations of 0.16 m2/pig vs 0.23 m2/pig during the nursery phase (24 pens per treatment) resulted in a decrease in daily feed intake (0.612 vs 0.654 kg/d; P < 0.005) and daily gain (0.403 vs 0.430 kg/d; P < 0.001). Pigs remained in the same (social) groups when moved to the grow-finish phase. Unlike Exp. 1, there was no effect of crowding during the grow-finish phase (0.60 m2/pig vs 0. 74 m2/pig) on daily feed intake or daily gain. The difference in results between experiments suggests that the response to crowding during the grow-finish phase may depend in part on whether pigs are mixed and sorted following movement from the nursery.     

烟台黑猪不同杂交组合猪肥育性能、胴体品质及肉质研究

研究测定了烟台黑猪与鲁育杜洛克、鲁育大约克和长白猪杂交商品猪的生长肥育性能、胴体品质及肉质。结果表明,大约克×烟黑组合日增重最高为717.37 g,料重比最低为2.97,与杜洛克×烟黑、长白×烟黑和烟黑×烟黑相比,日增重分别提高7.93%（P〉0.05）、16.22%（P〈0.05）和21.31%（P〈0.01）,料重比分别降低11.08%、3.88%、21.43%。4个组合的胴体性能及肉品质差异显著。其中,屠宰率以杜洛克×烟黑最高,比大约克×烟黑提高11.69%（P〈0.05）;眼肌面积也以杜洛克×烟黑最大,比烟黑×烟黑提高31.33%（P〈0.05）;瘦肉率以大约克×烟黑最高为60.24%,比烟黑×烟黑提高22.09%（P〈0.01）;大理石纹评分以烟黑×烟黑最高,其次是杜洛克×烟黑,分别比大约克×烟黑、长白×烟黑提高10.67%（P〉0.05）、38.02%（P〈0.05）和9.15%（P〉0.05）、36.12%（P〈0.05）;pH1以大约克×烟黑最高为6.66,其次是烟黑×烟黑组合为6.29,分别比杜洛克×烟黑、长白×烟黑提高14.63%（P〈0.01）、17.25%（P〈0.01）和8.26%（P〈0.01）、10.74%（P〈0.01）;失水率以杜洛克×烟黑最低,比长白×烟黑降低51.49%（P〈0.05）。4个组合的背最长肌氨基酸总量、鲜味氨基酸含量和必需氨基酸含量都以烟黑×烟黑组合最高,分别比大约克×烟黑和长白×烟黑提高10.07%（P〈0.01）和6.17%（P〈0.05）、9.55%（P〈0.01）和6.17%（P〈0.05）、11.18%（P〈0.01）和6.79%（P〈0.05）。背最长肌棕榈酸含量以杜洛克×烟黑最高,比大约克×烟黑提高10.59%（P〈0.05）;硬脂酸也以杜洛克×烟黑最高,分别比大约克×烟黑、长白×烟黑和烟黑×烟黑提高18.62%（P〈0.01）、20.5%（P〈0.01）和20.20%（P〈0.01）;油酸以烟黑×烟黑最高,比杜洛克×烟黑提高11.96%（P〈0.05）。     

L-精氨酸对肥育猪生长性能、营养物质消化率、气体排放和肉质的影响

本研究旨在探讨饲粮中添加不同水平的L-精氨酸对育肥猪生长性能、营养物质消化率、有害气体排放和肉品质的影响。本试验选择240头平均初始体重为(53.80±1.85)kg的三元杂交猪(杜长大),根据体重随机分为3组,每组8个重复,每个重复10头猪。试验有3种饲料,对照组饲喂玉米-小麦-豆粕型饲料(精氨酸水平为0.94%),另外两组饲料分别在基础日粮中添加0.05%和0.1%L-精氨酸。结果显示,L-精氨酸对育肥猪生长性能、养分消化率和有害气体排放均无显著影响(P> 0.05)。而随着饲粮中L-精氨酸添加量的增加,肌肉大理石纹评分呈显著线性增加(P <0.05),蒸煮损失和肌肉滴水损失呈显著线性下降(P <0.05)。总的来说,目前研究结果表明,日粮添加1.0 g/kg L-精氨酸有利于提高肥育猪的肉品质。