在含粗小麦粉的生长育成期猪日粮中添加植酸酶的效果

试验采用 5 4头杂交猪 (初始体重为 2 8.4± 0 .98kg)来评估在含粗小麦粉的生长育成日粮中添加植酸酶的效果。试验猪被随机分成 2组 :对照组和试验组。试验组日粮除了以每千克 5 0 0单位的植酸酶取代相应的无机磷以外 ,其它成分与对照组日粮相同。试验期分 3个日粮阶段 ,采用 Cr2 O3 为外源指示剂来测定营养成分的消化率 ,每 2周测定 1次猪的体重和采食量并计算饲料效率。在第 2和第 3个日粮阶段分别为 7d的 2个采样期中 ,每天随机采取猪的粪样并按栏混合 ,然后对粪样的干重以及 Ca、P、Cu、Zn的含量分别进行测定。试验结果表明 ,试验组和对照组之间无论是平均日增重还是平均日采食量均没有显著差异。 5～ 8周间对照组的料肉比高于试验组 ( P<0 .0 5 ) ,但在其它各阶段均无显著差异。干物质消化率在第 2日粮阶段中无显著差别 ,但在第 3阶段中试验组高于对照组 ( P<0 .0 1 )。 Ca的消化率也同样是在第 2阶段中 2组相似 ,但在第 3阶段中试验组高于对照组 ( P<0 .0 1 )。磷 ( P)的消化率则无论在第 2阶段 ( P<0 .0 5 )还是第 3阶段 ( P<0 .0 1 ) ,均是试验组高于对照组。试验结果表明 ,在含粗小麦粉的生长育成猪日粮中添加植酸酶可以达到同直接添加无机磷一样的效果。添加植酸酶可以促进含粗小麦粉日粮中钙     

复合饲料添加剂(DL)对育成期蓝狐消化、代谢的影响

以复合酶制剂为主 ,添加益生素、微量元素等多种饲料添加剂 ,配制成DL复合饲料添加剂 ,将其分为 5种剂量 ( 0 1 %、0 2 %、0 3%、0 4%、0 5 % )添加到基础日粮中 ,分别饲喂 6组 ( 1组对照 )各 1 0只 5 0日龄蓝狐 ,饲喂 1 4d。结果表明 :0 3%DL添加剂显著提高粗蛋白(CP)的表观消化率、代谢率和净蛋白的利用率 (P <0 0 5 ) ,同对照组相比 ,CP的表观消化率提高 1 0 2 8% ,CP的表观代谢率提高 7 42 % ,净蛋白的利用率提高 1 6 92 % ;0 2 %DL添加剂显著提高粗脂肪 (EE)及粗纤维 (CF)的消化率 (P <0 0 5 )与对照组相比 ,EE的消化率提高9 98% ,CF的消化率提高 1 2 0 5 %。各组DL饲料添加剂均能提高蓝狐育成期的采食量 ,其中0 2 %DL添加剂组的采食量最大     

Effects of Feed Intake Restriction on Performance and Carcass Characteristics of Finishing Beef Steers,

Crossbred steers (n = 264, 311 ± 1.6 kg initial BW) were blocked by BW, randomly assigned to one of four treatments (28 pens, 7 pens per treatment), and fed a common 90% concentrate diet to determine the effects of the severity of caloric restriction on animal performance and carcass characteristics. Treatments were 1) ad libitum access to feed for 151 d (AL100); 2) 75% of DMI by AL100 for 65 d, 95% of DMI by AL100 for 65 d, and ad libitum access to feed for 21 d (AL85); 3) 80% of DMI by AL100 for 65 d, 100% of DMI by AL100 for 65 d, and ad libitum access to feed for 21 d (AL90); and 4) 85% of DMI by AL100 for 65 d, 105% of DMI by AL100 for 65 d, and ad libitum access to feed for 21 d (AL95). Feed was offered for AL85, AL90, and AL95 based on DMI by AL100 the previous week. All steers were fed a similar quantity of DM for 4 d prior to initial, interim, and final BW determinations to minimize gastrointestinal fill differences. Overall DMI was greater (P<0.01) for AL100 than for the average of the remaining treatments and decreased linearly (P<0.01) among AL95, AL90, and AL85. Overall ADG (carcass-adjusted) was less (P<0.01) for AL85, AL90, and AL95 than for AL100, whereas overall ADG:DMI (carcass-adjusted) did not differ (P>0.10) between AL100 and the average of the remaining treatments. Overall ADG and ADG:DMI (carcass-adjusted) responded quadratically (P<0.05) with increasing DMI restriction. Hot carcass weight, longissimus area, and kidney, pelvic, and heart fat percentage were greater (P<0.05) for AL100 than for the remaining treatments and responded quadratically (P<0.10) among AL85, AL90, and AL95. Marbling score was greater (P<0.10) for AL100 than for the average of the remaining treatments, and the number of carcasses grading Prime + Choice tended to be higher (P<0.15) for AL100 and AL95. Restricting feed intake of finishing yearling steers to an average of 85 to 95% of ad libitum for 130 d of a 151-d feeding period generally resulted in slower ADG, lesser marbling scores, and carcasses that were lighter and leaner compared with yearling steers allowed ad libitum to feed and harvested after an equal number of days on feed.     

Use of Real-Time Ultrasound in Pigs During the Early Finishing Phase to Predict Carcass Composition at Slaughter

The possibility of predicting kilograms of lean pork, the percentage of lean, and lean gain per day using measurements taken during the early finishing phase was studied using real-time ultrasound measurements on 164 barrows. Initial live weight (IWT), ultrasound backfat (IUBF), and ultrasound loin muscle area (IULA) were determined at 16 to 19 wk of age (70 kg). Final measures were obtained as the average pen weight reached 110 kg (22 to 24 wk of age). Initial kilograms of lean pork (IKOL) and the percentage of lean (ILEAN) were estimated with IWT and IUBF as the independent variables. Average daily gain, backfat accretion (BFACR), and lean gain per day (LGPD) were calculated from the initial and final measures. Pearson correlation coefficients were determined among the variables at the initial and final measures. The IULA and IKOL were correlated with the amount of lean tissue at slaughter (FKOL) (r=0.305 and 0.315, respectively; P<.001). Initial estimates of backfat (IUBF) and percentage lean (ILEAN) were correlated with FLEAN (r=−0.650 and −0.661, respectively; P<0.001). The IWT and IKOL were the only measurements taken in the early finishing phase related to LGPD r= −0.210 and −0.204, respectively; P<0.05). Prediction equations for FKOL, FLEAN, and LGPD were estimated from linear regression procedures. The IWT and IUBF were predictors of FKOL (R²=0.235; P<0.001). IUBF or ILEAN were predictive of FLEAN (R²=0.409 or 0.437, respectively; P<0.001). Measurements from the early finishing phase accounted for less than 10% of the variation in LGPD, ADG, or BFACR. This study suggests that carcass fat (FUBF or FLEAN) at slaughter can be predicted using real-time ultrasound in the early finishing phase with moderate confidence, accounting for 40 to 50% of the variation. Measures of lean tissue content or muscling (FKOL or FULA) can also be predicted, but with less confidence and accounting for less of the variation (20 to 30%).     

不同木聚糖水平饲粮中添加木聚糖酶对断奶仔猪生长性能及肠道微生态环境的影响

本试验旨在研究不同木聚糖水平饲粮中添加木聚糖酶对断奶仔猪生长性能、肠道微生物代谢产物和菌群数量的影响.选择30头体重相近,遗传背景相似的28日龄“杜×长×大”三元杂交断奶阉公猪,采用2×3因子试验设计,设2个饲粮木聚糖酶添加量(0和1 000 U/kg)和3个饲粮木聚糖水平(4.58％、6.23％和7.54％),将仔猪...     

低蛋白质平衡氨基酸饲粮对生长猪生长性能、胴体品质及肠道健康的影响

本文旨在研究低蛋白质平衡氨基酸饲粮对生长猪生长性能、胴体品质、肌肉品质和肠道健康的影响。试验采用单因素完全随机设计,选择初始体重为(17.02±1.40)kg的健康"杜×长×大"三元杂交去势公猪16头,随机分为正常蛋白质组(饲粮粗蛋白质水平为18%,标准回肠可消化赖氨酸含量为0.93%)和低蛋白质组(饲粮粗蛋白质水平为14%,标准回肠可消化赖氨酸含量为1.03%)2个组,每组8个重复,每个重复1头猪。试验期共39 d。在试验结束当天对生长猪进行称重、结料和采血,并屠宰所有生长猪用于测定胴体品质、肌肉品质、肠道形态及消化酶活性。结果表明:与正常蛋白质饲粮相比,低蛋白质平衡氨基酸饲粮显著提高了生长猪背最长肌的亮度值(P<0.01)和黄度值(P<0.05);对小肠各肠段的绒毛形态无显著影响(P>0.05),但有提高空肠绒毛高度和隐窝深度比值的趋势(P=0.09);对生长猪的生长性能、胴体品质和肌肉品质无显著影响(P>0.05)。本试验结果表明,与正常蛋白质饲粮相比,标准回肠可消化赖氨酸含量为1.03%的低蛋白质平衡氨基酸饲粮能够维持生长猪正常生长性能,并有改善肠道健康状况的趋势。     

甜菜碱对生长猪的生长性能和胴体组成的影响

选用 96头杜长大生长猪 ,随机分成 4组 ,以研究日粮中添加不同水平甜菜碱 (10 0 0、15 0 0、2 0 0 0 mg/kg)对猪生长性能、胴体组成及肉质的作用效果。试验结果表明 ,与对照组相比 ,日粮中添加 10 0 0 mg/kg和 15 0 0 mg/kg甜菜碱组猪日增重分别提高 13.2 0 % (P<0 .0 1)、9.2 8% (P<0 .0 5 ) ,日均采食量分别增加 7.30 % (P<0 .0 5 )、7.33% (P<0 .0 1) ,料重比分别下降 7.93% (P<0 .0 1)、6 .5 5 % (P<0 .0 5 )。此外 ,10 0 0 mg/kg甜菜碱组猪的胴体瘦肉率和眼肌面积比对照组分别提高 7.15 % (P<0 .0 5 )、19.12 % (P<0 .0 5 ) ,胴体脂肪率与背膘厚分别减少 2 7.2 1% (P<0 .0 5 )、14 .86 % (P<0 .0 5 ) ;背最长肌中的肌红蛋白和肌内脂肪分别提高 34.2 1% (P<0 .0 1)、2 9.5 6 % (P<0 .0 1)     

低蛋白质饲粮添加甘氨酸对肉仔鸡生长性能、胴体组成和血液生化指标的影响

本试验旨在研究在低粗蛋白质(CP)饲粮中添加甘氨酸(Gly)对肉仔鸡生长性能、胴体组成和血液生化指标的影响。选用180只1日龄健康爱拔益加(AA)肉仔鸡(公雏),随机分为3组,每组6个重复,每个重复10只。3组分别为:正对照(PC)组,前期和后期饲粮CP水平分别为22.0%和20.0%;负对照组,前期和后期饲粮CP水平分别为18.0%和15.5%;Gly组,在负对照组基础上添加Gly,使饲粮Gly和丝氨酸水平为2.32%。试验期42 d,分为前期(1~21 d)和后期(22~42 d)2个阶段。结果表明:1)饲粮CP水平降低4.0~4.5个百分点,试验1~21 d的料重比(F/G)显著升高(P0.05),22~42 d的平均日增重(ADG)显著降低(P0.05);添加Gly后,1~21 d F/G显著降低(P0.05),22~42 d ADG显著升高(P0.05),达到了与PC组相似的生长性能。2)CP水平降低,肉仔鸡42日龄胸肌率降低了9.5%(P0.05)、腹脂率提高了60.3%(P0.05);添加Gly后,胸肌率提高了17.6%(P0.05),腹脂率降低了34.6%(P0.05),获得了与PC组相似的胴体组成。CP水平降低、添加Gly均未显著影响屠宰率、全净膛率和腿肌率(P0.05)。3)各组间血液生化指标均无显著差异(P0.05)。可见,低CP饲粮中添加Gly可以改善生长性能和胴体组成,结果提示了Gly在肉仔鸡低CP饲粮中的可应用性。     

Effects of Proportions of Steam-Flaked Corn and Grain Sorghum and Switching Grain Sources During the Finishing Period on Performance and Carcass Characteristics of Finishing Beef Steers

Three studies were conducted to determine effects of proportions of steam-flaked corn (SFC) and steam-flaked grain sorghum (SFGS) in the finishing diet (Exp. 1), effects of switching grain sources on d 56 of the finishing period on performance and carcass characteristics of finishing beef steers (Exp. 2), and effects of these two dietary ingredients on in vitro DM disappearance (IVDMD) (Exp. 3). For Exp. 1, 180 medium-framed beef steers (British × Continental) were used. Treatments included (DM basis) 100% SFC:0% SFGS, 75% SFC:25% SFGS, 50% SFC:50% SFGS, 25% SFC:75% SFGS, and 0% SFC:100% SFGS. Increasing the proportion of SFGS in the finishing diet increased (P<0.01) feed:gain for the overall experiment and resulted in a linear decrease (P<0.01) in calculated NE, NE, and ME values of the diet. No differences (P>0.10) were noted among treatments for carcass characteristics. In Exp. 2, 144 medium-framed beef steers (British × Continental) were used. Treatments were SFC fed from d 0 to end (Treatment 1), SFC fed from d 0 to 56 and SFGS fed from d 57 to end (Treatment 2), SFGS fed from d 0 to 56 and SFC fed from d 57 to end (Treatment 3), and SFGS fed from d 0 to end (Treatment 4). Experiments 1 and 2 were conducted concurrently, and steers on Treatments 1 and 4 were the same steers used in Exp. 1 and fed 100:0 and 0:100, respectively. Average daily gain was decreased (P<0.10), and feed:gain was increased (P<0.05) for the average of Treatments 2 and 3 vs Treatment 1 for the overall experiment. In vitro DM disapperance of diets used in Exp. 1 was similar (P>0.10) among treatments after 4, 12, 24, and 48 h of incubation. Results suggest no benefit from mixing SFC and SFGS in finishing diets, and switching grain sources during the finishing period may adversely affect performance.     

Effects of Delaying Implant and Programmed Rate of Gain on Performance and Carcass Characteristics of Yearling Beef Steers

Ninety-six steers (average BW = 335 ± 36 kg) were allotted in a completely randomized design with a 2 × 2 factorial arrangement of treatments. Factors were 1) implant on d 1 or no implant and 2) ad libitum access to feed on d 1 or programmed-fed for a target BW gain of 1.4 kg/d during the first 62 d of the feeding period. On d 63, all steers were implanted with Revalor-S® (Hoechst Roussel Vet, Overland Park, KS) and provided ad libitum access to feed until harvest. From d 63 to 116, ADG and gain efficiency (g gain/kg DMI) for steers programmed-fed to gain slowly were greater (P<0.05) than those for steers fed to gain rapidly during the first 62 d of the trial. Restricting feed intake to limit ADG during the first 62 d of the finishing period increased ADG during the remaining portion of the finishing period. Gain efficiency was increased (P=0.097) throughout the entire finishing period by limiting ADG during the first 62 d of the experiment. Steers implanted twice and fed to gain rapidly had the least fat in the 9th to 11th rib section; steers with a delayed implant and programmed-fed to gain slowly had the most fat in this same section. In this experiment, no significant interactions occurred except for fat weight in the 9th to 11th rib sections, although steers implanted on d 1 and fed to gain rapidly tended to have fewer days on feed.     

Influence of Betaine on Pasture,Finishing, and Carcass Performance in Steers

Two experiments were conducted to investigate the effects of supplemental betaine on steer performance, fat deposition, and carcass characteristics. In Exp. 1 (grazing phase), 80 steers (317 kg) were fed either 1.0 kg of a control supplement (30% CP) or 1.0 kg of the control supplement plus 20 g of betaine per head per day. Betaine supplementation had no effect on overall gain or fat deposition (P>0.10) but increased ADG (P<0.10) during d 46 to 90 (0.64 vs 0.72 kg; control vs betaine, respectively). The pasture groups remained intact and were moved to the feedlot for 141 d and fed a control diet or the control diet plus 20 g of betaine per head per day. Betaine had no overall effect on finishing gain (P>0.10); however, this response was variable by period. Betaine increased final fat thickness and fat thickness change (P<0.10), but did not affect marbling or longissimus area (P>0.10). Supplemental betaine on pasture increased feed intake, final BW, and hot carcass weight (P<0.05) and increased final fat thickness and fat thickness change (P<0.10) during the finishing phase. In Exp. 2, supplemental betaine (40 g/d) was fed to steers (averaging 584 kg) in 11 replications during the last week before harvest. The overall weighted average increase in dressing percentage when betaine was fed was +0.34% (P<0.05). There was no effect (P>0.10) on fat thickness or marbling. Season of year did not affect response.     

饲粮维生素A水平对肉牛屠宰性能及肉品品质的影响

牛肉具有高蛋白质、低脂肪的优点，是西方发达国家主要的消费肉类。在我国，随着人们生活水平的提高，牛肉消费量在快速增长。同时，消费者对牛肉品质也提出了更高的要求，“优质牛肉”、“高档牛肉”已成为消费时尚，促使人们不断寻求改善牛肉品质的方法。脂溶性维生素是一类动物所必需的营养素，主要包括维生素A、维生素D、维生素E和维生素K。其中，维生素A、维生素D、维生素E都能在不同程度上影响牛肉品质。目前，研究较多的是维生素D、维生素E对牛肉品质的影响，而关于维生素A影响牛肉品质的报道很少。试验通过饲喂不同维生素A水平的饲料，探讨其对肉牛屠宰性能及肉品品质的影响，为维生素A在肉牛生产中的应用提供理论依据。     

富乐旺对早期断奶仔猪生长性能和腹泻的影响

150头仔猪被随机分为5组,每组30头,进行饲养试验,探讨富乐旺对断奶仔猪生产性能和腹泻的影响。试验结果表明：与对照组相比,试验组平均日增重升高其中10mg／kg、15mg／kg和20mg／kg富乐旺添加组差异显著（P〈0．05）;平均日采食量升高;饲料系数和腹泻率、腹泻频率及死亡率降低。     

全棉籽对阉牛育肥性能、胴体性状及肉质的影响

本试验旨在探讨日粮中全棉籽替代棉籽饼和棉油对肥育阉牛肉用性能的影响.试验选取40头体况良好、平均初始体质量为(454.37±42.42)kg的利木赞杂交阉牛,随机分为4组,每组10头牛,分别饲喂4种不同全棉籽含量的精饲料(对照组0％,低全棉籽组7.1％,中全棉籽组13.5％,高全棉籽组22.0％),育肥期90 d.结果表明,日粮中全棉籽含量对肉牛干物质采食量、肉骨比、优质肉块百分比、pH、肌肉、肾脏、肺脏中棉酚残留量及血清生化指标无显著影响(P＞0.05);对肉牛日增体质量、胴体质量、屠宰率、净肉率、眼肌面积、背膘厚、饲料报酬、饲料成本、肝脏和心脏中棉酚残留量、剪切力、肉色等常规成分有显著影响(P＜0.05);日粮全棉籽含量为22.0％时,胴体质量、屠宰率、净肉率、肉骨比、眼肌面积、优质肉块质量、肌间脂肪在4个试验组中最低.结果表明,育肥阉牛日粮中用全棉籽替代棉籽饼和棉籽油会提高肉牛的生长速度,但会降低屠宰性能和胴体品质.     

Effects of Dietary Acetate and Propionate on Nutrient Digestibility,Ruminal Characteristics,and Performance by Steers Fed Diets Containing All-Concentrate or 20% Roughage

Four experiments were conducted to evaluate the effects of dietary volatile fatty acids (VFA) on nutrient digestibility, ruminal characteristics, and growth performance by finishing steers. Diets were based on sorghum grain in Exp. 1 and 2, and corn in Exp. 3 and 4. Experiment 1 was a digestibility study with eight steers used in two 4 x 4 latin square arrangements of steers and diets. Diets in the first square were all-concentrate (C) with 1 or 2% acetate (A) or 2% propionate (P), and diets in the second square were 20% rice straw (RS) with 1 or 2% A or 2% P. In Exp. 2, steers (four per treatment) were individually fed C or RS basal diets with 1.72% A or 5.00% P added to the C diet, and 1.14% A or 3.33% P added to the RS diet based on expected intake. In Exp. 3 and 4, C diets were diluted with 1.65 or 0.55% A, respectively. These diets were further diluted with 20% rice hulls (RH) in Exp. 3, and 20% RH and 20% RS in Exp. 4. The C diet was also diluted with 20% RS in Exp. 3 and considered a positive control. Adding A, P, or RS to C diet based on sorghum grain had no effect (P>0.10) on energy digestibility or N retention. In Exp. 2, P reduced (P<0.05) DMI and ADG, compared with A. Acetate improved (P<0.05) DMI of C and RH diet in Exp. 3, but only the RH diet in Exp. 4. Likewise ADG and, in most cases, carcass weights were improved (P<0.05) by A in C and RH diets, but not in RS diets. Dietary P reduced (P<0.05) ruminal acetate levels and increased (P<0.05) ruminal propionate in Exp. 2. Acetate may have potential to improve DMI and ADG of steers consuming diets containing all-concentrate or poorly digestible roughage.     

富乐旺对早期断奶仔猪生长性能和腹泻的影响

150头仔猪被随机分为5组,每组30头,进行饲养试验,探讨富乐旺对断奶仔猪生产性能和腹泻的影响。试验结果表明:与对照组相比,试验组平均日增重升高其中10mg/kg、15mg/kg和20mg/kg富乐旺添加组差异显著(P<0.05);平均日采食量升高;饲料系数和腹泻率、腹泻频率及死亡率降低。     

氨化麦秸对肉牛育肥及胴体渗出液的影响

秦杂一代公牛36头分3组进行90 d强度育肥,1、2组饲喂氨化麦秸与精料,3组饲喂未氨化麦秸与精料。结果表明:试验1、2组日增重840 g±90 g和820 g±76 g。对照组日增重520 g±120 g。试验组比对照组日增重提高310 g(P<0．01),屠宰率、净肉率分别提高8．305和4．945个百分点。试验组胴体渗出液平均每头507．75 mL,对照组无体液渗出。试验组每千克增重纯收入4．32元,比对照组(2．14元)高2．18元,效益显著。     

Comparison of Swine Diets Containing a Food Waste Product Made with Wheat Middlings and Corn or a Corn/Soybean Diet,

Although pigs will readily consume wet food waste (FW), the high moisture content contributes to spoilage and feeding management problems. The use of a dry, processed FW product was compared with a traditional corn and soybean (CS) diet using growing swine in two performance trials and one digestibility trial. The FW diet contained approximately 20% processed FW (DM basis). In Trial 1, 24 gilts (76.4 kg) housed in eight replicated pens (four pens per treatment) were fed in a 6-wk trial. Intake, BW gain, feed efficiency, and carcass characteristics were compared. Feed intake and BW gain averaged 3.4 and 3.6 kg of DM/d and 0.87 and 0.85 kg/d for gilts fed traditional and FW diets, respectively. There were no differences in these or any other measurements (P>0.05). In Trial 2, 12 barrows (84.3 kg) housed in four replicated pens (two pens per treatment) were fed in a 6-wk trial. Intake, BW gain, feed efficiency, and carcass characteristics were compared. Feed intake and BW gain averaged 3.1 and 3.3 kg of DM/d and 0.62 and 0.71 kg/d for barrows fed traditional and FW diets, respectively. Four growing gilts (68.2 kg) were used to compare digestibility in a crossover design. There were no differences (P>0.10) for DM, CP, ADF, or NDF digestibility when feed intake averaged 1.9 kg of DM/d for both FW and CS diets. The use of up to 20% processed FW may be suitable in commercial swine diets.     

饲粮可代谢生脂物质对生长猪生长性能和胴体品质的影响

本试验旨在探究可代谢生脂物质（MLS）对生长猪生长性能、胴体品质和肉质性状的影响。挑选体型相似、体重为28.15 kg±4.51 kg的18头健康杜×长×大三元杂交猪,随机分为3组,分别饲喂营养水平相同但MLS水平不同的饲粮,MLS水平分别为70.51（Ⅰ组）、68.09（Ⅱ组）和40.58 g/d（Ⅲ组）,试验期28 d,测定生长猪生长性能、胴体品质和肉品质相关指标。结果表明：不同MLS水平对猪平均日采食量、平均日增重和料重比影响均不显著（P>0.05）;3组中Ⅱ组的料重比最低。3组间生长猪屠宰率、背膘厚和眼肌面积等胴体指标均无显著差异（P>0.05）。3组中,Ⅲ组的熟肉率显著低于Ⅰ和Ⅱ组（P<0.05）,而其他肉品质指标如亮度值、大理石评分、滴水损失等均无显著差异（P>0.05）;屠宰后45 min及24 h肌肉pH变化差异很小（P>0.05）。综上所述,在本试验条件下,饲喂3种不同MLS水平饲粮,生长猪生长性能、胴体品质和肉质性状大部分指标差异均不显著,但对于优化配方以及今后的生产具有指导意义。     

饲粮可代谢生脂物质对生长猪生长性能和胴体品质的影响

本试验旨在探究可代谢生脂物质(MLS)对生长猪生长性能、胴体品质和肉质性状的影响。挑选体型相似、体重为28.15 kg±4.51 kg的18头健康杜×长×大三元杂交猪,随机分为3组,分别饲喂营养水平相同但MLS水平不同的饲粮,MLS水平分别为70.51(Ⅰ组)、68.09(Ⅱ组)和40.58 g/d(Ⅲ组),试验期28 d,测定生长猪生长性能、胴体品质和肉品质相关指标。结果表明:不同MLS水平对猪平均日采食量、平均日增重和料重比影响均不显著(P>0.05);3组中Ⅱ组的料重比最低。3组间生长猪屠宰率、背膘厚和眼肌面积等胴体指标均无显著差异(P>0.05)。3组中,Ⅲ组的熟肉率显著低于Ⅰ和Ⅱ组(P<0.05),而其他肉品质指标如亮度值、大理石评分、滴水损失等均无显著差异(P>0.05);屠宰后45 min及24 h肌肉pH变化差异很小(P>0.05)。综上所述,在本试验条件下,饲喂3种不同MLS水平饲粮,生长猪生长性能、胴体品质和肉质性状大部分指标差异均不显著,但对于优化配方以及今后的生产具有指导意义。