五味子、柠檬酸对生长肥育猪抗氧化功能和肉品质的影响

试验选择平均体重(20.8±0.9)kg的二元杂交(大白×长白)猪96头。随机分为4组,每组4个重复,公、母各半。对照组饲喂基础日粮,试验组日粮分别添加1%柠檬酸(CA组)、0.5%五味子(SC组)和1%CA+0.5%SC(CA+SC组),研究五味子、柠檬酸对生长肥育猪抗氧化功能和肉品质的影响。结果表明:日粮中添加0.5%SC、1%CA或1%CA+0.5%SC可显著降低背最长肌、血清、组织中丙二醛(MDA)含量(P0.05);添加0.5%SC或1%CA+0.5%SC可显著提高血清与组织中超氧化物歧化酶(SOD)和谷胱甘肽还原酶(GR)活性(P0.05);添加0.5%SC可显著降低背最长肌滴水损失(P0.05)。从试验结果可以看出,日粮中添加五味子与柠檬酸可提高血清与组织的抗氧化能力,改善部分肉品品质。     

饲粮异亮氨酸水平对肥育猪生长性能、胴体性状和肉品质的影响

本试验旨在研究饲粮异亮氨酸水平对肥育猪生长性能、胴体性状和肉品质的影响。选取体重为(77.0±0.1)kg的杜×长×大三元杂交去势公猪72头,随机分为3组,每组6个重复,每个重复4头猪。3组试验猪分别饲喂含0.25%(低异亮氨酸水平,表现为异亮氨酸缺乏,L-Ile组)、0.39%(NRC推荐异亮氨酸水平,N-Ile组,作为对照组)和0.53%(高异亮氨酸水平,表现为异亮氨酸超量添加,H-Ile组)标准回肠可消化异亮氨酸的饲粮。试验期为28 d。结果表明:饲粮异亮氨酸水平对肥育猪的平均日增重和平均日采食量没有显著影响(P0.05),但L-Ile组料重比较对照组显著增加(P0.05);随着饲粮异亮氨酸水平的增加,肥育猪背最长肌肌内脂肪含量线性提高(P0.05),而剪切力线性下降(P0.05);与对照组相比,采食异亮氨酸缺乏饲粮的肥育猪的背膘厚、眼肌面积和肉色评分显著降低(P0.05),采食异亮氨酸缺乏或超量添加饲粮的肥育猪的热胴体重、屠宰率以及背最长肌滴水损失和黄度值均显著降低(P0.05);随着饲粮异亮氨酸水平的增加,血清甘油三酯含量线性提高(P0.05),血清尿素氮含量线性下降(P0.05);与对照组相比,采食异亮氨酸超量添加饲粮的肥育猪的血清葡萄糖含量显著增加(P0.05),采食异亮氨酸缺乏饲粮的肥育猪的血清中游离的必需氨基酸、非必需氨基酸和总氨基酸的浓度显著降低(P0.05),而采食异亮氨酸缺乏或超量添加饲粮的肥育猪血清总胆固醇、低密度脂蛋白和高密度脂蛋白含量均显著降低(P0.05)。由此得出,饲粮中异亮氨酸缺乏对肥育猪生长性能、胴体性状和肌内脂肪含量有负面影响,而超量添加异亮氨酸会显著改善肌肉的剪切力和滴水损失,增加肌内脂肪含量,但会以降低热胴体重、屠宰率为代价。     

Influence of dietary vitamin E supplementation on "heavy" pig carcass characteristics, meat quality, and vitamin E status.

Crossbred "heavy" pigs (average weight 120 kg, slaughter weight above 160 kg) were supplemented with all-rac-alpha-tocopheryl acetate during the last 60 d of late finishing at doses of 25 (control), 50, 100, 200, or 300 mg/kg of diet. At the end of this period, the pigs were slaughtered. Carcass characteristics and the meat quality of pork chops from longissimus muscle (LM) at the last lumbar vertebra were evaluated on eight barrows from each dosage group. Alpha-tocopherol levels were determined in plasma during supplementation and in LM muscle after slaughter. Thiobarbituric acid reactive substances (TBARS) and drip loss were also evaluated in meat. Plasma alpha-tocopherol levels increased (P < .005) during supplementation in treated animals compared to controls, with a peak at 40 d. Alpha-tocopherol levels were higher (P < .05) in LM from pigs treated with 300 mg/kg than in controls (8.4 vs 5.6 microg/g). Dressing percentages correlated (P < .05) with the ratio of plasma alpha-tocopherol levels to the sum of cholesterol and triglycerides. Inhibition of TBARS during storage was related (P < .005) to vitamin E supplementation level, but drip losses in chops were not related to supplementation levels. We concluded that dietary vitamin E supplementation to heavy pigs during the last 60 d of finishing improves dressing percentage, reduces lipid oxidation, and increases the alpha-tocopherol concentration of tissues.     

饲粮添加苹果果胶寡糖对育肥后期猪胴体性状、肉品质和结肠主要菌群的影响

本研究旨在探讨饲料添加苹果果胶寡糖(APOS)对育肥后期猪胴体性状、肉品质和结肠主要菌群的影响。试验选取36头平均体重约为80 kg健康"杜×长×大"去势公猪,按照体重相近的原则随机分为3个处理,每个处理6个重复,每个重复2头猪。各处理分别饲喂在基础饲粮中添加0、200和400 mg/kg APOS的饲粮,试验期为28 d。结果表明,饲粮添加APOS未显著影响育肥猪生长性能(P0.05);饲粮添加APOS不同程度地提高了育肥猪的眼肌面积(P0.05)和肌内脂肪含量(P=0.07),不同程度地降低了育肥猪的肌肉滴水损失(P=0.06)和蒸煮损失(P0.05);另外,饲粮添加APOS还提高了育肥猪结肠食糜中总菌的数量(P=0.07),且显著提高了结肠食糜中挥发性脂肪酸的含量(P0.05)。综上所述,在饲粮中添加200或400 mg/kg APOS对育肥猪生长性能无影响,但可在不同程度上改善育肥猪胴体性状和肉品质,并调节了结肠主要菌群和挥发性脂肪酸产生。     

饲喂乳酸菌制剂对肥育猪生长性能、肉品质及风味物质含量的影响

试验旨在研究饲粮中添加乳酸菌制剂对肥育猪生长性能、肉品质及风味物质含量的影响。选取平均体重为(55±2)kg的杜×长×大三元杂猪240头,随机分为3个处理组,每组4个重复,每个重复20头试猪,公、母各半。对照组饲喂基础饲粮(玉米-豆粕型),2个试验组饲粮分别在基础饲粮中添加0.3%乳酸菌干粉和0.3%乳酸菌菌液,这2种制剂中乳酸菌含量均为1.2×10~9 CFU/g。试验期57 d,在饲养试验结束时,每个重复选择2头(1公1母)接近平均体重的试猪进行屠宰,测定胴体性状、肉品质和风味物质含量。结果表明:饲粮中添加乳酸菌干粉和乳酸菌菌液均对肥育猪的平均日增重、平均日采食量及耗料增重比无显著影响(P0.05),对肥育猪胴体直长、斜长、背膘厚、皮厚及眼肌面积也无显著影响(P0.05),对肌肉的肉色、大理石纹、pH、滴水损失率及剪切力无显著改善(P0.05);与对照组相比,饲粮中添加乳酸菌菌液显著降低背最长肌中次黄嘌呤含量(P0.05),但2个试验组肌苷酸、谷氨酸和肌内脂肪均无显著差异(P0.05)。综上所述,饲喂乳酸菌制剂对肥育猪生长性能、胴体性状和肉质无显著影响,但可降低肌肉中次黄嘌呤含量,有利于改善猪肉的风味。     

Effects of dietary magnesium and short-duration transportation on stress response, postmortem muscle metabolism, and meat quality of finishing swine

Crossbred pigs, heterozygous for the halothane gene, were used to determine the effects of long-term dietary supplementation of magnesium mica (MM) and short-duration transportation stress on performance, stress response, postmortem metabolism, and pork quality. Pigs were blocked by weight, penned in groups (six pigs per pen), and pens (three pens per diet) were assigned randomly either to a control corn-soybean meal diet or the control diet supplemented with 2.5% MM (as-fed basis; supplemented at the expense of corn). Diets were fed during the early-finisher (0.95% lysine, as-fed basis; 43.7 to 68 kg) and late-finisher (0.85% lysine, as-fed basis; 68 to 103 kg) periods. At the conclusion of the 71-d feeding trial, 12 pigs from each dietary treatment were selected randomly and subjected either to no stress (NS) or 3 h of transportation stress (TS). Dietary MM had no effect (P > or = 0.40) on ADG or ADFI; however, G:F was improved (P < 0.05) during the early-finisher period when pigs were fed MM-supplemented diets. Plasma glucose concentrations were increased in TS pigs fed the control diet, but transportation did not affect plasma glucose in pigs fed 2.5% MM (diet x transportation stress; P = 0.02). Dietary MM did not affect blood lactate, cortisol, insulin, NEFA, Ca, or Mg concentrations in response to TS (diet x transportation stress; P > or = 0.13); however, circulating lactate, cortisol, and glucose concentrations increased in TS pigs (transportation stress x time; P < 0.01). The LM from TS pigs fed MM had higher initial (0-min) and 45-min pH values than the LM from NS pigs fed the control diet (diet x transportation stress x time; P = 0.07). Lactic acid concentration and glycolytic potential were greater in the LM of TS pigs fed MM than TS pigs fed control diets (diet x transportation stress; P < or = 0.01). Although some trends were identified, neither MM (P > or = 0.15) nor TS (P > or = 0.11) altered the color or water-holding capacity of the LM and semimembranosus. The transportation model elicited the expected changes in endocrine and blood metabolites, but dietary MM did not alter the stress response in pigs. Conversely, although pork quality traits were not improved by dietary MM, delaying postmortem glycolysis and elevating 0- and 45-min muscle pH by feeding finishing diets fortified with MM may benefit the pork industry by decreasing the incidence of PSE pork in pigs subjected to short-duration, routine stressors.     

德氏乳杆菌对育肥猪血脂指标、胆固醇代谢和脂肪沉积相关酶活性及基因mRNA表达的影响

本试验旨在研究饲粮中添加德氏乳杆菌制剂对育肥猪血脂指标、肝脏胆固醇代谢和脂肪沉积相关酶活性、组织胆固醇代谢和脂肪沉积相关基因mRNA表达和皮下脂肪组织形态的影响。试验选用120头平均体重为(65.34±3.64)kg的健康"杜×(长×大)"育肥猪,随机分为2组,每组6个重复(栏),每个重复10头(公母各占1/2)。对照组饲喂基础饲粮,试验组饲喂在基础饲粮中添加0.10%德氏乳杆菌制剂的饲粮,预试期7d,试验期42d。结果显示:1)与对照组相比,试验组育肥猪的血清甘油三酯(TG)(P=0.08)和总胆固醇(TC)(P=0.06)含量均有降低趋势,血清总胆汁酸(TBA)含量显著降低(P0.05)。2)与对照组相比,试验组育肥猪的肝脏羟甲基戊二酰辅酶A还原酶(HMGR)活性有降低趋势(P=0.07),胆固醇7α-羟化酶活性(CYP7A1)显著增加(P0.05),脂肪甘油三酯脂酶(ATGL)活性极显著降低(P0.01)。3)与对照组相比,试验组育肥猪的回肠胆汁酸结合蛋白(IBABP)的mRNA相对表达量有降低趋势(P=0.07),皮下脂肪过氧化物酶体增殖物激活受体γ(PPARγ)的mRNA相对表达量显著增加(P0.05);皮下脂肪细胞直径有降低趋势(P=0.09)。结果提示,德氏乳杆菌可通过干扰育肥猪回肠对胆汁酸的吸收来调控肝脏胆固醇和脂肪代谢。     

亚麻籽对生长育肥猪抗氧化性能及肉品质的影响

文章旨在评估日粮添加不同水平的亚麻籽对生长育肥猪生长指标、血清和肌肉抗氧化指标及肉品质的影响.试验将576头体重接近的16周龄生长猪分为3组,每组8个重复,每个重复24头.试验育肥猪在26周龄出栏,整个试验期间3组分别饲喂亚麻籽添加水平为0、1％和2％的配合饲料.结果:1％和2％亚麻籽组育肥猪生长前期(16～20周)的...     

Effects of choice white grease or poultry fat on growth performance, carcass leanness, and meat quality characteristics of growing-finishing pigs.

Eighty-four crossbred gilts were used to evaluate the effects of dietary choice white grease (CWG) or poultry fat (PF) on growth performance, carcass characteristics, and quality characteristics of longissimus muscle (LM), belly, and bacon of growing-finishing pigs. Pigs (initially 60 kg) were fed a control diet with no added fat or diets containing 2, 4, or 6% CWG or PF. Diets were fed from 60 to 110 kg and contained 2.26 g lysine/Mcal ME. Data were analyzed as a 2 x 3 factorial plus a control with main effects of fat source (CWG and PF) and fat level (2, 4, and 6%). Pigs fed the control diet, 2% fat, and 4% fat had greater (P < 0.05) ADFI than pigs fed 6% fat. Pigs fed 6% fat had greater (P < 0.05) gain/feed (G/F) than pigs fed the control diet or other fat levels. Subcutaneous fat over the longissimus muscle from pigs fed CWG had more (P < 0.05) moisture than that from pigs fed PF. Feeding dietary fat (regardless of source or level) reduced (P < 0.05) the amount of saturated fats present in the LM. Similarly, 4 or 6% fat decreased (P < 0.05) the amount of saturated fats and increased unsaturated fats present in the bacon. No differences (P > 0.05) were observed for ADG, dressing percentage, leaf fat weight, LM pH, backfat depth, LM area, percentage lean, LM visual evaluation, LM waterholding capacity, Warner-Bratzler shear and sensory evaluation of the LM and bacon, fat color and firmness measurements, or bacon processing characteristics. Adding dietary fat improved G/F and altered the fatty acid profiles of the LM and bacon, but differences in growth rate, carcass characteristics, and quality and sensory characteristics of the LM and bacon were minimal. Dietary additions of up to 6% CWG or PF can be made with little effect on quality of pork LM, belly, or bacon.     

Effects of on-farm diets for organic pig production on performance and carcass quality

An experiment was conducted to evaluate the effects of a restriction to home-grown feedstuffs and abstinence from supplementation with synthetic amino acids (AA), as ideal objectives in organic pig production according to the IFOAM standards, on growth performance and carcass characteristics. One hundred individually housed pigs were allocated to four dietary treatments and fed from growing through finishing to compare three organic barley/wheat-based diets with an isocaloric conventional diet supplemented with synthetic AA. Protein sources in the organic treatments were either faba beans, supplemented with potato protein to the same AA level as the control diet, peas and lupines, or faba beans and lupines, both without further supplementation, leading to a lower level of limited AA. Supplementation of organic diets with potato protein resulted in the same performance as supplementing the conventional diet with synthetic AA, although crude protein levels differed markedly. Pigs fed the organic diets without AA supplementation grew more slowly (P < .05) and had a decreased feed intake in the grower period (P < .05) but nearly the same feed efficiency (P > .05) as pigs fed conventional or organic diets with AA supplementation. Carcass characteristics differed in percentage of lean meat and longissimus area, being lower in the treatments without AA supplementation (P < .05). However, the intramuscular fat was higher without AA supplementation (2.9% fat) than with supplementation (1.2% fat) (P < .01). The data show that the exclusion of AA supplementation resulted in a reduction in pig performance but in an increase in intramuscular fat content; the latter is an important aspect of eating quality characteristics.     

饲粮添加亮氨酸和谷氨酸对肥育猪生长性能、胴体性状和肉品质的影响

本试验旨在探讨饲粮添加亮氨酸和谷氨酸对肥育猪生长性能、胴体性状和肉品质的影响。试验选取体重为77 kg左右的"杜×长×大"肥育猪60头,随机分为5个组,每组12头猪,公母各占1/2。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加2.05%L-丙氨酸(等氮对照组)、1.00%亮氨酸+1.37%L-丙氨酸(亮氨酸组)、1.00%谷氨酸+1.44%L-丙氨酸(谷氨酸组)、1.00%亮氨酸+1.00%谷氨酸(亮氨酸+谷氨酸组)。试验期为60 d。结果表明:与对照组相比,谷氨酸组1~30 d的平均日采食量、末重和背膘厚均显著降低(P0.05),31~60 d的平均日增重降低了22.50%(P0.05);亮氨酸组、亮氨酸+谷氨酸组背最长肌和股二头肌中的肌内脂肪含量显著增加(P0.05),且亮氨酸+谷氨酸组1~30 d的平均日增重增加了8.04%(P0.05),31~60 d的平均日增重则降低23.70%(P0.05)。与等氮对照组相比,亮氨酸组和谷氨酸组的熟肉率、滴水损失和肉色均无显著差异(P0.05),亮氨酸+谷氨酸组肌肉黄度值显著降低(P0.05);各试验组背最长肌和股二头肌中风味氨基酸含量均无显著差异(P0.05)。上述结果提示,饲粮添加1.00%亮氨酸可降低1~30 d肥育猪的料重比,增加背最长肌肌内脂肪含量;饲粮添加1.00%谷氨酸或1.00%亮氨酸+1.00%谷氨酸可增加1~30 d的平均日增重,降低31~60 d的平均日增重;饲粮添加1.00%亮氨酸+1.00%谷氨酸可降低肉色黄度值,增加肌内脂肪含量,从而改善猪肉品质。     

Effects of adding poultry fat in the finishing diet of steers on performance, carcass characteristics, sensory traits, and fatty acid profiles

Use of poultry fat in the finishing diets of steers has not been studied as a potential source of added energy. Therefore, 60 Angus crossbred steers were fed 1 of 3 dietary treatments consisting of 1) a corn-soybean meal control diet devoid of added fat; 2) the control diet formulated with 4% tallow; or 3) the control diet formulated with 4% poultry fat. Addition of fat did not (P = 0.17) affect ADG for the 112-d study. The inclusion of tallow in the diet reduced (P < 0.05) ADFI of steers compared with those on the control diet; however, ADFI of steers fed poultry fat did not differ from those fed the control (P = 0.06) or the tallow (P = 0.36) diets. At d 55, steers consuming either fat source had improved (P < 0.05) G:F compared with steers fed the control diet. For the entire 112 d, steers consuming the poultry fat diet gained more efficiently (P < 0.05) than the control steers, and the tallow-fed steers were intermediate and not different from the other groups (P > or = 0.14). The inclusion of fat in the diet did not (P > or = 0.15) affect carcass characteristics. Steaks from the steers consuming diets with added fat were darker (lower L* value; P < 0.05) than the controls; however, dietary treatments did not (P > or = 0.10) affect any other objective color measurements or discoloration scores during retail display. Thiobarbituric acid reactive substances for LM steaks did not differ (P = 0.21) by dietary treatment. The cooked LM steaks from steers fed poultry fat did not (P > or = 0.80) differ in juiciness or flavor intensity from steaks of steers fed the control or tallow diets. There were also no differences (P = 0.18) in off flavors as a result of added dietary fat. In the LM and adipose tissue, percentages of total SFA were increased (P = 0.05) by adding supplemental fat to the diet, regardless of source. In the LM, total MUFA were decreased (P = 0.02) by adding supplemental fat. Conversely, diet did not (P > or = 0.14) affect the proportions of total PUFA in either tissue or total MUFA in the adipose tissue. Results indicated that replacing beef tallow in finishing diets with poultry fat, a more economical energy source, had no detrimental effects on growth performance, carcass characteristics, retail display life, fatty acid profiles, or palatability.     

Effects of dietary supplementation with L-carnitine and fat on blood acid-base responses to handling in slaughter weight pigs

Blood acid-base responses to handling were evaluated in slaughter weight pigs fed diets supplemented with l-carnitine and fat. The study was carried out as a randomized block design with a 2 x 2 factorial arrangement of treatments: 1) dietary L-carnitine supplementation (0 vs. 150 ppm, as-fed basis); and 2) dietary fat supplementation (0 vs. 5%, as-fed basis). Sixty pigs (91.1 +/- 5.14 kg BW) were housed in mixed-gender groups of five and had ad libitum access to test diets (0.68% true ileal digestible lysine, 3,340 kcal of ME/kg, as-fed basis) for 3 wk. At the end of the feeding period (110.3 +/- 7.52 kg BW), pigs were subjected to a standard handling procedure, which consisted of moving individual animals through a facility (12.2 m long x 0.91 m wide) for eight laps (up and down the facility), using electric prods (two times per lap). There was no interaction between dietary L-carnitine and fat supplementation for any measurement. Pigs fed 150 ppm of supplemental L-carnitine had lower baseline blood glucose (P < 0.05) and higher baseline blood lactate (P < 0.05) concentrations than the nonsupplemented pigs. After handling, pigs fed L-carnitine-supplemented diets had a higher (P < 0.05) blood pH and showed a smaller (P < 0.05) decrease in blood pH and base excess than those fed the nonsupplemental diets. Baseline plasma FFA concentrations were higher (P < 0.01) in pigs fed the 5% fat diet. After the handling procedure, blood glucose, lactate, and plasma FFA were higher (P < 0.05) in pigs fed the 5 vs. 0% fat diets, but blood pH, bicarbonate, and base excess were not affected by dietary fat. The handling procedure decreased (P < 0.01) blood pH, bicarbonate, base excess, and total carbon dioxide and increased (P < 0.01) blood lactate, partial pressure of oxygen, and glucose, and also increased (P < 0.01) rectal temperature. Free fatty acid concentrations were increased by handling in pigs fed both 0 and 5% fat and 150 ppm L-carnitine. In conclusion, dietary L-carnitine supplementation at the level and for the feeding period evaluated in the current study had a relatively small but positive effect on decreasing blood pH changes in finishing pigs submitted to handling stress; however, dietary fat supplementation had little effect on blood acid-base balance.     

饲粮中添加绿狐尾藻对肥育猪生长性能、血清生化指标和胴体品质的影响

本试验旨在研究饲粮中添加绿狐尾藻对肥育猪生长性能、血清生化指标和胴体品质的影响。采用单因素完全随机试验设计,选用40头初始体重为(55.20±2.18)kg的健康"杜×长×大"三元杂交猪,随机分为4个组,每组10个重复,每个重复1头猪。Ⅰ组(对照组)饲喂基础饲粮,Ⅱ、Ⅲ和Ⅳ组饲粮在基础饲粮中分别添加5%、10%和15%绿狐尾藻,试验期60 d。结果表明:1)与对照组相比,Ⅱ和Ⅲ组肥育猪的终末体重、平均日增重和料重比均无显著差异(P0.05);Ⅳ组的终末体重和平均日增重显著降低(P0.05),料重比显著增加(P0.05)。2)各组肥育猪的血清总蛋白、尿素氮、总胆固醇、甘油三酯、低密度脂蛋白、高密度脂蛋白含量和谷草转氨酶活性均无显著差异(P0.05);与对照组相比,Ⅲ组的血清谷丙转氨酶活性和Ⅳ组的血清白蛋白含量显著降低(P0.05)。3)各组肥育猪的胴体率、瘦肉率、屠宰率、胴体斜长、肉色、剪切力和大理石纹评分均无显著差异(P0.05);与对照组相比,Ⅲ和Ⅳ组的平均背膘厚和Ⅳ组的眼肌面积显著降低(P0.05),Ⅲ组的滴水损失有降低趋势(P0.05),Ⅱ和Ⅲ组的p H45 m in、p H24 h有增加趋势(P0.05)。由此可见,饲粮中添加10%绿狐尾藻对肥育猪的生长性能无显著影响,可改善血清生化指标,降低平均背膘厚,减缓肌肉p H下降速度,降低滴水损失,改善猪肉品质。     

Dietary lycopene supplementation improves meat quality,antioxidant capacity and skeletal muscle fiber type transformation in finishing pigs

This study aimed to investigate effects of dietary lycopene supplementation on meat quality,antioxidant ability and muscle fiber type transformation in finishing pigs.In a 70-day experiment,18 Duroc
Landrace
Yorkshire barrows were randomly allocated to 3 dietary treatments including a basal diet supplemented with 0,100 and 200 mg/kg lycopene,respectively.Each dietary treatment had 6 replicates with one pig each.Results showed that dietary 200 mg/kg lycopene supplementation increased muscle redness a^*value,intramuscular fat and crude protein contents,and decreased muscle lightness L^*and yellowness b^*values(P<0.05),suggesting that addition of 200 mg/kg lycopene to the diet of finishing pigs improved color,nutritional value and juiciness of pork after slaughter.Results also showed that dietary lycopene supplementation enhanced antioxidant capacity of finishing pigs(P<0.05).Moreover,dietary supplementation of 200 mg/kg lycopene significantly increased slow myosin heavy chain(MyHC)protein level and slow-twitch fiber percentage,and decreased fast MyHC protein level and fast-twitch fiber percentage(P<0.05),suggesting that the addition of 200 mg/kg lycopene to the diet of finishing pigs promoted muscle fiber type conversion from fast-twitch to slow-twitch.Together,we provide the first evidence that dietary 200 mg/kg lycopene supplementation improves meat quality,enhances antioxidant capacity and promotes muscle fiber type transformation from fast-twitch to slow-twitch in finishing pigs.     

包膜半胱胺对肥育猪生长性能、免疫功能、抗氧化能力及肠内容物消化酶活性的影响

本试验旨在研究日粮中添加不同水平包膜半胱胺(CCS)对肥育猪生长性能、免疫和抗氧化能力及十二指肠消化酶活性的影响。选择体重(62.12±1.43)kg的健康杜×长×大肥育猪160头,随机分为4个处理,每个处理组4个重复,每个重复10头(公、母各半)。对照组饲喂基础日粮,试验组在基础日粮的基础上分别添加100、200、400 mg/kg CCS。试验猪自由采食饮水,预试期5 d,正试期40 d。结果表明:CCS对肥育猪的平均日增重(ADG)、平均日采食量(ADFI)和耗料增重比(F/G)无显著影响,但100 mg/kg CCS组生长性能指标相对最佳;100、200 mg/kg CCS组血清IgM和补体C3水平均上升(P<0.05),C3水平随着CCS添加剂量的提高呈线性上升(P<0.05);CCS有提高血清Ig G水平的趋势(P=0.07),并呈二次升高(P<0.05);CCS提高了血清中总抗氧化能力(T-AOC)并呈二次变化(P<0.05);血清谷胱甘肽过氧化物酶(GSH-Px)水平和过氧化氢酶(CAT)活性随着CCS水平的提高呈线性及二次变化(P<0.05);肝脏GSH-Px和总超氧化物歧化酶(T-SOD)活性随着CCS水平的提高呈线性及二次增高(P<0.05);CCS提高了十二指肠总蛋白酶和总脂肪酶活性(P<0.05),使总淀粉酶活性呈二次上升(P<0.05)。可见,日粮中添加低剂量的CCS对肥育猪生产性能有一定改善趋势,CCS可提高肥育猪的免疫和抗氧化性能,促进肠道消化酶的分泌。在本试验中,CCS在肥育猪饲粮中的适宜添加水平为100 mg/kg。     

Effects of dietary leucine supplementation in low crude protein diets on performance,nitrogen balance,whole‐body protein turnover,carcass characteristics and meat quality of finishing pigs

Eighteen Duroc × Landrace × Yorkshire barrows, with an average initial body weight (BW) of 75.4 ± 2.0 kg, were randomly allotted to one of three diets with six replicates per treatment for 25 days. The diets comprised a normal protein diet (NP, 14.5% crude protein), a low crude protein diet supplemented with 0.27% alanine (LP + Ala, 10.0% crude protein), or a low crude protein diet supplemented with 0.40% leucine (LP + Leu, 10.0% crude protein). The whole‐body protein synthesis rate, whole‐body protein breakdown rate and protein deposition rate in pigs fed the LP + Leu diet were similar to the NP diet (P > 0.05), and both were significantly higher than pigs fed the LP + Ala diet (P < 0.05). The Longissimus muscle area (LMA) of pigs fed the LP + Leu diet was larger than those fed the LP + Ala diet (P = 0.05). In addition, drip loss and intramuscular fat of pigs fed the LP + Ala diet were higher than that of the others (P < 0.05). In conclusion, supplementation of leucine in low protein diet could stimulate protein deposition and improve the meat quality of finishing pigs more than an alanine‐supplemented one.     

Effects of Dietary Energy Density on Plasma Glucose and Lipid Profile, Morphological Aspects and Chemical Characteristics of Adipose Tissue in Finishing Pigs

Peroxisome proliferator-activated receptor-γ (PPAR-γ) plays a pivotal role in controlling adipogenesis. We hypothesized that changes in dietary energy density might alter fat deposition in finishing pigs via modulation of the expression of PPAR-γ. To test this hypothesis, thirty female finishing pigs were fed diets containing low (LD), medium (MD) or high (HD) energy density. Blood samples were collected on day 53, and then the pigs were sacrificed to collect samples of the dorsal subcutaneous (ST), abdominal (AT) and mesenteric (MT) adipose tissue. Compared with pigs fed the MD diet, malate dehydrogenase activity was increased in the ST and MT of pigs fed the HD diet, while activity was decreased in the MT of pigs fed the LD diet (P < 0.05). Glucose-6-phosphate dehydrogenase activity was increased in all three fat depots of pigs fed the HD diet (P < 0.05) in comparison with pigs fed the MD diet. Both HD and LD diets increased the size of the adipocytes in the AT and MT (P < 0.05). Pigs fed the HD diet had a higher cell proliferation index in the ST compared with pigs fed the other two diets (P < 0.05). Compared with pigs fed the MD diet, a decreased apoptosis index was seen in the ST of pigs fed the HD diet, and in the AT of pigs fed the LD diet, as well as in the MT of both HD and LD fed pigs (P < 0.05). PPAR-γ positive percentage was elevated in the ST and MT of HD fed pigs compared with pigs fed the MD and LD diets, while it was decreased in the ST of LD compared with MD fed pigs (P < 0.05). These results suggest that dietary energy density may regulate fat deposition in finishing pigs. It is possible that feeding a high energy diet may induce fat deposition via up-regulation of  PPAR-γ expression.     

饲粮减少矿物元素对育肥猪生长性能、肉品质、血清生化指标以及骨骼肌矿物元素含量的影响

本试验旨在研究饲粮中减少铁、锰、锌、镁和铜5种矿物元素添加量对育肥猪后期生长性能、肉品质、血清生化指标以及骨骼肌矿物元素含量的影响。选用体况良好、体重接近[(76.17±1.58)kg]的"杜×长×大"三元杂交育肥猪300头,随机分成3个组,每组10个重复,每个重复10头猪,公母各占1/2。对照组饲喂基础饲粮,试验组饲喂在基础饲粮基础上减少30%或60%矿物元素的饲粮。预试期3 d,正试期30 d。结果表明:与对照组相比,1)饲粮减少30%和60%矿物元素对育肥猪的生长性能和肉品质无显著影响(P0.05);2)饲粮减少30%和60%矿物元素,育肥猪血清氨含量显著升高(P0.05);减少60%矿物元素显著降低血清中总胆固醇的含量(P0.05),同时有降低血清总蛋白含量的趋势(P0.10);3)饲粮减少30%矿物元素对育肥猪骨骼肌中各矿物元素含量并无显著影响(P0.05),而减少60%矿物元素使得骨骼肌铜、铁和锰元素含量显著降低(P0.05)。由此得知,育肥猪饲粮中铁、锰、锌、镁和铜元素的含量可减少NRC(2012)推荐量的30%,而不会影响育肥猪后期的生长性能和肉品质。     

Effect of magnesium mica on performance and carcass quality of growing-finishing swine

A total of 240 crossbred pigs were used in two experiments to determine the effect of feeding magnesium mica (MM) during the growing-finishing period on animal performance and pork carcass characteristics. All pigs were blocked by weight, and treatments were assigned randomly to pens (five pigs/pen) within blocks. In each experiment, eight pens were allotted randomly to one of three treatments: 1) a negative control corn-soybean meal starter, grower, and finisher diet devoid of supplemental magnesium; 2) the control diets supplemented with 1.25% MM; and 3) the control diets supplemented with 2.50% MM. In Exp. 1, pigs were slaughtered at the University of Arkansas Red Meat Abattoir, whereas pigs in Exp. 2 were transported to a commercial pork packing plant and slaughtered according to industry-accepted procedures. In both experiments, dietary supplementation of MM had no (P > .10) effect on ADG, ADFI, or gain:feed ratio at any phase during the growing-finishing period. In Exp. 1, MM supplementation had no (P > .10) effect on carcass fatness or muscling. Moreover, Japanese color scores were not (P > .10) affected by feeding pigs MM; however, American color scores increased linearly (P < .01) with increasing levels of MM in the diet. Although MM supplementation did not (P > .10) affect L* and b* values for the longissimus muscle (LM), there was a linear increase (P < .05) in LM a* and chroma values associated with increased MM levels in swine diets. In Exp. 2, carcasses from pigs fed 1.25% MM had less (P < .05) fat opposite the LM at the 10th rib than untreated controls and pigs fed 2.50% MM and higher (P < .10) percentages of muscle than carcasses of untreated controls. Moreover, the LM from pigs fed 1.25% MM was less (P < .05) red and less (P < .05) yellow than the LM from pigs fed the control or 2.50% MM-supplemented diets. Drip loss from the LM was unaffected (P > .10) by inclusion of MM in the diet. Results from this study confirm that inclusion of MM, an inexpensive, inorganic magnesium source, in diets of growing-finishing swine has beneficial effects on pork carcass cutability and quality with no deleterious effects on live animal performance.