皮特兰、斯格、PIC猪肌肉加工品质的比较试验

为了评定皮特兰猪、斯格猪、PIC猪3个品种猪的肌肉加工品质,试验采用完全随机化设计,测定了3个品种猪肌肉滴水损失、熟肉率、嫩度、pH1值以及肌肉总蛋白含量。结果表明:斯格猪和PIC猪的肌肉滴水损失显著地低于皮特兰猪(P0.05),而熟肉率高于皮特兰猪(P0.05);斯格猪和PIC猪肌肉pH1值及剪切力均显著地高于皮特兰猪(P0.05);皮特兰猪肌肉总蛋白质含量显著地高于PIC猪,斯格猪居中;综合各项指标,斯格猪的肉质较好,而皮特兰猪肉质较差,PIC猪居中。     

斯格猪、斯八级进杂交猪生长育肥性能及肉质品质分析

通过对斯格猪及斯八级进杂交猪育肥性能、胴体性状及肉质品质分析。结果表明,斯格猪生长速度显著高于斯八级进杂交猪(P<0.05),全期增重与平均日增重分别比斯八级进杂交猪高9.39%和9.30%;瘦肉率、后腿比例、眼肌面积、三点平均背膘厚等胴体性状方面,斯格猪差异显著高于斯八级进杂交猪(P<0.05);在肉质品质方面,斯格猪在肉色、大理石纹、失水率方面亦显著高于斯八级进杂交猪(P<0.05),在熟肉率与剪切力方面两者无显著差异(P>0.05)。     

皮特兰猪的特征、特性与利用

皮特兰猪原产于比利时，是最近在欧洲流行的肉用型新品种。皮特兰猪的突出特点是背膘薄、胴体瘦肉率高，但其生长速度较慢，对应激又很敏感，ＰＳＥ肉发生率较高。因此，在我国杂交育种工作中慎用该品种，以避免其敏感基因扩散。     

圩猪与大约克猪的肌肉品质比较

为比较圩猪和大约克猪的肌肉品质,选取圩猪和大约克猪各10头,屠宰后取背最长肌,按照肉质性状测定标准对部分肉质性状和16种氨基酸含量进行测定。结果表明,肉色,圩猪比大约克猪高12.86%(P0.05);粗蛋白质,圩猪比大约克猪低6.34%(P0.05);大理石纹和肌内脂肪含量,圩猪比大约克猪分别高84%(P0.01)和150%(P0.01)。背最长肌谷氨酸含量、氨基酸总量、必需氨基酸含量和鲜味氨基酸含量,圩猪比大约克猪分别高11.08%(P0.01)、5.51%(P0.01)、4.67%(P0.01)和7.54%(P0.01);脯氨酸、亮氨酸和赖氨酸含量,圩猪比大约克猪分别高9.33%(P0.05)、5.14%(P0.05)和3.06%(P0.05);其他指标各组间差异不显著(P0.05)。说明圩猪具有较好的肌肉品质。     

皮特兰猪的引进与科学利用

皮特兰猪原产于比利时,是世界著名猪种,其瘦肉率最高,肌肉最丰满,“双肌”体型最典型——具有发达的背腰肌和腿肉。在当今养猪市场,皮特兰猪是极具利用价值的品种。 皮特兰猪1994 年引入我国后,在一些大型猪场及育种公司开展了驯化与利用工作,但尚未普遍推广。现将皮特兰猪的引进与利用中的若干技术问题介绍如下。1 生产性能 皮特兰猪具有瘦肉率高、背膘薄、眼肌面积大的优点。瘦肉率一般可达73%左右,背膘0.98cm,眼肌面积43 cm2,这些都大大优于其它品种。但其生长肥育性能却不及“杜”、“长”、“大”三大名种,育肥后期增重较慢,肥育期…     

皮特兰猪在海南的种性观察

皮特兰猪育成于比利时 ,以肌肉特别发达 ,瘦肉率高闻名于世 ,又以高度应激反应和劣质肉而为养猪生产者所畏惧。海口市罗牛山种猪场于 1 999年 3月由北京鲲鹏集团种猪场引进皮特兰种猪 1 9头 ,该场种猪直接来自原产地比利时。据称 ,此批种猪为“无应激皮特兰猪”。这批皮特兰猪引到海南后 ,对其品种特性进行了多方面的观察测试 ,现将情况报告如下 ,以供同行参考。1　引进皮特兰种猪的生存皮特兰种猪 1 9头 ,其中公猪 7头 ,母猪 1 2头 ,现存情况是 :7头公猪至今已死亡和淘汰 5头 ,其中因配种、打斗应激各死亡 1头 ,事故卡死 1头 ,肢瘫和阳萎各…     

定远猪及其一代杂种猪胴体,肌肉品质的比较研究

本试验将定远猪分别与长白、大约克和杜洛克杂交，对所产Ｆ１代肉猪作胴体性状和肌肉品质分析比较，结果发现，（１）要交Ｆ１代猪眼肌面积增大，眼肌重增加，前者分别比定远猪对照组提高０．９１￣９．３４ｃｍ＾２，后者分别比对照组高２０－４７％，达到显著水平；（２）各杂交系胴体瘦肉量增国极显著（１．９２￣３．１７ｋｇ，Ｐ〈０．０１），其肉详细交对照组提高７．８５￣９．５３个百分点；（３）杂交Ｆ１代猪皮重均明显减     

Sensory, physical, and chemical properties of pork loin chops from somatotropin-treated pigs of three stress classifications.

Forty-eight pigs of three known stress classifications were injected daily with porcine somatotropin (pST; 4 mg/d) or placebo. The effects of pST and stress classification on the sensory, physical and chemical characteristics of loin chops were observed. Chops from pST-treated animals were less tender and juicy than chops from control animals. Positive stress classification also significantly decreased juiciness but had no effect on tenderness and flavor. A significant interaction was observed for initial juiciness and sustained juiciness between chops from pST and stress-positive pigs. Whereas chops from carriers and normal pigs showed a reduction in juiciness traits with the pST treatment, among stress-positive animals both initial and sustained juiciness were increased with pST treatment. Treatment with pST had no effect on the fat, protein, and moisture content of the longissimus muscle. Furthermore, stress classification had no effect on the fat and moisture content of the longissimus muscle, but protein content was significantly higher in loin chops from stress-positive animals. Chops from pST-treated animals had significantly higher maximum shear force values, required more energy to break the sample, and had higher yield point values than chops from control animals, but stress classification did not affect the shear force values significantly. Treatment of stress-susceptible animals with pST does not lead to an increased incidence of pale, soft, exudative meat and may improve juiciness attributes of chops from stress-positive animals. However, pST treatment of animals, in this trial, led to a reduction of juiciness and tenderness of pork loin chops.     

Effect of porcine somatotropin, stress susceptibility, and final end point of cooking on the sensory, physical, and chemical properties of pork loin chops

Forty-eight pigs of three known stress susceptibility classes were injected daily with porcine somatotropin (pST; 4 mg/d) or a placebo. Each pig was injected in the neck once daily until taken off test, starting when the pigs weighed 59 kg. The pST treatment was terminated at weekly intervals when individual pigs reached 109 kg, but animals continued to be fed for six additional days to allow for required withdrawal time. The effect of pST and stress classification on the sensory, physical, and chemical characteristics of pork chops was observed. Also, the effect of two end-point temperatures (71 and 77 degrees C) on the sensory attributes was observed. The pST treatment of animals resulted in a small but significant decrease in panel scores for tenderness, juiciness, and flavor. Stress susceptibility class, however, decreased panel scores for tenderness only. The pST treatment reduced intramuscular fat and increased moisture in the longissimus muscle, but stress susceptibility class had no effect on proximate composition. The pST treatment and stress susceptibility decreased and increased Hunter L values of chops, respectively, indicating darker and lighter colors, respectively. Furthermore, a greater end-point temperature reduced sensory scores for tenderness and juiciness. These results suggest that pST treatment does not cause an increased incidence of pale, soft, exudative muscle. Also, the use of a lower temperature of end-point doneness (71 degrees C) should be implemented to optimize palatability of broiled pork chops regardless of pST treatment.     

Effects of exogenous porcine somatotropin (pST) administration on growth performance, carcass traits, and pork meat quality of Meishan, Pietrain, and crossbred gilts

Seventeen to twenty-three females of lean (Pietrain, PI), fat (Meishan, MS), or intermediate genotype (PI x [3/4 Large White x 1/4 MS]), referred to as crossbred (CR), were injected between 60 and 100 kg live weight with 6 mg/d of porcine somatotropin (pST) and compared to similar numbers of control females receiving the vehicle only. Average daily gain increased similarly in the three genotypes (125 g/d). Feed conversion ratio tended to decrease to a higher extent in MS (-2.0 kg of feed/kg of gain) than in the other two genotypes (-1.1 and -.9 kg of feed/kg of gain for CR and PI, respectively). A significant genotype x treatment interaction was also observed for backfat thickness (BF) and fat, muscle, and bone development. Effects of pST in PI, CR, and MS pigs were, respectively, -6.2, -9.6, and -16.1 mm for BF and 3.0, 6.8, and 11.8% carcass muscle. The influence of pST on physical measurements of meat quality was rather low, although desirable effects (P less than .05) were obtained on the reflectance and water-holding capacity of PI and CR. Intramuscular fat content was reduced by approximately 1% in MS and CR but not in PI. The metatarsals of pST-treated animals had a higher water content (except in PI), a lower mineralization, and a lower breaking strength (except in MS). The existence of breed variations in the response to pST might result in changes of the relative merit of crossbreeding schemes.     

优质猪肉生产和地方猪种利用

1　开展优质猪肉生产我国的养猪生产目前已经发展到一个新的阶段。在 90年代之前 ,我国人均猪肉占有量在 2 0ｋｇ以下 ,总量供应不足 ,这是第 1阶段。从 1991年至 1999年 ,人均猪肉占有量从 2 0ｋｇ猛增到 3 0ｋｇ左右 ;1997年达 2 9ｋｇ ;1998年达 3 1 1ｋｇ ;1999年 (估计 )达 3 1 7ｋｇ。供求矛盾基本解决 ,部分大、中城市出现猪肉相对过剩 ,这是第 2阶段。目前 ,人们对猪肉品质提出了新的要求 ,安全猪肉或优质猪肉的生产应运而生。这是我国养猪生产发展的第 3阶段。优质猪肉的基本概念有 2个 :一是猪肉的品质要好 ,特别是肌肉的颜色、肌…     

Effects of pea chips on pig performance, carcass quality and composition, and palatability of pork

Pea chips are produced as a by-product when field peas are processed to produce split peas for human consumption. The objective of this experiment was to test the hypothesis that inclusion of pea chips in diets fed to finishing pigs does not negatively influence pig growth performance, carcass composition, and the palatability of pork. A total of 24 barrows (initial BW: 58.0 ± 6.6 kg) were allotted to 1 of 4 treatments and fed early finishing diets for 35 d and late finishing diets for 35 d. A corn-soybean meal (SBM) control diet and 3 diets containing pea chips were formulated for each phase. Pea chips replaced 33.3, 66.6, or 100% of the SBM in the control diet. Pigs were housed individually, and all pigs were slaughtered at the conclusion of the experiment. Overall, there were no differences (P > 0.11) in final BW, ADFI, and G:F of pigs among treatments, but there was a quadratic response in ADG (P = 0.04), with the smallest value observed in pigs fed the control diet. Dressing percentage linearly decreased (P = 0.04) as pea chips replaced SBM in diets, but there were no differences (P > 0.20) among treatments in HCW, LM area, 10th-rib backfat, lean meat percentage, and marbling. Likewise, pH in loin and ham, drip loss, and purge loss were not influenced (P > 0.13) by treatment. However, there was a quadratic response (P = 0.08) in 24-h pH in the shoulder, with the smallest value present in pigs fed the diet, in which 66.6% of the SBM was replaced by pea chips. Subjective LM color and Japanese color score standard were reduced (quadratic, P = 0.03 and 0.05, respectively) and LM b* values and hue angle were increased (quadratic, P = 0.09 and 0.10, respectively) when pea chips replaced SBM in the diets. Ham L* (quadratic, P = 0.04), a* (linear, P = 0.02), b* (quadratic, P = 0.07), color saturation (linear, P = 0.02), and hue angle (quadratic, P = 0.05) were increased when pea chips replaced SBM. However, there were no differences (P > 0.16) in shoulder and fat color. Moreover, cook loss percentage, shear force, juiciness, and pork flavor of pork chops were not different (P > 0.10) among treatments, but tenderness of pork chops linearly decreased (P = 0.04) as SBM replaced pea chips. It is concluded that all the SBM in diets fed to growing-finishing pigs may be replaced by pea chips without negatively influencing growth performance or carcass composition. However, pigs fed pea chips will have pork chops and hams that are lighter, and chops may be less tender if pigs are fed pea chips rather than corn and SBM.     

互助猪胴体性状和肉脂品质的测定及其相关分析

测定了２５头互助猪的胴体性能和肉脂品质，结果表明，互助猪的胴体性能远远劣于国外瘦肉型猪，但优于国内某些地方猪种，瘦肉率低是其显著特点；肉脂品质优于国外瘦肉型猪，表现在良好肉色和肌间脂肪含量，相关分析表明，互助猪的产瘦肉能力与肉脂品质呈出一定的拮抗关系，表现为胴体瘦肉率愈高，背膘愈薄，肌间脂肪含量就愈低，贮存损失率也愈大。     

抗感败毒口服液对大鼠生长和血液理化指标的影响

为了评价抗感败毒口服液临床用药的安全性,对SD大鼠的生长和血液理化指标进行了试验研究,选用了健康大鼠80只,雌雄各半,随机分为高、中、低剂量组和对照组,其中高剂量组、中剂量组和低剂量组分别灌胃给予该口服液8 mL/kg、4 mL/kg和2 mL/kg体重,对照组按8 mL/kg体重灌服生理盐水,每天一次,连续给药35 d。各组末次给药24 h后,检测大鼠体重、血常规指标、血液生化指标、脏器系数及组织病理变化情况。结果表明,抗感败毒口服液各剂量组大鼠的体重、血液学检查、血液生化指标检查与对照组比较,均无显著差异（P>0.05）,雌性大鼠高剂量组的肝脏脏器指数与对照组相比有显著差异（P<0.05）,其他无显著差异（P>0.05）。肉眼观察实质器官无异常病变。结果提示,长期应用抗感败毒口服液对大鼠生长和血液理化指标无显著影响,临床用药安全。     

Comparison of histochemical characteristics in various pork groups categorized by postmortem metabolic rate and pork quality

The purpose of the present study was to investigate the variations in histochemical characteristics of muscle samples segregated according to metabolic rates (MR) and pork quality attributes. A total of 231 crossbred Duroc x (Yorkshire x Landrace) pigs was evaluated. Samples of the LM were taken to evaluate histochemical characteristics, postmortem MR, and meat quality. Samples were classified into fast, normal, and slow MR groups based on muscle pH at 45 min and R-value. Drip loss and lightness (L*) were used to assign samples to 1 of 4 quality classes. Pale, soft, and exudative pork belonging in the fast group had the greatest (P < 0.05) percentage of type IIb fibers, and RSE (reddish-pink, soft, and exudative) pork belonging in the fast group had a similar tendency. Additionally, RFN (reddish-pink, firm, and nonexudative) pork belonging in the normal group showed a lower (P < 0.05) percentage of type IIb fibers than PSE or RSE, regardless of MR, and DFD pork had the lowest (P < 0.05) percentage of type IIb fibers. In general, the fast-glycolyzing PSE pork with the lowest pH at both 45 min and 24 h had greater percentages of type IIb fibers than the fast-glycolyzing RFN pork. There were more fiber-type composition differences between quality classes in pork undergoing a fast rate of metabolism compared with pork undergoing a normal rate of metabolism. It can be concluded that muscle histochemical characteristics are associated with early postmortem MR, the extent of glycolysis, and, thereby, pork quality; however, these effects are limited to the pigs exhibiting a fast glycolytic rate.