Effect of dietary supplementation with mulberry(Morus alba L.) leaves on the growth performance,meat quality and antioxidative capacity of finishing pigs

The present study was conducted to evaluate the effect of dietary mulberry(Morus alba L.) leaves powder(MLP) supplementation on meat quality of finishing pigs.A total of 40 Duroc×Landrace×Yorkshire pigs(initial body weight of(40.5±0.63) kg) were randomly allotted into two treatments,fed either with control diet or 15% MLP diet for 85 d.The results showed that MLP diet decreased(P≤0.05) average daily gain(ADG) and increased(P<0.05) feed/gain ratio(F/G) in the finishing and whole period.MLP diet also decreased(P<0.05) carcass weight,dressing percentage,last rib and average backfat depth.However,MLP diet increased(P<0.05) intramuscular fat(IMF) content,decreased(P<0.05) shear force,cooking loss and drip loss.In addition,MLP diet increased(P<0.05) total antioxidative capacity,glutathione peroxidase and tended(P<0.10) to increase total superoxide dismutase in serum.In longissimus thoracis,myosin heavy chain(MyHC) I and IIa mRNA levels were increased(P≤0.05) for MLP diet.In conclusion,15% MLP supplementation reduced the growth performance and carcass traits,but improved meat quality of finishing pigs possibly through the change of myofiber characteristics,enhancement of antioxidative capacity and increase of IMF.

Effects of dietary protein/energy ratio on growth performance,carcass trait,meat quality,and plasma metabolites in pigs of different genotypes

Background： The protein/energy ratio is important for the production performance and utilization of available feed resources by animals. Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment. This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance, carcass traits, meat quality, and plasma metabolites of pigs of different genotypes. Methods： Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups （Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio; n = 24 per treatment） in a 2 x 2 factorial arrangement. Blood and muscle samples were collected at the end of the nursery, growing, and finishing phases. Results： We observed significant interactions （P 〈 0.05） between breed and diet for total fat percentage, intramuscular fat （IMF） content, protein content in biceps femoris （BF） muscle, and plasma urea nitrogen （UN） concentration in the nursery phase; for average daily gain （ADG）, average daily feed intake （ADFI）, dry matter, IMF content in psoas major （PM） muscle, and plasma total protein and albumin concentrations in the growing phase; and for drip loss and plasma UN concentration in the finishing phase. Breed influenced （P 〈 0.05） growth performance, carcass traits, and meat quality, but not plasma metabolites. Throughout the trial, Landrace pigs showed significantly higher （P 〈 0.0_5） ADG, ADFI, dressing percentage, lean mass rate, and loin-eye area than did Bama mini-pigs, but significantly lower （P 〈 0.0.5） feed/gain ratio, fat percentage, backfat thickness, and IMF content. Dietary protein/energy ratio influenced the pH value, chemical composition of BF and PM muscles, and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase, and plasma concentration of UN. Conclusions： Compared with Landrace pigs, Bama mini-pigs showed slower growth and lower carcass performance, but had better meat quality. Moreover, unlike Landrace pigs, the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs. These results suggest that, in swine production, low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment.

Effects of conditioners(single-layer, double-layer and retentionconditioner) on the growth performance, meat quality and intestinal morphology of growing and finishing pigs

This experiment was conducted to investigate the effects of feed conditioners(single-layer, double-layer and retentionconditioner) on the growth performance, meat quality and intestinal morphology of pigs throughout the growing to finishing phase. A total of 96 growing pigs((28.70±3.20) kg) were selected and randomized into three treatment groups with four replicates per group. Eight pigs were used per replicate for the 17-week feeding trial. The grower diet was given at 0 to 6 weeks and a finisher diet was given at 6 to 17 weeks. The treatments were as follows: SC diet(control; single-layer conditioning), DC diet(double-layer conditioning), and RC diet(retention-conditioning). Starch gelatinization was significantly higher(P<0.05) in the RC treatment than in the SC treatment, however, there was no significant difference in the starch gelatinization between the DC group and the RC group. In the growing phase, the feed to gain index(F:G) was significantly lower(P<0.05) in the RC group than in the SC and DC groups. Between growing and finishing, the F:G was the lowest(P<0.05) in the SC group compared to the RC or DC group. Drip loss, a measurement of meat quality, was significantly lower(P<0.05) in longissimus dorsi tissue collected from pigs fed the RC diet than in tissues collected from pigs fed the SC diet. The intestinal quality of the duodenum and jejunum tissues showed a significant increase(P<0.05) in the crypt depth and villus height in the RC group compared to the SC-or DC-treated pigs. These results demonstrated that the retentionconditioner treatment decreased the F:G in growing pigs, improved intestinal morphology and enhanced the meat quality in the finishing pigs. However, the retention-conditioner treatment had a negative impact on growth performance in the finishing pigs.

Comparative Study on Growing-finishing Performance and Meat Quality of Different Hybrid Combinations in Pigs

[Objective] The aim of this study was to investigate the production performance of three pig cultivars through their fattening performance, carcass traits and meat quality for facilitating its application in practical production. [ Method] Three pig cultivars were selected including Yesong （ F1 hybrid of pure-bred wild boar cross with songliao black sow as female parent） hybrid pigs, D × L × Y pigs from three-way cross and L x Y pigs from two-way cross. The test pigs in early period （before 60 kg） and late period （after 60 kg） were all fed with diets of the same nutritional level by free feeding and drinking water. The pre-test period was 3 d, while the test period was 120 d. Every 30 days, pigs with an empty stomach were weighed on morning, and when fattening to 120 d, five pigs with good growth and development in each cultivar were selected for slaughter to determine carcass traits and meat quality. [ Result] Under the same diets and feeding conditions, average daily gain and weight gain in the whole period of pigs from three-way cross were all significantly higher than those of pigs from two-way cross, and also extremely higher than those of Yesong pigs. There was no difference in dressed carcass percentage, backfat thickness and proportion of hind leg among three hybrid combinations. Lean meat percentage and eye muscle area of pigs from three-way cross and pigs from two-way cross were all significantly higher than those of Yesong pigs. Yesong pigs had relatively darker carnation, but marble vein （P〈0.05） and water loss rate （P〈0. 01 ） of Yesong pigs were relatively fewer than those of pigs from two-way cross and pigs from three-way cross. Shear force of Yesong pigs was significantly higher than that of pigs from two-way cross and pigs from three-way cross, [ Conclusion] Yesong hybrid pigs make full use of heterosis between wild pigs and Songliao black pigs for improvement of its meat quality, but some values of major economic traits in Yesong hybrid pigs is still lower than those in pigs from thrae-way cross and pigs from two-way cress.

Technological, Sensorial and Nutritional Meat Quality Traits from Pig Fed with Conventional and Unconventional Diets

The aim of the study was to evaluate the impact of unconventional food resources on the quality of pig meat. 90 pigs of which 20 were slaughtered at 180 days old for meat quality evaluation. It came out from the study that the highest L* and b* were obtained in A0 commercial feed, while the highest a* was recorded in A3 (P Longissimus dorsi) were lower in control group than in experimental groups. The cooking loss and water-holding capacity of the meat from A4 were higher than those of other treatments. Luminance, redness, yellowness, chroma values and pH of the pork had increased during the post-mortem aging time for the both diet treatments while the hue value decreased (P < 0.05). Nutritionally, the protein content, the fat content, the dry matter content and the ash content varied respectively from 24.45% to 26.87%, 0.52% to 1.6%, 26% to 27.5% and 1.1% to 1.79% with the highest protein contents found in meat from unconventional feed A4 (P < 0.01) while the highest fat content (1.6%) was obtained from meat of the control group A0 (P < 0.001). The texture of the meat from the control group was better than those of experimental groups (P < 0.01). Overall, unconventional diet based on Azolla and Moringa improves technological and nutritional pork quality.

Relationship between Muscular Malic Enzyme Activity and Meat Quality in Pigs

[ Objective] To investigate the relationship between muscular malic enzyme （ME） activity and meat quality in pigs. [ Method] Three pig breeds, Exi pigs, Changye x Exi hybrid pigs and Landrace xYorkshire pigs were selected. Then the ME activity and meat traits were detected, and the relationship between ME activity and meat quality were analyzed with SAS software. [ Result] The Exi pigs had the highest ME activity and intra- muscular fat （IMF） content （ P 〈 0.05）. The pH2 value, drip loss and muscle shear force of Landrace xYorkshire pigs were higher than that of Exi pigs significantly （P 〈 0.05）. [ Conclusion] The ME activity has a certain correlation with meat quality of pigs. The muscular ME activity has signifi- cantly positive correlation with IMF content and significantly negative correlation with drip loss and muscle shear force.

The Influence of Lairage Conditions for Finishing Pigs on Behavior,Biochemical Indicators and Meat Quality

A total of 60 crossbred(Large White×Landrace) pigs of halothane genotype NN(castrated males and females) were allotted to three treatments:3 h lairage with toys,3 h lairage and 0 h lairage in a randomized complete block design and used to evaluate the influence of lairage conditions on behavior, biochemical indicators and meat quality for finishing pigs at slaughter.Behavior of the pigs was scored subjectively during lairage.Blood samples were taken at exsanguination s to measure blood temperature, plasma Cortisol,ACTH,glucose,lactate,plasma enzymes and hematological indices.Post-mortem meat quality measurements included muscle colour value(MCV),electrical conductivity(EC),pH at 45 min and 24 h from Longissimus thoracis(LM) and Semimembranosus(SM) mucles and drip loss from LM. The results showed that 3 h lairage group with toys demonstrated significantly improved behavior than the group without toys at 3 sampling times.All the pigs showed increasing calmness as the time of lairage progressed.The omission of lairage increased plasma Cortisol,ACTH,glucose and lactate(P【0.05),and decreased plasma lactate dehydrogenase(LDH),and creatine kinase(CK)(P【0.05).No biochemical index was influenced by the presence or absence of toys during lairage(P【0.05).Muscle colour value, electrical conductivity,pH at 45 min and 24 h from LM and SM and drip loss were not affected by any treatment(P【0.05).Pigs provided 3 h lairage,with or without toys,exhibited lower red blood cell(RBC), hemoglobin(HGB),and haematocrit(HCT) when compared to 0 h lairage.3 h lairage with or without toys resulted in higher white blood cell(WBC) and lymphocyte(W-SCC) levels than 0 h lairage.None of the hemocytic indices in pigs given lairage was affected by the presence or absence of toys.We conclude from this pilot study that in local commercial conditions,from the point of view of animal welfare and meat quality,lairage time of 3 h after short travel was beneficial.Pigs resting showed increased relief from stress and a recovery in immune competence.Holding pigs in lairage with toys for a few hours after arrival at the abattoir may be beneficial for the animal’s well-being.

Effect of Cassava Leaf (<i>Manihot esculenta </i>) Level in Guinea-Pigs (<i>Cavia porcellus </i>) Meal on the Physico-Chemical and Techno-logical Properties of Its Meat

The present study was carried out to evaluate the effect of different rates of dried cassava leafs in diet as replacement of protein sources on the weight gain and carcass yield of guinea-pigs, as well as on the physico-chemical and technological properties of guinea-pigs’ meat. A total of forty-eight (48) eight-week-old guinea-pigs were divided in a completely randomized experimental design, in four groups and fed with the experimental foods. These experimental foods were formulated as follows: cassava-leaf (Manihot esculenta) powder was incorporated at concentrations of 0%, 8%, 10% and 12% respectively in replacement of protein sources for R0, R1, R2 and R3. Each treatment consisted of a group of 12 guinea pigs per paddock (6 males and 6 females). The initial weight (IW), final weight (FW), daily weight gain (DWG) and total gain (TG) were evaluated. At the 22nd week, animals of each group were sacrificed by bleeding, then skinned and eviscerated. Carcasses were cut, and some parts (loin, thigh and shoulder) were collected, deboned and analysed. The highest FW and carcass yield (CY) were obtained with the use of 10% cassava leafs (R2): 556 g (FW), 42.65% (CY) for males and 529.17 g (FW), 37.39% (CY) for females. The incorporation of 8% (R1) and 12% (R3) cassava leafs led to a significant increase (P < 0.05) in protein levels in the loins (22.89%) and shoulders (22.43%) of females and the thighs (21.68%) and shoulders (21.09%) of males. However, protein levels of male fed with R3 in the various parts studied were higher than females fed with the same diet. The study of the technological parameters of guinea-pig’s meat showed that the incorporation of 8% and 12% cassava leafs in the diet resulted in a significant decrease in the water holding capacity and technological yield in the different parts studied. These results show that, the incorporation of cassava leafs in guinea-pigs’ diet made it possible to obtain good growth (R2) and meat of good technological quality.

Wnt gene expression in adult porcine longissimus dorsi and its association with muscle fiber type,energy metabolism,and meat quality

This study investigated the expression profiles of Writ genes in adult porcine Iongissimus dorsi （LD） from different porcine genotypes and their associations with meat quality. The results showed that Wnt5a gene expression level was the highest in Jinhua （JHP） pigs, followed by Zhongbai （ZBP）, DurocxZhongbai （DZB）, and Duroc×Yorkshire×Landrace （DYL） pigs, with significant differences between ZBP, DZB, and DYL （P〈0.05）. This genotypic order was reversed for Wnt7a, Wnt10b, and Wnt11 expression, with JHP and DYL having the lowest and highest expressive levels, respectively. Wnt5a expression was negatively correlated with pH,5 min and ApH （P〈0.01）, some glycolytic markers （P〈0.05）, and positively correlated with meat color （a＊）, shear force （SF） value （P〈0.05）, myosion heavy chain （MyHC） I mRNA proportion （P〈0.01）, turnover ratio of creatine phosphate （CP）, and creatine kinase （CK） activity （P〈0.05）. Opposite correlations were observed for Writ2, Wnt7a, Wnt10b, and Wnt11. These results revealed that Wnt5a, Wnt7a, Wnt10b, and Wnt11 gene expressions in adult porcine muscle contributed to differences between porcine genotypes and affected pork quality. Wnt5a gene expression could be beneficial for the formation of high quality pork by regulating muscle fiber types and postmortem energy metabolism.

Effects of the Sheep Polyclonal Antibodies Against the Porcine Adipocyte Plasma Membrane Proteins on Porcine Carcass Composition and Meat Quality

To detect the effects of the polyclonal antibodies raised in sheep against porcine adipocyte plasma membranes on the porcine carcass composition and meat quality, 30 pigs assigned into 6 treatment groups were given intraperitoneal injections of sheep antipig adipocyte plasma membrane immunoglobulin （ASIg） or sheep nonimmune serum immunoglobulin （NSIg）. At the end of the experiment, the pigs were slaughtered at 90 kg body weight, and carcasses and meat quality were evaluated. The results showed that when pigs intraperitoneally immunized with 20 or 30 mg ASIg at 15 kg body weight, 20 mg purified ASIg twice at 15 and 60 kg body weight, or 20 mg purified ASIg at 60 kg body weight, respectively, their lean meat percentage, fat meat percentage, backfat thickness, loin eye area leaf fat weight, caul fat weight, heart weight, liver weight, and kidney weight were significantly affected. However, the kidney weight, lurrg weight, dressing percentage, and spleen weight did not remarkably change. Our results indicated that pigs intraperitoneally immunized with 20 or 30 mg ASIg at 15 kg body weight, and 20 mg ASIg twice at 15 and 60 kg body weight, have significantly different drip loss rate, cooked meat ratio, tenderness, storage loss rate, muscle fiber diameter, moisture content, dry matter content, crude protein content, and crude fat content from the control group that received 20 mg NSIg at 15 kg body weight. However, meat pH, meat color value, meat marbling score, inosinate, and myohemoglobin were not significantly affected. Our results indicated ASIg could not significantly affect the content of most muscular amino acids and intramuscular fatty acids.

大蒜素对育肥猪生长性能、屠宰性能及肉品质的影响

试验探讨了不同水平的大蒜素对育肥猪生长性能、屠宰性能及肉品质的影响,确定大蒜素在育肥猪生产中的最适添加水平。试验选择体重相近的健康的“杜×长×大”三元杂交育肥猪250头,随机分成5组,每组5个重复,每个重复10头猪。对照组育肥猪饲喂基础饲粮,大蒜素组育肥猪分别饲喂含有50(试验组1)、100(试验组2)、200(试验组3)、400 mg/kg(试验组4)大蒜素的试验饲粮。预试验1周,正式试验期42 d。结果显示,与对照组比较,试验组3和试验组4育肥猪末重显著提高(P<0.05),试验组3的平均日增重提高了11.60%(P<0.05),试验组2和试验组3育肥猪的料重比降低了8.64%和11.96%(P<0.05)。试验组3组育肥猪的宰前活重显著高于对照组(P<0.05);试验组2、试验组3和试验组4育肥猪的胴体重显著高于对照组(P<0.05),背膘厚度显著低于对照组(P<0.05)。试验组3和试验组4育肥猪的背最长肌pH值显著高于对照组(P<0.05),滴水损失显著低于对照组和试验组1(P<0.05),肌苷酸含量显著高于对照组(P<0.05);试验组3背最长肌的红度显著高于对照组和试验组1(P<0.05),试验组2、试验组3和试验组4背最长肌的剪切力显著低于对照组(P<0.05)。试验组3和试验组4育肥猪背最长肌中的总氨基酸、总必需氨基酸及鲜味氨基酸含量显著高于对照组(P<0.05)。研究表明,在育肥猪饲粮中添加适量的大蒜素可以提高生长性能和屠宰性能,改善肌肉品质,大蒜素的最适添加水平为200 mg/kg。

Quality of Soppressata salami from Pugliese Pigs as Affected by Rearing System

Twenty four male pigs were assigned to two groups of 12 each during the last fattening phase: one group was reared outdoor (OUT group) and fed on natural pasture, while the other group was reared indoor (IND group) and fed on commercial feedstuff. Meat was processed into Soppressata salami according to traditional protocol. Meat and Soppressata salami were analyzed for nutritional, textural and color parameters. Meat and Soppressata salami showed significantly higher proportion of unsaturated fatty acids in OUT than that in IND group. Ameliorated nutritional indexes in terms of n-6/n-3 ratio, and thrombogenic index were found both in meat and Soppressata salami in OUT group. Texture Profile Analysis showed lower values in the tested samples from OUT thanINDgroup. Lightness, redness, and chroma parameters were higher both in meat and Soppressata salami in OUT group;whereas hue parameter was lower in Soppressata salami from OUT pigs. Outdoor rearing improved fatty acid profile, nutritional indexes, color and mechanical properties of pork meat thanks to natural pasture, greater space allowance and physical exercise of animal during the fattening phase. Meat features strictly affected the quality of the Soppressata salami produced by using traditional protocol.

Comparative Study on Pig Raising between Bio-bed System and Cement Ground System

In order to conduct the comparison of pig raising under different raising modes, a total of 40 pigs with the weights of 20 - 30 kg were randomly divided into two groups （experimental group , fermentation bed; control group, cement ground）. During a 81-day-test, pigs in the two groups were fed with same diets, and growth performance of pigs was compared. After the feeding, six pigs of each group were slaughtered in order to examine meat quality. The results showed that average daily gain of pigs in test group was 17.93% higher than that in control group, difference between the two groups was significant. Feed weight ratio of pigs in test group was 14.73% lower than that in control group, difference between the two groups was not significant. Color, water loss, drip loss, intramuscular fat, etc. of meat in test group were all better than that in control group, difference of drip loss between the two groups was extremely significant, while differences of col- or, water loss and intramuscular fat （IMF） between the two groups were not different. Pig raising by bio-bed system could improve growth performance and pork quality comparing with cement ground system.

Determination of Slaughter Performance in Transgenic Pigs Harboring Inducible IGF-I Gene

[ Objective] This study aimed to investigate the slaughter performance of transgenic pigs harboring IGF-I gene under tetracycline induction. [ Method ] Pigs were given diets with the addition of tetracycline. After 45 d of tetracycline induction, experimental pigs were weighed and slaughtered for parameter determina- tion. [ Result] The lean meat percentage of experimental pigs was improved by 8.92%, but various blood biochemical parameters and carcass components exhibited no significant changes. [ Conclusion ] Under tetracycline induction, transganic pigs harboring IGF-I gane demonstrated an increase in lean meat percentage without abnormal changes in other parameters.

苜蓿减量替代豆粕日粮在猪生产中的应用

畜牧业集约化养殖模式带来了很多负面问题,比如过度依赖精料、粮食消耗大、母猪繁殖性能下降、猪肉品质变差等。目前猪日粮大多以常规玉米-豆粕型为主,导致我国优质蛋白质饲料短缺问题日益严重,畜牧业生产中的大豆严重依赖于进口。紫花苜蓿蛋白质含量高,被称为“牧草之王”,具有替代豆粕的潜力。文章综述了苜蓿减量替代豆粕日粮在猪中的应用效果,以及苜蓿对猪生长和繁殖性能、肠道健康、猪肉品质的影响及机制,以推动优质饲草在猪中的高效利用,减少传统日粮对豆粕的过度依赖,推动畜牧业提质增效和草-畜有机融合。

巴民和松巴民杂交猪生长性能、胴体和肉质性状的比较研究

本试验旨在通过测定巴克夏公猪与民猪母猪的二元杂交猪(简称巴民猪)和松辽黑猪公猪与巴民母猪的三元杂交猪(简称松巴民猪)的生长性能、胴体和肉质性状,比较分析利用地方品种、地方培育品种和引进品种进行三元杂交的优势和可行性。试验选用出生日龄相近的巴民猪200头,松巴民猪196头,用于生长性能测定;选用100 kg体重的巴民猪50头,松巴民猪45头,屠宰用于测定胴体性状和肉质性状。结果表明,松巴民猪日增重和饲粮转化率显著高于巴民猪(P<0.05),校正至100 kg日龄和校正至100 kg体重背膘厚均显著低于巴民猪(P<0.05);松巴民猪平均背膘厚和肌内脂肪含量显著低于巴民猪(P<0.05),瘦肉率显著高于巴民猪(P<0.05),其他肉质指标差异不显著(P>0.05)。综上所述,松巴民猪生长速度和饲料利用率均高于巴民猪,瘦肉率亦有所提高,肌内脂肪含量虽有所下降,但也达到了4%,保持了民猪的优良肉质特性,因此饲养松巴民三元杂交猪将具有更高的经济效益。

益生菌发酵中草药对育肥猪胴体性状及肉品质的影响

为了探讨益生菌发酵中草药对育肥猪胴体性状和肉品质的影响。试验选择72头体重为(25.00±0.50 kg)的杜×长×大三元杂交猪作为试验研究对象,随机分成4组,每组3个重复,每个重复6头。试验Ⅰ组(对照组)饲喂基础日粮,试验Ⅱ组(基础日粮+1%发酵中草药)、试验Ⅲ组(基础日粮+2%发酵中草药)和试验Ⅳ组(基础日粮+3%发酵中草药)。预试期1周,正试期12周,统计分析各试验组的胴体性状指标和肉品质指标。结果显示:与试验Ⅰ组相比,试验Ⅲ和Ⅳ组显著提高了育肥猪的胴体重、屠宰率和胴体瘦肉率(P<0.05);育肥猪的肌肉嫩度、肌内脂肪和大理石花纹明显改善(P<0.05),同时提高了猪肉中蛋白水平,降低了粗脂肪和挥发性盐基氮含量(P<0.05)。结果表明,益生菌发酵中草药可以提高育肥猪的胴体性状指标及改善猪肉品质,发酵中草药适宜添加量为3%。

冷藏条件下猪肉pH变化及采样时间对滴水损失影响

研究测定了商品猪肉质性状、宰后猪肉pH的变化及采样时间和储藏时间对猪肉失水率和滴水损失的影响。结果表明:猪肉45 min pH为6.01,肉色和大理石纹评分分别为3.57和3.63,失水率和24 h滴水损失分别为14.77%和1.33%。0~4℃条件下,肌肉pH随储藏时间的延长总体呈降低趋势,宰后5 h肌肉pH显著降低,宰后7 h pH极显著降低,之后趋于平稳,到120 h宰后pH又升高到5.85,但仍显著低于45 min。宰后2 h取样测定的肌肉失水率比宰后6 h、24 h分别降低32.59%(P<0.05)、38.23%(P<0.05),宰后9 h采样的失水率比24 h采样的失水率降低32.33%(P<0.05)。宰后2 h取样0~4℃冷藏条件下测定的24 h滴水损失随冷藏时间延长逐渐降低,24 h至72 h之间极显著降低,72 h至168 h之间降低幅度较小,没有明显差异。胴体0~4℃冷藏排酸24 h后取样测定的24 h滴水损失随冷藏时间延长逐渐降低,其中,48 h、72 h、96 h、120 h、144 h的滴水损失比24 h的滴水损失分别降低52.65%(P<0.01)、70.09%(P<0.01)、77.57(P<0.01)、82.87%(P<0.01)、69.47%(P<0.01);96 h、120 h的滴水损失比48 h的分别降低52.63%(P<0.05)、63.82%(P<0.01)。不同采样时间测定的24 h滴水损失不同,以排酸后采样测定的24 h滴水损失较高。

核桃青皮粉及其提取物对猪生长性能、胴体性状和肉品质的影响

【目的】研究核桃青皮粉及其提取物对育肥猪生长性能、胴体和肉质性状的影响。【方法】选取90头健康、体重约80 kg的“杜×长×大”三元杂交育肥阉公猪,随机分为3组,每组3个重复,每个重复10头猪。对照组育肥猪饲喂基础饲粮,核桃青皮粉试验组及其提取物试验组分别在基础饲粮中添加0.1%核桃青皮粉和0.1%核桃青皮粉提取物。预试期10 d,正试期40 d。试验第41天,测定每头猪初始体重、终末体重及各组采食量。试验结束后,每个重复中选取2头体重接近平均体重的试验猪进行屠宰,测定胴体性状、肉质性状,以及背最长肌的氨基酸和脂肪酸含量。【结果】与对照组相比,饲粮中添加核桃青皮粉或其提取物对育肥猪末重、平均日增重、平均日采食量、料重比、胴体直长、胴体斜长、胴体重、屠宰率、眼肌面积、板油重以及背最长肌pH_(45 min)、滴水损失、加压损失、大理石纹评分、红度均无显著影响(P>0.05),但可显著提高育肥猪背膘厚、背最长肌黄度和肌内脂肪含量(P<0.05)。与对照组相比,除了组氨酸,核桃青皮粉组育肥猪背最长肌中其他氨基酸含量均有一定提高,而核桃青皮提取物组的氨基酸含量与对照组的差异不大,核桃青皮粉组和提取物组多不饱和脂肪酸总含量均比对照组含量有一定提高。【结论】饲粮添加0.1%核桃青皮粉及其提取物对生长性能和胴体性状无负面影响,二者均可改善育肥猪肉质性状,核桃青皮粉效果更佳。

性别对五莲黑猪胴体性能及肉品质的影响比较

选择体重100 kg左右的五莲黑猪20头屠宰(10头阉割公猪,10头母猪),研究不同性别试验猪的胴体性能和肉品质。结果表明,性别对试验猪的胴体性能、背最长肌脂肪酸含量影响不显著,对肉的L值和剪切力及蛋氨酸、亮氨酸、酪氨酸、赖氨酸、鲜味氨基酸含量、鲜味氨基酸占总氨基酸比例影响显著。其中,与阉公猪组相比,母猪组肉的L值极显著提高9.97%(P<0.01),剪切力极显著降低31.05%(P<0.01),蛋氨酸和酪氨酸分别提高61.29%(P<0.05)、18.95%(P<0.01);亮氨酸、赖氨酸、鲜味氨基酸含量、鲜味氨基酸占总氨基酸比例阉公猪组分别比母猪组显著提高11.88%(P<0.05)、80.73%(P<0.05)、11.16%(P<0.05)、7.38%(P<0.05)。说明性别对五莲黑猪肉的部分氨基酸含量影响显著,对猪肉的品质有一定影响。