性别和添加卵磷脂对育肥猪生长性能、肉质和肌肉胶原含量的影响

本文旨在探讨性别和日粮添加卵磷脂对肥育猪生长性能、肉质、肌肉胶原蛋白含量及胶原合成关键基因表达的影响。试验选择272头二元杂交猪(阉割公猪和后备母猪各半),将其随机分到2×2因子组别中,包括2个性别(后备母猪和阉割公猪)和2个日粮(基础日粮和0.4%卵磷脂)。饲养5周后对猪只进行屠宰,取背长肌进行肉质和胶原蛋白含量的测定。分析骨骼肌参与胶原蛋白合成的关键基因(I型胶原COL1A1,III型胶原COL3A1,α-subunit prolyl4-hydroxylase(P4H)、赖氨酰化氧化酶(Lysyloxidase)和metalloproteinase-1(金属蛋白酶-1,MMP-1)的mRNA相对表达水平。结果显示:卵磷脂提高了阉割公猪和后备母猪的饲料转化率(P <0.05),但对采食量、平均日增重和屠宰率无显著影响(P> 0.05)。卵磷脂对肌肉剪切力、胶原蛋白含量及相关基因表达均无显著影响(P> 0.05)。阉割公猪生长速度和COL1A1基因mRNA相对表达水平均显著高于后备母猪(P <0.05)。但育肥猪性别对最长肌背膘厚度、胶原蛋白含量和相关基因表达水平无显著影响(P> 0.05)。综上所述,卵磷脂在不影响猪肉品质的前提下提高了育肥猪的饲料转化率。因此,在夏季高脂育肥猪日粮中添加卵磷脂有益于生产。     

Effects of fasting and transportation on pork quality development and extent of postmortem metabolism

One hundred seventy-seven pigs were used to determine the interaction effects of fasting and length of transport prior to harvest on pork muscle quality. The study design was a 2 x 2 x 3 factorial, which involved two genetic sources, fasting (F) or no fasting (N) of pigs 48-h prior to harvest, and three transport times (0.5, 2.5, or 8.0 h) on a semitrailer to the packing plant. Genetic source was a significant source of variation (P < 0.05) for most composition and muscle quality variables. Fasting reduced hot carcass weight 3.6% (P < 0.05), but length of transport did not affect hot carcass weight (P > 0.05). There were no differences (P > 0.05) in percent lean among fasting and transport treatments. Fasted pigs had higher longissimus dorsi (LD) ultimate pH (pHu), darker lean color, higher marbling score and lower 7-d purge loss, 24-h drip loss, and cooking loss (P < 0.05) than nonfasted pigs. Meat from pigs that were transported 8.0 h had lower glycolytic potential (GP), higher LD and semimembranosus (SM) pHu, darker lean color, and lower L*, 7-d purge loss, 24-h drip loss, cooking loss, and shear force values than meat from pigs transported 0.5 h (P < 0.05). Meat from pigs transported 2.5 h had higher LD and SM pHu and lower L*, 7-d purge loss, 24-h drip loss, and cooking loss than meat from pigs transported 0.5 h (P < 0.05). Meat from pigs transported 8.0 h had higher LD pHu and color scores and lower L* and cooking loss than meat from pigs transported 2.5 h (P < 0.05). The fasting x transport interaction was significant for SM pHu, L*, color score, and drip loss. Fasting improved SM pHu, L*, color score, and drip loss for pigs that were transported 0.5 h (P < 0.05), but when pigs were transported for 2.5 h or 8.0 h, fasting had little or no effect on these muscle quality traits. Fasting lowered GP and increased LD pHu for pigs from the genetic source with the higher initial pork quality (P < 0.05), while fasting had no effect on pork quality for pigs from the genetic source with the lower initial pork quality (P > 0.05). Longer transport times resulted in lower GP and higher LD pHu regardless of genetic source. Fasting and length of transport each had positive effects on pork quality, but length of transport effects was greater in magnitude. When pigs were transported for 0.5 h, fasting for 48 h prior to harvest improved pork quality, but when pigs were transported 2.5 or 8.0 h, fasting had little effect on pork quality.     

Influence of environmental temperature on growth, muscle and adipose tissue metabolism, and meat quality in swine.

An experiment involving 32 individually housed, castrated male pigs was conducted to determine the effects of environmental temperature (12 degrees C = T12 or 28 degrees C = T28) on the performance, carcass characteristics, muscle and adipose tissue metabolism, and meat quality of pigs fed to achieve equal rates of weight gain between 8 and 92 kg live weight. The T12 pigs had less muscle (P less than .01) and more subcutaneous fat (P less than .01) in the ham than did T28 animals. Thyroids and adrenals were heavier (P less than .01) in T12 than in T28 pigs. Percentage of type I muscle fibers was higher (P less than .01) and fiber cross-sectional areas smaller (P less than .01) in semispinalis muscle (SS) of T12 pigs, whereas no effect of temperature was noticed in longissimus muscle (LD). Cold exposure induced a larger increase in oxidative metabolism in SS (+30 to 32%, P less than .001) than in LD (+14 to 17%, P less than .10) and an enhanced glycolytic metabolism in LD (P less than .05). Lipid concentration was higher in SS of T12 than in that of T28 pigs. Lipogenic enzyme activities and unsaturation of backfat were higher in T12 than in T28 pigs, whereas no effect of temperature was noticed in leaf fat. Cold treatment resulted in a faster postmortem pH decline (P less than .01), higher glycolytic potential (P less than .01), and lower ultimate pH (P less than .01) in LD. The results indicate that 12 degrees C vs 28 degrees C induced detrimental effects on growth, ham composition, and muscle and adipose tissue quality.     

不同肉质改良剂在肉猪肥育阶段的试验效果

随着国民经济发展和人民生活水平不断提高 ,人们对畜产品质量的要求也越来越高 ,对优质无公害放心肉的需求量越来越大 ,这种趋势将会持续增长。随着我国规模化养猪业的发展 ,在高产、高效的同时 ,如何生产符合国家有关标准和确保消费者健康安全的优质猪肉是养猪者所面临的重要问题。各科研单位开发研制的肉质改良剂 ,正是在国家安全生产猪肉的有关政策法规基础上生产出的高科技产品 ,对发展安全、高效、优质的放心肉和促进养猪业可持续发展都具有重要的现实意义。肉质改良剂具有促进生长、降低料耗、提高肉的持水性和改善肉色、提高饲料利用…     

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     

宰前运输应激对肉牛屠宰性能和牛肉品质的影响

30头西门塔尔杂交牛随机均分为2组,对照组(不运输组)和试验组(运输组),试验组肉牛经12 h的宰前运输。结果表明,与对照组相比,试验组屠宰率和净肉率分别显著降低了2.28(P0.05)和1.68个百分点(P0.05);试验组在12 h(P0.01)、24 h(P0.05)的肌肉滴水损失显著升高,但2组间在72 h的肌肉滴水损失差异不显著(P0.05);在45 min时的肌肉剪切力值,试验组比对照组高17.11%,差异显著(P0.05),在24,48,72 h时,2组间差异均不显著(P0.05);在12 h的肌肉p H值,试验组比对照组低9.33%,差异显著(P0.05),但在45 min,24,48,72 h的p H值,2组间差异均不显著(P0.05);2组间肌肉颜色差异不显著(P0.05);试验组肌糖元含量比对照组低24.03%(P0.05),肌肉乳酸含量比对照组高28.65%(P0.05),而肌肉乳酸脱氢酶、肌酸激酶2组间均差异不显著(P0.05)。结果表明,肉牛经12 h的宰前运输,降低了肉牛的屠宰性能和牛肉品质。     

Effects of feeding frequency on meat quality traits and Longissimus muscle proteome in finishing pigs

Sixty‐four barrows with an initial body weight of 59.8 ± 2.1 kg were allocated to one of the two feeding frequency regimes (had free access to diet and fed two meals per day). Pigs had free access (FA) to feed were fed on an ad libitum basis during the 8‐week experimental period. Pigs fed twice daily (M2) were allowed to consume their meals in 2 h. Pigs fed twice daily had lower average daily feed intake (p < 0.01) and average daily gain (p < 0.1), but a greater G:F (p < 0.05) than FA pigs. Lower perirenal fat deposition, hot carcass weight, intramuscular fat content (p < 0.05) and dressing percentage (p < 0.1) were found in M2 pigs compared with FA pigs. Activities of citrate synthase, β‐hydroxylacyl‐CoA dehydrogenase and lactate dehydrogenase were greater in the Longissimus muscle (LM) of M2 pigs compared with FA pigs (p < 0.05). Proteomic analysis revealed that expression abundances of proteins involved in glucose metabolism, energy production and lipid utilization were upregulated, but expression levels of proteins participating in protein and amino acid metabolism, stress response and redox homeostasis were downregulated in the LM of M2 pigs than those in FA pigs (p < 0.05). In conclusion, the less meal frequency impairs growth rate, has marginal effects on carcass and meat quality traits and affects expression abundances of proteins in the LM of finishing pigs.     

日粮添加马铃薯粉对育肥猪生长性能、胴体性状和肉品质的影响

本研究旨在评估非常规饲料资源马铃薯粉在育肥猪上的应用,研究其对猪生长性能、胴体性状和肉品质的影响.试验将450头体重一致的育肥猪随机分为3组,每组5个重复,每个重复30只.对照组饲喂基础日粮,两个处理组分别饲喂马铃薯粉添加水平为10％和20％的日粮,试验为期56?d.结果:与对照组相比,10％马铃薯粉组29～56?d及...     

Effects of two dietary crude protein levels on finishing performance,meat quality,and gene expression of market lambs

Seventeen crossbred lambs were assigned randomly to low-protein (LP; 8% crude protein [CP]; n = 9) and high-protein (HP; 13% CP; n = 8) diets for 9 weeks. The final body weight, average daily feed intake (ADFI), and average daily gain (ADG) of the HP lambs were significantly higher (P < 0.05) than the LP lambs; however, gain to feed ratio (G:F) for the LP lambs was significantly higher (P < 0.05) than the HP lambs. Hot carcass weight (HCW), adjusted fat thickness, and drip loss of longissimus dorsi (LD) muscle were significantly higher (P < 0.05) for the HP than LP lambs. In contrast, instrumental color values L*, a*, b*, C*, and hue angle (H) of meat from the LP lambs scored significantly higher (P < 0.05) than the HP lambs. The LD muscle from HP lambs had significantly greater CLA of cis-9 trans-11 isomer (P < 0.05) than the LP lambs. The gene expression of metabolism and meat quality-related genes of LP was significantly higher than HP (P < 0.05). These results suggest that a higher dietary CP level promotes growth performance for finishing lambs, whereas lower dietary CP level is beneficial for meat quality, especially when evaluating color characteristics in the final product.     

Effect of dietary Rhodobacter capsulatus on cholesterol, triglycerides concentration, and meat quality of finishing pigs

The study was designed to investigate the effect of Rhodobacter capsulatus on serum and meat cholesterol, fatty acid composition in meat, as well as meat quality of finishing pigs. A total of 16 120-day-old Landrace female pigs of about 60 kg initial body weight were randomly assigned into two groups. The pigs were fed a supplemented diet with 0.04% dietary R. capsulatus or a control diet for 60 days. Total cholesterol and low density lipoprotein-cholesterol concentration in serum was significantly lowered ( P  < 0.05) in the pigs fed the R. capsulatus supplemented diet compared to the control diet. Carcass weight, carcass length, shoulder fat, back fat and loin fat thickness, longissimus muscle (LM) area, and color score did not differ significantly between the pigs fed the R. capsulatus supplemented diet and control diet. Among the nutrient composition of LM meat, neutral fat and triglyceride concentration were significantly ( P  < 0.05) reduced in the finishing pigs by dietary supplementation of R. capsulatus . The proportions of n-6 PUFA were higher ( P  < 0.05) in the pigs fed the R. capsulatus supplemented diet than in the pigs fed the control diet. The supplementation of dietary R. capsulatus to finishing pig diet played important roles in reducing serum cholesterol and meat triglycerides, as well as in increasing polyunsaturated fatty acid content in LM meat.     

Effects of dietary chromium supplementation on performance, carcass characteristics, and meat quality of growing-finishing swine: a meta-analysis

Dietary Cr supplementation has potential to decrease fat and increase lean in carcasses of growing-finishing swine. However, effects of Cr supplementation on performance and economically important carcass and meat quality characteristics varied considerably among studies. Therefore, a meta-analysis was designed to quantitatively describe effects obtained in several independent studies. To accommodate differences in methodology among studies, standardized effect sizes (Hedges's g) were calculated for results from 31 studies, in which Cr was supplemented as complexes of Cr Met chelate, Cr nanocomposite, Cr nicotinate, Cr propionate, Cr tripicolinate, or Cr yeast in diets for growing-finishing swine. Summary statistics were calculated by frequentist fixed and random effects, and hierarchical Bayesian models. With characteristics related to carcass quality, observed heterogeneity (P < 0.10) could not adequately be explained in a meta-regression by differences in initial BW and amount of Cr supplemented. Random effects and Bayesian models to summarize effect sizes for these characteristics showed similar results. According to random effects models, dietary Cr supplementation decreased (P < 0.05) 10th-rib fat thickness (mean effect size = -0.479; 95% confidence intervals = -0.680 to -0.279; 24 studies; 59 comparisons), whereas percentage carcass lean (mean effect size = 0.614; 95% confidence intervals = 0.366 to 0.863; 22 studies; 52 comparisons) and LM area (mean effect size = 0.571; 95% confidence intervals = 0.364 to 0.778; 29 studies; 72 comparisons) increased. Average daily gain and G:F, which did not present heterogeneity, were improved by Cr supplementation, whereas no effects were detected in characteristics (CIE color, drip loss, cook loss, shear force) related to meat quality. Some publication, or other small-study bias, was evident in results on growth and feed efficiency. However, directions of mean effect sizes were not changed by application of the trim-and-fill method to correct for bias.     

中草药饲料添加剂及不同饲粮类型对生长肥育猪肉脂品质的影响

选取胎次、日龄、体重相近的长白ד苏黑”生长肥育猪60头,随机分为6组,每组10头,公母各半。采取纯中草药制剂、中草药VE/Se合剂、抗生素三种不同添加剂和全植物性饲粮、含鱼粉饲粮两种不同饲粮类型,进行饲养试验和屠宰测定,并对背最长肌、背部脂肪进行采样,测定分析其肉脂品质。结果表明,应用纯中草药制剂和中草药VE/Se合剂,采取全植物性饲粮,能改善生长肥育猪的肉脂品质。     

Effects of high-protein/low-carbohydrate swine diets during the final finishing phase on pork muscle quality

The aim of this study was to lower the glycogen stores in pork muscle in order to improve pork muscle quality by feeding an ultra-high-protein/low-carbohydrate (HIPRO) diet. Forty-eight barrows (average live weight = 92 kg) were assigned across five treatments and two replications (four or five pigs per treatment by replication combination). All barrows were fed a control diet (13.1% CP) until their assigned treatment began. A treatment was the number of days the barrows were fed the HIPRO diet prior to slaughter (0, 2, 4, 7, or 14 d). The HIPRO diet (35.9% CP) was 97% extruded soybeans. Daily feed intake and weekly live weights were recorded for all barrows. At-death blood glucose levels were determined. Muscle pH, temperature, and electrical impedance were measured in the longissmus lumborum and semimembranosus muscles at 45 min, 3 h, and 24 h postmortem. Glycolytic potential; Minolta L*a*b* values; visual scores for color, firmness, and marbling; water-holding capacity traits (drip loss, purge loss, and cooking loss); and Warner-Bratzler shear force values were determined in the longissmus thoracis et lumborum. Weight gain per day decreased the longer the pigs were fed the HIPRO diet (P < 0.05). Daily feed intake decreased during the 1st wk on the HIPRO diet but returned to near-control levels during the 2nd wk, which when coupled with the continued decreases in daily gain resulted in substantial decreases in feed efficiency during the 2nd wk on the HIPRO diet (P < 0.05). Blood glucose levels and glycolytic potentials were not lowered by feeding the HIPRO diet (P > 0.05); therefore, no differences in rate of pH decline or ultimate pH among dietary treatments were found (P > 0.05). Likewise, there were no differences among dietary treatments in any of the measured meat quality attributes (P > 0.05). Feeding barrows the HIPRO diet for a time period prior to slaughter decreased feed intake, rate of gain, and feed efficiency and was not effective at lowering glycolytic potential or improving pork muscle quality.     

Effects of dietary lysine/protein ratio and fat levels on growth performance and meat quality of finishing pigs

This study aimed to evaluate the effects of dietary lysine/protein ratio and fat levels on the growth, carcass characteristics and meat quality of finishing pigs fed feed made from food waste, including noodles and chocolate. Four dietary treatments, 2 levels of lysine/protein ratio (0.035 and 0.046) and 2 levels of fat (3.3% and 6.0%), were adapted to a 2 × 2 factorial arrangement. Each diet for the finishing pigs contained the same levels of adequate crude protein (16%) and lysine (0.58–0.75%), and similar levels of high total digestible nutrients (90.2–92.6%). In total, 32 LWD pigs with an average body weight of 57.2 kg were assigned to 4 dietary groups. The pigs were slaughtered at about 115 kg. Growth performance was not influenced by the dietary treatments. Carcass characteristics were slightly influenced by the dietary fat level. As the dietary lysine/protein ratio decreased, the marbling score of Longissimus dorsi muscle increased and the intramuscular fat (IMF) increased from 6.82% to 9.46%. Marbling score was not significantly influenced by the dietary fat level. These results indicate that IMF increased without adverse effects on growth, carcass characteristics and meat quality, when pigs were fed a diet with low lysine/protein ratio.     

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.     

芽孢杆菌对育肥猪生长性能和肉品质的影响

试验选择平均体重为(23.5±0.89)kg的三元商品猪75头用于评估日粮添加芽孢杆菌对生长育肥猪生长性能和肉品质的影响。共分为3组,每组5个重复,每个重复5头猪。对照组饲喂两阶段(生长和育肥期)基础日粮,试验组分别在基础日粮中添加0.015%和0.03%的芽孢杆菌。试验开展16周。结果:试验全期(0~16周)日增重和增重耗料比表现为显著线性升高(P<0.05);6周肥猪干物质消化率随日粮芽孢杆菌添加水平的升高显著线性升高(P<0.05)。0.03%芽孢杆菌组显著提高了6和16周血液葡萄糖水平(P<0.05);日粮芽孢杆菌添加水平显著线性提高16周肥猪粪中乳酸杆菌和大肠杆菌含量(P<0.05)。日粮芽孢杆菌添加水平显著线性提高了第3天猪肉感官指标、滴水损失和屠体重(P<0.05)。因此,利用芽孢杆菌作为益生菌添加到饲料中可以提高生长肥育猪的生长性能和胴体质量。     

Effects of dietary supplementation with betaine on muscle growth,muscle amino acid contents and meat quality in Cherry Valley ducks

The effects of dietary betaine supplementation on growth performance, carcass characteristics, muscle amino acid contents, meat quality, antioxidant capacity, myogenic gene expression and mechanistic target of rapamycin (mTOR) signalling pathway in Cherry Valley ducks were evaluated. A total of 720 1‐day‐old Cherry Valley ducks were randomly distributed into four groups with six replicates of 30 birds for a 42‐day feeding trial. Ducks were fed a basal diet supplemented with 0 (control), 250, 500 or 1,000 mg/kg betaine, respectively. Growth performance was not affected by betaine. Incremental levels of betaine linearly (p < 0.05) increased the breast muscle yield and linearly (p < 0.05) decreased the subcutaneous fat thickness and the abdominal fat yield. The contents of methionine, serine, glycine, glutamate and total non‐essential amino acid in breast muscle were linearly (p < 0.05) increased by betaine supplementation. With increasing betaine levels, the drip loss and the content of malondialdehyde (MDA) were linearly (p < 0.05) decreased, and the redness of meat (linear p < 0.05), the activities of catalase (CAT) (linear p < 0.05) and total superoxide dismutase (T‐SOD) (linear p < 0.05, quadratic p < 0.05) were increased. Moreover, the myogenic differentiation factor 1 (MyoD1) mRNA expression and the mTOR mRNA expression and protein phosporylation were linearly (p < 0.05) up‐regulated, and the myostatin (MSTN) mRNA expression was linearly (p < 0.05) down‐regulated by betaine supplementation. Overall, this study indicated that betaine supplementation did not affect the growth performance of Cherry Valley ducks, but could linearly increase some amino acid contents in breast muscle, especially glycine, and increase muscle antioxidant activity to improve meat quality. Moreover, betaine supplementation could improve the breast muscle yield by increasing MyoD1 mRNA expression, decreasing MSTN mRNA expression and regulating mTOR signalling pathway.     

α-硫辛酸对肉仔鸡肉品质及肌纤维组织特性的影响

本试验研究了α-硫辛酸对肉仔鸡肉品质及肌纤维组织学特性的影响。采用单因子四水平有重复试验设计,将240只1日龄AA肉仔鸡,随机分为4个处理组,每组6个重复,每个重复10只,分别饲喂在玉米-豆粕型基础日粮上添加硫辛酸0、300、600、900mg/kg的日粮,试验期42d。结果表明:硫辛酸显著降低肉仔鸡平均日增重(P0.05)和日采食量(P0.05);硫辛酸显著增加肉仔鸡肌肉a(P0.05),显著降低肌肉b(P0.05)、剪切力(P0.05);硫辛酸显著降低肉仔鸡肌纤维直径(P0.05),并显著增加肌纤维密度(P0.05);硫辛酸组显著增加慢肌(P0.05)、快红肌(P0.05)、肌球蛋白重链基因mRNA的相对表达百分比(P0.05),并显著降低快白肌肌球蛋白重链基因mRNA的相对表达百分比(P0.05)。本试验结果表明,硫辛酸可以通过影响肉仔鸡肌纤维组织特性、肌纤维类型的分布,而改善肉品质。