晋南牛公牛与阉牛育肥性能和肉品质的比较研究

旨在研究比较晋南牛公牛和阉牛的育肥性能、屠宰性能和肉品质。选择健康状况良好、体重相近的晋南公牛和阉牛各10头,通过300 d的强度育肥试验后屠宰测定各项指标。结果显示,公牛组的平均日增重、宰前活重、胴体重、屠宰率和眼肌面积均显著高于阉牛组(P0.05),而优质切块率组间差异不显著(P0.05)。屠宰排酸72 h后,阉牛组大理石花纹评分显著高于公牛组、剪切力显著低于公牛组(P0.05)。而pH值、失水率和肉色组间差异不显著(P0.05),阉牛组大理石纹等级平均达到三级以上,接近于生产高档牛肉的标准。因此,晋南牛可通过阉割育肥生产高档牛肉。     

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。     

虫草真菌发酵中草药培养基对生长肥育猪生产性能和胴体品质的影响

随机选择65日龄、均重25.0kg的杜长大生长猪160头,随机分为4组,研究虫草真菌液体发酵中草药培养基对生长肥育猪生产性能和胴体品质的影响。结果表明,日粮中添加100mg/kg、200mg/kg和300mg/kg虫草真菌液体发酵中草药培养基后,与对照组相比,生长肥育猪的日增重分别提高了7.64%、9.23%和11.19%(P≤0.05或P≤0.01),采食量分别提高了2.72%、1.37%和2.10%(P≥0.05),料肉比分别降低了4.58%、7.19%和8.17%(P≤0.05或P≤0.01),屠宰率分别提高了2.95%、5.66%和8.53%(P≤0.05或P≥0.05),瘦肉率分别提高了0.60%、2.67%和6.64%(P≥0.05),背膘厚分别降低了4.29%、5.71%和8.29%(P≤0.05或P≥0.05)。结论:虫草真菌液体发酵中草药培养基可明显提高生长猪生产性能,改善育肥猪胴体品质。     

Effect of grazing and dietary protein on eating quality of Podolian beef

Twenty-four young Podolian bulls were used to evaluate the effect of rearing system (extensive vs. intensive) in relation to postmortem aging (11 and 18 d) on the eating quality of the meat, with the diet of outdoor animals adjusted to the protein content of the indoor system (15% CP) or to the minimum protein content required for satisfactory growth (12% CP). At 415 ± 9.35 (SE) d of age, with a mean BW of 337.5 ± 16.51 (SE) kg, animals were allotted to 3 groups for the finishing period (172 d): 1) indoor group receiving a diet at 15% CP; 2) grazing animals receiving a diet at 15% CP of DM; and 3) grazing animals receiving a diet at 12% CP of DM. Longissimus dorsi lumborum muscle sampled from the right half and divided longitudinally into 2 sections was aged in vacuum packaging at 4°C until 11 and 18 d postmortem, respectively. Rearing system did not affect (P > 0.05) color, Warner-Bratzler shear force, texture profile, water-holding capacity, and most of the sensory attributes of the beef steaks. However, sensory tenderness was less in the meat from outdoor animals receiving a diet with 15% CP than in meat from outdoor animals receiving a diet with 12% CP or from the indoor group (P < 0.05). Meat aged 18 d showed decreased Warner-Bratzler shear force (P < 0.001), hardness (P < 0.001), cohesiveness (P < 0.05), springiness (P < 0.05), gumminess (P < 0.01), chewiness (P < 0.01), and thawing loss (P < 0.01) compared with meat aged for 11 d. Prolonging the aging time up to 18 d significantly increased b* (yellowness; P < 0.05), cooking losses (P < 0.001), and the intensity of all the texture sensory attributes, namely, juiciness and fatness (P < 0.05), chewiness, tenderness, and flavor (P < 0.01). Significant correlations were found between instrumental and sensory variables (range of r = -0.55 to -0.85, P < 0.05 to 0.001). Overall, in the present study, the rearing system did not markedly affect meat sensory and physical properties. Thus, we conclude that an outdoor system, even with reduced protein supplementation, may represent a valid farming system for local breeds in Mediterranean areas characterized by poor-quality pastures. However, an extended aging period is suggested to improve the main factor limiting the quality of this product, namely, reduced tenderness.     

Flavomycin effects on performance of beef bulls and nutrient digestibility in wethers

For 28 weeks a feeding experiment was conducted to determine the effects of dietary flavomycin on performance of beef bulls. In the first and second half of the trial, 40 animals (average initial weight 352 kg) had free access to corn silage or beet pulp, respectively, both supplemented with an appropriate concentrate containing 0 or 10 mg/kg of the antibiotic. Daily flavomycin intake was 39 to 46 mg when the animals were on the corn silage diet and 51 to 54 mg when they were fed the beet pulp diet. The animals fed the corn silage-based diet supplemented with flavomycin showed a non-significant improvement of daily gain (1.4%) and feed conversion (2.3%). When the beet pulp-based diet was fed, flavomycin significantly increased daily gain (15.2%, P less than 0.002) and feed conversion efficiency (9.1%, P less than 0.03). For the overall feeding experiment the positive effect of flavomycin feeding was 6.7% on body weight gain (P less than 0.09) and 5.2% on feed conversion (P less than 0.13). Flavomycin did not affect carcass yield of beef bulls. Also the effect of flavomycin on diet digestibility was studied in wethers fed a mixture of beet pulp and concentrate, containing 0 or 10 ppm flavomycin. No significant effect from the antibiotic on digestion of dry matter, crude protein, fibre, fat, ash and N-free extract was observed.     

蛋白质水平对肉牛育肥效果的影响

试验设计5个营养水平的精料补充料配方,分别饲喂5个试验组肉牛,并与不添加精料补充料的对照组进行比较。结果显示,各试验组平均总增质量和平均日增质量均优于对照组,经济效益也明显高于对照组。5个营养水平中,23%蛋白水平增质量效果最好,11%蛋白质水平经济效益最佳。     

饲粮添加益生菌对山羊屠宰性能、肉品质和器官发育的影响

为探明饲粮添加益生菌对山羊屠宰性能、肉品质和器官发育的影响,本研究将36只健康、体重相近的2月龄左右努比亚母羊随机分为3组,每组12只羊,试验羊分别饲喂添加0?(试验Ⅰ组)、0.5‰?(试验Ⅱ组)和1.0‰?(试验Ⅲ组)益生菌的基础饲粮,试验期为70?d.结果表明:1)?试验Ⅱ组山羊的胴体重和后腿重显著高于试验Ⅲ组(P?<0.05),试验Ⅱ组山羊的宰前活重、屠宰率和眼肌面积均高于其他两组(P?>?0.05).2)?各组间山羊的肌肉pH、熟肉率、失水率、剪切力和肉色无显著差异(P?>?0.05).3)?试验Ⅲ组山羊的心脏重量和指数显著低于试验Ⅰ组(P??0.05).4)?试验Ⅱ组山羊的十二指肠绒毛高度和绒毛高度/隐窝深度(villus?height/crypt depth,?VH/CD)显著高于试验Ⅲ组(P??0.05).综上所述,饲粮中添加低水平益生菌在一定程度上能够改善山羊的屠宰性能和器官发育.     

半胱胺和糖萜素对育肥后期荷斯坦公牛生产性能和产肉品质的影响

选择生长肥育后期(440 kg左右)的试验牛18头,随机分成3组.研究日粮中添加糖萜素和半胱胺对育肥后期荷斯坦公牛的生产性能、屠宰性能及肉品质的影响.结果表明:日粮中添加糖萜素显著提高了日增重(P<0.05).同时,净肉率和屠宰率显著高于对照组(P<0.05);臀腰肌中氨基酸总量显著提高(P<0.05),甘氨酸、组氨酸和精氨酸含量显著高于对照组.添加半胱胺组净肉率和屠宰率提高,其中屠宰率差异极显著(P<0.01);异亮氨酸含量极显著高于对照组(P<0.01),赖氨酸、组氨酸、亮氨酸含量显著高于对照组(P<0.05).     

日粮添加盐酸吡格列酮和维生素E对黄羽肉鸡生长性能和肉品质的影响

试验旨在研究盐酸吡格列酮(Pioglitazone hydrochloride,PGZ)与维生素E(Vitamin E,VE)联合使用对黄羽肉鸡生产性能和肉品质的影响。试验选取70日龄体重相近的母鸡[BW=(1.69±0.01) kg]800只,随机分为4个处理组,每个处理组5个重复,每个重复40只鸡。对照组饲喂基础日粮(含30 mg/kg VE),PGZ组饲喂基础日粮+15 mg/kg PGZ,VE组饲喂基础日粮+170 mg/kg VE,PGZ+VE组饲喂基础日粮+15 mg/kg PGZ+170 mg/kg VE,试验期28 d。试验结束后,每个重复选择体重接近平均体重的3只鸡进行屠宰试验。结果表明:与对照组相比,日粮添加VE显著增加黄羽肉鸡平均日采食量(P0.05);PGZ组、VE组和PGZ+VE组显著降低血清总胆固醇和甘油三酯的含量(P0.05),且与对照组相比,PGZ组和PGZ+VE组显著降低低密度脂蛋白的含量(P0.05)。PGZ组与PGZ+VE组显著提高黄羽肉鸡腹脂率(P0.05);日粮添加PGZ显著降低腿肌蒸煮损失(P0.05),同时,PGZ组和PGZ+VE组黄羽肉鸡腿肌肌内脂肪含量(Intramuscular fat,IMF)显著性提高(P0.05),且PGZ+VE组黄羽肉鸡腿肌肉色红度比对照组增加了18.98%(P=0.086)。综上所述,日粮添加15 mg/kg PGZ和170 mg/kg VE(总含量为200 mg/kg)可提高黄羽肉鸡的生长性能,并改善黄羽肉鸡肉品质,尤其提高腿肌IMF含量。     

能量和蛋白来源对生长育肥猪生长性能、胴体性状和肉质的影响

试验旨在探讨饲粮能量和蛋白来源对育肥猪生长性能、养分消化率、血清生化指标、胴体性状以及肉质的影响。试验采用2×2因子试验设计,选取DLY育肥猪60头[平均体重(81±7.89) kg],随机分为4个处理,每个处理5个重复,每个重复3头猪。饲粮能量来源包括玉米和小麦,饲粮蛋白来源包括豆粕和菜粕。4个处理分别饲喂玉米-豆粕型、玉米-菜粕型、小麦-豆粕型、小麦-菜粕型饲粮,试验期28 d。结果表明:①4种饲粮对猪平均日采食量和平均日增重无显著影响(P0.05),但玉米豆粕组的料重比显著低于其余3组(P0.05)。②能量和蛋白来源显著影响养分的消化率。与小麦饲粮相比,玉米饲粮极显著提高了粗脂肪、干物质、灰分、钙和磷的消化率以及能量的利用率(P0.01);与豆粕饲粮相比,菜粕饲粮极显著提高了钙、磷的消化率和能量的利用率(P0.01),显著提高了干物质的消化率(P0.05)。③与豆粕饲粮相比,菜粕饲粮极显著提高了猪血清尿素氮的含量(P0.01);与小麦饲粮相比,玉米饲粮显著提高了猪血清总蛋白水平,显著降低了胰岛素样生长因子Ⅰ水平。④玉米豆粕组的眼肌面积显著高于玉米菜粕组(P0.05);与玉米菜粕组相比,小麦菜粕组显著降低了肌肉的蒸煮损失(P0.05),显著提高了肌内脂肪含量(P0.05)。由此可见,4种饲粮对育肥猪的生长性能无显著影响,但显著影响猪养分的表观消化率,且对育肥猪胴体性状、肉质有一定的影响。     

Some nutritional and genetic considerations in the performance testing of beef bulls

Performance testing started after it was recognized that growth traits were heritable. In the early years of performance testing there was a tendency to feed higher levels of energy for longer periods of time. More recently, the trend has been to feed lower levels of energy for shorter periods. There are still differences in opinion as to the appropriate level of energy to use. Although it is important that the level of energy fed is adequate to correctly establish a bull's ability to gain, it is essential to know that it will pose no risk of impaired spermatogenesis or cause any degree of laminitis. Clinical observations and research on overfeeding clearly show that both libido and spermatogenesis can be impaired by excess energy intake. The damage in 2-year-old bulls can be very extensive and in some animals it may not be reversible. The scant amount of research in yearling bulls indicates that there is considerable potential danger from overfeeding energy as well. Test stations are under used in regard to performing research that would help identify heritable defects that would interfere with the productive and reproductive efficiency of beef cattle. The first performance testing programs emphasized average daily gain from weaning to 1 year of age, so "performance" has traditionally meant rate of gain to most cattle raisers. The term "performance" is now starting to acquire a broader and more inclusive definition. For many breeders, it now includes weight per day of age, which is in part a maternal trait, and some kind of male evaluation for reproductive potential that can also be extrapolated to the female side. One of the first breakthroughs in this regard was to recognize the heritability of testicular size, and that testicular size could be fairly accurately determined by scrotal circumference measurement. It was also found that there was a favorable relationship between larger testicle size and the ability to produce high quality semen. As a result, it became a common practice to include scrotal circumference measurements in the published bull test results. However, many test station patrons were, and still are, content to consider the scrotal circumference measurement alone as an evaluation of a bull's breeding potential. Unfortunately, less than half of the bulls finishing a performance test at ages ranging from 11 to 14 months will be able to produce semen of completely acceptable quality.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effect of dietary iron and copper on performance and oxidative stability in broiler leg meat

1. An experiment was carried out to determine the effect of removal of supplemental iron and copper from broiler diets during the last 3 weeks before slaughter on broiler performance, tissue vitamin E concentrations and oxidation values in raw; cooked and stored broiler leg meat. 2. Removal of supplemental iron and copper from the diet slightly decreased food efficiency; the differences were significant only when both minerals were removed simultaneously 3. Effect of iron withdrawal on iron concentration in tissue was low. However, total copper concentration in tissue was reduced in animals deprived of iron or both minerals simultaneously. 4. Removal of dietary iron and copper did not affect vitamin E concentration in raw and cooked meat, while stored meat showed lower concentrations in animals deprived of iron and copper simultaneously. 5. The removal of iron and copper from the diet reduced oxidation values in cooked broiler leg meat as measured by the thiobarbituric acid-reacting substances method (TBARS).     

Breeding performance of beef bulls assigned to two-sire cow groups on pasture

Angus, Polled Hereford and Santa Gertrudis bulls from ages 1 through 5 and 7 yr were assigned to 26 two-sire breeding groups. Each year, straightbred and crossbred cows of these breeds were allotted at random within breed composition, age of dam and calving date to breeding groups on pasture. Sires within each breeding group or pair were the same age at breeding and were two of the three breeds of sires. Neither calving rate nor the proportion of calves born by one vs the other sire in the two-sire breeding groups was affected by sire age among breeding groups. For a given breed, there was no uniformity among the sires in the proportion of calves they sired in their two-sire breeding groups. The proportion of calves born for the 26 sire pairs averaged .64 vs .36 (SE = 0.4 for either high or low value) for one vs the other sire in a sire pair with no indication that calving rate was affected by unequal proportions of calves by sires within sire pairs. Cows calved significantly earlier in the calving period (b = -.775 +/- .127) as calving rate increased among sire pairs. The number of days from the start of the breeding period to calf birth was affected by differences between sires in sire pairs for 8 of the 26 pairs, but there were no significant differences due to sire pair or breed of sire because of interaction between these two variables.     

燃料乙醇DDGS对肉仔鸡生产性能、肉品质及胫骨质量的影响

分析燃料乙醇DDGS营养成分及毒素含量,研究此种DDGS对肉仔鸡生产性能、肉品质及骨骼质量的影响。试验选用240只1日龄科宝艾维茵48肉仔鸡,随机分成4组,每组6个重复。对照组饲喂基础日粮,1～21日龄阶段,试验Ⅰ、Ⅱ、Ⅲ组饲喂含有10%燃料乙醇的DDGS日粮;22～35日龄和36～49日龄两个阶段,试验Ⅰ、Ⅱ、Ⅲ组分别饲喂含有10%、20%和30%燃料乙醇的DDGS日粮。结果表明:DDGS显著降低1～21日龄肉仔鸡采食量(P<0.05);DDGS显著增加肉仔鸡腿肌黄度(P<0.05);DDGS显著增加肉仔鸡骨矿物含量(P<0.05)、胫骨长度(P<0.05)及胫骨重量(P<0.05)。DDGS具有改善胫骨质量的作用。     

牛至油对育肥猪生长性能和肉品质的影响

文章旨在研究不同浓度的牛至油对肥育猪生长性能和肉质特性的影响。试验选择32头阉割公猪和32头后备母猪随机分成4个组,对照组饲喂基础日粮,试验组分别在基础日粮中添加0.2、0.4和0.8mg/kg牛至油,试验共开展5周。试验结束后禁食12h,称重后屠宰。经过一夜的冷却,从屠体上取50cm的腰肌(每组8头,4头公猪、4头母猪)。日粮中添加牛至精油对生长猪末重、日增重、屠宰率均无显著差异(P>0.05),同时各组最长肌嫩度、屠宰后45min和24h后的pH、肉色及感官特性也无显著差异(P>0.05)。此外,脂质氧化试验结果显示,日粮添加牛至油对肌肉无明显的抗氧化作用(P>0.05)。综上所述,由于胴体和肉质属性均无显著变化,说明本试验中日粮添加不同水平牛至油对猪的肉质参数没有影响。     

中草药提取物对育肥猪生长性能和肉质的影响

试验选择体重60kg左右的"长大"二元杂交阉公猪180头,根据"胎次一致、品种相同、体重相近"的原则,随机配对分成复方1#、复方2#、复方3#3个试验组和1个对照组。研究中草药提取物对育肥猪生产性能和肉质的影响。研究结果表明,中草药提取物组均能提高生长肥育猪的生长速度和提高饲料报酬;有效提高猪的抗病能力;可显著提高猪的胴体瘦肉率,增大眼肌面积,降低背膘厚;有效改善育肥猪肉质。     

谷胱甘肽对肉羊生长性能、屠宰性能及肉品质的影响

选择东北细毛羊×德国肉用美利奴的杂交一代肉羊12只,分成对照组、试验Ⅰ组和Ⅱ组,每组4只,研究谷胱甘肽对肉羊生长性能、屠宰性能及肉品质的影响。试验期60 d。结果表明:与对照组相比,谷胱甘肽显著提高了肉羊的日增重(P<0.05),试验Ⅰ组、Ⅱ组分别提高了14.6%和11.4%;降低了肉羊的料重比(P<0.05),试验Ⅰ组、Ⅱ组分别降低了11.0%和8.1%。试验Ⅰ组的净肉率和GR值显著高于对照组(P<0.05),Ⅱ组的宰前活重显著高于对照组(P<0.05);试验Ⅰ组肉的剪切力显著低于对照组(P<0.05);试验Ⅰ组、Ⅱ组的滴水损失显著低于对照组(P<0.05),而熟肉率显著高于对照组(P<0.05),且两试验组间差异不显著(P>0.05);各试验组宰后45 min内肉的pH没有显著差异(P>0.05),但试验Ⅰ组24 h的pH极显著地高于其他2组(P<0.01)。     

饲粮中添加黄芩提取物对肉鸡生长性能、营养物质消化率和肉质的影响

文章旨在研究饲粮中添加黄芩提取物对肉鸡生长性能、营养物质消化率和肉质的影响。试验选取平均体重接近的1日龄AA肉鸡100只,称重后随机分为4组,试验1、2、3组在对照组基础饲粮基础上分别添加0.02%、0.04%、0.06%的黄芩提取物,处理42 d。试验结果:与对照组相比,试验2、3组肉鸡21日龄体重分别显著提高10.5%、9.3%(P<0.05),试验1、2、3组肉鸡42日龄体重分别显著提高8.7%、11.9%、10.4%(P<0.05)。1~21日龄,试验2、3组肉鸡ADG分别显著提高11.2%、10.0%(P<0.05);22~42日龄,试验1、2、3组肉鸡ADG分别显著提高9.5%、12.5%、10.9%(P<0.05),试验2、3组FCR分别显著降低12.7%、8.2%(P<0.05);1~42日龄,试验1、2、3组肉鸡ADG分别显著提高8.8%、12.2%、10.7%(P<0.05),试验2、3组FCR分别显著降低11.0%、7.8%(P<0.05)。试验1、2、3组肉鸡对饲粮中氮的消化率较对照组分别显著提高8.2%、9.8%、7.5%(P<0.05),试验2、3组肉鸡对GE的消化率分别显著提高8.5%、7.3%(P<0.05),试验2组肉鸡对饲粮中DM的消化率提高8.0%(P<0.05)。试验1、2、3组肌肉第5天的滴水损失较对照组分别显著降低14.9%、15.7%、15.2%(P<0.05)。表明,黄芩提取物可以促进肉鸡生长,改善养分消化率和肉质,添加量为0.06%时效果最好。