猪肌浆中某些元素含量与肌肉和骨骼生长的关系

研究了定远猪及其杂交F1代猪肌浆中Ca、P、Zn、Mn、Mg等元素含量与肌肉生长和后肢发育之间的相关性。结果表明，杂交使得猪肌浆中的Ca含量显著降低(P＜0.01)，导致肌浆Ca、P比例改变并升高；肌浆Mg、Mn、Zn含量变化不明显。杂交F1代猪肌浆中Ca、Zn与肌肉蛋白质含量间呈较高的正相关，r=0.84～0.91，(定远猪r=0.40)，肌浆Ca、Zn水平可能是肌肉生长的指示剂。肌浆Mn、Zn含量与后躯及后肢骨骼发育状况间的关系尚未能肯定。     

猪肌浆中某些元素含量与肌肉和骨骼生长的关系——定远猪及其二元杂交猪肌浆中的Ca、P、Mg、Mn、Zn的含量与肌肉生长和后肢发育之间的相关性比较

研究了定远猪及其杂交F1代猪肌浆中Ca、P、Zn、Mn、Mg等元素含量与肌肉生长和后肢发育之间的相关性，结果表明，杂交使得猪肌浆中的Ca含量显著降低（P＜0.01），导致肌浆Ca、P比例改变并升高；肌浆Mg、Mn、Zn含量变化不明显，杂交F1代猪肌浆中Ca、Zn与肌肉蛋白质含量间呈较高的正相关，r=0.84-0.91,(定远猪r=0.40)，肌浆Ca、Zn水平是肌肉生长的指示剂。肌浆Mn、Zn含量与后躯及后肢骨骼发育状况间的关系尚未能肯定。     

日粮中蛋白质和赖氨酸在β—激动剂的控制下对猪生长和肌肉发育的影响

试验选用３０头三元杂交猪，经饲养试验和屠宰测定（９头猪）后，比较三种蛋白质水平的日粮在苯乙醇胺的作用下对猪生长和产肉性能的影响。结果表明，日粮蛋白质水平降低２％－３．８４％，赖氨酸基本满足需要时，１５，２５ｍｇ／ｋｇ苯乙醇胺有助于增重和肌肉增长。４０－６０ｋｇ体重阶段，日粮蛋白质水平降低２％以内，且赖氨酸的供给量较高，猪的生长速度维持在较高水平；当日粮蛋白质水平下降２％以上，苏氨酸的限制性即表现出来，若希望保持高速增长，应考虑补充苏氨酸。６０－９０ｋｇ体重阶段，在低蛋白质日粮条件下（第二，三组），苯乙醇胺能有效保持高增长速度。     

植酸酶对生长肥育猪生长性能、营养素利用、胴体和肌肉品质影响的研究

选用60头平均体重28．3kg的杜长大杂种猪，随机分成2组，每组30头。在生长期（28～58kg）每组分成3圈（重复），每圈10头；在肥育期（58～95kg）每组分成6圈（重复），每圈5头。试验组饲粮中添加植酸酶750FTU／kg（FTU为植酸酶的活性单位），对照组饲粮中不添加植酸酶。生长期和肥育期饲粮钙磷比分别为1．15：1和1．18：1。试验结果显示，（1）饲粮中添加植酸酶使生长期、肥育期和生长肥育全期的平均日增重显著提高（P〈0．05），对平均日采食量和料重比无显著影响（P〉0．05）；（2）添加植酸酶对胴体和肌肉品质的影响不明显（P〉0．05）；（3）添加植酸酶对生长期养分（干物质、有机物、粗蛋白质、粗灰分、钙、磷）的消化率无显著影响（P〉0．05），但显著提高肥育期养分的消化率（P〈0．01）；（4）添加植酸酶未能提高生长期养分的吸收量（P〉0．05），但显著提高肥育期粗灰分（P〈0．01）和磷（P〈0．05）的吸收量；（5）添加植酸酶使生长期粪中铜的含量显著降低（P〈0．05），但对其他养分含量无显著影响（P〉0．05），添加植酸酶对肥育期粪中养分含量无显著影响（P〉0．05）；（6）添加植酸酶对生长期粪中养分的排泄量均无显著影响（P〉0．05），但有减少铜排泄量的趋势（P〉0．05），添加植酸酶使肥育期磷的排泄量显著降低（P〈0．05），并有降低氮和金属微量元素（铜、锌、铁、锰）排泄量的趋势（P〉0．05）。试验结果表明，饲粮中添加植酸酶可促进猪生长肥育期的增重，提高肥育期对养分的消化利用，降低生长期粪中铜的含量，减少肥育期粪中磷的排泄量；添加植酸酶对胴体和肌肉品质无不良影响。     

红三叶N、P、K、Ca、Mg元素含量与动态研究

本文研究了红三叶（Trifoliumpratense）各器官在不同生育期N、P、K、Ca、Mg等元素的含量，目的在于揭示其各器官对N、P、K、Ca、Mg的积累能力、对不同元素的选择性吸收以及N、P、K、Ca、Mg在各器官的季节动态。结果表明：红三叶不同器官对各元素的积累能力不同，N：叶＞花＞根＞茎；P：花＞叶＞根＞茎；K和Ca：叶＞花＞茎＞根；Mg：根＞叶＞茎＞花。不同器官对元素选择性吸收系列不同，根为N＞K＞Ca＞Mg＞P；茎：N＞Ca＞K＞Mg＞P；叶：N＞Ca＞K＞P＞Mg；花：N＞Ca＞K＞P＞Mg；红三叶是一种典型的N－Ca型植物。此外，K、P、K、Ca、Mg在根、茎、叶、花中的动态变化有6种基本类型，Ⅰ－渐增型（／）、Ⅱ－递减型（＼）、Ⅲ－U型、Ⅳ－∩型、Ⅴ－增波型（～）、Ⅳ－降波型（～）。     

蒙脱石对生长肥育猪生长性能和血清矿物元素含量及骨骼特征的影响

本研究探讨了日粮中添加不同水平蒙脱石对生长肥育猪生长性能、血清矿物元素含量和骨骼特征的影响。试验选用120头体重(34.79±3.42)kg健康杜×长×大三元杂交猪,按体重相近、公母各半的原则,随机分为5个处理,分别饲喂在基础日粮中添加0、0.5%、1.0%、2.5%和5.0%蒙脱石的日粮,每个处理6个重复,每个重复4头猪。试验期56 d,分生长和肥育2个阶段饲养。结果表明:日粮中蒙脱石添加量达5.0%时会显著降低猪肥育阶段和试验全期日增重和饲料转化效率(P0.05);随日粮蒙脱石的添加水平升高,猪骨骼中钾、钠、镁、锌、铁、铜和锰的含量极显著减少(P0.01)。添加量达2.5%时,骨骼钙含量显著增加(P0.05),磷舍量也有增加的趋势(P0.05)。综上,日粮添加蒙脱石水平达到或高于2.5%时,会降低生长肥育猪生长性能,减少骨骼微量元素沉积。     

饲粮中添加二甲酸钾对肥育猪生长性能、胴体性状和肌肉品质的影响

为探讨饲粮中以二甲酸钾替代抗生素促生长剂对肥育猪生长性能、胴体性状和肌肉品质的影响,选取体重（62.33±1.45）kg的杜长大三元肥育猪18头,分置于同一栋猪舍的18个猪栏内,并随机将每6个栏划分为一组,即分为对照组、黄霉素组和二甲酸钾组。对照组饲喂玉米-豆粕型基础饲粮,黄霉素组在基础饲粮中添加4%黄霉素预混剂0.125 g/kg,二甲酸钾组在基础饲粮中添加98%二甲酸钾6 g/kg,预试期7 d,正试期50 d。结果表明,生长性能方面,黄霉素组、二甲酸钾组与对照组在结束重、日增重和料重比方面均差异显著（P〈0.05）,而黄霉素组与二甲酸钾组彼此之间在结束重、日增重、料重比3个指标上差异均不显著（P〉0.05）;胴体性状方面,3组猪在屠宰率、平均背膘厚、腿臀比例、皮率、骨率、肥肉率、瘦肉率7个指标上的差异均不显著（P〉0.05）;肌肉品质方面,3组猪在肉色、大理石纹、pH1、pH2、失水率5个指标上的差异均不显著（P〉0.05）。鉴于二甲酸钾添加于肥育猪饲粮中具有与抗生素类似的促长作用,同时对胴体性状和肌肉品质未产生不良影响,而且避免了抗生素促生长剂所带来的抗药性、药物残留等安全问题,可以将二甲酸钾作为一种安全、可靠、无公害的促生长饲料添加剂,应用到优质猪肉的生产中。     

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。     

在种母鸡按标准饲喂条件下雏鸡卵黄囊中钙、磷、锰、锌含量的探讨

从按NRC标准饲养的种母鸡所产种蛋新孵出的AA肉用雏鸡中随机选取80只(公母各半),测定卵黄囊中钙、磷、锰和锌的含量及其与出壳体重和卵黄囊重的相关回归关系。结果表明,雏鸡出壳体重为48.15±0.37g,卵黄囊重为7.50±0.16g,卵黄囊中钙、磷、锰、锌的含量分别为26.86±1 90mg、49.46±1.69mg、0.018±0.002mg、0.222±0.011mg。雏鸡卵黄囊重与出壳体重的相关和回归关系显著(P≤0.05,r=0.60,b=0.25),卵黄囊重对出壳体重的回归方程为:Y=0.25X-3.75,卵黄囊中锌和磷的含量与出壳体重的相关及回归关系显著(P≤0.05,r=0.60,b=0.25),卵苏囊 重对出体重的回归方程为y=0.25x-3.75。卵苏囊中锌和磷的含量与出壳体重的相关及回归关系显著(P≤0.05)r=0.22,0.37:b=0.067,1.69)。因此,可由出壳体重估测卵黄囊重,对通过出壳体重估测卵黄囊中锌和磷的含量,也获得较为满意的结果。     

古浪灌区土壤耕层有效锌、锰、铜、铁

摘要：在2009-2010年,对古浪县井灌区、河灌区和引黄灌区326个土壤样点的耕层有效锌、锰、铜、铁含量进行定量监测分析,旨在为该区土壤合理施肥提供科学依据。结果表明,井灌区、河灌区和引黄灌区分别有81.6%、67.1%和41.7%的耕地土壤有效锌含量低于作物的需锌临界值,缺锌状况比较严重;3个灌区土壤有效锰含量分别为5.64～10.12、6.46～14.68和7.22～15.17 mg/kg,有效铜含量分别为0.42～1.12、0.90～2.00和0.81～2.47 mg/kg,均高于作物需锰（5.0 mg/kg）和铜临界值（0.2 mg/kg）,属高含量水平;3个灌区土壤有效铁含量分别为2.88～8.08、2.42～13.19和2.61～14.22 mg/kg,平均为5.40、10.20和12.30 mg/kg,虽高于作物需铁临界值（4.5 mg/kg）,但3个灌区仍分别有18.5%、6.4%和3.7%的耕地土壤有效铁含量低于作物需铁临界值。因此,3个灌区土壤耕层土壤有效锌含量严重缺乏,有效锰和有效铜含量丰富,局部地方缺铁;3个灌区种植作物时均需施锌肥,适当施铁肥,不需施锰和铜肥,施肥量依作物种类和土壤状况不同而异。     

Differential microRNA expression profiling and target gene prediction in the muscle tissues of clenbuterol-fed Chinese miniature swine

MicroRNAs (miRNAs) regulate gene expression by inhibiting the translation of target RNA. Clenbuterol (CLB) is a β-adrenergic agonist that has the ability to modify muscle characteristics by promoting protein synthesis and inhibiting the growth of fat. To determine the expression profile of miRNAs in the muscle of CLB-treated Chinese miniature swine and to predict their target genes, 13 microRNAs were detected and analyzed. We found that miR-133, miR-206, and miR-1 exhibited the highest expression, although no difference in expression levels was observed between the control and the treatment groups, whereas miR-29a and miR-29b were differentially expressed in the CLB-treated muscles. Furthermore, we analyzed the relationship between miR-29a/b expression, muscle growth, and candidate target genes, and determined that the expression of the four target genes (HnRNPF, SWI/SNF, TPM1, and LPL) was regulated by miR-29a and miR-29b and were functionally related to muscle development.     

奶牛隐性乳房炎与被毛中Zn、Cu、Mn含量的关系

分别用火焰原子吸收光谱法检测了健康对照组奶牛和 CMT/BMT 法检验为阳性的奶牛的被毛中 Zn、Cu、Mn 的含量,研究奶牛隐性乳房炎与被毛微量元素 Zn、Cu、Mn的关系。试验选择 1 个乳区患隐性乳房炎组(Ⅰ组)、2 个乳区患隐性乳房炎组(Ⅱ组)、3个乳区患隐性乳房炎组(Ⅲ组)、4个乳区患隐性乳房炎组(Ⅳ组)和健康对照组(Ⅴ组)。结果表明,Ⅰ组的Cu、Mn含量与Ⅲ组的差异显著(P<0.05),其他各组间的差异均不显著(P>0.05)。     

Immunohistological study on bovine, swine and ovine skeletal muscle fibers for the localization of fatty acid translocase FAT/CD36

The present immunohistological study was conducted to investigate the localization of fatty acid translocase CD36 (FAT/CD36) in the skeletal muscle (Biceps femoris) fibers of bovine, swine and ovine. The results showed that CD36 was mainly localized in type I muscle fiber of these animals. In contrast, FAT/CD36 localization in type II fiber was insignificant in the types of muscle in the present experiments, suggesting that type II fiber of bovine, swine and ovine might lack fatty acid translocase FAT/CD36.     

Relationships between muscle growth potential,intramuscular fat content and different indicators of muscle fibre types in young Charolais bulls

Genetic selection in favor of muscle growth at the expense of fat should affect characteristics of muscles, and therefore beef quality. This study was conducted with two extreme groups of six animals selected among 64 Charolais young bulls ranked according to their genetic potential for muscle growth. Muscle characteristics were assessed in Rectus abdominis (RA, slow oxidative) and Semitendinosus (ST, fast glycolytic) muscles. Intramuscular fat content and proportions of myosin heavy chains I (slow) and IIA (fast oxido‐glycolytic) and certain indicators of oxidative metabolism (activities of citrate synthase (CS), isocitrate dehydrogenase and cytochrome‐c oxidase (COX); expression of H‐fatty acid binding protein (FABP)) were higher in RA than in ST muscle. Genetic selection for muscle growth reduced intramuscular fat content and the activities of some oxidative metabolism indicators (namely CS, COX only). The positive correlation between muscle triacylglycerol content and A‐FABP messenger RNA level (a marker of adipocyte differentiation) (r = 0.53, P < 0.05) suggests that A‐FABP may be a good marker of the ability of bovines to deposit intramuscular fat. In conclusion, the metabolic muscle characteristics which respond to the selection process in favor of muscle growth clearly differ from the muscle characteristics which allow muscle types to be differentiated.     

Effects of monensin on Mg, Ca, P and Zn metabolism and tissue concentrations in lambs

A study consisting of two trials was conducted to determine the effects of monensin on the apparent absorption and retention of magnesium (Mg), phosphorus (P), calcium (Ca) and zinc (Zn) and to determine mineral changes in tissue and ruminal fluid. Eight lambs (39 kg) were used in trial 1, and 10 lambs (37 kg) were used in trial 2. Animals were blocked by weight and fed a high concentrate diet with or without 20 mg/kg monensin. Trials began with a dietary adjustment period lasting 18 d in trial 1 and 21 d in trial 2. Animals were then placed in metabolism stalls for a 10-d stall adjustment period followed by a 12-d collection period. Collections to determine mineral balance were made during the first 10 d of the collection period. Blood and ruminal fluid samples were taken on d 11 of the collection period. Lambs were slaughtered on d 12 of the collection period and tissue samples were collected. Monensin supplementation increased (P less than .05) Mg retention 42.0%. Urinary Ca excretion decreased (P less than .05) 60.0% when monensin was fed. Monensin supplementation decreased (P less than .05) liver Ca and bone Ca, 45.5 and 2.9%, respectively. Apparent P digestibility increased (P less than .05) 40.0% and P retention increased (P less than .10) 26.8% due to monensin supplementation. Both apparent absorption and retention of Zn increased (P less than .01) 50.0 and 45.0%, respectively, with monensin supplementation. Ruminal fluid Zn concentrations decreased (P less than .05) 33.0% with the addition of monensin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Relationship between weaning age and antibiotic usage on pig growth performance and mortality

A total of 2,184 pigs (DNA 600 × PIC L42) were used to evaluate the effects of weaning age and antibiotic (AB) use on pig performance from weaning to marketing in a commercial production system. Experimental treatments were arranged in a 3 × 2 factorial with main effects of weaning age (18.5, 21.5, or 24.5 d of age) and with the use of ABs or an antibiotic-free (NAE) program. At birth, pigs were ear tagged, and the date of birth and sex recorded. Pigs were weaned from a 4,000-sow farm over four consecutive weeks. Four weaning batches (one per week) of 546 pigs were used. Each weaning batch had one-third of pigs of each weaning age. Pigs were placed in pens by weaning age and then randomly assigned to an AB or NAE program. There were 14 replicate pens per treatment and 26 pigs per pen (13 barrows and 13 gilts). Pigs allocated to the AB program were fed a diet containing 441 mg/kg chlortetracycline (CTC) from day 8 to 21 postweaning. They were also administered 22 mg/kg of body weight (BW) of CTC via drinking water for five consecutive days after a porcine respiratory and reproductive syndrome outbreak during week 7 after weaning. In the first 42 d postweaning, increasing weaning age improved (linear, P < 0.001) BW at day 42, average daily gain (ADG), and average daily feed intake (ADFI). From weaning to 197 d of age, increasing weaning age increased (linear, P < 0.001) ADG and ADFI. Pigs on the AB program had greater (P = 0.031) ADG and ADFI compared with NAE pigs. An interaction (linear, P = 0.005) was observed for feed efficiency (G:F). When ABs were provided, increasing weaning age did not result in any change in G:F; however, in the NAE program, increasing weaning age increased G:F. Pigs on the AB program had lower (P < 0.001) total losses (mortality and removals) than those on the NAE program. Increasing weaning age marginally (linear, P = 0.097) decreased total losses. Increasing weaning age decreased (quadratic, P < 0.001) the number of pigs treated with an injectable AB but the AB program did not (P = 0.238). The weight sold (at 197 d of age) per pig weaned was increased (linear, P = 0.050) by increasing weaning age and by using AB in feed and water (P = 0.019). In summary, increasing weaning age linearly improved most of the pig performance criteria and relatively the short-term use of ABs reduced mortality and removals with both factors contributing to increased weight sold per pig weaned.     

猪瘟超前免疫对仔猪生长及抗体水平的影响

选择品种、日龄、胎次相同,初生重和产仔数相近的约长撒三元杂交仔猪两窝,随机分为两组,窝内仔猪头数为组内重复数,一窝12头仔猪进行猪瘟超前免疫为试验组,另一窝9头进行正常免疫对照,测定仔猪1～60日龄的生长速度、饲料利用率及猪瘟抗体水平。结果表明:猪瘟超前免疫可以降低仔猪发病率,提高成活率;但会对仔猪的生长发育及饲料利用率产生负面影响。