嘉兴黑猪新品系选育研究

嘉兴黑猪新品系是以优良地方品种嘉兴黑猪为基本育种素材,导入18.75%外来瘦肉型公猪血缘,采用现代遗传育种学原理,经过10多年的精心培育而成.尤其是经过"九五"期间6年5个世代系统严格选育,其主要经济性状均已达到或超过育种目标.初产母猪头胎平均产仔数11.27头,产活仔10.86头,经产母猪平均产仔数达14.36头;纯种猪肥育期(25～75kg)日增重493 g,料重比3.36;75 kg屠宰胴体瘦肉率52.1%,平均背膘厚2.75 cm.以新品系猪为母本,用长白公猪、大约克公猪、皮特兰公猪进行二元杂交,3个杂交组合肥育期(25～90 kg)平均日增重587 g,料重比为3.29;90kg屠宰平均胴体瘦肉率为55.5%,屠宰率72.17%,平均背膘厚为3.04 cm,其生产水平达到了"二洋一土"杜长嘉三元杂种猪的水平.筛选出的最优杂交组合长白猪×新品系,日增重634 g,料重比3.07,胴体瘦肉率55.4%,是一个较理想的高产、优质杂交组合,值得生产上大力推广利用.     

梅山猪、通城猪与湖北白猪的杂交猪生产性能观察

此试验以梅山猪、通城猪为父本,测定其与湖北白猪的杂交猪肥育性能、胴体与肉质性状及繁殖性能。结果表明,梅湖杂交猪肥育期日增重514.39g、料重比3.56、瘦肉率56.53%、肌内脂肪含量3.91%,初产母猪产仔数12.36头、产活仔数11.73头,二胎母猪窝产仔数15.67头、产活仔数15.17头;通湖杂交猪肥育期日增重511.47g、料重比3.72、瘦肉率53.72%、肌内脂肪含量3.51%,初产母猪产仔数10.32头、产活仔数10.24头,二胎母猪产仔数12.20头、产活仔数11.80头。两组合料重比、初产产活仔数差异显著;瘦肉率、肌内脂肪含量、初产及二胎产仔数差异极显著。说明杂交猪具有良好的繁殖性能和胴体与肉质性状,且梅湖杂交组合效果优于通湖杂交组合。     

滇陆（N1）系猪选育及杂交利用研究报告

滇陆N1系猪选择D1系(长白、太湖各半血)公猪和约乌二元杂母猪组成基础群,采用群体继代选育法,历时7年,完成了0～5世代6个世代的选育,5世代核心群参配母猪99头,24d内受胎97头,情期受胎率97.97%.初产仔(11.00±2.11)头,产活仔(10.18±2.25)头,经产(12.54±2.83)头.同胞育肥猪达90kg体重日龄184d,料重比3.251,胴体瘦肉率51.25%.与英系大约克杂交,杂种优势显著,杂优猪151日龄体重90kg,料重比3.211,日增重842g,杂种优势率36.25%,胴体瘦肉率57.45%.产仔数和瘦肉率主选性状遗传性基本稳定,体型外貌基本一致.     

滇陆新品系猪选育及杂交利用研究报告

滇陆新品系猪 (N1系 ) ,选择D1系 (长白、太湖猪各半血 )公猪和约乌二元杂母猪组成基础群 ,采用群体继代选育法 ,历时 7年 ,完成了 0～ 5世代六个世代的选育。五世代核心群参配母猪 99头 ,2 4天内受胎 97头 ,情期受胎率 97 97%。初产仔 1 1 0 0± 2 1 1头 ,产活仔 1 0 1 8± 2 2 5头 ,经产 1 2 54± 2 83头。同胞育肥猪达 90kg体重日龄 1 84天 ,料重比 3 2 5,胴体瘦肉率 51 2 5%。与英系大约克杂交 ,杂种优势显著 ,杂优猪 1 51日龄体重 90kg ,料重比 3 2 1 ,日增重 84 2 g ,杂种优势率 3 6 2 5%,胴体瘦肉率 57 45%。产仔数和瘦肉率主选性状遗传性基本稳定 ,体型外貌基本一致。已全面完成合同规定各项主要技术经济指标     

二花脸猪和双肌臂大约克、新丹系长白猪的选育与杂交利用研究

二花脸、双肌臀大约克、新丹系长白纯种和长·二、大·二杂种经产母猪46、389、215、34、42窝的窝总产仔数分别是15.57、11.81、11.89、14.97、15.02头,窝产活仔数分别是14.80、11.45、11.66、14.44、14.60头;前三组纯种和大×二、长×二、大×长·二、长×大·二杂种共7组每组各20头育肥猪的全期日增重分别是480.3、829.8、806.3和741.4、720.4、781.5、770.3g,料重比分别是3.89、2.81、2.83和3.26、3.29、3.23、3.26,每组各屠宰6头的平均瘦肉率分别是43.65%、65.54%、65.81%和53.93%、54.02%、58.73%、59.46%,各组母猪平均每头年产瘦肉量分别是737.15、1283.38、1282.88和1236.48、1230.43、1298.65、1368.46kg。     

桑梓湖长白猪新品系选育与推广研究报告

桑梓湖长白猪新品系以新丹系和原有老丹系长白为材料,全年实行大群测定,运用Blup育种软件选育,经过1997～2001年共5年四个世代的测定与选择,其主要经济性状已达到了育种目标。初产母猪平均产仔数(10.82±0.97)头,经产母猪平均产仔数(11.58±0.84)头,长白公猪达100kg日龄(158.9±8.2)天,30～100kg日增重(868.8±87.5)克,料重比2.25±0.11,校正100kg背膘(1.32±0.18)厘米,长白母猪100kg日龄(157.3±6.82)天,30～100kg日增重(841.1±80.7)克,料重比2.39±0.16,校正100kg背膘(1.35±0.19)厘米。运用BLUP分析五年选育累计,日龄缩短3.52天,背膘降低2.02毫米。长白眼肌面积(48.98±3.73)厘米2,胴体瘦肉率69.05%,且氟烷基因阴性,肉质优良;长大日增重达855.2g,达100kg日龄163.1天,达100kg背膘厚1.51cm,窝产仔数11.32头。用地方改良品种作母本,桑梓湖长白做父本,日增重提高61克,背膘下降0.56厘米,活体估测瘦肉率上升10.11%,呈显著或极显著差异。近五年来在选育同时,共向社会提供种猪19549头,其中长白原种3611头,商品猪3.1万头,创利1109万元,创社会效益1.96亿元。     

苏钟猪的选育

苏钟猪是以太湖猪和外来良种为亲本,运用现代遗传育种理论及先进的育种手段,历时10余年精心培育的优质高产瘦肉猪母系品种,2001年通过江苏省新品种审定.该猪全身被毛白色,经产母猪平均产仔数14.25～14.35头,乳头数7～8对,达90 kg体重日龄为175～177天,胴体瘦肉率54.32%～54.49%;以苏钟猪为母本的二元(大约克×苏钟)杂优猪,育肥性能好,达90 kg体重日龄为160～163天,日增重702.67～727.23 g,料重比3.11,胴体瘦肉率58.79%～58.90%.     

我国五地区五品种生长肥育猪生产性能和胴体品质试验报告

在全国选择具有典型区域、气候和猪种特点的五地区五品种生长肥育猪258头,以玉米—豆粕型日粮为基础日粮,预混料统一配制,在日粮充分营养水平下测定了不同品种生长肥育猪的生产性能和胴体品质。长白×大白×北京黑猪全期(20～100kg阶段)日增重、饲料采食量、饲料转化率分别为0.76kg/d、2.14kg/d、2.74。杜×长×大猪全期日增重、饲料采食量、饲料转化率分别为0.68kg/d、2.05kg/d、3.01。杜×大×长猪全期日增重、饲料采食量、饲料转化率分别为0.72kg/d、1.78kg/d、2.56。长白×荣昌猪全期日增重、饲料采食量、饲料转化率分别为0.70kg/d、2.02kg/d、2.85。长白×哈白猪全期日增重、饲料采食量、饲料转化率分别为0.59kg/d、2.13kg/d、3.59。从总体生长情况来看,去势公猪日增重、饲料采食量有高于小母猪的趋势,饲料转化率有低于小母猪的趋势。从不同品种生长情况来看,长白×大白×北京黑猪全期生长情况好于其它各品种猪,其次为杜×大×长猪。从胴体品质来看,去势公猪与小母猪大部分胴体品质差异不显著(P>0.05),近上市体重时,杜×长×大猪瘦肉率较其它品种猪高,长白×哈白猪屠宰率较其它品种略高。     

长白与大白猪正反杂交组合生产性能的比较研究

对长白、大白猪的正反杂交组合长×大和大×长的繁殖、生长、肉用性能进行了测定。试验结果表明 :大×长在产仔数、日增重、瘦肉率、背膘厚、眼肌面积、胴体长等性状及体型上优于长×大 ,而在其它性状上基本接近。     

不同杂交组合猪肥育性能的研究

对大白猪×山西白猪、大白猪×马身猪、大白猪×大白猪、马身猪×马身猪和山西白猪×山西白猪等5个组合猪肥育性能研究。选择体重相近、健康的猪作为试验猪,平均体重30 kg,每个组合10头,公母各半,单圈饲养,通过饲养试验和屠宰试验测定不同组合猪的日增重、饲料转化率和胴体指标。结果表明:①大白猪×山西白猪组、大白猪×马身猪组平均日增重,达90 kg体重日龄和饲料转化率分别为769.7 g/d和731.4 g/d;162.1 d和170.3 d;3.08∶1和3.40∶1;②大白猪组×山西白猪组,大白猪组×马身猪组平均屠宰率、瘦肉率、背膘厚、眼肌面积分别为72.85%和70.68%;64.65%和57.90%;2.70 cm和3.64 cm;38.43 cm2和35.60 cm2;29.53%和28.08%。     

新美系猪选育群及其杂交组合的杂交效果分析

试验共设6个组,包括杜、长、大三个纯种组和长×大、大×长、杜×长大三个杂交组,每组选取健康的、体重约25 kg的试验猪12头,公母各半,经过预饲调整后每组选取10头开始正式试验。饲养至组平均体重达100 kg左右时,每组选取4头（2♂2♀）进行屠宰测定和肉质分析,并计算了三个杂交组猪的各主要经济指标的杂优率（H）。结果表明,目前选育群各品种猪的日增重830 g以上,料肉比2.53以下,瘦肉率67%以上,肉质优良。三个纯种组中生长速度以杜洛克为最快,平均日增重达912 g;料肉比以大白猪的最低,为2.35;长白猪的屠宰率、胴体斜长、眼肌面积、瘦肉率最高,背膘厚最薄;6个组中杜×长大商品猪生长最快,平均日增重达977 g,料肉比为2.34,并有较理想的杂优率,而相对于长×大和大×长组合而言,许多重要经济性状,如背膘厚、眼肌面积、后腿比例、脂率、贮存损失等,大×长的杂优率均优于长×大,表明大×长组合也是非常有效的杂交组合,可为筛选新的杂优组合提供参考依据。     

猪肌肉糖原磷酸化酶基因的多态性及其与胴体和肉质性状的相关分析

试验旨在寻找不同品种猪的差异表达基因,并对其遗传效应进行初步分析。应用抑制消减杂交技术获得了在梅山猪、长白猪和大白猪中差异表达的肌肉糖原磷酸化酶(glycogen phosphorylase,muscle form,PYGM)基因及其全长cDNA序列,序列分析结果表明,猪PYGM基因编码842个氨基酸,与人、牛、狗、小鼠、大鼠和羊的氨基酸序列具有96%、97%、96%、96%、96%和97%的相似性,而且该基因在各组织中表达量均很高。通过序列比对发现,在3′非翻译区(3′UTR)125 bp处存在1个突变。利用PCR-RFLP方法,在大白猪、梅山猪、长白纯种猪和170头大白×梅山F2代资源家系中检测了该突变位点的多态性并进行性状关联分析,结果表明,该位点的多态性与瘦肉率、骨率、肥肉率、平均背膘厚、眼肌面积、胴体长显著相关,尤其是活体瘦肉率AA基因型(大白猪、长白猪优势基因)比BB基因型(梅山猪优势基因)高3%,肥肉率低5%,与外来猪种瘦肉率显著高于本地猪的性状表现是一致的。因此,猪PYGM基因125 bp位点可能是一个潜在的分子标记辅助常规育种位点。     

杜洛克猪、长白猪、大白猪和梅山猪组合配套杂交商品猪屠宰性能和肉质性状研究

为研究杜洛克猪(D)、长白猪(L)、大白猪(Y)和梅山猪(M)组合的配套杂交商品猪(DLYM)的胴体品质和肉质特性,本试验对其屠宰性能和肉质性状进行了系统测定。结果表明,DLYM瘦肉率为53.97%±6.82%;平均背膘厚为3.32 cm±0.52 cm;眼肌面积为46.01 cm²±3.14 cm²;屠宰后45 min的pH₁为6.69±0.52;熟化24 h后pH₂为5.68±0.74;屠宰后45 min光反射值为41.59±4.24;屠宰后24 h光反射值为49.42±5.61;大理石纹为2.33±0.07;滴水损失为3.58%±0.25%;剪切力为4.82 kg±1.36 kg。综合测定结果表明,DLYM杂交商品猪瘦肉率适中,在肉质性状和胴体品质方面表现突出,非常适应西南地区对优质猪肉的需求,达到了胴体与肉质平衡发展的需求,是一种简洁高效的优质杂交组合模式。     

The pH1 of longissimus dorsi muscle in purebred and commercial pigs

The pH was measured at 45 min post-mortem (pH₁) in the longissimus dorsi muscle (lumbar region) of 8 188 pigs as a criterion of meat quality. The results showed that purebred animals had a lower average pH₁ (6.53 ± 0.01) than commercial (6.59 ± 0.01) and that the Irish Landrace breed had a lower average (6.48 ± 0.01) than the Large White (6.64 ± 0.01). The proportion of pH₁ values < 6.0 was greater in Irish Landrace than in Large White pigs. The incidence of pH₁ < 6.0 was 5% for all pigs and 11% for purebred Landrace. Females had a greater number of pH₁ values < 6.0 than had male castrates.     

Evaluation of the South African Dorper as a terminal sire breed for growth,carcass, and palatability characteristics

The South African Dorper is an important terminal meat sire breed in Africa that was recently imported into the United States. The objective of this study was to evaluate the Dorper as a terminal meat sire breed for U.S. production. Semen from purebred Dorper sires was used to artificially inseminate Columbia ewes to produce F1 crossbred lambs. Growth and carcass characteristics of F1 Dorper-Columbia lambs (n = 165), F1 Suffolk-Columbia (n = 89), and purebred Columbia lambs (n = 207) were compared based on subsets of the total number of animals. The F1 Dorper lambs grew significantly slower (313 g x d(-1)) and weighed less (29.8 kg) than F1 Suffolk- (357 g x d(-1), 33.5 kg) and Columbia-sired lambs (328 g x d(-1), 31 kg) at 77 d of age. However, at a weaning age of 118 d weaning weight and ADG did not differ (P > 0.20) among sire breed groups. Postweaning growth of F1 Dorper(239 g xd(-1)) wether lambs did not differ from that of purebred Columbia wethers (230 g x d(-1)) but was less than that of F1 Suffolk lambs (259 g x d(-1); P= 0.09). Feed efficiency did not differ among breed types. Breed types had similar dressing percentages (53%), shoulder fat depth (2.8 mm), body wall thickness (3 cm), leg conformation score (Choice), Yield grade (2.4), and Quality grade (Choice). Weight of wholesale shoulders and racks made up approximately 38% of the carcass weight in the Columbia and F1 Suffolk-Columbia type but only 33% in the F1 Dorper-Columbia lambs. However, the more expensive wholesale loins from F1 Dorpers were heavier (P < 0.01) than the other breed types. Total weights of wholesale legs were similar among F1 Dorpers and F1 Suffolks but were heavier than those for the purebred Columbia (P < 0.05). Percentages of total wholesale primal cuts were similar among breed types (P > 0.10). Chemical composition of the carcass did not differ significantly between breed types with a mean composition of 52% moisture, 30% lipid (ether extract), 17% protein, and 0.76% ash. Warner-Bratzler shear force values were less (P < 0.05) and sensory panel ratings for tenderness were significantly more favorable for lamb chops from Dorper sired lambs. Dorper rams can be used as terminal meat sires to produce lambs whose growth rate to 118 d of weaning age, postweaning ADG and feed efficiency, and carcass characteristics are similar to that of Suffolk crossbred lambs and purebred Columbia lambs but with a slight improvement in tenderness.     

淮猪及杂交后代肌纤维直径变化及其与肉质关系的研究

对不同品种和杂交组合肥育猪(淮猪、长淮、大长淮)采用单因子试验设计,在相同条件下,研究不同血缘比例对淮猪肌纤维直径的影响。结果表明:淮杂猪的背最长肌和股二头肌肌纤维直径显著高于淮猪(P<0.05)。淮猪的肌纤维直径介于中国地方猪与国外瘦肉型猪之间。肌纤维直径与胴体性状(瘦肉率、眼肌面积、背最长肌全重、背最长肌率、脂肪)呈较强的相关性。淮杂猪肉质理化性状中(肉色评分、大理石纹评分、贮藏损失)3项指标明显变差(P<0.05),但pH值变化不显著。作者认为淮猪杂交后代的肌纤维直径较纯种淮猪粗,淮杂猪肉质也较纯种淮猪差。     

Advanced Onset of Puberty in Gilts of Thrifty Genotype (Iberian Pig)

The Iberian pig is an autochthonous breed of the Mediterranean area, reared extensively in the central and southern areas of Spain and Portugal and that is known worldwide for the production of Iberian ham. The characteristics of the Iberian ham are related to its abundance of intramuscular fat, owing to the high capacity of the pig to accumulate fat under its skin and between the muscular fibres. This ability to store excess fat enables survival during periods of scarcity and it has been found in other antique animal breeds and even in humans, being named as the thrifty genotype. The reproductive management of the Iberian pig, in spite of a lack of accurate information unlike in other swine breeds, is based on the assumption of lower reproductive precocity and efficiency than the modern commercial breeds. The current study characterized and compared the onset of puberty in gilts of Iberian breed and meat commercial crosses (Large White × Landrace) reared in the same conditions by assessing weekly plasma progesterone profiles. At the end of the experimental period, when the gilts became 180 days old, the percentage of Iberian females that had reached puberty was 72.2%, with a mean age and weight of 160.5 ± 2.6 days and 92.9 ± 4.7 kg, respectively. The percentage of Large White × Landrace cross‐breed females reaching puberty at 180 days was only 15% (p < 0.05). The mean age and weight were 165.0 ± 4.1 days and 107.8 ± 2.2 kg (p < 0.05), respectively. Thus, converse to the traditional assumption, onset of puberty was advanced in Iberian gilts. These results are important for the reproductive management of the Iberian pig but, at the same time, may set the basis for future studies on the metabolism–reproduction link and, specifically, on the possible relationship between earlier accumulation of fat and attainment of puberty.     

Genetic variation of in vivo muscle glycerol,glycogen, and pigment in Danish purebred pigs

Heritability values of glycerol, glycogen and pigment concentrations measured on muscle biopsy samples from longissimus dorsi obtained from 85?kg boars of Danish purebred pigs (Landrace, Yorkshire, and Duroc) and their genetic correlations to performance and meat quality traits were calculated. The heritability values of glycogen, pigment, and glycerol were 0.38±0.02, 0.17±0.02, and 0.065±0.016, respectively. Glycogen was negatively related to the feed conversion ratio (FCR) (r _g =?0.25±0.06) and ultimate meat pH (r _g =?0.41±0.04), and positively to the carcass meat percentage (r _g =0.35±0.04), L* (lightness of meat, r _g =0.32±0.04) and a* (redness of meat, r _g =0.12±0.03). Pigment was positively related to the FCR (r _g =0.12±0.05), the meat percentage (r _g =0.28±0.05), and a* (r _g =0.59±0.04), and negatively to the L* (r _g =?0.46±0.06). The concentrations of pigment and glycogen (r _g =0.27±0.05) were interrelated. Based on the heritability values and the signs of the genetic correlations the present data suggest that it is possible to select for higher ultimate pH and improved colour by selection for either lower muscle glycogen or higher pigment concentration, respectively. However, the positive genetic correlation between these two traits may restrict the efficiency of simultaneous selection for lower glycogen and higher pigment. All genetic parameter estimates presented are calculated across three purebreds. Values for each breed are warranted for use in pig production. However, this requires more animals per breed.     

湖北白猪优质系选育进展报告

为充分利用地方猪种资源,培育优质、高效的专门化母本新品系,以长白猪、梅山猪、通城猪和湖北白猪为遗传资源,进行了湖北白猪新品系的选育。经过6个世代持续选育,各品种在品系的血统比例分别为45.15%、23.39%、7.08%和24.38%。湖北白猪优质系初产母猪产仔数达12.13头/窝,经产母猪达13.52头/窝,经产母猪产活仔数12.74头/窝;肥育期平均日增重达到621.39 g,达90 kg体重日龄为179.26 d,料重比3.15。90 kg体重阶段屠宰率为74.96%,屠体背膘厚为2.64cm,瘦肉率为58.69%,眼肌面积为38.02 cm2,肌内脂肪含量3.05%。     

Production of Ban miniature pig embryos by in vitro fertilization: A comparative study with Landrace

Ban is an endangered miniature pig breed in Vietnam. This study aimed to set up an in vitro embryo production (IVP) system for this breed. Ban's epididymal sperm concentration (1240 ± 35 × 10⁶/mL) was lower (P < 0.01) compared with Landrace (4160 ± 42 × 10⁶/mL). However, sperm characteristics before and after freezing in Ban and Landrace were similar. The numbers of follicles with diameter larger than 2 mm per ovary in Ban females treated with equine chorionic gonadotropin and human chorionic gonadotropin (27.1 ± 1.3) were higher (P < 0.05) than those in Landrace (12.9 ± 2.0) and in non‐hormone stimulated Ban (no > 2 mm follicles). After in vitro maturation, the percentages of oocytes with expanded cumulus cells and the first polar body (matured oocytes) were not different among Ban, hormone‐stimulated Ban and Landrace. The percentages of two‐cell embryos and morulae derived from oocytes collected from three sources did not differ. However, the rate of blastocysts derived from oocytes in non‐stimulated Ban (4.0 ± 3.8%) was lower (P < 0.05) than that in Landrace (15.3 ± 1.8%). In conclusion, an effective IVP system for good quality embryos in Ban, that is essential for genetic conservation of this breed, was established.