淮猪杂交育肥及胴体性能测定

分别选取4窝长白猪×淮猪(长淮组)、大约克猪×淮猪(大淮组)和淮猪(淮猪组)进行育肥和胴体性能测定。试验结果表明,试验猪的日增重差异不显著(P>0.05),但大淮猪平均日增重(626.13±76.82)g(65.24%)、长淮猪平均日增重(587.00±59.58)g(54.91%)均有高于淮猪(378.93±67.74)g的趋势。长淮猪料肉比(3.04)比淮猪(4.54)降低了49.34%,大淮猪料肉比(3.27)比淮猪降低了38.84%。试验猪的平均屠宰率都在70%以上,各组差异不显著(P>0.05)。大淮猪的胴体斜长(74.50±1.91)cm显著长于淮猪(68.50±3.70)cm,(P<0.05)。长淮猪的眼肌面积(36.45±4.80)cm2显著大于淮猪(21.02±4.23)cm2,(P<0.01)。大淮猪后腿比例(31.08±1.97)%有高于淮猪(28.74±1.24)%的趋势。瘦肉率长淮猪(56.69±1.79)%和大淮猪(53.13±1.41)%均极显著(P<0.01)高于淮猪(44.89±2.15)%。淮猪皮(14.10±1.55)%比长淮猪(7.81±0.56)%和大淮猪(8.39±0.81)%高出5个百分点以上,且差异极显著(P<0.01)。3组猪的肉质性状指标都在正常值范围内,肉质优良,未发现有PSE或DFD等劣质肉。     

“杜长嘉”商品猪毛色分离现象的遗传分析

通过对504窝5828头杜长嘉商品猪毛色分离的调查,发现杜长嘉商品猪群体中通常有全白色、棕红色、白黑花斑、棕白花斑、黑棕花斑和全黑色6种毛色[5],且不同毛色长嘉母本的后代毛色的构成比不同。其结果如下:①纯白长嘉母猪后代:全白色0 4486±0 1868、棕红色0 1842±0 1426、白黑花斑0 0708±0 1175、棕白花斑0 0264±0 0706、黑棕花斑0 0844±0 1203、全黑色0 1856±0 1240;②黑斑长嘉母猪后代:全白色0 3685±0 2191、棕红色0 0899±0 1069、白黑花斑0 1773±0 1482、棕白花斑0 0546±0 0874、黑棕花斑0 1045±0 1236、全黑色0 2052±0 1651。     

Adjustment of pig or litter weights to a 21-day basis in Duroc, Landrace, and crossbred swine

A total of 457 Duroc, 137 Landrace, 131 Duroc x Landrace, and 110 three-and four-breed crossbred pigs were used to estimate multiplicative adjustment factors. Sixty-one Duroc, 24 Landrace, 18 Duroc x Landrace, and 16 three- and four-breed crossbred litters were weighed every 3 or 4 d from 13 to 30 d of age. Prediction equations for estimating pig weights from birth to 30 d and from 13 to 30 d of age are presented. Multiplicative adjustment factors for adjusting pig or litter weights to a 21-d basis for pigs or litters that are weighed between 13 and 30 d of age for different breeds and crossbred combinations are listed. Breed, litters within breed, and pigs within litter x breed effects adjusted for age at weighing were different (P less than .01). Quadratic regression coefficients of weight on age of pig from 13 to 30 d of age did not differ (P greater than .10) from zero for Landrace and three- and four-breed crossbred pigs but were significant for Duroc and Duroc x Landrace pigs.     

Phenotypic and genetic variation in hematological traits of Pietrain-Meishan-F2 crossbred pigs

Hematological traits are essential parameters for veterinary practice to quantify health status of individuals and herds. A major problem with the interpretation of hematological values is their pronounced variability that is to a great extend caused by non-systematic factors. Differences in breeds and populations are providing evidence for different genotypes in this regard, although there is no information available in swine about the nature and shares of participating genes. Goal of the present paper was to evaluate the additive-genetic share of total variability of traits of the red and white blood cell count. The results are based on 139 F2-pigs of a Pietrain-Meishan-family. Medium to high heritabilities have been estimated for the numbers of neutrophiles, the mean corpuscular hemoglobin concentration and the hemoglobin content, and for the shares of basophile granulocytes, platelets and lymphocytes. No meaningful shares of additive genetic variance were obvious in the other traits. Shares of additive genetic variance of the above mentioned traits argue for the existence of favourable and unfavourable gene variants to be involved in their phenotypic variation. Isolation of these variants might improve the diagnostical use of those traits in the future and provide a measure to advance general health in the pig.     

Effect of VRTN gene polymorphisms on Duroc pig production and carcass traits,and their genetic relationships

The thoracic vertebral number is associated with body length and carcass traits, and represents one of the most important traits in the pig industry. Recent studies have shown that vertnin (VRTN) gene is associated with variations in the vertebral number in commercial European pigs. However, the genetic relationships and effect of this VRTN gene in pig production and carcass traits remain uncertain. Therefore, we investigated the genetic relationships among traits such as vertebral numbers, carcass weight and length‐related traits, and meat production traits, and the effect of VRTN gene polymorphisms on these traits in a Duroc purebred population selected for its meat production traits. Highly positive genetic correlations were obtained between the thoracic vertebral numbers and length‐related traits (0.56 to 0.84), whereas low correlations were obtained with production traits and carcass weight (?0.16 to 0.05). VRTN gene polymorphisms indicated that the number of thoracic vertebrae and length‐related traits were significantly associated with the VRTN genotype, but had no significant effect on production traits and carcass weight. The results indicate that VRTN gene may be used as an effective selection marker to obtain pigs with high thoracic vertebral numbers and length‐related traits, without adversely affecting meat production traits.     

Factors affecting longevity in maternal Duroc swine lines

A competing risks approach was used to evaluate the influence of several pre-farrowing factors on risk of culling due to different causes in Duroc swine, these having low fertility, low productivity, lameness and mortality. Culling due to low fertility increased for average daily gains during the growth test lower than 585 g/day, whereas culling due to low productivity and mortality increased with low levels of backfat thickness at the end of the growth test. Lesser loin depths at first farrowing reduced culling due to low productivity but increased culling due to lameness. Furthermore, a higher average daily gain from the end of the growth test to first mating increased culling by all causes. A complementary analysis was carried out to evaluate the influence of these factors on risk of culling without taking into account the specific reason of failure. In this second analysis, the factors were included as time-dependent covariates whose relative importance changed throughout the sows' productive life. Expected survival functions and replacement rates have been calculated in different hypothetical situations in order to determine the optimal animal body type at first farrowing to maximise longevity, which under our production conditions is independent of average daily gain from birth until the end of the growth test, but from the end of the growth test to first mating average daily gain should not be over 485 g/day; backfat thickness should be more than 16 mm at the end of the growth test and maintain this level until the first parturition without exceeding 19 mm; loin depth should be kept below 45 mm at first farrowing.     

Malignant hyperthermia in a crossbred landrace-large white pig

Abstract

Extract

Malignant hyperthermia is a rare and usually fatal complication of general anaesthesia. It occurs in man (Britt and Kalow, 1970 Britt, B. A. and Kalow, W. 1970. Malignant hyperthermia: a statistical review. Can. Anaesth. Soc. J., 17: 293–315. [Crossref], [PubMed] , [Google Scholar]) and in certain breeds of pigs, the, Landrace (Hall et al., 1966 Hall, L. W., Woolf, N., Bradley, J. W. P. and Jolly, D. W. 1966. An unusal reaction to suxamethonium chloride. Br. med. J., 3: 594–594.  [Google Scholar]; Berman et at, 1970 Berman, M. C., Harrison, G. G. and Bull, A. B. 1970. Changes underlying halothane-induced malignant hyperpyrexia in Landrace pigs. Nature. Lond., 225: 653–655.  [Google Scholar]; Harrison et al., 1970 Harrison, G. G., Berman, M. C., Heekman, R., Bull, A. B., Terblanche, J. and Kench, J. E. 1970. “Anaesthetic induced malignant hyperpyrexia — Some observations of the syndrome in Landrace pigs”. In Ill Asian Australasian Congress of Anesthesiology, Canberra. Butterworths 158–166.  [Google Scholar]) the Poland China (Jones et al., 1972 Jones, E. W., Nelson, T. E., Anderson, I. L., Kerr, D. D. and Burnap, T. K. 1972. Malignant hyperthermia in swine. Anesthesiology, 36: 42–51.  [Google Scholar]), the Pietrain (Allen et al., 1970 Allen, W. M., Harding, J. D. J. and Paterson, D. S. P. 1970. Experimentally induced acute stress syndrome in Pietrain pigs. Vet. Rec., 87: 64–69.  [Google Scholar]) and the Large White (Mawdesley-Thomas, 1969 Mawdesley-Thomas, L. E. 1969. Cited by Allen, W. M. et al. (1970) [Google Scholar]).     

Validation of the QTL on SSC4 for meat and carcass quality traits in a commercial crossbred pig population

Porcine chromosome 4 harbours many quantitative trait loci (QTL) affecting meat quality, fatness and carcass composition traits, detected in resource pig populations previously. However, prior to selection in commercial breeds, QTL identified in an intercross between divergent breeds require confirmation, so that they can be segregated. Consequently, the objective of this study was to validate several QTL on porcine chromosome 4 responsible for meat and carcass quality traits. The experimental population consisted of 14 crossbred paternal half-sib families. The region of investigation was the q arm of SSC4 flanked by the markers S0073 and S0813. Regression analysis resulted in the validation of three QTL within the interval: Minolta a * loin, back fat thickness and the weight of trimmed ham. The results were additionally confirmed by factor analysis. Candidate genes were proposed for meat colour, which was the most evident QTL validated in this study.     

两个杜洛克品系杂交试验报告

以台系、美系杜洛克进行正反交试验，对四个组合的繁殖、肥育等项目进行测定并经过统计分析，结果表明：不同品系间杂交组合在配种受胎、产仔、肥育性能等方面表现出较大杂交优势，且台美组合为最优，其正常分娩率、窝产仔数、窝产活仔数、初生窝重、断奶窝重的杂交优势率分别为7.2%、21.1％、32.3%、36.4%和40.8%。日培重、耗料增重比的杂交优势率分别为：10.8%、-7.5%。可见，台美组合表现出良好的配合力，可作为生产杜长大（或杜大长）杂交繁育体系终端父本的最佳选择。     

Heritability and genetic correlation estimates of semen production traits with litter traits and pork production traits in purebred Duroc pigs

We estimated heritabilities of semen production traits and their genetic correlations with litter traits and pork production traits in purebred Duroc pigs. Semen production traits were semen volume, sperm concentration, proportion of morphologically normal sperms, total number of sperm, and total number of morphologically normal sperm. Litter traits at farrowing were total number born, number born alive, number stillborn, total litter weight at birth, mean litter weight at birth, and piglet survival rate at birth. Litter traits at weaning were litter size at weaning, total litter weight at weaning, mean litter weight at weaning, and piglet survival rate from birth to weaning. Pork production traits were average daily gain, backfat thickness, and loin muscle area. We analyzed 45,913 semen collection records of 896 boars, 6,950 farrowing performance records of 1,400 sows, 2,237 weaning performance records of 586 sows, and individual growth performance records of 9,550 animals measured at approximately 5 mo of age. Heritabilities were estimated using a single-trait animal model. Genetic correlations were estimated using a 2-trait animal model. Estimated heritabilities of semen production traits ranged from 0.20 for sperm concentration to 0.29 for semen volume and were equal to or higher than those of litter traits, ranging from 0.06 for number stillborn and piglet survival rate at birth to 0.25 for mean litter weight at birth, but lower than those of pork production traits, ranging from 0.50 for average daily gain to 0.63 for backfat thickness. In many cases, the absolute values of estimated genetic correlations between semen production traits and other traits were smaller than 0.3. These estimated genetic parameters provide useful information for establishing a comprehensive pig breeding scheme.     

台系杜洛克猪产仔数重复力的评定

为了解台系杜洛克母猪重复力遗传参数在国内的适应性,充实完善台系杜洛克猪产仔数的重复力,继续选育提高杜洛克猪育种水平及经济效益。通过采用组内相关的方法,对某大型种猪企业的台系杜洛克猪1~8胎次产仔数的重复力进行估测。结果表明:台系杜洛克猪1~8胎次的平均产仔数分别为8.6头、9.65头、9.35头、9.00头、8.30头、8.80头、7.65头;台系杜洛克猪8个胎次平均产仔数为8.44头;台系杜洛克猪产仔数的重复力为0.42。     

Genetic parameters for feed efficiency traits and their relationships with growth and carcass traits in Duroc pigs

Genetic parameters for feed efficiency traits of 380 boars and growth and carcass traits of 1642 pigs (380 boars, 868 gilts and 394 barrows) in seven generations of Duroc population were estimated. Feed efficiency traits included the feed conversion ratio (FCR), and nutritional (RFI(nut)), phenotypic (RFI(phe)) and genetic (RFI(gen)) residual feed intake. Growth and carcass traits were the age to reach 105-kg body weight (A105), loin eye muscle area (EMA), backfat (BF), intra-muscular fat (IMF) and meat tenderness. The mean values for RFI(phe) and RFI(gen) were close to zero and for RFI(nut) was negative. All the measures of feed efficiency were moderately heritable (h(2) = 0.31, 0.38, 0.40 and 0.27 for RFI(nut), RFI(phe), RFI(gen) and FCR respectively). The heritabilities for all growth and carcass traits were moderate (ranged from 0.37 to 0.45), except for BF, which was high (0.72). The genetic correlations of RFI(phe) and RFI(gen) with A105 were positive and high. Measures of RFI were correlated negatively with EMA. BF was more strongly correlated with measures of RFI (r(g) > or = 0.73) than with FCR (r(g) = 0.52). Selection for daily gain, EMA, BF and IMF caused favourable genetic changes in feed efficiency traits. Results of this study indicate that selection against either RFI(phe) or RFI(gen) would give a similar correlated response in carcass traits.     

FTO基因多态性与杜洛克公猪生长性状的关联研究

旨在分析肥胖相关基因(FTO)多态性位点(g.400CG与c.46-139AT)与杜洛克猪群的生长性状的关联性,为该位点的分子标记辅助选择提供理论依据。试验采集了广东某猪场374头杜洛克猪核心群公猪的DNA样本,并测定杜洛克公猪的生长性状,用高分辨率熔解曲线(HRM)技术检测基因型,并进行标记-性状关联分析。结果表明:FTO基因g.400CG和c.46-139AT位点多态性分别与杜洛克公猪100 kg背膘厚、瘦肉率、饲料转化率、体高、体长等性状存在显著相关。g.400CG位点CC基因型个体平均背膘厚显著低于CG与GG型,瘦肉率显著高于后两者,GG型个体的饲料转化率显著低于CC型与CG型个体(P0.05);c.46-139AT位点AT基因型在体长和体高上均显著高于AA型和TT型(P0.05),存在明显的杂合子效应。g.400CG位点CC基因型是优势基因型,可用于背膘薄、瘦肉率高的新品系的选育,而GG型具有更高的饲料化率,有一定的潜在价值;c.46-139AT位点在体长和体高方面存在杂合效应,可为选育种工作提供参考。     

Quantitative trait loci analysis for growth and carcass traits in a Meishan x Duroc F2 resource population

We constructed a pig F2 resource population by crossing a Meishan sow and a Duroc boar to locate economically important trait loci. The F2 generation was composed of 865 animals (450 males and 415 females) from four F1 males and 24 F1 females and was genotyped for 180 informative microsatellite markers spanning 2,263.6 cM of the whole pig genome. Results of the genome scan showed evidence for significant quantitative trait loci (<1% genomewise error rate) affecting weight at 30 d and average daily gain on Sus scrofa chromosome (SSC) 6, carcass yield on SSC 7, backfat thickness on SSC 7 and SSC X, vertebra number on SSC 1 and SSC 7, loin muscle area on SSC 1 and SSC 7, moisture on SSC 13, intramuscular fat content on SSC 7, and testicular weight on SSC 3 and SSC X. Moreover, 5% genomewise significant QTL were found for birth weight on SSC 7, average daily gain on SSC 4, carcass length on SSC 6, SSC 7, and SSC X and lightness (L value) on SSC 3. We identified 38 QTL for 28 traits at the 5% genomewise level. Of the 38 QTL, 24 QTL for 17 traits were significant at the 1% genomewise level. Analysis of marker genotypes supported the breed of origin results and provided further evidence that a suggestive QTL for circumference of cannon bone also was segregating within the Meishan parent. We identified genomic regions related with growth and meat quality traits. Fine mapping will be required for their application in introgression programs and gene cloning.     

不同品系杜洛克后代商品猪胴体性状的比较分析

为研究不同品系杜洛克作为终端父本对其后代商品猪胴体性状的影响,选取214和108头分别由美系和加系杜洛克公猪配种、出生时间相近(±2 d)和体重相近(35±5 kg)的后代三元商品猪进行育肥饲养,结束饲养后开展屠宰试验,测定背膘厚度、眼肌厚度、瘦肉率和肋骨数.结果显示:加系杜洛克商品后代的背膘厚度、眼肌厚度显著(P<0...     

Quantitative trait loci mapping in an F2 Duroc x Pietrain resource population: I. Growth traits

Pigs from the F(2) generation of a Duroc x Pietrain resource population were evaluated to discover QTL affecting growth and composition traits. Body weight and ultrasound estimates of 10th-rib backfat, last-rib backfat, and LM area were serially measured throughout development. Estimates of fat-free total lean, total body fat, empty body protein, empty body lipid, and ADG from 10 to 22 wk of age were calculated, and random regression analyses were performed to estimate individual animal phenotypes representing intercept and linear rates of increase in these serial traits. A total of 510 F(2) animals were genotyped for 124 micro-satellite markers evenly spaced across the genome. Data were analyzed with line cross, least squares regression, interval mapping methods using sex and litter as fixed effects. Significance thresholds of the F-statistic for single QTL with additive, dominance, or imprinted effects were determined at the chromosome- and genome-wise levels by permutation tests. A total of 43 QTL for 22 of the 29 measured traits were found to be significant at the 5% chromosome-wise level. Of these 43 QTL, 20 were significant at the 1% chromosome-wise significance threshold, 14 of these 20 were also significant at the 5% genome-wise significance threshold, and 10 of these 14 were also significant at the 1% genome-wise significance threshold. A total of 22 QTL for the animal random regression terms were found to be significant at the 5% chromosome-wise level. Of these 22 QTL, 6 were significant at the 1% chromosome-wise significance threshold, 4 of these 6 were also significant at the 5% genome-wise significance threshold, and 3 of these 4 were also significant at the 1% genome-wise significance threshold. Putative QTL were discovered for 10th-rib and last-rib backfat on SSC 6, body composition traits on SSC 9, backfat and lipid composition traits on SSC 11, 10th-rib backfat and total body fat tissue on SSC 12, and linear regression of last-rib backfat and total body fat tissue on SSC 8. These results will facilitate fine-mapping efforts to identify genes controlling growth and body composition of pigs that can be incorporated into marker-assisted selection programs to accelerate genetic improvement in pig populations.     

Effect of sperm concentration in an ejaculate on morphometric traits of spermatozoa in Duroc boars

The experimental material consisted of 75 ejaculates collected form 8 Duroc boars. The ejaculates were divided into three groups according to sperm concentration in an ejaculate. An ejaculate was obtained from each boar monthly and it was used to make microscopic preparations to examine spermatozoa morphology. In each preparation morphometric measurements were taken of fifteen randomly selected spermatozoa characterized by normal morphology. The following measurements of spermatozoa were taken: length and width of the spermatozoa head, head area, length of the flagellum, perimeter of the spermatozoon head and total spermatozoon length. The results were used to calculate indicators of spermatozoa morphology. Moreover, assessments were made of frequency of morphological defects to isolate spermatozoa with primary and secondary abnormalities following the Blom classification system. It was found that the concentration of spermatozoa in the ejaculate influenced the morphometric characteristics of spermatozoa. Ejaculates with low sperm concentrations are characterized by larger spermatozoa as compared to ejaculates with high sperm concentrations. However, sperm concentration in the ejaculate does not much influence the shape of spermatozoa.