Responses in residual feed intake in lines of Large White pigs selected for growth rate on restricted feeding (measured on ad libitum individual feeding)     

N.H. Nguyen  C.P. McPhee  & C.M. Wade 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2005,122(4):264-270

Residual feed intake (RFI) represents the deviation of the actual ad libitum food consumption of each animal from that predicted from combination of growth rate, backfat and metabolic body weight measurements. After 4 years of divergent selection of pigs in lines for either high or low postweaning growth rate on restricted feeding, the high line exhibited a significant reduction in RFI relative to the low line. This indicated, to some extents, a lower energy requirement for maintenance in the high than in the low line, possibly because of reduced physical activity of the animals. Estimates of genetical parameters showed that RFI was moderately heritable and those genetic correlations of RFI with carcass backfat and food conversion ratio were moderate to highly positive.  相似文献   

Responses in carcass lean pH at 24 hours post-mortem in lines of Large White pigs selected for growth rate on a fixed ration over a set time     

N.H. Nguyen  C.P. McPhee  G.R. Trout 《Livestock Science》2006,100(2-3):84-90

A restricted maximum likelihood analysis applied to an animal model showed no significant differences (P > 0.05) in pH value of the longissimus dorsi measured at 24 h post-mortem (pH24) between high and low lines of Large White pigs selected over 4 years for post-weaning growth rate on restricted feeding. Genetic and phenotypic correlations between pH24 and production and carcass traits were estimated using all performance testing records combined with the pH24 measurements (5.05–7.02) on slaughtered animals. The estimate of heritability for pH24 was moderate (0.29 ± 0.18). Genetic correlations between pH24 and production or carcass composition traits, except for ultrasonic backfat (UBF), were not significantly different from zero. UBF had a moderate, positive genetic correlation with pH24 (0.24 ± 0.33). These estimates of genetic correlations affirmed that selection for increased growth rate on restricted feeding is likely to result in limited changes in pH24 and pork quality since the selection does not put a high emphasis on reduced fatness.  相似文献   

Screening techniques and sources of resistance to root diseases in cool season food legumes     

Alessandro Infantino  Mohamed Kharrat  Luca Riccioni  Clarice J. Coyne  Kevin E. McPhee  Niklaus J. Grünwald 《Euphytica》2006,147(1-2):201-221

Summary Soil-borne fungal diseases are among the most important factors, limiting the yield of grain legumes in many countries worldwide. Root rot, caused by Aphanomyces euteiches, Rhizoctonia solani, Fusarium solani and wilt, caused by several formae speciales of Fusarium oxysporum are the most destructive soil-borne diseases of pea, chickpea, lentil, fababean and lupin. The most effective control of these diseases is achieved through the use of resistant varieties. In this paper, recent advances in conventional and innovative screening methods for disease resistance are presented. Many grain legume accessions, which are maintained in national and international germplasm collections, have been evaluated for disease resistance and numerous resistant varieties have been released following incorporation of identified resistance genes from these sources. Recent identification of molecular markers tightly linked to resistance genes has greatly enhanced breeding programs by making marker assisted selection (MAS) possible and allowing the development of varieties with multiple disease resistance. Progress in the understanding of the biology of soil-borne fungal pathogens of grain legumes is also reviewed with particular reference to the genetic structure of their populations, diagnosis and host–pathogen interaction.  相似文献   

Application of biotechnology in breeding lentil for resistance to biotic and abiotic stress     

Frederick J. Muehlbauer  Seungho Cho  Ashutosh Sarker  Kevin E. McPhee  Clarice J. Coyne  P. N. Rajesh  Rebecca Ford 《Euphytica》2006,147(1-2):149-165

Summary Lentil is a self-pollinating diploid (2n = 14 chromosomes) annual cool season legume crop that is produced throughout the world and is highly valued as a high protein food. Several abiotic stresses are important to lentil yields world wide and include drought, heat, salt susceptibility and iron deficiency. The biotic stresses are numerous and include: susceptibility to Ascochyta blight, caused by Ascochyta lentis; Anthracnose, caused by Colletotrichum truncatum; Fusarium wilt, caused by Fusarium oxysporum; Sclerotinia white mold, caused by Sclerotinia sclerotiorum; rust, caused by Uromyces fabae; and numerous aphid transmitted viruses. Lentil is also highly susceptible to several species of Orabanche prevalent in the Mediterranean region, for which there does not appear to be much resistance in the germplasm. Plant breeders and geneticists have addressed these stresses by identifying resistant/tolerant germplasm, determining the genetics involved and the genetic map positions of the resistant genes. To this end progress has been made in mapping the lentil genome and several genetic maps are available that eventually will lead to the development of a consensus map for lentil. Marker density has been limited in the published genetic maps and there is a distinct lack of co-dominant markers that would facilitate comparisons of the available genetic maps and efficient identification of markers closely linked to genes of interest. Molecular breeding of lentil for disease resistance genes using marker assisted selection, particularly for resistance to Ascochyta blight and Anthracnose, is underway in Australia and Canada and promising results have been obtained. Comparative genomics and synteny analyses with closely related legumes promises to further advance the knowledge of the lentil genome and provide lentil breeders with additional genes and selectable markers for use in marker assisted selection. Genomic tools such as macro and micro arrays, reverse genetics and genetic transformation are emerging technologies that may eventually be available for use in lentil crop improvement.  相似文献   

Biomass production and related characters in the core collection of Pisum germplasm     

K.E. McPhee  F.J. Muehlbauer 《Genetic Resources and Crop Evolution》2001,48(2):195-203

Retention of residue on the soil surface following harvest is an effective method of reducing soil erosion from both wind and water. The pea crop produces small amounts of residue to effectively reduce soil erosion. Severe erosion occurs in pea production areas such as the Palouse Region of the US Pacific Northwest (PNW) when low residue crops such as spring pea or lentil are followed by fall-sown wheat. The current study was conducted to determine the range of total aboveground biomass (TAB), seed yield, and straw (residue) production from the plant identification (PI) accessions that comprise the core collection of Pisum germplasm. In addition, the potential for increasing seed yield and straw production simultaneously was evaluated. Three hundred and ninety PI accessions were screened in the field in 1996 and 1997. The variation for TAB, seed yield and straw production among the PI accessions exceeded that of the controls both years. Seed yield was positively correlated with straw production (r = 0.81, p< 0.01) indicating that seed and straw production can be increased simultaneously through positive selection for both traits. Significant favorable variation is present among accessions in the USDA core collection of Pisum germplasm which could be used to increase both seed yield and total biomass production of adapted breeding lines.  相似文献   

Targeting of cyclic AMP degradation to beta 2-adrenergic receptors by beta-arrestins     

Perry SJ  Baillie GS  Kohout TA  McPhee I  Magiera MM  Ang KL  Miller WE  McLean AJ  Conti M  Houslay MD  Lefkowitz RJ 《Science (New York, N.Y.)》2002,298(5594):834-836

Catecholamines signal through the beta2-adrenergic receptor by promoting production of the second messenger adenosine 3',5'-monophosphate (cAMP). The magnitude of this signal is restricted by desensitization of the receptors through their binding to beta-arrestins and by cAMP degradation by phosphodiesterase (PDE) enzymes. We show that beta-arrestins coordinate both processes by recruiting PDEs to activated beta2-adrenergic receptors in the plasma membrane of mammalian cells. In doing so, the beta-arrestins limit activation of membrane-associated cAMP-activated protein kinase by simultaneously slowing the rate of cAMP production through receptor desensitization and increasing the rate of its degradation at the membrane.  相似文献   

Characterization of core collection of lentil germplasm for phenology, morphology, seed and straw yields   总被引：4，自引：0，他引：4  

A. Tullu  I. Kusmenoglu  K.E. McPhee  F.J. Muehlbauer 《Genetic Resources and Crop Evolution》2001,48(2):143-152

Increasing and maintaining crop residues in predominantly cereal-based rotations of the US Pacific Northwest is critical to controlling soil erosion. The core collection of lentil (Lens culinaris Medik.) germplasm comprising 287 accessions was evaluated for variation in phenological, morphological and growth parameters including seed yields and residue amounts over a two-year period under conventional tillage and no-till conditions. The objectives of this study were (i) assess lentil genetic variation in germplasm for variation in biomass production and seed yield, (ii) assess the relationship of phenological and morphological traits with biomass and seed yield and (iii) identify high biomass producing germplasm for use as parents in the breeding program. Days to flowering and days to maturity ranged from 31 to 78 and from 71 to 106 days, respectively. Time to flowering in terms of cumulative heat units was a more efficient measurement than days to flowering. Plant height and plant canopy width had a significant association with total biomass, seed yield and residue amounts. Total biomass ranged from 788–6389 kg ha^–1 under conventional tillage, while the range under no-till conditions was 1045–6195 kg ha^–1. Most of the lines with higher biomass also produced the highest seed yields and residue amounts. Overall, only one accession produced more residue than `Laird'. In the more favorable environment of 1997, six accessions exceeded the control cultivars, `Laird' and `Indianhead', for residue amounts, and seven and twenty-four accessions exceeded control cultivars, `Pardina' and `Brewer', for seed yield. Results indicated that plant height, canopy width at maturity and seed yield explained most of the variation in biomass and residue production. Large seeded germplasm consistently had a longer reproductive growth period than small seeded accessions and had 17%, 7% and 21% more biomass, seed yield and residue, respectively. Our data indicated significant variation in lentil germplasm for biomass, seed yield and residue amounts to warrant their use in the breeding program.  相似文献   

CEREBELLAR HYPOPLASIA OF GENETIC ORIGIN IN CALVES     

B. M. O'Sullivan  B.V.Sc  Ph.D. C. P. McPhee  M. Sc  Ph.D. 《Australian veterinary journal》1975,51(10):469-471

Within 2 years, following the introduction of 2 Shorthorn bulls from the same stud into an Australian Illawarra Shorthorn (AIS) herd, 16 calves were born with cerebellar hypoplasia. All affected calves were the progeny of one bull mated to the daughters of the other. All other progeny of these bulls, most of which were from AIS dams, were normal. Affected calves exhibited severe ataxia, consistent head movement and abduction of the forelimbs. Microscopic changes in the cerebellum included sparsity of cells of the granular layer, loss of Purkinje cells and narrowing of the molecular layer. Observations on the frequencies of normal and abnormal calves are consistent with the hypothesis that the condition is caused by an autosomal recessive gene for which affected calves were homozygous and which was introduced into the herd in heterozygous condition by both of the Shorthorn bulls. Evidence is given for an unusually high frequency of the gene in the stud of origin of the Shorthorn bulls and a procedure for reducing its frequency is outlined. The possibility of a viral or toxic aetiology is discussed but is considered to be an unlikely explanation for the condition in this herd.  相似文献   

ISOLATION OF BLUETONGUE VIRUS SEROTYPE 20 FROM THE SEMEN OF AN EXPERIMENTALLY-INFECTED BULL   总被引：1，自引：0，他引：1  

I M Parsonson  A J Della-Porta  D A McPhee  D H Cybinski  K R Squire  H A Standfast  M F Uren 《Australian veterinary journal》1981,57(5):252-253

  相似文献   

Development and evaluation of empirical equations to interconvert between twelfth-rib fat and kidney, pelvic, and heart fat respective fat weights and to predict initial conditions of fat deposition models for beef cattle     

McPhee MJ  Oltjen JW  Fadel JG  Perry D  Sainz RD 《Journal of animal science》2008,86(8):1984-1995

The Davis growth model (DGM) simulates growth and body composition of beef cattle and predicts development of 4 fat depots. Model development and evaluation require quantitative data on fat weights, but sometimes it is necessary to use carcass data that are more commonly reported. Regression equations were developed based on published data to interconvert between carcass characteristics and kilograms of fat in various depots and to predict the initial conditions for the DGM. Equations include those evaluating the relationship between the following: subcutaneous fat (SUB, kg) and 12th-rib fat thickness (mm); visceral fat (VIS, kg) and KPH (kg); DNA (g) in intermuscular, intramuscular, subcutaneous, and visceral fat depots and empty body weight; and contributions of fat (kg) in intramuscular (INTRA), SUB, and VIS fat depots and total body fat (kg). The intermuscular fat (INTER, kg) contribution was found by difference. The linear regression equations were as follows: SUB vs. 12th-rib fat thickness (n = 75; P < 0.01) with R(2) = 0.88 and SE = 10.00; VIS vs. KPH (kg; n = 78; P < 0.01) with R(2) = 0.95 and SE = 2.82; the DNA (g) equations for INTER, INTRA, SUB, and VIS fat depots vs. empty body weight (n = 6, 5, 6, and 6; P = 0.08, P < 0.01, P < 0.01, and P = 0.05) with R(2) = 0.57, 0.93, 0.93, and 0.66, and SE = 0.03, 0.003, 0.02, and 0.03, respectively; and initial contribution of INTRA, SUB, and VIS fat depots vs. total body fat (n = 23; P < 0.01) for each depot, with R(2) = 0.97, 0.99, and 0.97, and SE = 0.61, 0.93, and 1.41, respectively. All empirical equations except for DNA were challenged with independent data sets (n = 12 and 10 for SUB and VIS equations and n = 9 for the initial INTER, INTRA, SUB, and VIS fat depots). The mean biases were -2.21 (P = 0.12) and 2.11 (P < 0.01) kg for the SUB and VIS equations, respectively, and 0.05 (P = 0.97), -0.37 (P = 0.27), 1.82 (P = 0.08), and -1.50 (P = 0.06) kg for the initial contributions of INTER, INTRA, SUB, and VIS fat depots, respectively. The random components of the mean square error of prediction were 73 and 26% for the SUB and VIS equations, respectively, and similarly were 99, 85, 62, and 61% for the initial contributions of INTER, INTRA, SUB, and VIS fat depots, respectively. Both the SUB and VIS equations predicted accurately within the bounds of experimental error. The equations to predict initial fat contribution (kg) were considered adequate for initializing the fat depot differential equations for the DGM and other beef cattle simulation models.  相似文献