Fleece rot and body strike in Merino sheep. V. Heritability of liability to body strike in weaner sheep under flywave conditions

1991 ◽  
Vol 42 (2) ◽  
pp. 279 ◽  
Author(s):  
HW Raadsma
Keyword(s):  
Maximum Likelihood ◽  
Indirect Selection ◽  
Sudden Onset ◽  
Direct Selection ◽  
Mass Selection ◽  
Genetic Progress ◽  
High Heritability ◽  
Quasi Maximum Likelihood ◽  
Indicator Trait

The prevalence of body strike was monitored in 740 mixed sex weaner progeny from 43 sires, representing 15 different Merino genotypes. A flywave, characterized by a sudden onset in the prevalence of flystrike, occurred over a 2 month period which coincided with unseasonally high rainfall. A total of 190 strikes were treated in 176 sheep representing a strike rate of 25.7 strikes per 100 sheep and a prevalence of 23.8%. The majority of strikes (92.6%) were body strikes with 19.7% of all sheep affected. The heritability of susceptibility to body strike expressed as prevalence was 0.26�0.12 for both least squares (LS) and restricted maximum likelihood (REML) procedures. The heritability of liability to body strike using quasi-maximum likelihood procedures and assuming a continuous underlying scale was 0.53 which agreed well with estimates from the LS and REML analysis after transformation (0.54�0. 25). Predicted genetic progress in the reduction of susceptibility to body strike was calculated for mass selection where the best 5% of rams and 60% of ewes were selected, with a starting prevalence of 20% body strike, assuming (a) an environment exposed to continuous flywaves, and (b) an environment with infrequent flywaves. After 20 years of direct selection the prevalence of body strike would be reduced to 7.2% and 16.1% for the two environments respectively. Indirect selection based on (c) a variable prevalence of fleece rot with a long term average of 30% and (d) fleece rot expressed at 80% would reduce the prevalence of body strike to 6% and less than 2% respectively. Indirect selection based on (e) a hypothetical indicator trait with a continous distribution, a high heritability (0.4) and a moderate genetic correlation with liability to body strike (0.4), would also reduce the prevalence of body strike to less than 2% after 20 years of selection.

Solvent retention capacities as indirect selection criteria for sugar snap cookie quality in Chinese soft wheats

2008 ◽  
Vol 59 (10) ◽  
pp. 911 ◽  
Author(s):  
Yong Zhang ◽  
Qijun Zhang ◽  
Zhonghu He ◽  
Yan Zhang ◽  
Guoyou Ye
Keyword(s):  
Selection Criteria ◽  
Selection Criterion ◽  
Indirect Selection ◽  
Mean Value ◽  
Soft Wheat ◽  
Direct Selection ◽  
Genetic Progress ◽  
Retention Capacity ◽  
Cookie Quality ◽  
Solvent Retention

Development of soft wheat cultivars with high sugar snap cookie quality is one of the most important breeding objectives in south China. Lack of an efficient criterion for selection for soft wheat quality is the main reason slowing genetic progress. Seventeen Chinese soft wheat genotypes grown at three locations in 2000–01 and 2001–02 wheat seasons in the Southern Winter Wheat Region, were used to investigate the potential of solvent retention capacity (SRC) parameters as indirect selection criteria for improving cookie diameter. All traits investigated displayed medium to high broad-sense heritability. Lactic acid SRC and sucrose SRC had the highest heritability, with the estimate being 0.92 and 0.86 on across-environment genotype mean value, while ranging from 0.93 to 0.99 and from 0.95 to 0.99, respectively, in the six individual environments. Sucrose SRC was highly significantly and negatively correlated with cookie diameter on both phenotypic and genotypic levels, with values of –0.86 (P < 0.001) and –0.91 (P < 0.001) on across-environment genotype performance, and ranging from –0.71 (P < 0.01) to –0.86 (P < 0.001) and from –0.79 (P < 0.001) to –0.93 (P < 0.001), respectively, in the six environments. Sucrose SRC was found to be a good selection criterion for improving cookie diameter. When applying the same intensity, genetic progress on cookie diameter achieved through sucrose SRC selection was as efficient as that for cookie diameter itself on across-environment genotype performance, while slightly less efficient on within-environment genotype performance, with the relative selection efficiency ranging from 0.81 to 0.90. Moreover, indirect selection through sucrose SRC was always more efficient than direct selection under the assumption of equivalent cost, with the relative efficiency of 1.52 based on across-environment selection, and ranged from 1.22 to 1.36 on within-environment selection.

Testing strategies of pigs for measurement of feed efficiency: relative improvement in feed efficiency from relying solely on indirect selection compared to indirect selection for faster growth rate and higher percent lean

2016 ◽  
Author(s):  
Monchai Duangjinda ◽  
Wootichai Kenchaiwong ◽  
Wuttigrai Boonkum ◽  
John W. Mabry
Keyword(s):  
Feed Efficiency ◽  
Simulated Data ◽  
Indirect Measurement ◽  
Indirect Selection ◽  
Direct Selection ◽  
Genetic Progress ◽  
Testing Strategies ◽  
Direct Measurements ◽  
Genetic Regression ◽  
Direct Measures

The objective of this study was to compare different testing strategies of pigs involving direct measurement of feed efficiency in pig. Using simulated data software, we collected individual information for FCR and grouped trials into direct and indirect measurement. The direct FCR included measurement of FCR in both sexes (100M-100F), in boars only (100M), in 50% of boars and 50% of gilts (50M-50F), and in only 50% of boars (50M-0F). Direct measures of FCR (0M-0F) in indirect selection were not used. The highest and the lowest genetic regression responses in FCR were observed for 100M-100F and indirect selection scenarios (0M-0F). Among direct selection, the increase in genetic progress was directly related to the percent of pigs tested for FCR. Using FCRs records more than 50% (50M-50F or 100M) can raise response higher than 80%. Meanwhile, 0M-0F showed a loss in genetic gain more than 50% when compared with 100M-100F. These results suggest using direct measurements on at least 50% of all pigs for genetic evaluation in FCR.

scholarly journals Protogyny in Autumn Migration: Do Male Birds ”Play Chicken”?

The Auk ◽  
2005 ◽  
Vol 122 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Alexander M. Mills
Keyword(s):  
Migratory Birds ◽  
Indirect Selection ◽  
Male Competition ◽  
Autumn Migration ◽  
Direct Selection ◽  
Differential Migration ◽  
The North ◽  
Parsimonious Explanation ◽  
Ground Conditions ◽  
Wintering Ground

AbstractProtandry, the earlier arrival of males than of females on breeding areas, occurs in many taxa, including many migratory birds. Numerous hypotheses have been generated to explain protandry. Using bird-banding records, I show that protogyny, the earlier migration of females, frequently occurs in the autumn, though it is less universal and less dramatic than spring protandry. In one species, it occurs in both hatch-year and adult birds. When (1) spring and autumn, (2) departures and arrivals, and (3) breeding and wintering ground conditions are considered, hypotheses generated only to explain spring protandry can be more thoroughly evaluated. Using that approach, the most parsimonious explanation of differential migration between the sexes explains earlier male arrival in spring and later male departure in autumn through either (1) indirect selection operating on intrasexual male competition for territories or (2) direct selection operating on intersexual relations requiring males to be present on breeding territories when females are present. In autumn-protogynous species, males may ”play chicken,” balancing the benefits of remaining longer than females and protecting territories for subsequent years against the costs of remaining in the north under deteriorating conditions and delaying the acquisition of a good winter territory.Protogynie et migration automnale: Est-ce que les mâles ”jouent les dégonflés”?

scholarly journals Identifying Stabilising Effects on Survey Based Life Satisfaction Using Quasi-maximum Likelihood Estimation

2021 ◽  
Author(s):  
Johannes Klement
Keyword(s):  
Life Satisfaction ◽  
Maximum Likelihood ◽  
Maximum Likelihood Estimation ◽  
Negative Binomial ◽  
Measurement Instrument ◽  
Likelihood Estimation ◽  
Satisfaction Scale ◽  
Quasi Maximum Likelihood ◽  
The Stability

AbstractTo which extent do happiness correlates contribute to the stability of life satisfaction? Which method is appropriate to provide a conclusive answer to this question? Based on life satisfaction data of the German SOEP, we show that by Negative Binomial quasi-maximum likelihood estimation statements can be made as to how far correlates of happiness contribute to the stabilisation of life satisfaction. The results show that happiness correlates which are generally associated with a positive change in life satisfaction, also stabilise life satisfaction and destabilise dissatisfaction with life. In such as they lower the probability of leaving positive states of life satisfaction and increase the probability of leaving dissatisfied states. This in particular applies to regular exercise, volunteering and living in a marriage. We further conclude that both patterns in response behaviour and the quality of the measurement instrument, the life satisfaction scale, have a significant effect on the variation and stability of reported life satisfaction.

HERITABILITY OF SINGLE PLANT YIELD AND INCIDENCE OF BLACK POD DISEASE IN COCOA

2007 ◽  
Vol 43 (4) ◽  
pp. 455-462 ◽  
Author(s):  
G. LOCKWOOD ◽  
F. OWUSU-ANSAH ◽  
Y. ADU-AMPOMAH
Keyword(s):  
Large Scale ◽  
Mass Selection ◽  
Single Plant ◽  
Plant Yield ◽  
Clone Selection ◽  
Level Data ◽  
Family Level ◽  
Black Pod ◽  
Black Pod Disease

Broad sense heritabilities were estimated in three long-term cocoa clone trials in Ghana, with 20, 18 and 15 entries. They were 0.15, 0.05 and 0.15 for yield in pods per plant, and 0.26, 0.19 and 0.40 for incidence of ‘bad’ pods, mostly due to black pod disease, caused by infection with Phytophthora spp. The low heritability of single plant yield, which has been known for 80 years, has been widely overlooked in cocoa research and extension, compromising the success of clone selection programmes. The heritability of the incidence of black pod disease is high enough to justify mass selection where family level data are not available. The findings will be applied in a new large-scale programme in Ghana to select clones that are high yielding in the presence of P. megakarya.

scholarly journals Successful Treatment of Sudden Hepatitis Induced by Long-Term Nivolumab Administration

2017 ◽  
Vol 10 (1) ◽  
pp. 368-371 ◽  
Author(s):  
Keisuke Imafuku ◽  
Koji Yoshino ◽  
Kei Yamaguchi ◽  
Satoshi Tsuboi ◽  
Kuniaki Ohara ◽  
...  
Keyword(s):  
Malignant Melanoma ◽  
Liver Function ◽  
Immune Checkpoint ◽  
Fulminant Hepatitis ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Corticosteroid Treatment ◽  
Sudden Onset ◽  
Oral Corticosteroids

Immune checkpoint inhibitors have drastically changed in the treatment of many kinds of malignancies, especially malignant melanoma. The focus of the recent experiments has not only been on their efficacy but also immune-related adverse events (irAEs). We report a case of fulminant hepatitis due to nivolumab. In this case, the patient had undergone long-term nivolumab therapy. He did not complain of any symptoms but his liver enzyme levels were extremely elevated (grade 4). We promptly decided to start oral corticosteroids in the patient. His liver function rapidly improved. The dose of corticosteroids was gradually reduced. Our case demonstrates that sudden onset fulminant hepatitis can occur despite the safe use of long-term nivolumab therapy. The irAE can improve rapidly with proper corticosteroid treatment. This report will be useful for the physicians who always use immune checkpoint inhibitors.

scholarly journals The limits of sexual conflict in the narrow sense: new insights from waterfowl biology

2012 ◽  
Vol 367 (1600) ◽  
pp. 2324-2338 ◽  
Author(s):  
Patricia L. R. Brennan ◽  
Richard O. Prum
Keyword(s):  
Sexual Conflict ◽  
Female Preference ◽  
Indirect Selection ◽  
Direct Selection ◽  
Sensory Bias ◽  
Indirect Benefits ◽  
Female Preferences ◽  
Male Display ◽  
Male Displays ◽  
Coercive Mating

Sexual conflict occurs when the evolutionary interests of the sexes differ and it broadly applies to decisions over mating, fertilization and parental investment. Recently, a narrower view of sexual conflict has emerged in which direct selection on females to avoid male-imposed costs during mating is considered the distinguishing feature of conflict, while indirect selection is considered negligible. In this view, intersexual selection via sensory bias is seen as the most relevant mechanism by which male traits that harm females evolve, with antagonistic coevolution between female preferences and male manipulation following. Under this narrower framework, female preference and resistance have been synonymized because both result in a mating bias, and similarly male display and coercion are not distinguished. Our recent work on genital evolution in waterfowl has highlighted problems with this approach. In waterfowl, preference and resistance are distinct components of female phenotype, and display and coercion are independent male strategies. Female preference for male displays result in mate choice, while forced copulations by unpreferred males result in resistance to prevent these males from achieving matings and fertilizations. Genital elaborations in female waterfowl appear to function in reinforcing female preference to maintain the indirect benefits of choice rather than to reduce the direct costs of coercive mating. We propose a return to a broader view of conflict where indirect selection and intrasexual selection are considered important in the evolution of conflict.

The extended algorithm for quasi maximum likelihood parameter estimation

2021 ◽  
Author(s):  
Alfira Mulya Astuti ◽  
Setiawan ◽  
Ismaini Zain ◽  
Jerry D. T. Purnomo
Keyword(s):  
Parameter Estimation ◽  
Maximum Likelihood ◽  
Quasi Maximum Likelihood
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