Wyniki wyszukiwania - AGRO

1

Maternal effects on the conformation traits in half-bred horses

100%

Torzynski G., Wolc A., Szwaczkowski T.

Journal of Animal and Feed Sciences

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2005

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tom 14

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nr 4

595-605

2

Analysis of the laying rhythm and reproductive traits of geese

100%

Rosinski A., Nowaczewski S., Kontecka H., Bednarczyk M., Elminowska-Wenda G., Bielinska H., Maczynska A.

Folia Biologica

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2006

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tom 54

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nr 3-4

3

Milk trait heritability and correlation with heterozygosity in yak

100%

Jiang X. P., Liu G. Q., Wang C., Mao Y. J., Xiong Y. Z.

Journal of Applied Genetics

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2004

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tom 45

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nr 2

4

Extract viscosity of winter rye heritability and correlation to kernel characters

100%

Gan Y., McLeod J. G., Scoles G. J., Campbell G. L.

Plant Breeding and Seed Science

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1996

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tom 40

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nr 3-4

5

The effect of inbreeding level and genetic factors on longevity in Arabian oryx (Oryx leucoryx)

86%

Szablewski P., Wolc A., Szwaczkowski T.

Animal Science Papers and Reports

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2006

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tom 24

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nr 4

6

Estimation of genetic parameters for monthly egg production in laying hens based on random regression models

86%

Wolc A., Szwaczkowski T.

Journal of Applied Genetics

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2009

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tom 50

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nr 1

41-46

Heritability and genetic correlations of monthly egg production under random regression models were estimated. Three layer lines (A22, A88, K66) in six consecutive generations were analysed. A22 (13,770 recorded hens) and A88 (13,950 recorded hens) are maternal lines of Rhode Island White birds selected on egg production and shell colour; K66 (9,351 recorded birds) is a paternal line of Rhode Island Red birds selected on egg weight. Eight models with different orders of Legendre polynomials were applied. Adequacy of the models was checked by the Akaike Information Criterion. According to the most adequate model including second order Legendre polynomials for fixed effects and third order for additive genetic and permanent environmental effects, relatively high heritabilities were estimated in the first (h²=0.3) and final (h² above 0.3) periods of production with a substantial decrease in heritability during the egg production peak. Methodology based on random regression animal models can be recommended for genetic evaluation of laying hens.

7

Obstetrical problems and stillbirth in beef cattle

86%

Citek J., Hradecka E., Rehout V., Hanusova L.

Animal Science Papers and Reports

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2011

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tom 29

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nr 2

Out of 5970 calvings, 4.29% had an abnormal course (dystocia). The occurrence of stillbirths was 6.98% of all births and 4.15% of normal course births. Stillbirths occurred in 70.31% of dystocias. The highest frequency of stillbirths was in Blonde d´Aquitaine (8.59%) and the lowest in Gasconne (3.96%) cows. A narrow pelvis and an oversized foetus were the causes of more than 50% cases of dystocia. In Charolaise, an extremely high occurrence of oversized foetus, while in Blonde d´Aquitaine uterine inertia were found. A narrow pelvis was especially frequent as the cause of dystocia in the Aberdeen Angus and Limousine breeds. On analysis of stillbirths the most important effect was of the calving course with 24.47% impact on variability. Difficult calving increased the odds of stillbirth by 76 compared to normal calving. The heritability of stillbirth was estimated as 7.80%. It is recommended to restrict the use of sires with a higher incidence of dystocia or stillbirth in the offspring. As genetically determined variability is very low, other systematic measures are necessary to control stillbirth and dystocia. These are: supervision of the herd, obstetrical assistance, appropriate heifer rearing, mating cows at the proper live weight and proper nutrition during the pregnancy.

8

The exact moments of estimator of the intraclass correlation coefficient. Balanced model

86%

Niedokos E.

Colloquium Biometryczne

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1997

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tom 27

9

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Genetic parameters assessment of siliquae associated with stress indices in rapeseed cultivars

86%

Rameeh V.

Annales Universitatis Mariae Curie-Skłodowska. Sectio E. Agricultura

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2012

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tom 67

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nr 4

10

Analysis of genetic components of winter oilseed rape (Brassica napus ssp. oleifera ) regeneration ability under in vitro culture

86%

Turczynowska A., Siatkowski I., Broda Z.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

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2015

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tom 96

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nr 1

11

Grading standards and their effect on estimates of variance components and genetic trends in the silver fox [Vulpes vulpes L.]

86%

Wierzbicki H., Filistowicz A.

Journal of Animal and Feed Sciences

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2003

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tom 12

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nr 1

12

Genetic control of morphological and physical characteristics determining resistance to lodging in barley [Hordeum vulgare L.]

86%

Jezowski S., Surma M., Adamski T.

International Agrophysics

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2001

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tom 15

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nr 3

13

Estimates of heritability for first and second lactation test-day milk production in Polish Black-and-White cattle

86%

Ptak E., Jagusiak W., Jamrozik J.

Animal Science Papers and Reports. Supplement

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2004

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tom 22

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nr 2

14

Estimation of variance components for performance traits in Ukrainian pig populations

86%

Getya A., Chub O., Willeke H., Wierzbicki H.

Animal Science Papers and Reports. Supplement

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2004

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tom 22

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nr 2

15

Genetic aspects of racing performance in Polish pure-bred Arab horses. I. Genetic parameters

86%

Sobczynska M., Kownacki M.

Journal of Applied Genetics

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1997

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tom 38

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nr 2

The objective of this study was to estimate variance components of Polish Arab horses’ racing performance. The traits studied were the log of annual earnings and rank. Fixed effects of the year of race, herd, sex, the annual number of starts and random animal and permanent environment effects were evaluated on both earnings and rank at finish in Polish Arab horses. The obtained data included 2243 records on 4- and 5-year-old horses by 143 sires. Only races in which 4- and 5-year-olds competed were used. Heritability estimates of earnings and rank at finish were 0.22 and 0.25, respectively. Repeatability estimates of these traits were the same as heritability estimates. All the estimates of genetic and phenotypic correlations between the log of earnings and rank at finish were high and positive. Earnings and rank are good criteria for genetic improvement. Rank seems to be a better measure of racing performance.

16

Correlations and heritability of the characters determining the seed yield of the long-raceme alfalfa [Medicago sativa L.]

86%

Bodzon Z.

Journal of Applied Genetics

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2004

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tom 45

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nr 1

17

The effect of selection for traits of low heritability conducted in noninbred populations on the basis of progeny or performance tests

86%

Sobczynska M., Kownacki M.

Journal of Applied Genetics

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1995

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tom 36

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nr 2

The investigations were carried out to compare selection conducted on the basis of progeny with that on the basis of animals'own performance. Selection was conducted for the body weight at weaning (at the age of 21 days), which is a trait of low heritability (h²=0.1). It was run throughout 15 generations, whereas in generations 13 and 14 three experimental replicas were crossed to obtain population free of inbreeding. A cumulated response to selection was higher in the group selected on the basis of animals' own performance, but after crossing the replicas it decreased clearly in the both groups. The cumulated selection differential was higher in the group selected on the basis of animals' own performance. However, a statistical analysis of the obtained results showed no significant difference between the two selection methods.

18

Heritability of usable traits of long-wool sheep

86%

Kmiec M., Stepien A.

Genetica Polonica

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1992

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tom 33

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nr 3

19

The inheritance of plant height in crosses involving short-stem rye genotypes

86%

Izdebski R.

Journal of Applied Genetics

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1995

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tom 36

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nr 4

The paper presents results of studies on the inheritance of plant height in four short-stem genotypes of rye selected from genotypically different collection materials. Short-stem genotypes P-2, P-9, P-30 and P-52 were crossed to a tall-stem inbred line Uniwersalne 145 (S₁₇). The genotype P-2 was additionally crossed to a related, but tall-stem line P-2 W. In each cross combinations six generations - P₁, P₂, F₁, F₂, B₁ (F₁ × P₁) and B₂ (F₁ × P₂) - were examined. Distribution of plant height in hybrid generations had a continuous character, which indicated a polygenic determination of short stem in all "P" genotypes under study. Results of the genetic analysis (degrees of dominance, Burton method, Mather and Cavalli scaling tests, a six-parameter model of inheritance) showed a significant role of additive, dominant and epistatic gene action in genetic determination of short stem in the "P" genotypes. Only in the cross Uniwersalne 145 × P-52 one of the applied methods (a six-parameter model) has not confirmed a significant role of epistasis and dominance. In the cross combinations Uniwersalne 145 × P-2, Uniwersalne 145 × P-9 and Uniwersalne 145 × P-30 a reduction of the plant height was influenced by homozygote × homozygote and homozygote × heterozygote interactions as well as by dominance effects, whereas the plant height increase was influenced by heterozygote × heterozygote interaction as well as by effects of additive gene action. The combination P-2W × P-2 was found to have reverse relationships. The revealed epistasis had a duplicate character. The heritability of plant height was relatively high and varied from 70.4% to 84.9% depending on the cross combination.

20

Resistance risk assessment: realized heritability, cross resistance and resistance stability of acetamiprid in the cotton aphid, Aphis gossypii Glover (Homoptera: Aphididae)

72%

Mokbel E. M. S.

Journal of Plant Protection Research

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2018

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tom 58

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nr 4

The cotton aphid, Aphis gossypii is an economically significant insect pest infesting various important crops and vegetables. The neonicotinoid, acetamiprid was recommended against aphids with excellent results. Resistance emergence and environmental pollution makes acetamiprid a favorable alternative to conventional insecticides. The aims of the present work were to predict acetamiprid resistance risk in A. gossypii, investigate cross resistance to other tested insecticides and explore acetamiprid stability in the absence of selection. A field-collected population from Sharqia governorate, Egypt was selected with acetamiprid. After 16 generations of selection, there was a 22.55-fold increase in LC50 and the realized heritability (h2) of resistance was 0.17. Projected rates of resistance indicated that, ifh2 = 0.17 and 50% of the population was killed at each generation, then a tenfold increase in LC50 would be expected in 12.2 generations. If h2 was 0.27 then 7.63 generations would be needed to achieve the same level. In contrast, with h2 of 0.07 it necessitates about 30 generations of selection to reach the same level. Cross resistance studies exhibited that the selected strain showed obvious cross resistance to the other tested neonicotinoid members, moderate cross resistance to alpha-cypermethrin and no cross resistance to pymetrozine. Fortunately, resistance to acetamiprid in the cotton aphid was unstable and resistance reverses the nearby susceptible strain throughout five generations without exposure to acetamiprid. Our results exhibited cotton aphid potential to develop resistance to acetamiprid under continuous selection pressure. The instability of acetamiprid makes A. gossypii amenable to resistance management tactics such as rotation with pymetrozine.

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