Genetic parameters estimation in an Italian horse native breed to support the conversion from agricultural uses to riding purposes

2019 ◽  
Vol 137 (2) ◽  
pp. 200-210 ◽  
Author(s):  
Michela Ablondi ◽  
Andrea Summer ◽  
Matteo Vasini ◽  
Marica Simoni ◽  
Alberto Sabbioni
2017 ◽  
Vol 39 (3) ◽  
pp. 339 ◽  
Author(s):  
Melina Zacarelli Pirotta ◽  
Fabiana Mota da Silva ◽  
Marcos Doniseti Michelotto ◽  
Alessandra Pereira Fávero ◽  
Ignácio José de Godoy ◽  
...  

 Peanut is an oilseed crop of great importance for Brazilian agribusiness. A major factor affecting its production is pest incidence, mainly thrips. This study aimed to evaluate the potential for resistance to Enneothrips flavens in genotypes derived from the cross between IAC 503 and the amphidiploid (A. magna x A. cardenasii)4x and to estimate the genetic and phenotype parameters in these genotypes, allowing for better targeting in the selection. The experiments were conducted in a Federer augmented block design with additional checks in two generations (F3 and F4). Resistance to thrips was evaluated by its natural infestation and the symptoms of attacks by the insect. They were also evaluated using agronomic trait indicators of interspecific segregating with cultivated species. The results indicated that the selected progeny exhibited high resistance to thrips compared to commercial genotypes, and they had the amphidiploid as the insect resistance source. Some progenies selected as resistant also had good production traits, but with the degree of suitability to the A. hypogaea L. genotypes still low, the use of a backcross as an alternative for the introgression of resistance genes and the consequent recovery of adapted genotypes of superior recurring parents is suggested. 


2014 ◽  
Vol 59 (No. 7) ◽  
pp. 302-309 ◽  
Author(s):  
L. Vostrý ◽  
Z. Veselá ◽  
A. Svitáková ◽  
H. Vostrá Vydrová

The most appropriate model for genetic parameters estimation for calving ease and birth weight in beef cattle was selected. A total of 27 402 field records were available from the Czech Charolais breed. For estimation of genetic parameters for calving ease and body weight, three bivariate models were tested: a linear-linear animal model (L-LM) with calving ease classified into four categories (1 – easy; 2–4 – most difficult), a linear-linear animal model (SC-LM) in which calving ease scores were transformed into Snell scores (Snell 1964) and expressed as percentage of assisted calving (ranging 0–100%), and a bivariate threshold-linear animal model (T-LM) with calving ease classified into four categories (1 – easy, 2–4 – most difficult). All tested models included fixed effects for contemporary group (herd × year × season), age of dam, sex and breed of a calf. Random effects included direct and maternal genetic effects, maternal permanent environmental effect, and residual error. Direct heritability estimates for calving ease and birth weight were, with the use of L-LM, SC-LM, and T-LM, from 0.096 ± 0.013 to 0.226 ± 0.024 and from 0.210 ± 0.024 to 0.225 ± 0.026, respectively. Maternal heritability estimates for calving ease and birth weight were, with the use of L-LM, SC-LM, and T-LM, from 0.060 ± 0.031 to 0.104 ± 0.125 and from 0.074 ± 0.041 to 0.075 ± 0.040, respectively. Genetic correlations of direct calving ease with direct birth weight ranged from 0.46 ± 0.06 to 0.50 ± 0.06 for all tested models; whereas maternal genetic correlations between these two traits ranged from 0.24 ± 0.17 to 0.25 ± 0.53. Correlations between direct and maternal genetic effects within-trait were negative and substantial for all tested models (ranging from –0.574 ± 0.125 to –0.680 ± 0.141 for calving ease and from –0.553 ± 0.122 to –0.558 ± 0.118 for birth weight, respectively), illustrating the importance of including this parameter in calving ease evaluations. Results indicate that any of the tested models could be used to reliably estimate genetic parameters for calving ease for beef cattle in the Czech Republic. However, because of advantages in computation time and practical considerations, genetic analysis using SC-LM (transformed data) is recommended.


2019 ◽  
Vol 19 (3) ◽  
pp. 595-604 ◽  
Author(s):  
Magdalena Szyndler-Nędza ◽  
Robert Eckert ◽  
Mirosław Tyra ◽  
Grzegorz Żak ◽  
Karolina Szulc ◽  
...  

AbstractThe aim of the study was to determine genetic parameters of live performance traits in pigs of three native breeds maintained in Poland. As part of the conservation programmes, the Puławska (Puł), Złotnicka White (ZW) and Złotnicka Spotted (ZS) breeds are monitored for productivity based on performance test results of these breeds. The study included 6042 gilts and 2406 boars of the Puławska breed, 866 Złotnicka White gilts, and 903 Złotnicka Spotted gilts. The genetic parameters were estimated separately for each breed, and also separately for sexes in the case of the Puławska breed. The components (co)variance and genetic parameters were estimated using the REML method for the animal model taking into account different combination of fixed and random effects. Convergence of the iterative process was achieved by the selection of AIREML algorithm. The coefficients of genetic and phenotypic correlations between measurements of slaughter traits and daily gain were low for all breed groups. In turn, the relationships between backfat thickness measurements and carcass meat percentage were estimated as high. Only the correlations of slaughter traits with loin eye height were not uniform for the analysed breed groups. The coefficients of heritability (h2) were high and intermediate for all breeds and sexes. The highest heritability coefficients were obtained for daily gain (0.58 in ZW to 0.80 in Puł gilts), followed by backfat thickness (0.37 in Puł gilts to 0.64 in ZW) and carcass meat percentage (0.40 in ZS to 0.56 in ZW). The lowest coefficients were obtained for loin eye height (0.24 in Puł boars to 0.40 in ZW). The estimated genetic parameters could be used to verify selection indices of the breeds included in the genetic resources conservation programmes.


2012 ◽  
Vol 34 (3) ◽  
pp. 138
Author(s):  
Veronika Yuneriati Beyleto ◽  
Sumadi (Sumadi) ◽  
Tety Hartatik

<p>This research was conducted to estimate heritability, repeatability and genetic correlation values on growth traits of Boerawa goat at Sumber Rejeki farmer group at Campang Village, Gisting District and Karya Makmur I and Karya Makmur II farmer group at Wonoharjo and Sukoharjo Village, Sumber Rejo District, Tanggamus regency, Lampung province. Data consisted of production record and 238 Boerawa goat derived from 93 PE and 7 Boer buck.<br />The research was started on October 30, 2009 up to January 30, 2010. The results indicated that heritability value of birth weight, weaning weight, yearling weigth, average of preweaning daily gain, and average of postweaning weight<br />analyzed by paternal half-sibs correlation were 0.80±0.40; 0.30±0.17; 0.80±0.04; 0.32±0.18 and 0.30±0.17, respectively. The repeatability values of birth weight, weaning weight and yearling weight analyzed based on two<br />recording per every dam were 0.42±0.07; 0.32±0.08; 0.30±0.08; 0.30±0.08 and 0.53±0.06. The genetic correlation values among birth weight and weaning weight, birth weight and yearling weight, weaning weight and yearling weight,<br />average of preweaning weight and postweaning weight daily gain analyzed by paternal half-sibs correlation were 0.50±0.04; 0.44±0.08; 0.21±0.03 and 0.20±0.05, respectively. The result also indicated that the heritability and<br />repeatability values was high and the genetic correlation values were moderate to high.</p><p>(Key words: Boerawa goat, Genetic parameter, Growth character)</p>


1997 ◽  
Vol 65 (2) ◽  
pp. 247-255 ◽  
Author(s):  
M. H. Yazdi ◽  
G. Engström ◽  
A. Näsholm ◽  
K. Johansson ◽  
H. Jorjani ◽  
...  

AbstractThe Baluchi breed is the most common native breed of Iran adapted to harsh environments in the eastern parts of the country. The data used in the present study, collected from two research flocks at the Abbasabad sheep breeding station in north-east Iran, included 20 534 animals descended from 363 sires, 5992 dams, 282 maternal grandsires, and 2865 maternal granddams during the period 1966 to 1989. The traits recorded were: birth weight (BW), weaning weight (WW), weight at 6 months (W6), weight at 12 months (YW), pre-weaning gain (WG), post-weaning gain (PWG), lamb fleece weight (LFW), ewe fleece weight sheared before first joining (FW1) and adult ewe fleece weight (FW). Genetic parameters, estimated with restricted maximum likelihood and a two-trait animal model, were similar in the two flocks. Direct heritabilities for the various body weight traits were moderate and varied between 0·13 and 0·32, while the maternal heritabilities were low and varied between 0·01 and 0·12. Direct and maternal genetic correlations between WW and weights at later ages were moderate to high (0·59 to 0·96). Direct heritabilities of weight gain measures varied between 0·12 and 0·19, while no significant maternal influence on either of these weight gain measures could be detected. The estimates of direct genetic correlation between WG and PWG were positive and varied between 0·54 and 0·74, while negative maternal genetic correlation (0·17 on average) between WG and PWG was detected. For LFW, direct heritability was low and no maternal heritability could be shown. For FW1, both direct and maternal genetic influences were demonstrated (0·07 to 0·26). Direct genetic correlation between LFW and FW1 was very low and close to zero, while maternal genetic correlation was positive and relatively high (0·72 on average). The relative contributions to phenotypic variance from variance components due to common environmental effects ranged from 0·01 to 0·15 for all traits. The repeatability of FW was low (0·03 to 0·12).


2021 ◽  
Vol 5 (Supplement_S1) ◽  
pp. S180-S184
Author(s):  
Hamad M Saad ◽  
R Mark Enns ◽  
Milton G Thomas ◽  
Lee L Leachman ◽  
Scott E Speidel

Author(s):  
Yanca Araujo Frias ◽  
Osmar Gabriel Trigo Marques de Oliveira ◽  
João Victor Tino Dellaqua ◽  
Evandro Pereira Prado ◽  
Paulo Renato Matos Lopes ◽  
...  

The objective of this work was to verify the influence of the percentage of failures in a forest genetics experiment in the estimation of genetic parameters. The study consisted in the evaluation of two experiments of full‑sib families under randomized complete block design with three replicates conducted in the state of Minas Gerais, Brazil. The experiment I was evaluated in January 2002, with approximately 60 months of age. The experiment II was evaluated in January 2003, with 45 months of age. In both experiments, the evaluations consisted of the measurement of the diameter at breast height and plant height. For all the investigated genetic parameters, an increase in the amplitude of the estimates was verified due to the increase in the number of experimental failures. Variances and negative heritabilities were detected, from 35% of failure, indicating that in such cases, this proportion of failure may be problematic to estimate genetic values, to estimate the gain with the selective process and for make decision.


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