Asociación entre la evaluación genética y el juzgamiento en pista de bovinos lecheros y de carne ... more Asociación entre la evaluación genética y el juzgamiento en pista de bovinos lecheros y de carne Associação entre a avaliação genética e a aparência externa na pista de julgamento de bovinos de leite e de corte Summary Background: a concern for breeders is whether an animal ranking based on genetic evaluations is similar to that obtained from show-ring judging. Objective: to determine the association between rankings for Braunvieh (BR) and Brown Swiss (BS) cattle of Mexico based on show-ring judging and their respective expected progeny differences (EPDs) or predicted transmitted abilities (PTAs). Methods: ranking values from judging were transformed using the rankit transformation. For each breed, Pearson correlation analyses were performed between the transformed rank values of the animals obtained from judging at the show-ring and their EPD or PTA values. Results: using the complete databases, in both breeds the correlation coefficient estimates were low (<0.18) but different from zero (p<0.05). The correlation coefficient considering PTAs for milk yield in BS was slightly higher than those obtained for any EPD for growth traits in BR. Correlations in adult animals (0.18 to 0.23) were different from zero (p<0.05) and higher than those of young animals or calves, while those within males or females were similar. Correlations within years of judging in the show-ring were variable and did not indicate any specific trend. Conclusions: show-ring rank results are associated with genetic evaluation of animals, although the magnitude is low. Selection of breeding animals based on show-ring judgment could be used as a complementary tool to genetic evaluation.
A laboratory evaluation was carried out to determine the parasitic capacity of the nematode Roman... more A laboratory evaluation was carried out to determine the parasitic capacity of the nematode Romanomermis iyengari on III and 1V instar larvae of the mosquitoes Aedes aegypti, Anopheles pseudopuntipennis, and Culex quinquefasciatus, applying a dose of 10 nematodes larva − − − − −1 . The effectiveness of R. iyengari in larvae of An. pseudopunctipennis in the field was evaluated
In toxicological studies, the preference or non-preference of insects in experiments with a dicho... more In toxicological studies, the preference or non-preference of insects in experiments with a dichotomous response variable is frequently tested. This type of experiment, when over-dispersion is assumed, has been modeled using the Beta-Binomial distribution. Hypotheses of non-preference H0 1 2 : ; p p = = F H G I K J can be tested using the generalized likelihood ratio; however, for small samples, a good approximation to the asymptotic distribution of the statistic is not achieved. This research had the objective of designing a non- parametric Bootstrap technique on the likelihood ratio statistic in a Beta-Binomial model, to test non-preference in experiments with two choices. The proposed test of hypothesis uses as test criterion the likelihood ratio ̂ . d d e j Using the Bootstrap technique, the sample distribution ̂ ̂ F d d
The altitudinal pattern of genetic variation in Pinus hartwegii Lindl. populations was explored f... more The altitudinal pattern of genetic variation in Pinus hartwegii Lindl. populations was explored for seedling height growth, frost damage, grass-stage, and phenological stage of the terminal shoot. A provenance test was conducted with open-pollinated seed from 13 populations collected along an altitudinal transect (3000–3600 m) at the National Park Pico de Tancítaro, Michoacán, center-west Mexico. Height growth of seedlings in a nursery was assessed at seven and 18 months of age. Frost damage at −15 °C was evaluated in laboratory at 18 months of age; proportion of plants that had left grass-stage and stage of shoot development was assessed at the age of 22 months. Significant differences among provenances (P < 0.0001) were detected for all of the evaluated characters. The variation among populations was structured as a moderate altitudinal cline, with populations from lower altitudes showing larger height growth in seedlings, larger proportion of frost damages, fewer seedlings in grass-stage and more seedlings with developed shoot, whereas in populations from higher altitudes, seedlings exhibiting shorter plant height, lower percentages of frost damage, more seedlings with unbroken grass-stage, and fewer seedlings with advanced shoot development were displayed. Options for seed and seedling movement along the altitudinal gradient are discussed under the scope of reforestation, aiming at ecological restoration, conservation of forest genetic resources, and assisted migration considering global warming. We suggest delineation of two altitudinal seed zones (Zone I: 3000–3350 m; Zone II: 3350–3700 m).
Asociación entre la evaluación genética y el juzgamiento en pista de bovinos lecheros y de carne ... more Asociación entre la evaluación genética y el juzgamiento en pista de bovinos lecheros y de carne Associação entre a avaliação genética e a aparência externa na pista de julgamento de bovinos de leite e de corte Summary Background: a concern for breeders is whether an animal ranking based on genetic evaluations is similar to that obtained from show-ring judging. Objective: to determine the association between rankings for Braunvieh (BR) and Brown Swiss (BS) cattle of Mexico based on show-ring judging and their respective expected progeny differences (EPDs) or predicted transmitted abilities (PTAs). Methods: ranking values from judging were transformed using the rankit transformation. For each breed, Pearson correlation analyses were performed between the transformed rank values of the animals obtained from judging at the show-ring and their EPD or PTA values. Results: using the complete databases, in both breeds the correlation coefficient estimates were low (<0.18) but different from zero (p<0.05). The correlation coefficient considering PTAs for milk yield in BS was slightly higher than those obtained for any EPD for growth traits in BR. Correlations in adult animals (0.18 to 0.23) were different from zero (p<0.05) and higher than those of young animals or calves, while those within males or females were similar. Correlations within years of judging in the show-ring were variable and did not indicate any specific trend. Conclusions: show-ring rank results are associated with genetic evaluation of animals, although the magnitude is low. Selection of breeding animals based on show-ring judgment could be used as a complementary tool to genetic evaluation.
A laboratory evaluation was carried out to determine the parasitic capacity of the nematode Roman... more A laboratory evaluation was carried out to determine the parasitic capacity of the nematode Romanomermis iyengari on III and 1V instar larvae of the mosquitoes Aedes aegypti, Anopheles pseudopuntipennis, and Culex quinquefasciatus, applying a dose of 10 nematodes larva − − − − −1 . The effectiveness of R. iyengari in larvae of An. pseudopunctipennis in the field was evaluated
In toxicological studies, the preference or non-preference of insects in experiments with a dicho... more In toxicological studies, the preference or non-preference of insects in experiments with a dichotomous response variable is frequently tested. This type of experiment, when over-dispersion is assumed, has been modeled using the Beta-Binomial distribution. Hypotheses of non-preference H0 1 2 : ; p p = = F H G I K J can be tested using the generalized likelihood ratio; however, for small samples, a good approximation to the asymptotic distribution of the statistic is not achieved. This research had the objective of designing a non- parametric Bootstrap technique on the likelihood ratio statistic in a Beta-Binomial model, to test non-preference in experiments with two choices. The proposed test of hypothesis uses as test criterion the likelihood ratio ̂ . d d e j Using the Bootstrap technique, the sample distribution ̂ ̂ F d d
The altitudinal pattern of genetic variation in Pinus hartwegii Lindl. populations was explored f... more The altitudinal pattern of genetic variation in Pinus hartwegii Lindl. populations was explored for seedling height growth, frost damage, grass-stage, and phenological stage of the terminal shoot. A provenance test was conducted with open-pollinated seed from 13 populations collected along an altitudinal transect (3000–3600 m) at the National Park Pico de Tancítaro, Michoacán, center-west Mexico. Height growth of seedlings in a nursery was assessed at seven and 18 months of age. Frost damage at −15 °C was evaluated in laboratory at 18 months of age; proportion of plants that had left grass-stage and stage of shoot development was assessed at the age of 22 months. Significant differences among provenances (P < 0.0001) were detected for all of the evaluated characters. The variation among populations was structured as a moderate altitudinal cline, with populations from lower altitudes showing larger height growth in seedlings, larger proportion of frost damages, fewer seedlings in grass-stage and more seedlings with developed shoot, whereas in populations from higher altitudes, seedlings exhibiting shorter plant height, lower percentages of frost damage, more seedlings with unbroken grass-stage, and fewer seedlings with advanced shoot development were displayed. Options for seed and seedling movement along the altitudinal gradient are discussed under the scope of reforestation, aiming at ecological restoration, conservation of forest genetic resources, and assisted migration considering global warming. We suggest delineation of two altitudinal seed zones (Zone I: 3000–3350 m; Zone II: 3350–3700 m).
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Papers by Gustavo Valverde