Legendre polynomials

Reaction norms for the study of genotype-environment interaction for growth and indicator traits of sexual precocity in Nellore cattle

M. V. A. Lemos, Chiaia, H. L. J., Berton, M. P., Feitosa, F. L. B., Aboujaoude, C., Venturini, G. C., Oliveira, H. N., Albuquerque, L. G., and Baldi, F., Reaction norms for the study of genotype-environment interaction for growth and indicator traits of sexual precocity in Nellore cattle, vol. 14, pp. 7151-7162, 2015.

The objective of this study was to quantify the magnitude of genotype-environment interaction (GxE) effects on age at first calving (AFC), scrotal circumference (SC), and yearling weight (YW) in Nellore cattle using reaction norms. For the study, 89,152 weight records of female and male Nellore animals obtained at yearling age were used. Genetic parameters were estimated with a single-trait random-regression model using Legendre polynomials as base functions.

Random regression models using different functions to model milk flow in dairy cows

M. M. M. Laureano, Bignardi, A. B., L. Faro, E., Cardoso, V. L., Tonhati, H., and Albuquerque, L. G., Random regression models using different functions to model milk flow in dairy cows, vol. 13, pp. 7528-7541, 2014.

We analyzed 75,555 test-day milk flow records from 2175 primiparous Holstein cows that calved between 1997 and 2005. Milk flow was obtained by dividing the mean milk yield (kg) of the 3 daily milking by the total milking time (min) and was expressed as kg/min. Milk flow was grouped into 43 weekly classes. The analyses were performed using a single-trait Random Regression Models that included direct additive genetic, permanent environmental, and residual random effects.

Evaluation of alternative schemes for recording body weights in meat-type quails by using random regression

L. P. Silva, Ribeiro, J. C., Leite, C. D. S., Sousa, M. F., Bonafé, C. M., Caetano, G. C., Crispim, A. C., and Torres, R. A., Evaluation of alternative schemes for recording body weights in meat-type quails by using random regression, vol. 12, pp. 1533-1539, 2013.

Data from 8759 meat-type quails from the UFV1 strain and 9128 from the UFV2 strain were used to assess the possibility of reducing the number of body weight records in genetic evaluations. The evaluated animals were weighed weekly since hatching to the 6th week of life, with up to 7 records of body weight for each bird.

Genetic evaluation of Alpine goats using different milk control intervals

F. G. Silva, Torres, R. A., Brito, L. F., Silva, L. P., Menezes, G. R. O., Brito, L. C., Euclydes, R. F., and Rodrigues, M. T., Genetic evaluation of Alpine goats using different milk control intervals, vol. 12, pp. 2455-2464, 2013.

The objective of this study was to compare the results of genetic evaluations by using different milk control intervals to reduce the cost of milk yield controls without harming the quality of genetic evaluation of the animals. We analyzed test day milk yield data from the Goat Sector of Universidade Federal de Viçosa. After editing and checking for errors in the database, there were 20,710 records of test day milk yield for the 667 first lactations of Alpine goats, constituting the complete file, with 7-day control intervals.

Breeding value accuracy estimates for growth traits using random regression and multi-trait models in Nelore cattle

A. A. Boligon, Baldi, F., Mercadante, M. E. Z., Lôbo, R. B., Pereira, R. J., and Albuquerque, L. G., Breeding value accuracy estimates for growth traits using random regression and multi-trait models in Nelore cattle, vol. 10, pp. 1227-1236, 2011.

We quantified the potential increase in accuracy of expected breeding value for weights of Nelore cattle, from birth to mature age, using multi-trait and random regression models on Legendre polynomials and B-spline functions. A total of 87,712 weight records from 8144 females were used, recorded every three months from birth to mature age from the Nelore Brazil Program. For random regression analyses, all female weight records from birth to eight years of age (data set I) were considered.

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