Cox-Gompertz model for analysis of the time of stay in an Anglo-Nubian goat herd

Cleide Mayra Menezes Lima, Vera Lucia Damasceno Tomazella, Severino Cavalcante de Sousa Junior, José Elivalto Guimarães Campelo, Luciano Silva Sena, Waldomiro Barioni Junior

Abstract


Anglo-Nubian goats are hardy animals able to adapt to tropical environments, where their farming is usually held on pasture. However, climatic conditions in this environment also favor endoparasitism, which implies a negative aspect if sensitivity to worm infections interferes by reducing the reproductive lifespan of females, as their stay in the herd is a trait of great importance for efficient goat farming. In this respect, this study proposes to use the survival analysis methodology with the Cox-Gompertz proportional hazards model to assess the length of stay in the herd by relating the removal of females due to death with worm infection being the main cause to other forms of culling, using information from 101 Anglo-Nubian goats born from 2009 to 2013 in an experimental herd from Teresina - PI, Brazil. The Cox-Gompertz proportional hazards model chose body condition score, birth weight and birth season as important covariates (p-value bigger smaller 10%). Body condition score showed to be a favorable factor for the longer stay of the goats in the herd. Eggs per gram, age at first kidding, birth type and dam age were not significant. The Cox-Gompertz proportional hazards model is suitable for fitting the statistical model to estimate the length of stay in the herd, with censoring related to endoparasitism in Anglo-Nubian goats.

Keywords


Body condition score; Censoring; Culling; EPG; Famacha.

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References


Akaike, H. (1974). A new look at the statistical model identification. IEEE Transactions on Automatic Control, 19(6), 716-723. doi: 10.1109/TAC.1974.1100705

Batista, J. F., Campelo, J. E. G., Morais, M. F., Silva, P. O., Magalhães, P. C., Barçante, F. P. D. S., & Mendonça, I. L. (2014). Endoparasitismo gastrintestinal em cabras da raça Anglonubiana. Revista Brasileira de Saúde e Produção Animal, 15(2), 318-326. doi: 10.1590/S1519-99402014000200016

Bishop, S. C. (2012). A consideration of resistance and tolerance for ruminant nematode infections. Frontiers in Genetics, 3(1), 168. doi: 10.3389/fgene.2012.00168

Castañeda-Bustos, V. J., Montaldo, H. H., Valencia-Posadas, M., Shepard, L., Pérez-Elizalde, S., Hernández-Mendo, O., & Torres-Hernández, G. (2017). Linear and nonlinear genetic relationships between type traits and productive life in US dairy goats. Journal of Dairy Science, 100(2), 1232-1245. doi: 10.3168/ jds.2016-11313

Charlier, J., Voort, M., Kenyon, F., Skuce, P., & Vercruysse, J. (2014). Chasing helminths and their economic impact on farmed ruminants. Trends in Parasitology, 30(7), 361-367. doi: 10.1016/j.pt.2014.04.009

Colosimo, E. A., & Giolo, S. R. (2006). Análise de sobrevivência aplicada. São Paulo, SP: Editora Blucher.

Conrado, V. D. C., Arandas, J. K. G., & Ribeiro, M. N. (2015). Regression models to predict the weight of Caninde goat breed through morphometric measures. Archivos de Zootecnia, 64(247), 277-280. doi: 10. 21071/az.v64i247.400

Cornelius, M. P., Jacobson, C., & Besier, R. B. (2014). Body condition score as a selection tool for targeted selective treatment-based nematode control strategies in Merino ewes. Veterinary Parasitology, 206(3-4), 173-181. doi: 10.1016/j.vetpar.2014.10

Costa, V. M. M., Simões, S. V. D., & Riet-Correa, F. (2011). Controle das parasitoses gastrintestinais em ovinos e caprinos na região semiárida do Nordeste do Brasil. Pesquisa Veterinária Brasileira, 31(1), 65-71. doi: 10.1590/S0100-736X2011000100010 .




DOI: http://dx.doi.org/10.5433/1679-0359.2021v42n5p2937

Semina: Ciênc. Agrár.
Londrina - PR
E-ISSN 1679-0359
DOI: 10.5433/1679-0359
E-mail: semina.agrarias@uel.br
Este obra está licenciado com uma Licença Creative Commons Atribuição-NãoComercial 4.0 Internacional