Genetic and environmental factors affecting lactation curve from dairy goats

Authors

  • Heraldo Cesar Gonçalves Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção e Exploração Animal, Botucatu, SP
  • Francisco Stefano Wechsler Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção e Exploração Animal, Botucatu, SP
  • Alcides Amorim Ramos Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção e Exploração Animal, Botucatu, SP
  • Lilian Martini Pulz Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Botucatu, SP
  • Tiago Creste Losi Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Botucatu, SP
  • Nívea Regina de Oliveira Felisberto Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Botucatu, SP
  • Helen Fernanda Barros Gomes Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Botucatu, SP
  • Ana Paula Giasseti Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Botucatu, SP

Keywords:

lactation cycle, multiphasic function, kidding interval, milk yield

Abstract

The objective of this study was to investigate the environmental factors affecting lactation curve traits and to estimate their genetic parameters by means of two methods of analysis. The data originated from 1,336 lactations of 687 goats, raised in seven farms over seven years and belonging to one of three breeds (1 - Alpine, 2 - Saanen and 3 - Toggenburg). The diphasic function was used to adjust the lactation curves. The curve trait means were as follows: days until peak in phases 1 and 2 (TP1 and TP2): 95.24 and 105.35; length of phases 1 and 2 (DF1 and DF2): 213.04 and 185.20 days; peak milk yield in phases 1 and 2: 2.14 and 1.87 kg; initial milk yield in phases 1 and 2 (PLF1 and PLF2): 1.12 and 0.86 kg; initial milk yield (PLI): 1.99 kg; milk yield during phases 1 and 2 (PLF1 and PLF2): 300.29 and 335.01 kg; and total milk yield: 635.30 kg. The following effects were observed: year on PF1, PF2, PLI and PLF1; kidding season on TP1, PLF1 and PLI; and year x season interaction on DF2 and PLF2. A linear effect of age at kidding was observed for PLIF2 and a quadratic effect was observed for PF1, PF2, PLIF1, PLI and PLF1. A farm-breed effect was detected for TP1, DF2, PF2, PLIF2, PLI, PLF1 and PLF2. The heritability estimates for curve traits, obtained through two methods of analysis, stayed all below 0.20, excepting PLT, for which the estimate was 0.30. The same occurred to the repeatability estimates, excepting PLT and PLI, for which the estimates were higher than 0.20.

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Published

2013-11-28

Issue

Section

GENETIC

How to Cite

Genetic and environmental factors affecting lactation curve from dairy goats. (2013). Bulletin of Animal Husbandry, 61(1), 13-30. http://35.198.24.243/index.php/bia/article/view/1333

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