Artículos de revistas
Produção de leite, leite residual e concentração hormonal de vacas Gir × Holandesa e Holandesa em ordenha mecanizada exclusiva
Fecha
2005-12-01Registro en:
Arquivo Brasileiro de Medicina Veterinaria e Zootecnia. Minas Gerais: Arquivo Brasileiro Medicina Veterinaria Zootecnia, v. 57, n. 6, p. 820-824, 2005.
0102-0935
10.1590/S0102-09352005000600018
S0102-09352005000600018
WOS:000236601600018
WOS000236601600018.pdf
Autor
Universidade Estadual Paulista (Unesp)
Inst Zootecnia
Universidade de São Paulo (USP)
Institución
Resumen
In a machine milking system in which calves were not present, oxytocin concentration (OT), cortisol release (CORT), milk yield and residual milk were evaluated for cows of three genetic groups: 1/2Gir x 1/2Holstein (n=6, genetic group F2), 1/4Gir x 3/4Holstein (n=6, genetic group F3) and Holstein (n=6, genetic group H). Group H had higher milk yield than groups F2 and F3, whereas OT was similar among groups. The increase in OT during milk-ing was greater for H and F3 than for F2. Residual milk for F2 was' higher than for F3 and H. The CORT for F2 was higher than for cows of the other two genetic groups. Cows from F2 and F3 were more stressed than H cows during machine milking, but the Gir x Holstein groups did release suffficient OT to induce an effective milk letdown response.