Genetic and phenotypic trends for milk yield and milk composition traits of Saanen goats from Mexico
Por:
Torres-Vazquez, JA, Valencia-Posadas, M, Castillo-Juarez, H, Montaldo, HH
Publicada:
1 oct 2010
Resumen:
The objective of the study was to estimate the genetic and phenotypic trends for milk yield (MILK, n=1041), fat yield (FAT. n=487), protein yield (PROT, n=477), lactose yield (LACT, n=401), fat content (%FAT, n=487), protein content (%PROT, n=477) and lactose content (%LACT, n=401). analyzing first lactation records adjusted to 305-d, obtained between 2000 and 2006 from 10 Saanen goats flocks from Guanajuato, Mexico. Predicted breeding values (PBV) were obtained with single-trait animal models that included phantom parent groups. Genetic trends were estimated as the regression of the PBV on year of birth. Phenotypic trends were estimated as the linear regression coefficients of production records on the year of birth. The annual genetic trends for MILK, FAT, PROT and LACT were 2.99 +/- 1.06 kg, -0.21 +/- 0.09 kg, -0.10 +/- 0.04 kg and -0.19 +/- 0.09 kg, respectively (P<0.05). Annual genetic trends for %FAT, %PROT and %LACT were close to zero (P>0.05). The mean annual genetic trend for
Filiaciones:
Montaldo, HH:
Univ Nacl Autonoma Mexico, Dept Genet & Bioestadist, Fac Med Vet & Zootecnia, Mexico City 04510, DF, Mexico
|