PMID- 17117360
OWN - NLM
STAT- MEDLINE
DCOM- 20070405
LR  - 20061122
IS  - 1676-5680 (Electronic)
IS  - 1676-5680 (Linking)
VI  - 5
IP  - 3
DP  - 2006 Jul 31
TI  - Genetic trend for milk yield in Guzerat herds participating in progeny testing 
      and MOET nucleus schemes.
PG  - 454-65
AB  - Genetic trends for 305-day milk yield (P305) in Brazilian Guzerat herds under 
      selection were compared. Data from 4898 lactations of 3179 purebred and crossbred 
      cows from various regions of Brazil were used. Milk yield was adjusted for mature 
      age and the contemporary groups were defined as herd and calving year. Genetic 
      parameters were estimated using the MTDFREML program. The model included the 
      random effects of animals and permanent environment, and herd-calving year, 
      calving season and genetic composition as fixed effects. Genetic trends were 
      estimated by linear regression of weighted average estimated breeding values as a 
      function of calving year. The average P305 was 2065 +/- 922 kg and the 
      heritability was 0.23 +/- 0.03. The annual genetic trend in estimated breeding 
      values of cows for P305 was 7.09 +/- 0.71 kg between 1987 and 2004, and 6.47 +/- 
      2.35 kg between 1997 and 2004. For cows born and raised in the multiple ovulation 
      and embryo transfer (MOET) nucleus, this trend was 36.46 +/- 24.54 kg/year 
      between 1997 and 2004, 183.14 +/- 47.94 kg/year between 1997 and 2000, and 9.13 
      +/- 19.19 kg/year between 2001 and 2004. An average inbreeding coefficient of 
      0.04 was found for inbred MOET cows in 2004. Increasing the size of the family 
      and introducing new progenies changed reliabilities and predicted transmitting 
      ability estimates of MOET sires. In conclusion, there was a positive genetic 
      trend for milk yield in the MOET nucleus at low inbreeding coefficients due to 
      the increased accuracy and estimated genetic merit, but no changes in the average 
      milk yield were observed.
FAU - Peixoto, M G C D
AU  - Peixoto MG
AD  - Embrapa Gado de Leite, Juiz de Fora, MG, Brasil.
FAU - Verneque, R S
AU  - Verneque RS
FAU - Teodoro, R L
AU  - Teodoro RL
FAU - Penna, V M
AU  - Penna VM
FAU - Martinez, M L
AU  - Martinez ML
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20060731
PL  - Brazil
TA  - Genet Mol Res
JT  - Genetics and molecular research : GMR
JID - 101169387
SB  - IM
MH  - Animals
MH  - Breeding
MH  - Cattle/*genetics
MH  - *Crosses, Genetic
MH  - Dairying
MH  - Embryo Transfer/*veterinary
MH  - Female
MH  - Lactation/*genetics
MH  - Linear Models
MH  - *Quantitative Trait, Heritable
MH  - Reproducibility of Results
EDAT- 2006/11/23 09:00
MHDA- 2007/04/06 09:00
CRDT- 2006/11/23 09:00
PHST- 2006/11/23 09:00 [pubmed]
PHST- 2007/04/06 09:00 [medline]
PHST- 2006/11/23 09:00 [entrez]
AID - 0215 [pii]
PST - epublish
SO  - Genet Mol Res. 2006 Jul 31;5(3):454-65.