milk: Milk production
In pedigreemm: Pedigree-Based Mixed-Effects Models

milk	R Documentation

Milk production

Description

Records of the milk production of 3397 lactations from first through fifty parity Holsteins. These were 1,359 cows, daughters of 38 sires in 57 herds. The data was downloaded from the USDA internet site. All lactation records represent cows with at least 100 days in milk, with an average of 347 days. Milk yield ranged from 4,065 to 19,345 kg estimated for 305 days, averaging 11,636 kg. There were 1,314, 1,006, 640, 334 and 103 records were from first thorough fifth lactation animals.

Format

A data frame with 3397 observations on the following 9 variables.

id: numeric identifier of cow
lact: number of lactation for which production is measured
herd: a factor indicating the herd
sire: a factor indicating the sire
dim: number of days in milk for that lactation
milk: milk production estimated at 305 days
fat: fat production estimated at 305 days
prot: protein production estimated at 305 days
scs: the somatic cell score

Source

USDA web site. http://www.aipl.arsusda.gov/

References

2010. A.I. Vazquez, D.M. Bates, G.J.M. Rosa, D. Gianola and K.A. Weigel. Technical Note: An R package for fitting generalized linear mixed models in animal breeding. Journal of Animal Science, 88:497-504.