Lactation curves for milk yield, fat, and protein content in Slovenian dairy sheep

A. Komprej*, G. Gorjanc, D. Kompan, M. Kovac

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Lactation curves for daily milk yield, fat, and protein content in three dairy sheep breeds were estimated by the repeatability animal model using test-day records. A total of 38 983 records from 3068 ewes of Bovec, Improved Bovec, and Istrian Pramenka breeds, collected between the years 1994 and 2002, were analysed. The three-trait repeatability animal model included breed and lambing season as fixed. The stage of lactation within each breed was modelled by the modified Ali-Schaeffer's lactation curve. Parity and litter size were used as covariates in quadratic and linear regression, respectively. Common flock environment, additive genetic effect, permanent environment over lactations as well as within lactation were treated as random. The average daily milk yield was 1090 g in Bovec, 1010 g in Improved Bovec, and 731 g in Istrian Pramenka breeds. Overall means for fat and protein content were 6.59 and 5.53% for Bovec, 6.22 and 5.33% for Improved Bovec, and 7.20 and 5.63% for Istrian Pramenka. Breed, lambing season, stage of lactation, parity, and litter size significantly (P <0.001) affected all three observed milk traits, with the only exception of parity in fat and litter size in protein content. The shape of lactation curves for daily milk yield in Bovec and Improved Bovec breeds fitted well to the general lactation curve in dairy sheep. Daily milk yield was increasing in the first month of lactation and decreasing thereafter. In Istrian Pramenka, the shape of lactation curve was more or less atypical, with daily milk yield decreasing almost throughout the entire lactation. Lactation curves for fat and protein content were opposite to the lactation curves for daily milk yield in all three breeds.

Original languageEnglish
Pages (from-to)231-239
Number of pages9
JournalCzech journal of animal science
Volume57
Issue number5
Publication statusPublished - May 2012

Keywords / Materials (for Non-textual outputs)

  • dairy sheep
  • milk traits
  • test-day records
  • lactation curves
  • TEST-DAY MODELS
  • EAST FRIESIAN EWES
  • TEST-DAY RECORDS
  • GENETIC-PARAMETERS
  • LITTER SIZE
  • COMPONENTS
  • COWS
  • PERFORMANCE
  • CHIOS
  • STAGE

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