The most part of Italian Brown Swiss milk goes to cheese so casein is fundamental. The trait currently used in selection is protein content tested in routine milk recording (test-day protein content). Now is possible to determine casein content on each cow by Fourier Transform Infrared Spectroscopy (IR). This allows to analyse casein routinely for each test day. In this study, 1022 milk samples...

The objective of this study was to estimate the genetic parameters for infection status (INF), as indicator of mastitis, SCS (i.e., log-transformed SCC), and milk yield (MY), by using a Gibbs sampling algorithm. The data comprised 17,843 test-day records of 2040 ewes. The pedigree file included 2948 animals. A bivariate variance component analysis was performed using the TM software. Fixed effe...

Information from 7712 lactations of Holstein dairy cows was collected from 33 commercial herds around Ithaca, NY in the 3 yr from 1981 to 1983. The data were divided into subsets corresponding to lactation 1, lactation 2, and lactation 3 or greater. To estimate heritabilities of dystocia, retained placenta, metritis, ovarian cysts, milk fever, and mastitis, a mixed linear model (herd-year fixed...

Genetic parameters were estimated with restricted maximum likelihood for individual test-day milk, fat, and protein yields and somatic cell scores with a random regression cubic spline model. Test-day records of Holstein cows that calved from 1994 through early 1999 were obtained from Dairy Records Management Systems in Raleigh, North Carolina, for the analysis. Estimates of heritability for in...

Previous studies in Holstein have shown 35% to 51.8% heritability in milk production traits, such as milk yield, fat, and protein, using pedigree data. Other studies in complex human traits could be captured by common single-nucleotide polymorphisms (SNPs), and their genetic variations, attributed to chromosomes, are in proportion to their length. Using genome-wide estimation and partitioning a...

Test day (TD) milk yield and protein percentage models and genetic parameters estimation has been studied in Latxa and Manchega milk ewes. Genetic parameters for test day data were estimated under a multivariate animal model which considered production in successive test days in first lactation as different traits and under a univariate animal model considering milk and protein percentage test ...

the aim of this study was to estimate genetic parameters of age at first calving and its relationship with productive traits of holstein dairy cows. a total of 24491 first lactation records (2x 305d) which were collected from 1995 to 2009 were used. the general linear model (glm) procedure was applied to determine effective factors on studied traits. herd-year-season (hys) and age at first calv...

Abstract Milk fever, or hypocalcemia, has a significant economic impact on the dairy industry and increases risk of other costly disorders including ketosis displaced abomasum. The objective this study was to identify genetic variants, genes molecular mechanisms causing variation in development milk fever. A genomic based mixed linear animal model fitted include single nucleotide polymorphisms ...