the objective of the present study was to estimate genetic trends for lactation milk yield, persistency of milk yield, somatic cell count and interval between first and second calving in holstein dairy cows of iran. the dataset consisted of 210,625 test day and 25,883 first parity cows with milk yield recorded from july 2002 to september 2007 comprising 97 herds in iran. breeding values of anim...

The objective of the present study was to estimate genetic trends for lactation milk yield, persistency of milk yield, somatic cell count and interval between first and second calving in Holstein dairy cows of Iran. The dataset consisted of 210,625 test day and 25,883 first parity cows with milk yield recorded from July 2002 to September 2007 comprising 97 herds in Iran. Breeding values of anim...

lactoferrin (lf) is a bioactive protein present in all external secretions such as milk that plays important role in the innate host defense. therefore, the lf has a major role in bovine mammary gland defense during mastitis. in this study, 5’-flanking region of bovine lf gene containing three single nucleotide polymorphisms (snps) at positions −602 (t/g), −600 (a/g) and -586 (t/c) were screene...

placental lactogen is a polypeptide hormone that is produced by the placenta, also known as chorionic somatomammotropin hormone. it has both growth hormone and prolactin activities on growth, lactation, and luteal steroid production. the objective of this study was to investigate the bovine placental lactogen (bpl) gene polymorphism of holstein cows in razavi khorasan province. blood samples we...

the aim of this study was to test the genotypes effect of dgat1 gene on breeding value in iranian holstein milk production traits. for this purpose, 103 semen samples of registered bulls were collected and then genotyped for partial region of dgat1 gene. the studied traits were milk yield (my), fat yield (fy), protein yield (py), fat percentage (fp) and protein percentage (pp). first lactation ...

AIM The aim was to estimate genetic factors affecting the first lactation milk production traits in Kankrej cattle of North Gujarat. MATERIALS AND METHODS The 475 first lactation records of Kankrej cows that were maintained at the Livestock Research Station, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, Gujarat, over a period of 35 years from 1980 to 2014 were studie...

The objective of the study was to estimate the genetic relationships between detailed reproductive traits derived from ultrasound examination of the reproductive tract and a range of performance traits in Holstein-Friesian dairy cows. The performance traits investigated included calving performance, milk production, somatic cell score (i.e., logarithm transformation of somatic cell count), carc...

Genetic and phenotypic parameters for production traits and somatic cell count (SCC) for Jersey dairy cattle in Zimbabwe were estimated. A total of 10986 lactation records were obtained from Zimbabwe Livestock Identification Trust, with cows calving in the period from 1996 to 2008. An ASReml program fitting an animal model was used for the analyses. Heritability estimates for milk yield, fat yi...

Fatty acid composition influences the nutritional quality of milk and the technological properties of butter. Using a prediction of fatty acid (FA) contents by mid-infrared (MIR) spectrometry, a large amount of data concerning the FA profile in bovine milk was collected. The large number of records permitted consideration of more complex models than those used in previous studies. The aim of th...