Genetic and non-genetic correlations of the average somatic cell score (SCS) at different stages oflactation (100, 150, 200, 305 and 365 days in milk) with lactation performance were estimated based on thefirst lactation records of Iranian Holstein calving during 2000 to 2009. (Co) variance components wereestimated using derivative-free REML based on multiple traits animal models. The estimated...

Objective: The cows that don’t have access to sufficient energy in their ration can get sickness. Milk production has a high priority in metabolism of dairy cows so lactating cows are more prone to get sick This can ruin all the benefits of higher milk yield because of the higher prevalence of the disorders. Methods: Data for this research had gathered from a herd with 1600 Holstein cattle in E...

objective: the cows that don’t have access to sufficient energy in their ration can get sickness. milk production has a high priority in metabolism of dairy cows so lactating cows are more prone to get sick this can ruin all the benefits of higher milk yield because of the higher prevalence of the disorders. methods: data for this research had gathered from a herd with 1600 holstein cattle in e...

The objective of the present study was to quantify the relationships among body condition score (BCS; scale 1 to 5), live weight (WT) and milk production in Irish Holstein-Friesian spring calving dairy cows. Data were from 66 commercial dairy herds during the years 1999 and 2000. The data consisted of up to 9886 lactations with records for BCS or WT at least once pre-calving, or at calving, nad...

genetic and non-genetic correlations of the average somatic cell score (scs) at different stages oflactation (100, 150, 200, 305 and 365 days in milk) with lactation performance were estimated based on thefirst lactation records of iranian holstein calving during 2000 to 2009. (co) variance components wereestimated using derivative-free reml based on multiple traits animal models. the estimated...

Bovine lactoferrin (LTF) is a member of the transferrin family of iron-binding proteins. This protein is present in a wide variety of biological fluids and shows important physiological functions in body. In this study, 404 blood samples were collected from Holstein dairy farms in Iran. A 301 bp fragment of intron 6 in bovine LTF gene was amplified and the animals were genotyped using polymeras...

The aim of the present study was to estimate genetic and phenotypic parameters of milk production traits in the first and second lactations of Romanian Simmental dairy cattle. For the estimation of variance, heritability, genetic and phenotypic correlations among milk yield, fat yield, protein yield, and percentages of fat and protein, 3400 first and second lactation records over a period of fi...

The objectives of this study were to analyze the genetic properties of three measures of lactation persistency in Polish Holstein-Friesian cows, and possibly to choose one measure which could be used for estimation of breeding value for lactation persistency in the Polish dairy cattle population. Data included 117,327 first three lactations of 110,141 cows calved in 1995-2009. The lactation cur...