data related to holstein dairy cattle from 1987 to 2004 were obtained from animal breeding center of iran to estimate the genetic and phenotypic trends. variance components and genetic parameters of the first lactation records were estimated using restricted maximum likelihood method and aireml algorithm through matvec program. animal breeding values were predicted through multiple-trait animal...

efficiency is defined as a concept that determines the input output ratios in an economic system. data envelopment analysis method is a useful tool to estimate the efficiency of a unit. the purpose of this study was to estimate technical efficiency and to determine return to scale of holstein cattle farms in guilan province. therefore, the information including the number of labor and dairy cow...

This study was conducted to estimate the potential acid production value (PAPV) of major diets and to determine the relationship between dietary PAPV and dairy production traits. Estimation of PAPV of major cattle feeds was based on an in vitro technique, which determined the degree of Ca dissociation from CaCO3. Data on feeds and production traits were collected on 744 multiparous lactating Ho...

Genetic correlations between first calving interval (CI) and linear type traits in South African Holstein and Jersey cattle were estimated to assess the possibility of using type information as selection criteria for CI. All linear type traits routinely evaluated under the National Genetic Evaluation Programme (18 for Jersey and 17 for Holstein) were considered. Data were obtained from the Nati...

26 herds with 71 586 individual records were used. We tested a hypothesis that milk efficiency was influenced by the elevation of the farm, housing system, breed, area of altitude, and by the cooling of dairy cows. There were 20 herds from lowlands and 6 herds from mountains, 20 herds from free-stall housing, 6 herds from tie-stall housing. 8 herds consisted of Slovakian Pied cattle, 4 herds of...

This report is on infestation with Chorioptes bovis of Holstein cattle on a dairy farm included 900 cowsin Tabriz. Ten heifers and 25 milking cows under the age of 5 years were infested. Clinical signs consisted ofalopecia, crusts, ulcerations and superficial skin fissures. Pruritus and itching were severe in all cases.Lesions were present around the base of the tail, on the neck and below the ...

The aim of the present study was to determine effect adding different sized feed particles and live yeast culture (LY) rations dairy cattle on their metabolic energy balance some blood parameters under heat stress conditions. In this study, four Holstein-Fresiean (600 ± 25 kg BW) in middle lactation, which gave multiple births, were used. fed with diets containing 2 doses LY additives (0 1 g/da...

Automatic milking systems (AMS) rely upon voluntary cow traffic (the voluntary movement of cattle around a farm) for milk harvesting and feed consumption. Previous research on conventional milking systems has shown differences between dairy cow breeds for intake and milk production, however, the ability to manipulate voluntary cow traffic and milking frequency on AMS farms through breed selecti...

We estimated the allele and genotype frequencies of IGF-I/SnaBI gene polymorphism and the concentration of this protein in Holstein dairy cows. We also examined the association with milk yield (305-day milk yield) and milk components (fat and protein percentage, and 305-day milk protein and fat yield). Blood IGF-I levels were measured and genotyping was performed on 250 Holstein cows of four di...

BACKGROUND Bovine leukocyte adhesion deficiency (BLAD), deficiency of uridine monophosphate synthase (DUMPS), complex vertebral malformation (CVM), bovine citrullinaemia (BC) and factor XI deficiency (FXID) are autosomal recessive hereditary disorders, which have had significant economic impact on dairy cattle breeding worldwide. In this study, 350 Holstein cows reared in Turkey were screened f...