the objective of this study was to explore the reproductive consequences of using sex-sorted semen on sex ratio, conception rate and reproductive disorders (dystocia, abortion, stillbirth) in holstein heifers. reproduction performances records which were collected during 2006 to 2013 from 4 large dairy herds in isfahan province of iran were used and analyzed by genmod procedure of sas software....

The study aimed to determine the effect of different fixed factors (breed, region, calving year, season, parity and lactation stage) on daily milk production (yield content) four dairy cattle breeds under heat stress conditions (THI?72). research was conducted a set test-day records (Simmental, Holstein-Friesian, Red Holstein Brown Swiss) reared in Republic Serbia (Region Ma?va, Podunavlje Šuma...

Farm location is an important factor in dairy farms, as it is closely associated with temperature and humidity that are crucial factors of influencing the physiological conditions and productivity of cows especially during the lactation period. The purpose of this study was to determine the effect of farm location on the physiological conditions and productivity of cows. The study was involved ...

The aim of this study was to identify the deficiency of uridine monophosphate synthase (DUMPS) and the complex vertebral malformation (CVM) in Iranian Holstein bulls. A total of 144 blood samples were prepared of Holstein bulls in Abbas Abad Animal Breeding Center and Ferdowsi University of Mashhad's Dairy Farm in Khorasan state of Iran. Genomic PCR-RFLP protocol was performed to amplify the po...

Lifetime dairy production, reproduction and growth traits of 75 females sired by Holstein, Jersey or Brown Swiss bulls and Holstein-Friesian x Gir dams of 1/2 to 3/4 Holstein-Friesian fractions were compared. The animals were in a single herd under the same management. Milk, fat and protein yields, concentrates fed, reproduction, and weights were recorded throughout the lifetime of the cows. Th...

the objective of this study was to evaluate the effect of different milking frequencies in the first 6 weeks of lactation on milk production and milk constituents, blood metabolic profiles and reproductive performance of fresh dairy cows. the milking frequencies imposed were three times daily milking for 42 days (3x), six times daily milking for the first 21 days of lactation and three times da...

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...

The objective of this research was to determine the prevalence, risk factors and consequent effect of dystocia on lactation performance in Holstein dairy cows in Iran. The data set consisted of 55,577 calving records on 30,879 Holstein cows in 30 dairy herds for the period March 2000 to April 2009. Factors affecting dystocia were analyzed using multivariable logistic regression models through t...

BACKGROUND Here, we jointly summarise scientific evidence for genetic variation in resistance to infection with Mycobacterium bovis, the primary agent of bovine tuberculosis (TB), provided by two recent and separate studies of Holstein-Friesian dairy cow populations in Great Britain (GB) and Ireland. METHODS The studies quantified genetic variation within archived data from field and abattoir...

The objective of this study was to estimate the genetic parameters of milk protein yields in Iranian Holstein dairy cattle. A total of 1,112,082 test-day milk protein yield records of 167,269 first lactation Holstein cows, calved from 1990 to 2010, were analyzed. Estimates of the variance components, heritability, and genetic correlations for milk protein yields were obtained using a random reg...