________________________________________________________________________________ Abstract Belgian Blue double-muscled (BBDM) heifers (n = 341) were used to investigate the effect of body weight (BW) at first calving at an age of two years (BWC). Females with a birth weight (BWB) <40 kg realized a lower body weight gain (BWG) up to an age of four months and they also had a significant lower BWC....

Utilizing pasture-based systems may increase cow comfort during late gestation and calving as it lacks the constraints of confinement housing. The objective of this study was to quantify lying behavior and activity of Holstein dairy cows housed on pasture during the 6 d before calving. Sixteen Holstein dairy cows were moved to pasture 3 weeks before their projected calving date. Data loggers we...

Background: No dairy breed or crossbreed has superior overall performance in all environments; therefore, it is necessary to determine which the most suitable for Mexican tropic and what proportion of European optimum reproduction. Objective: To assess effect Bos taurus (Bt) genes on reproductive Holstein×Zebu (HZ) Brown Swiss×Zebu (BZ) cows, compare these genotypes a dual-purpose production sy...

to describe proportion and pattern of culling in commercial dairy herds of khorasan razavi province, this survey was carried out from 21st march 2008 to 20th march 2009 in 15 industrialized dairy herds. for each culled cow data related to parity at culling, last calving to culling interval and primary reason for culling were recorded. annual herd exit rate was 20.9%. out of a total of 652 culle...

productive and reproductive traits have great importance in international dairy cattle breeding objectives. production, reproduction (days open and calving interval) and pedigree data of iranian holstein dairy cattles were collected between 2002 and 2012 from 47 herds in isfahan province. the data set consisted of 30179 records from 18837 registered iranianholstein dairy cattles. single trait r...

to estimate the genetic parameters for production and reproduction traits in holstein cows, information from 15 herds recorded by animal breeding center of iran during 1980 – 2004, were employed. estimations were made using restricted maximum likelihood method under an animal model ranging df-reml and matvec software. estimates of heritabilities for yield traits were moderate and ranged from 0....

Various studies have validated that genetic divergence in dairy cattle translates to phenotypic differences; nonetheless, many consider the breeding goal, or associated traits, generally been small scale, often undertaken controlled environments, and they lack consideration for entire suite of traits included goal. Therefore, objective present study was fill this void, doing so, provide produce...