Recent publications indicate that the prevalence of perinatal mortality has increased in some dairy industries and an increased proportion of this loss is not associated with the traditional risk factors for perinatal mortality. The objectives of this study were to establish the prevalence of perinatal mortality (calf death within 24 h of calving) in Irish dairy herds and to determine the curre...

Three models for the analysis of functional survival data in dairy cattle were compared using stochastic simulation. The simulated phenotype for survival was defined as a month after the first calving (from 1 to 100) in which a cow was involuntarily removed from the herd. Parameters for simulation were based on survival data of the Canadian Jersey population. Three different levels of heritabil...

This study was conducted to estimate the additive genetic components of calf mortality in the first month of age, calving difficulty, and birth weight in Holstein dairy cows in the central regions of Iran. The records comprised 61,200 calves born between 1990 and 2011 from 60 dairy herds. Different threshold-linear models in three groups of univariate, bivariate, and multivariate models were us...

The aim of this study was to evaluate the effect calving season on postpartum changes certain blood metabolites and minerals body condition score evaluation (BCS) in Montbeliard dairy cows reared under semi-arid conditions. Blood samples were collected from 74 clinically healthy 10 semi-intensive Algerian herds once month during a whole year. Animals grouped according occurrence their four diff...

Trait-by-trait and multiple trait bioeconomic modeling were used to derive farm-specific economic weights (EW) for a wide range of traits under different production and economic circumstances to define breeding objectives for Holstein dairy cattle in Iran. Production parameters and economic data were gathered on 10 dairy farms from March 2008 to February 2010. The EW (economic values multiplied...

The main objective of this study was to estimate the genetic parameters for multi-trait evaluation of birth weight (BW), gestation length (GL) and calving difficulty (CD) in first-parity Iranian Holstein dairy cattle. The data included 29,950 calving records collected during 1995 to 2014 by the Animal Breeding and Improvement Center of Iran. A threshold-linear sire-maternal grandsire model was ...

The objective of the present study was to estimate genetic parameters for test-day milk, fat and protein yields and 305-day-yields in Murrah buffaloes. 4,757 complete lactations of Murrah buffaloes were analyzed. Co-variance components were estimated by the restricted maximum likelihood method. The models included additive direct genetic and permanent environmental effects as random effects, an...

Data collected from Jersey herd in the central highland environment of Ethiopia was used to estimate genetic parameter and trend analysis for reproductive/fertility traits. Totally, 11,933 reproductive records recorded during last 30 years were analysis. Traits studied NSC (number service per conception), DO (days open), CI (calving interval), AFC (age at first calving) AFS service). Genetic ph...

retrospective data from sebele dairy farm were analysed for reproductive performance of friesian/holstein cows. three hundred records from 1989 to 1995 were used. the herd was zero grazed and the data was analysed for age at first calving (afc), calf birth weights (bw), calving interval (ci), days open (do), calving rate (cr), reproductive wastage (rw) and calving difficulty (cd); dystocia, aft...