Five alternative models were applied for analysis of dystocia and stillbirth in first and second parities. Models 1 and 2 were included only to estimate the parameters required for model 4, and models 3 and 5 are included only as comparisons to the model 4 estimates. Variance components were estimated by multi-trait REML, including cows with valid calving records for both parities. For the effe...

The objectives of this work were to compare reproduction and parturition traits of the Criollo breed Romosinuano as straightbred and crossbred cows with Angus and Brahman, to estimate heterosis and direct and maternal genetic breed effects, and to describe calf loss, cow removals from the project, the occurrence of calving difficulty, inadequate calf vigor at birth, and udder problems by cow br...

Calving records from April 1998 to September 2006 comprising 104,572 calving events from 16 dairy herds of Iran were used to analyze the potential effect of dystocia on calf stillbirth and productive traits in Iranian Holsteins. Statistical analyses of production traits were performed using a linear mixed model procedure. Also, a logistic regression model was constructed to analyze the effect o...

Records of 547, 2-yr-old heifers of three breed groups were used to evaluate the relative influence of dam's body and pelvic measurements, calf birth weight, sire birth weight and some relative measures (ratios) of calf birth weight and dam weight at calving on calving difficulty. The data were analyzed by regression and least squares procedures. The full model explained 32.5% of the variation ...

four hundered and ninety five (495) smallholder dairy farms active in 52 villages of different cities in chaharmohalo bakhtiari province, keeping 1321 lactating within a total of 2811 mature cows (lactating and dry) were used. these herds were taken during winter 2009 to summer 2010 to assess some of the production, reproductive and economic performance traits under smallholder management syste...

The heritabilities for and the genetic, phenotypic, and environmental correlations among calving difficulty scores (CDS) and measures of size of the pelvic inlet were estimated using 547 records of 2-yr-old heifers from three synthetic breed groups. Calving difficulty score was treated first as a trait of the dam and then as a trait of the calf and was analyzed on three scales: raw scores from ...

Abstract Fall-calving Herford-SimAngus heifers were individually fed either 100% (control; CON, n = 10) or 70% (nutrient restricted; NR, 12) of NASEM metabolizable energy and protein requirements from d 160 gestation to calving. Postpartum cows until 149 lactation, then tall fescue hay pasture as a single group through parity 2. Second cow performance calf size measured at birth, 30, 60 post-ca...

In this study 495 smallholder dairy farms in 52 villages of different township in southwestern province of Iran (Chaharmohal and Bakhtiari province) included 1321 lactating cows and 2811 total mature cows (lactating and dry) during winter 2009 to summer 2010 were used to estimate economic opportunities insmallholder dairy farms. Questionnaire survey was used to collect data from last year infor...

Genetic improvement in beef and dairy cattle reproductive traits has historically been hampered by the availability and accuracy of applicable genetic predictions. Reproductive trait phenotypes are generally time-consuming to measure, categorical and/or threshold in nature, often are not collected in the context of inventory-based performance recording systems, and typically of lower relative h...