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 objective of this study was to investigate the effect of birth weight (BW) on future milk production and reproductive performance in Iranian Holstein cattle. Records of Holstein cows between 1967 and 2010 were obtained from the Animal Breeding Center of Iran. Birth weights within each herd were grouped into five categories based on the standard normal distribution curves (z ≤-0.8416, -0.841...

The purpose of the research was to study main indicators reproductive ability Black-and-White cows, depending on proportion Holstein genes. As material for there were taken data breeding and zootechnical records cows breed CJSC Semenovsky Breeding Plant Mari El Republic. results showed that with an increase in thorough-bredness improved. Thus, first-calf heifers a low genes (up 12.5 %) had late...

Potential variables for the reproductive success of beef cows were evaluated. Included in model age cow at calving; interval between Julian calving date and end breeding season; body weight conditions calving, 75 days post-partum mean daily variation these dates. Logistic regression was used analysis, with parameters evaluated using odds ratio statistic, estimating chance pregnancy. The rate pr...

Department of Molecular Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA, Department of Pediatrics, Brown University Medical School, Providence, RI 02912, USA, Departments of Medicine and Cell and Developmental Biology, University of Pennsylvania, 954 Biomedical Research Building (BRB) II/III, 421 Curie Boulevard, Philadelphia, PA 19104, USA and Depar...

The effects of inbreeding, heterosis, recombination loss, and percentage Holstein on the estimation of predicted transmitting abilities for fertility traits (calving interval, number of days from calving to first insemination, nonreturn rate, number of inseminations) and correlated traits (milk yield at test nearest d 110 and body condition score) were examined in a mixed population of Holstein...

Whether to select for longer life in the herd or shorter calving interval depends on the genetic and phenotypic relationships among herd life, amount of milk in first lactation, and calving interval. Herd life and average calving intmwal are essentially phenotypically uncorrelated. The phenotypic and genetic correlations of herd life and milk in first lactation ranged from .19 to .25 and from ....

A national sample of cow-calf producers was contacted to participate in a study to describe selected calving management practices on operations throughout the United States. Information was gathered on calving season, frequency of dystocia, frequency of observation, timing of assistance, and calving facilities. Regional and herd size differences existed in all parameters evaluated. Most calves ...

The objective was to quantify the strength of the relationship between body condition score (BCS) and live weight (LW) in pasture-based Holstein-Friesian dairy cattle, and to determine the kg LW per unit BCS. A total of 26021 test-day records with information on both BCS (1-10 scale, where 1 is emaciated and 10 is obese) and LW across 1110 lactations from one research farm were used in the anal...