Three methods of sire evaluation were compared empirically--herdmate comparison, least squares, and maximum likelihood. Michigan Dairy Herd Improvement Association Holstein data representing 10,620 first lactation records and 1,003 herd-year groups were analyzed. Forty individual bulls representing three artificial insemination units were evaluated. The rank correlations among herdmate comparis...

OBJECTIVES Because of the herd-immunity phenomenon, the benefits of immunization against hepatitis A extend beyond those received by those who are vaccinated. This analysis estimates the impact of herd immunity on the cost-effectiveness of routine hepatitis A immunization among US children. PATIENTS AND METHODS In an economic model, the costs and benefits of hepatitis A immunization were esti...

Estimates of heritability within herd (h(WH)(2) ) that were generated with daughter-dam regression, daughter-sire regression, and REML were compared, and effects of adjusting lactation records for within-herd heritability on genetic evaluations were evaluated. Holstein records for milk, fat, and protein yields and somatic cell score (SCS) from the USDA national database represented herds in the...

correlation between breeding value of crude milk (cm) and energy-corrected milk (ecm) was studied based on a total of 774,013 test day records belongs to 88,456 first-parity holsteins dairy cattle calving during 1997-2009 in 165 herds (from six provinces). genetic analysis of the traits was carried out by a fixed regression test day model. in the model, effects of herd, calving year, production...

The aim of this study was to develop an adapted random regression test-day model for milk urea (MU) and to study the possibility of using predictions and solutions given by the model for management purposes. Data included 607,416 MU test-day records of first-lactation cows from 632 dairy herds in the Walloon Region of Belgium. Several advanced features were used. First, to detect the herd influ...

A cross-sectional study with a random cluster sampling design was carried out to estimate the seroprevalence of bovine herpesvirus type 1 (BHV-1) in non-vaccinated dairy herds in Hamedan province, west of Iran. Simple random sampling was used for selection of cattle in each herd. Informative data about each herd and selected animals were recorded by the farm manager in a provided questionnaire....

The linear model method of VanRaden and Klaaskate for analyzing herd life was expanded. Information on conception and protein yield was included in the estimation of predicted herd life of Israeli Holsteins. Variance components were estimated by a multitrait animal model. Heritability was slightly higher for herd life than for number of parities, but genetic correlations were close to unity. An...

A cross-sectional study was performed to determine the odds of having a positive paratuberculosis ELISA result if the dam was ELISA positive in Texas beef cattle, adjusted for individual and herd-level risk factors for seropositivity. Texas beef cattle (n = 2,621) were tested for paratuberculosis by using a commercial ELISA and microbiologic culture of feces for Mycobacterium avium subsp. parat...

Using monthly test day records the genetic parameters of Iranian Holstein cattle in first lactation were studied. Data of 277400 test-day milk records from 65320 cows and 2210 sires were analyzed by an animal random regression model using restricted maximum likelihood methodology. The model included herd-test-date, interaction between year-season of calving, days in milk (linear and quadratic) ...