The aim of the present study was to estimate the genetic parameters and genetic trends of somatic cell score (SCS) in the first 3 lactations of Iranian Holstein cows by random regression (RR) animal model by using Restricted Maximum Likelihood (REML) method. The data set used in this analysis included observations of 340318 test-day records of 41526 cows in 288 herds; 89969 test-day of 11750 co...

The study was carried out at Agarfa ATVET College dairy farm to evaluate the reproductive performance of Holstein Friesian× Arsi and Holstein Friesian ×Boran cattle. For the study, records compiled from 1983 to 2012 at the Agarfa dairy farm were used as original data. The effects of breed, bloodlines, season and parity on the reproductive traits were evaluated. Data were analyzed using the gene...

Data on productive and reproductive performance of cows in dual-purpose herds were analyzed to determine the effect of some environmental and genetic factors on saleable milk yield (SMY), lactation length (LL), daily saleable milk per lactation (DMYL), calving interval (CI), and daily saleable milk per calving interval (MYCI) in dual-purpose herds in Yucatan, Mexico. Repeatabilities (re) for th...

With the aim of analysis the variability of somatic cell count (SCC) of dairy cattle in conditions of Mediterranean region in Croatia, 217,509 test-day records, collected from January 2005 until April 2010, were extracted from HPA (Croatian Agricultural Agency) database. Milk recording in Croatia occurs according to the AT4 milk recording method. Somatic cell count (SCC) in milk samples taken f...

the objectives of this study were to 1) describe the risk factors, incidence, production and reproduction consequences of retained placenta in dairy cows, and 2) estimate the financial losses associated with retained placenta. calving records from march 2008 to december 2013 comprising 59,341 calving were included in the data set. the effects of risk factors on retained placenta incidence were ...

Objective-To assess the effect of lameness on culling of dairy cows in Tehran province. Design- Historical cohort study. Study population and procedures- 7067 first- and second-parity Holstein dairy cows that calved from March, 21 2007 to March, 20 2008 were until next calving or culling. Logistic regression was conducted data. Results-The overall lactational culling rate for eligible cows i...

calving records of iranian buffaloes from april 1991 to june 2010 comprising 1,151 herds with 34,911 calving events were used to evaluate reported secondary sex ratio, stillbirth, and calf birth weight. logistic regression models were applied to analyze stillbirth and calf sex at birth, and statistical analysis of calf birth weight was performed using a linear mixed model. overall, the ratio of...

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 trends for lactation milk yield, persistency of milk yield, somatic cell count and interval between first and second calving in Holstein dairy cows of Iran. The dataset consisted of 210,625 test day and 25,883 first parity cows with milk yield recorded from July 2002 to September 2007 comprising 97 herds in Iran. Breeding values of anim...

The effects of non-genetic factors (sex of calf, calf birth weight, age of cow, season of calving) affecting gestation length (GL) and open days period (OP) in the Ngaoundere Gudali cattle of the Adamawa (Cameroon) was investigated. Mean GL was 293.4 ± 0.4 d. Sex of the calf significantly (P< 0.05) affected GL, with male calves being carried in utero approximately 3 days longer than the females...