the objective of this study was to analyze the association of somatic cell score (scs) with milk, fat and protein yields across parities. records of production traits and somatic cell counts (scc) from first, second and third parity that were collected by the animal breeding center of iran from 1993 to 2010 were used.all animals were grouped into six classes according to scc and production trai...

the objective of this study was to determine the effects of two different time of gnrh injection after artificial insemination (a.i) (d 6 and d 12) on reproductive performances of holstein cows during the warm season.  cows randomly assigned to treatments 1) no gnrh injection (control, n = 300),2) gnrh injection at day 6 after a.i (g6, n=300) and 3) gnrh injection at day 12 after a.i (g12, n=30...

this study was carried out to investigate the relationship between early lactation curve parameters andcalving interval in holstein cows of iran. in order to describe the lactation curve, the incomplete gammafunction was fitted to 5,754,428 test-day milk records corresponding to 766,108 lactations on 315,634 cowsin 2,448 herds. cows with higher milk yield during early lactation had shorter calv...

Objective was to determine the influence of breed and quantity of milk replacer fed on the performance of dairy calves. Forty-two bull calves (n = 20 Holstein and n = 22 Jersey, 2 ± 1 d old) in a 2 × 2 factorial arrangement were observed through 11 weeks of age. Holstein and Jersey calves on the lower plane of nutrition were fed a 20% protein and 20% fat milk replacer at a rate of 454 g / d. Ho...

Service-sire conception rate (SCR), a phenotypic fertility evaluation based on conventional (nonsexed) inseminations from parities 1 through 5, was implemented for the United States in August 2008. The SCR model contains the categorical fixed effects of parity for lactations 1 to 5; state-year-month of insemination group; 6 standardized milk yield groups; service number for inseminations 1 to 7...

The purpose of the present study was to examine the ability of a tetraparental Chimera in producing IVF embryos. Cumulus oocytes complexes (COCs) were matured in vitro for 22 h. Frozen-thawed sperm of a Chimera (CH), as well as Japanese Black (JB), Limousin (L), Japanese Brown (JBr), Holstein (H) bulls were used for IVF. The chromosome preparations were made from peripheral lymphocytes. Based o...

the present study aimed to estimate the effects of parity, calving season and year of calving on the prevalence of subclinical mastitis in holstein cows. a total of 2682 records from 869 holstein cows in a large dairy farm (azarbaijan province, iran), respecting the period from 2006 to 2009, were collected. data was analyzed using proc mixed of sas software by mivque method. subclinical mastiti...

Investigation of Technical Efficiency and Economic Value Some Production, Reproductive, Survival Growth Traits Holstein Cows in Pars Agriculture Industry Ardabil Province

Feedlot closeout data is an important tool for measuring cattle performance and management practices for cattle production systems. Often, closeouts are quickly scrutinized by feedlot managers and cattle owners for economics and typical performance measurements and then filed. Unfortunately, a plethora of data that is reported in closeout reports is never adequately analyzed. A dichotomy of dat...