The objective of this study was to investigate the effect of inbreeding on lactation performance in Holstein cows of Iran.The pedigree file contained information of 1,025,281 animals born between 1965 and 2007.Lactation performance records from March 2000 to April 2009 comprising 193,501calving events on 123,751 cows in 85 dairy herds were included in the data set. The potential consequent effe...

the objective of this study was to investigate the effect of inbreeding on lactation performance in holstein cows of iran.the pedigree file contained information of 1,025,281 animals born between 1965 and 2007.lactation performance records from march 2000 to april 2009 comprising 193,501calving events on 123,751 cows in 85 dairy herds were included in the data set. the potential consequent effe...

percentages and yields of fat, crude protein (cp), true protein (tp) and non-protein nitrogen (npn) wereassessed in milk of four groups of holstein cows, at early, mid and late lactation (days in milk 20-70, 71-110, 111-150 and 151-210), on a diet rich in concentrates during a hot summer. four milk samples were taken from individual cows at 10-day intervals. milk fat percentages were close to b...

in order to evaluation of genotype by environment interactions in holstein cows, iran was divided into cold, middle cold, temperate and hot climate regions. for this purpose used from 39570, 35813 and 18955 records for milk, fat and protein yields, respectively, to progeny test for 35 sires that have 50 daughters in each climate. the data were collected by the centre of breeding and improvement...

this study was conducted to evaluate production response of early lactating cows to rumen protected fats. twelve (nine multiparous and three primiparous) holstein cows (26±4 d in milk) were empolyed in a replicated 3×3 latin square design of 21-d periods. each period consisted of 14 days of adaptation and 7 days of sampling. cows received diets containing either one of two types of protected fa...

Dairy cattle breeding programs have been based in the selection for traits related to milk production. In this research a data set of 63 herds of East Azerbaijan province Holstein cattle, collected during 2002-2013 by the Iranian Animal Breeding Center was used to estimate the repeatability and heritability of three traits of economic importance. Genetic parameters for first three lactations of...

this study was performed to evaluate the effects of crud protein (cp) level on dry matter intake in prepartum period, productive performance and health of fresh cows. twenty multiparous holstein cows were assigned randomly to one of two dietary treatments. dietary treatments were treatment 1, 13% cp of dm (control), and treatment 2, 16% cp of dm. diets were similar in lactation net energy and r...

dairy cattle breeding programs have been based in the selection for traits related to milk production. in this research a data set of 63 herds of east azerbaijan province holstein cattle, collected during 2002-2013 by the iranian animal breeding center was used to estimate the repeatability and heritability of three traits of economic importance. genetic parameters for first three lactations of...