The association of birth type (single vs. double) and pregnancy type (single vs. double) with lactation performance and lactation curve was investigated in Holstein cows in Iran. Data of 243298 lactations on 138021 cows in 261 herds collected during January 2000 to December 2012 were used. The average twinning rate was 3.64% and ranged from 1.44% (primiparous) to 5.41% (multiparous). Factors as...

A total of 648 purebred Holstein and 319 backcross Holstein × Jersey dairy cattle were compared for production, reproduction, health, linear type, and growth traits. Animals were born between 2003 and 2009 and were housed in the University of Wisconsin-Madison Integrated Dairy Facility. All animals had Holstein dams; lactating dams were mated to unproven Holstein sires to produce purebred (cont...

Young calves are known to be formed with laminar bone in long-bone cortex during growing periods and the osteon formation begins later. Previously, we reported that an 11-year-old giant Holstein cow with dermal dysplasia showed a delayed osteon formation. An 8.5-year-old cow, born from the giant Holstein cow, also showed some dermal dysplasia and the outer-half layer of the child almost retaine...

complex vertebral malformation(cvm) isanautosomal recessivehereditarydisorder caused bya point mutation in position 559 inexon 4 of the slc35a3 gene on chromosome 3 inholstein dairy cattle.this mutationchanges the function of uridine 5-diphosphate-n-acetylglucosamine transporter protein bythe substitution of valine for phenylalanine at position 180 of this protein. the disease causes premature ...

The study was carried out in Sahiwal, Holstein Friesian, Jersey and crossbred cattle and Murrah, Bhadwari, Jaffarabadi, Nagpuri and Surti buffaloes maintained at different organized herds to work out the polymorphism at growth hormone locus and study its effect on birth weight. A 223 bp fragment of the gene was amplified and digested with Alu I restriction enzyme. Two alleles, L and V with thre...

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...

thirty two multiparous holstein cows were used in a randomized block design to investigate the effects of feeding diets included two different source of nonfiber carbohydrate during the transition period on dry matter intake (dmi), lactational performance, blood metabolites and parturitional characteristics. cows received total mixed rations containing either macaroni wastes(mw) or steam-flaked...

in this study we estimated the allele and genotype frequencies of scd1 and dgat1 gene polymorphism. the analysis was conducted on 408 holstein cows from five dairy herds in isfahan province. genotypes were identified using pcr-rflp technique. two genetic variants (a and v) of the scd1 gene were observed in this experiment. the frequency of a-allele ranged from 0.49 to 0.66, while frequency of v...