The dairy farming systems of Western Europe are based on a simple feeding system composed of grazed and preserved grass, maize silage and concentrates in variable proportions. There is, nevertheless, a great diversity of feeding strategies between dairy farms. Over 5 years, we studied the direct and delayed effects of four feeding strategies on the lactation and reproduction performances of Hol...

The objective of this study was to investigate the genetic relationship between body condition score (BCS) and reproduction traits for first-parity Canadian Ayrshire and Holstein cows. Body condition scores were collected by field staff several times over the lactation in herds from Québec, and reproduction records (including both fertility and calving traits) were extracted from the official d...

This study was designed to determine the culling rates of 23 Holstein dairy herds (with an average size of180 cows per herd) in Neyshabur area in northeastern Iran over a period of three years from 2001 to 2003.The average annual culling rate was 13.1%, (98.5% involuntary and 1.5% voluntary). Of the total disposals(1612 cows), 53.48% were culled by the end of five years of age. Poor fertility w...

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...

The traits particularly important for milk production include milk yield, protein percentage, fat percentage, and the somatic cell score. Alpha-lactalbumin (α-LA) is an important whey protein of cow milk, and is also present in the milk of many other mammalian species. In this study, we analyzed the genetic polymorphisms of the α-LA gene and their relationship to milk production traits (milk yi...

Data from 113 Dutch organic farms were analysed to determine the effect of cross-breeding on production and functional traits. In total, data on 33 788 lactations between January 2003 and February 2009 from 15 015 cows were available. Holstein-Friesian pure-bred cows produced most kg of milk in 305 days, but with the lowest percentages of fat and protein of all pure-bred cows in the data set. C...

Genetic and phenotypic performance of U.S. Holstein embryo-split and nuclear-transfer clones was documented for yield and fitness traits. For cows, mean genetic superiority based on pedigree was 186 kg of milk, 9 kg of fat, and 7 kg of protein for embryo-split clones and 165, 10, and 8 kg, respectively, for nuclear-transfer clones compared with the population for the same birth year; pedigree a...

The objectives of this study were to estimate from test day records the genetic and environmental (co)variance components, correlations, and breeding values to increase genetic gain in milk yield of Lucerna and US Holstein cattle. The effects of repeated observations (within cow) were explained by first-order autoregressive processes within and across lactations using an animal model. Estimates...

the study was carried out on 120 crossbred holstein × shahiwal dairy cows for a period of 150 days to quantify the influence of dietary energy and protein intake on yield and composition of milk. total 12 dairy farms having similar housing systems and holding at least 20 dairy cows in between mid to late lactation were selected for study purposes. the farms were located in the peri-urban and ur...

csn1s1is one of the major genes encoding milk proteins of mammals. in this study we determined allele frequencies of csn1s1-5` flanking region as well as exon 17 variants and their effects on milk traits in three indigenous cattle breeds mazandarani, golpaygani (bos indicus) and sarabi (bos taurus) and holstein cattle in iran. csn1s1*b variant was nearly fixed in holstein but ranged from 0.40 t...