Recently, test day models (TDM) began to be increasingly used for the genetic evaluation of dairy cattle. The main advantage of the TDM compared with the 305 days lactation yield models is that more effects can be used in the evaluation. Therefore, the TDM is more accurate than the lactation models. The main disadvantage is the increased comput...ational requirement, but this can be offset by improvements in computer capabilities.
The topic of this paper is the use of a fix regression test day model to estimate the inheritabilities of test day data from Hungarian Holstein-Friesian dairy cattle. The inheritability was 0.26 for milk production, 0.2 for fat production, 0.24 for protein production and 0.06 for the somatic cell count.
The aim of the present study was to determine marker proteins those are associated with functional longevity of dairy cattle. Holstein-Friesian cows were grouped based on their performance as follows: group 1) individuals with good longevity traits; group 2) short production life because of poor reproduction traits; group 3) short production li...fe with low milk yield. Twelve individuals were sampled in each group, blood and milk samples were collected from cows. Blood samples were analysed with two dimensional polyacrylamide gel electrophoresis (2D PAGE), MALDI TOF/TOF and nanoLCMS/MS. The milk samples were analysed with MALDI TOF/TOF and nanoLC-MS/MS. Using the optimized gel based proteomic approach,
we have succesfully separated 143 proteins in the group1, 139 proteins in the group2 and 136 proteins in the group3, but we could not find significant differences between groups in the expression pattern. Using MALDI TOF/TOF and nanoLC-IonTrap MS, we have found eleven protein sequences those were expressed only in the samples of good longevity group.
We carried out the examinations on a farm of 500 cows where We examined the body condition of the stock every month. We recorded the body condition data together with the milk production and calving data. We analysed the daily milk production as well as the body condition. During the examinations we sought an answer how the body condition and t...he production level change during the lactation period.
The authors examined the body condition with relation to reproduction of Holstein-Friesian cows on three dairy farms in the South Plain region. During the examination they analyzed the data of 516 births of 494 Holstein-Friesian cows. They were trying to find correlation between the first service, the service period and the service rates. The e...xaminations with regard to the correlations were different from the ones published in the professional literature. The body condition at the time of calving affected the interval from calving to the first service but not the conception
rates or the service period. The examinations did not prove any correlations between body condition changes and reproduction.
In Hungary, an intensive dairy population has developed in the last few decades as the result of upgrading to Holstein-Friesian. Intensive milk production, adjusted with housing and feeding, unfavorably affected secondary traits. The number of days between two calvings has increased remarkably and productive lifetime has decreased drastically....In the interest of profitable milk production, it is important that cows should be able to stay in the herd as long as possible, in order to have great lifetime productivity.
The aim of this paper was to compare the production and pedigree of cows with eight or more lactations to cows which were culled after their first lactation.
It can be stated that cows with longer herd lives produced more milk in their first lactation than those which were culled after their first lactation. When analyzing the pedigree effect of sires, this could not be proven, although some bulls, mainly of Hungarian origin, appeared at a higher frequency. In the analysis of the effect of dams, it was found that many of the offspring of the cows with longer herd lives had similarly great lifetime productivity. Correlation between herdlife and milk production quantity traits was found to be mild or stronger (r>0,60), while according to our analysis, there is no correlation between herdlife and milk production quality traits.