the aim of the present study was to compare the occurrence and duration of clinical mastitis in different seasons, stages of lactation period and parities in a holstein dairy farm in iran. a retrospective epidemiological survey from april 2005 to march 2008 was conducted on 884 clinical mastitis cases of 7437 lactations. data of each case including calendar-date of mastitis onset, days in milk ...

The aim of the present study was to compare the occurrence and duration of clinical mastitis in different seasons, stages of lactation period and parities in a Holstein dairy farm in Iran. A retrospective epidemiological survey from April 2005 to March 2008 was conducted on 884 clinical mastitis cases of 7437 lactations. Data of each case including calendar-date of mastitis onset, days in milk ...

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...

Random regression models (RRM) are used for genetic estimations of milk traits in dairy cows. RRM utilize data on traits that are repeated during the time, such as milk trait, which allows of the evaluation of the test day production information. In this study, to estimate genetic parameters for milk production trait, test day records (TDR) were collected from the first lactation of Holstein co...

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...

random regression models (rrm) are used for genetic estimations of milk traits in dairy cows. rrm utilize data on traits that are repeated during the time, such as milk trait, which allows of the evaluation of the test day production information. in this study, to estimate genetic parameters for milk production trait, test day records (tdr) were collected from the first lactation of holstein co...

the objective of this study was to investigate the effect of principal components (pc) of the regression coefficients (co)variance matrix on the lactation curve, and on the formation of selection index to modify the curve, based on these pc’s, and as well to estimate additive genetic and phenotypic variances and heritability of the constructed selection index. lactation period of 301 d (5-305) ...

this experiment was performed to investigate whether feeding xylose-treated soybean meal (xsbm) or corn gluten meal (cgm) is economically better under field conditions. ninety-four multiparous early lactating holstein cows (55±5 days in milk and 2.82±0.41 body condition score) were used in a completely randomized design. cows were randomly assigned to one of two treatments: xsbm or cgm as the m...

In surrogate pregnancies genetic parents have little opportunity for early bonding with their infants either prenatally (in utero) or during the immediate postnatal period. Procedures commonly used to induce lactation include both pharmacologic and nonpharmacologic methods often in combination. Studies reporting induced lactation are sparse due to the rarity of augmented lactation. Here we repo...

the genetic parameters for milk production and milk fat traits for first to third parities were estimated using single, multi trait and repeatability models. the genetic parameters for test day milk records were also estimated using random regression model. the test day records and 305 day milk records of 17055 cows from 10 herds collected between years 1996-2007 in khorasan razavi province wer...