the study was carried out at agarfa atvet college dairy farm to evaluate the reproductive performance of holstein friesian× arsi and holstein friesian ×boran cattle. for the study, records compiled from 1983 to 2012 at the agarfa dairy farm were used as original data. the effects of breed, bloodlines, season and parity on the reproductive traits were evaluated. data were analyzed using the gene...

This study was conducted to estimate the potential acid production value (PAPV) of major diets and to determine the relationship between dietary PAPV and dairy production traits. Estimation of PAPV of major cattle feeds was based on an in vitro technique, which determined the degree of Ca dissociation from CaCO3. Data on feeds and production traits were collected on 744 multiparous lactating Ho...

The objective of this study was to determine effect of dietary essential oil (EO) compounds, which contained cinnamaldehyde, eugenol, peppermint, coriander, cumin, lemongrass, and an organic carrier on feed intake, milk composition, and rumen fermentation of dairy cows during heat exposure. Thirty-two Holstein cows (days in milk= 60 ± 5) were assigned to one of two treatment groups: a Control a...

The purpose of this study was to monitor current and predict future rates of inbreeding in the Danish dairy breeds. Calves born from 1999 until 2003 and registered as Danish Holstein (1,883,983), Danish Jersey (336,966), or Danish Red (261,047) were reference populations. Average complete generation equivalent was approximately 7. For calves born in 2003, average inbreeding was 3.9, 3.4, and 1....

The aim of this study was to investigate effects of DGAT1, OPN and PPARGC1A candidate genes on milk production traits in Iranian Holstein cattle. Several papers have studied single nucleotide polymorphisms (SNPs) and their association with economic traits in dairy cows, but the combined effect of these genes has not been examined in Iranian Holstein cattle population. Blood samples were collect...

We examined whether infrequent milk sampling for progesterone analysis could be used as a management or diagnostic tool by the dairy farmer to predict delayed ovarian cyclicity in dairy cows. The data included 1040 lactations from 324 Swedish Red cows and 183 Swedish Holstein cows and were randomly divided into two datasets. A logistic regression model was fit to the first dataset and the model...

Bovine genital campylobacteriosis is one of the most economically important diseases of dairy cattleresulting in lowered fertility, embryo mortality and abortion, repeated returns to service, reduced pregnancyrates and extended calving intervals. While the occurrence of repeat breeding syndrome and abortions arereported from many Iranian dairy cattle farms, little information is available regar...

There is a general need for higher objectivity and accuracy in describing the physiological fertility performance of dairy cows. To develop the alternative meaningful starting points for the selection of genetically superior dairy cows, this study focused on the detection of low progesterone concentrations, which are indicative of estrus events. Three mathematical approaches were used: one base...

This study examined the use of PGF(2α) and estradiol benzoate (EB) either with or without GnRH to synchronize estrus in dairy cows for timed artificial insemination (TAI) under field conditions. First, Holstein dairy cows with a corpus luteum (CL) received 500 μg cloprostenol and were then randomly allocated to three groups: no further treatment (control, n=236); treatment with 1 mg EB 56 h aft...

electrocardiography (ecg) may be used to recognize cardiac disorders. levels of milk production may change the serum electrolytes which its imbalance has a role in cardiac arrhythmia. fifty high yielding and fifty low yielding holstein dairy cows were used in this study. electrocardiography was recorded by base-apex lead and blood samples were collected from jugular vein for measurement of seru...