in this investigation 13699 data related to milk production from 2716 holstein first calving and daughter from 167 sire cows were analyzed based on random regression model (rr/cf) and reml method incomplete lactating (5-90 days) and (5-120 days) in correlations to complete lactating were 0.67 and 0.72, respectively with progress in complete 5-240 day was 0.91 the correlation value for lactating...

The aim of this study was to investigate the effect of diets containing roasted soybean (R), extruded soybean (E) or their combination (RE) on dairy cow performance and milk fatty acid (FA) profile. Nine multiparous lactating Holstein cows (680 ± 25 kg BW; 90 ± 10 DIM; means ± SD) were randomly assigned to a triple 3 × 3 Latin square design. Dry matter intake (DMI), apparent nutrient dige...

in the research the genetic investigation productive and reproductive traits and changes trend the traits in years, seasons and different lactation periods and genetic evaluation cows and bulls of 785 records for milk and 665 records for fat yield and reproductive information during years 1998 to 2003 of 207 dairy cows ghezlagh farm aboureyhan campus (university of tehran) studied. the least sq...

Organic agriculture addresses the public demand to diminish environmental pollution of agricultural production. Until now, however, only few studies tried to determine the integrated environmental impact of conventional versus organic production using life cycle assessment (LCA). The aim of this article was to review prospects and constraints of LCA as a tool to assess the integrated environmen...

Twenty crossbred lactating multiparous cows were used in a 28-day study to compare dry matter intake (DMI), milk yield, milk composition and Bacillus thuringiensis (Bt) protein concentrations in plasma when fed diets containing Bollgard II(®) cottonseed (BGII) or a control non-genetically modified isogenic cottonseed (CON). Bollgard II cottonseed contains the Cry1Ac and Cry2Ab insecticidal prot...

A method of finding the parameters pertaining to one of the variables of milk production, constituent production, and constituent percentage when the parameters pertaining to the two other variables are known is presented. The method is based on the expectation of products of random variables. This method and the delt~ approximation method are compared to sampling estimates from simulated data....

The aim of this article was to investigate the impact of feed sources and feeding system on milk production and milk marketing in the Babille district of Eastern Hararghe zone. Data were collected using a structured questionnaire which was administered to 152 randomly selected sample dairy cow keepers in the district. Data was analyzed using descriptive methods and regression analysis. Data fro...

introduction: lactation yield and persistency are two economic important traits in dairy cow. the production level of a dairy cow is determined by a joint effect of genetic and environmental factors.the main factors determining the total amount of milk production are milk yield at the peak of lactation and persistency as well as length of lactation period. persistency are defined as a extent to...

The efficient production of milk drives the profitability of the dairy enterprise. Within a dairy herd, total milk production is determined by the proportion of cows producing milk at any given time and the level of milk production of the individual cows within the herd (Vandehaar, 1998). Both of these factors are dramatically affected by reproductive efficiency. Improving reproductive efficien...