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...

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...

Energy is the most limiting nutritional component in diets for high-producing dairy cows. Palmitic (C16:0) and stearic (C18:0) acids have unique and specific functions in lactating dairy cows beyond a ubiquitous energy source. This review delineates their metabolism and usage in lactating dairy cows from diet to milk production. Palmitic acid is the fatty acid (FA) found in the greatest quantit...

the potential of bulk starter fermentation strategy for production of a cost-effective and safe source of β-galactosidase was investigated. three different bulk starter media with different compositions were selected, and an industrial yogurt starter culture strain, l. bulgaricus dsm 20081 was cultivated in these media under ph-controlled conditions (ph=5.6) at 43°c. the media consisted of 1) b...