the objective of this study was to determine the optimum replacement strategy using dynamic programming for dairy herds in fars province. a dairy cow is kept several lactations for milk production in the herd. after spending several lactations, milk production gradually begins to decline, while animal health problems rises simultaneously. so one of the most important management decisions of dai...

Introduction Investigating and comparing the two systems Comparing some technical efficiency ratios and profit Points to note about the comparison Conclusions References Abstract. In this study, budgets of herd dynamics, feed and energy supply, production and profit of alternative dairy farm systems were used to examine the effects of changing a 230 cow Holstein-Friesian (HF) dairy system to a ...

this study was carried out to control johne’s disease (jd) without interfering with tuberculosis (tb)control programme. a dairy herd (n>1500 heads) was used over a period of 6 years, from 1994 to 1999 forthis investigation. the herd had a history of heavy infection with mycobacterium avium paratuberculosis(map) with culling rates of 1.5 and 5%, in 1991 and 1995, respectively. the mean annual lo...

Leitner, G. 162 INTRODUCTION Economic pressure drives modern dairy farmers to exert continuous efforts to maximize profitability. This is achieved by constant improvement of genetic selection, nutrition, and herd management. Modern dairy farms are characterized by high levels of computerized data acquisition, which provides on-line information on cows' milk yield, milk composition and body weig...

BACKGROUND Eradication of bovine tuberculosis (bTB) through the application of test-and-cull programs is a declared goal of developed countries in which the disease is still endemic. Here, longitudinal data from more than 1,700 cattle herds tested during a 12 year-period in the eradication program in the region of Madrid, Spain, were analyzed to quantify the within-herd transmission coefficient...

OBJECTIVES Commercial cow milking tasks, regardless of dairy size, have been documented in many regions of the world as strenuous work requiring high muscular effort, awkward positions, and task repetition. Large-herd dairies are common in the U.S., while Europe historically has mostly small-herd dairies. The objective of this study was to compare the upper limb muscle activity during milking t...

BACKGROUND Mycobacterium avium subsp. paratuberculosis (MAP) infections in cattle are generally challenging to detect and cost-effective test strategies are consequently difficult to identify. MAP-specific antibody ELISAs for milk and serum are relatively inexpensive, but their utility is influenced by a number of factors such as herd size, herd composition and diagnostic sensitivity. The sensi...

Managers of high producing dairy herds have known for some time that optimizing reproductive efficiency is an essential issue in maintaining profitability of a dairy herd. A recent survey by the University of Wisconsin Center for Dairy Profitability asked a random sample of 2,700 dairy producers in Wisconsin to rank the importance of different dairy issues to the future profitability of their b...

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...

for their participation in conducting the trial and analyzing the data, Rich Silacci-Cal Poly Dairy Herd Manager (SLO, CA) for animal care and management, Cal Poly Dairy employees (SLO, CA) for animal care and treatment/ control application, DSM Nutritional Products (Basel, Switzerland) for funding and analysis of treatment/ control enzyme activity, Cumberland Valley Analytical Services (Maugan...