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Open Access. Powered by Scholars. Published by Universities.®

2014

Life Sciences

California Polytechnic State University, San Luis Obispo

Articles 1 - 2 of 2

Full-Text Articles in Business

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson Dec 2014

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson

Master's Theses

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping.

In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced …


The Effects Of Implementing Cow Cooling For Oostdam Dairy: Benefits From Milk Production, Feed Intake, And Reproduction, Mark Oostdam Mar 2014

The Effects Of Implementing Cow Cooling For Oostdam Dairy: Benefits From Milk Production, Feed Intake, And Reproduction, Mark Oostdam

Dairy Science

Heat stress has a major effect on management decisions for a dairy operation because of the decrease in the cows productivity. Dairy cattle loose efficiency of economic production due to lower milk yields and decreased pregnancy rates. Milk loss due to heat stressed cows in California averages a loss of 293 kg of milk/cow/year(St.-Pierre et al., 2003), and with milk prices reaching record highs, dairies are losing out on increased revenue opportunity. Increases in reproductive infertility from heat stress also affect revenue for a dairy operation by reducing conception rates (Hansen 1997) and pregnancy rates, which causes the average days …