Author : Tamar Cohen-Davidyan
Publisher :
ISBN 13 : 9781658413954
Total Pages : pages
Book Rating : 4.4/5 (139 download)
Book Synopsis Development of an On-farm Model to Predict Flow of Manure to the Liquid and Solid Systems on Commercial Dairy Farms by : Tamar Cohen-Davidyan
Download or read book Development of an On-farm Model to Predict Flow of Manure to the Liquid and Solid Systems on Commercial Dairy Farms written by Tamar Cohen-Davidyan and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Methane (CH4) from dairy production systems represents a substantial portion of the greenhouse gases (GHG) released from the livestock sector of agricultural production in California USA. Many factors aside from normal biological mechanisms contribute to the amount of CH4 produced at a dairy facility. These include facility type (e.g., freestall or non-freestall) herd size including the make-up of the herd (i.e., lactating or non-lactating) management practices, fluctuations in ambient temperature and humidity, as well as diet composition. In addition to CH4 emissions, there are other environmental and public health implications of cattle housing and management practices. Where cattle deposit manure can play a crucial role in the flow and storage of manure on a dairy facility as manure handling and storage, in the liquid form, is a large source of CH4 emissions from dairy facilities. The purpose of this research was to develop an on-farm modeling tool to assist dairy farmers and regulators make informed decisions relative to manure management and evaluate mitigation options. Critical evaluation of model outputs led to development of on-farm data collection to obtain information on factors that influence total volatile solids entering the liquid and solid manure systems, but that were farm specific or not available in literature. Based on this approach, it was determined that the key missing variable in the model was a gap in current research relative to time budgets of cattle locations within pens on an annual basis. While all dairy farms vary by herd structure and management, there are overarching similarities among them, such as animal age and stage of lactation, as well as pen type. This study evaluated time on concrete, body condition score, diet composition and environmental conditions over a year on four commercial dairy sites in the San Joaquin Valley (SJV) of California. Two participating dairies were freestall facilities, and the other two were traditional California drylot dairies. Results show that lactating cattle are the animal class which contributes the largest proportion of volatile solids to the liquid manure system, and that, as a class, lactating cows housed in freestalls spent 74% of their time on concrete on an annual basis with 78% of manure volatile solids being diverted into the liquid manure system with the remaining 22% in the solid system. In contrast, lactating cows housed in non-freestall facilities spent 33% of their time on concrete annually with 51% of the manure entering the liquid system and the remaining 49% in the solid system. Remaining classes of cattle contributed minimal amounts to the liquid system due to pen structure and animal behaviors. Results highlight the importance of housing and pen type, as well as animal management, on the eventual fate of manure going into each manure collection system.