Development of Predictive Equations for Thermal Conductivity of Compost Bedding

Flávio A Damasceno,Patrícia F P Ferraz,Lorenzo Leso,George B Day,Matteo Barbari,Randi A Black,Tales J Fernandes,Joseph L Taraba,Rafaella R Andrade,Jeffrey M Bewley,Carlos E A Oliveira

doi:10.3390/app11188503

Abstract

Among animal facilities, compost-bedded pack (CBP) barns have attracted a lot of attention from milk producers and the scientific community. Systematic investigation of the main thermal properties utilizing sawdust in CBP barns is of environmental and economic relevance. In this paper, the aim was to (a) develop predictive equations for the thermal conductivity (k) of compost bedding as a function of moisture content (MC), the degree of compaction (DCo), and particle size (PS); and (b) investigate the links between k and depth within bedding material. Samples of compost bedding materials were collected from 42 commercial CBP barns distributed throughout Kentucky (USA). From these predictive equations, it was possible to understand how the MC, DCo, and PS of the bedding materials may influence the behavior of k. These results are very useful for solving obstacles to simulate and predict the variable outcomes of the compost bedding materials process in CBP barns, allowing for its optimization, consequently reducing the time and energy spent on their optimization and allowing for simulation and assessment of compost bedding process modifications. The results of the current study may have important implications in the design and management of bedded pack barns.

Highlights

(0.0, 0.1, 0.2, 0.3, and 0.4 MPa) of the bedding materials in Figures 4a and 4b, respectively. These results indicate that the values of k increased as moisture content (MC) and static compaction (SC) increased, likely due to a reduction in the volumetric fraction of air within the bedding material [35]
SCs (0.0, 0.1, 0.2, 0.3, and 0.4 MPa) of the bedding materials in Figure 4a and 4b, respectively. These results indicate that the values of k increased as MC and SC increased, likely due to a reduction in the volumetric fraction of air within the bedding material [35].8 of
Studies were conducted to evaluate the effect on thermal conductivity (k) with the variation in moisture content (MC), the degree of compaction (DCo ), particle size (PS), and the depth of bedding material from different compost-bedded pack (CBP) barns

Summary

Introduction

In the late 1980s, innovative dairy producers in the state of Virginia (USA) introduced a new loose-housing system for dairy cattle, generally referred to as a compost-bedded pack (CBP) barn [1]. CBP barns have been introduced in many other US states, and in other countries [2]. In CBP barns, cows are provided with an open bedded pack area where cows can stand, walk, and rest without restriction to areas or postures. Research showed that CBP barns have the potential to improve animal welfare, but results strictly depend on pack management, especially pack moisture content [2,3]

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