Spatial Distribution of Bedding Attributes in an Open Compost-Bedded Pack Barn System with Positive Pressure Ventilation in Brazilian Winter Conditions

Abstract

The objective of this study was to characterize the dependence and spatial distribution of bedding attributes in an open compost-bedded pack barn (CBP) system with positive pressure ventilation during the winter period in Brazil. The study was conducted in July 2021, in the Zona da Mata region, Minas Gerais, Brazil. The bedding area (shavings and wood sawdust) was divided into a mesh with 44 equidistant points. At each point, the bedding temperature at the surface (tB-sur) and at a depth of 0.2 m (tB-20) and the air velocity at bedding level (vair,B) were measured, and bedding samples were collected. The bedding samples were used to determine the moisture level and pH at the surface (MB-sur e pHB-sur) and at a depth of 0.2 m (MB-20 and pHB-20). The spatial behavior of the variables was evaluated using geostatistics techniques. For all variables, the occurrence of strong spatial dependence was verified. Through the maps, it was observed that tB-sur, tB-20, MB-sur, MB-20, and vair,B showed high spatial variability, whereas pHB-sur and pHB-20 demonstrated low variation. On the surface, values of tB-sur < 20 °C and MB-sur > 60% were observed. At the subsurface, there was a predominance of tB-20 < 40 °C, MB-20 > 60%, and pH > 9, which are indications of low bedding composting activity.

Physicochemical Bedding Quality in Compost-Bedded Pack Barn Systems for Dairy Cows: A Systematic Review

“…-34.7 ± 5.6 25 -54.1 ± 17.0 25 -8.0 25,26 0.96 25,26 0.24 25,26 1.22 25,26 46.08 25,26,27 48.0 25,26 Winter -31.2 ± 5.9 25 -55.0 ± 16.4 25 -9.0 25,26 1.12 25,26 0.28 25,26 1.78 25,26 44.80 25,26,27 40.0 25,26 Fall FB -28.3 ± 6.9 25 -62.0 ± 14.0 25 -8.4 1 They also analyzed the bacteriological bedding composition, characterized facilities, environment, and production costs; 2 average data, without individual separation by period; 3 average data from different depths (15, 30, 61, and 91 cm); 4 average data from different depths (15 and 30 cm); 5 results in ppm or g•kg −1 were converted to % (standardization); 6 not specified, but subject to calculation, through C:N and N; 7 they also analyzed the bacteriological bedding composition and milk, and characterized facilities, environment, and animal indicators; 8 measurements were also performed in spring and fall periods, but only winter and summer data were listed; 9 several materials were used, and no separation between results is indicated; 10 average data at a depth of 20 cm; 11 average data from surface bedding samples; 12 they also analyzed the bedding bacteriological composition, the animal health and behavior, as well as the cheese quality; 13 not specified at what depth data were collected, but, based on the values, it is understood that these are subsurface data; 14 this study used different CBPs treatments. CBP 1-lact.…”

“…In CBP systems, M B is considered one of the most challenging parameters to control since it is directly influenced by management and local climatic conditions [7]. The difficulty maintaining M B was reported through the results achieved in some of the listed studies, in which the minimum and maximum M B values were less than 10% and greater than 60%, respectively (Barberg et al [30], Black et al [11], Giambra et al [31], Oliveira et al [28], Llonch et al [29], Nogara et al [33], Andrade et al [4], Freu et al [34], and Oliveira et al [27]-Table 3).…”

“…Since t B-Sur. is essential for the thermal comfort of housed animals, its evaluation can be based on the range of between 4 and 24 • C, usually considered as the level of thermal comfort for lactating dairy cattle [27,43]. Considering this range for the t B-Sur.…”

“…assessment, the results of some studies showed that in fall and winter, the t B-Sur. conditions were thermally comfortable for the animals, allowing them to spend more time lying down and partake in activities of leisure and rumination (Black et al [11], Andrade et al [4] and Oliveira et al [27]-Table 3). However, in spring and summer, conditions of t B-Sur.…”

“…In CBPs, managing the bedding properly, with basis on the environmental factors in each facility, is considered the crucial point to achieving satisfactory performance with its use [7,26]. Due to the importance of bedding management in CBP systems, conducting studies to evaluate/characterize the bedding quality and monitor the composting process's efficiency in this system type is essential [4,27]. Some studies with this objective have been conducted in different places [5,11,19,[28][29][30][31][32][33][34] which, in addition to specific climatic conditions, have notable differences in facility types, materials, and bedding management practices.…”