Association between Mastitis Occurrence in Dairy Cows and Bedding Characteristics of Compost-Bedded Pack Barns

Abstract

Compost-bedded pack barns (CB) are receiving increasing attention as a housing system that can potentially improve the welfare of dairy cows. This study characterized the frequency and profile of pathogens isolated from clinical (CM) and subclinical (SCM) mastitis in dairy cows housed in CB. It evaluated the association between mastitis occurrence and bedding characteristics in CB systems. Over six months, seven dairy herds were visited monthly for milk and bedding sample collections. Milk samples from mastitis cases were submitted to microbiological identification by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF MS). Bedding samples were submitted to physical-chemical (pH, organic matter, moisture, and carbon to nitrogen ratio) and microbiological counting (total bacterial counts, coliforms, streptococci, and staphylococci) analyses. Regression analysis was used to determine the association between mastitis occurrence and CB characteristics. Our results showed that Escherichia coli and environmental streptococci were the most frequently isolated pathogens from CM cases, while Staphylococcus chromogenes and contagious pathogens (Staphylococcus aureus and Streptococcus agalactiae) were the most commonly isolated from SCM cases. Bedding moisture content was positively associated with the incidence of CM. The bedding carbon to nitrogen ratio was negatively associated with the incidence of SCM, and the bedding total bacteria counts tended to be associated with the incidence of SCM. Bedding counts of coliforms positively associated with the prevalence of SCM. Our results can support decision-makers in the dairy industry seeking strategies for bedding management and mastitis control.

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

“…, and CBP 3-lact. were considered in this systematic review for composition of average values; 15 other materials (cereal husks and ground crop residues); 16 the main objective was to evaluate the nitrogen losses during the process; 17 22 data obtained by dry matter; 23 only one collection was carried out in the summer; 24 they also evaluated compost piles, after removing the material from the CBPs; 25 average data at depth of 15 cm; 26 data obtained 11 weeks after starting the composting process; 27 data calculated from C:N and N; 28 they also analyzed the chemistry milk composition; 29 average data from different depths (10 and 20 cm); 30 they also examined the bedding mechanical properties; 31 they also analyzed animal welfare and production indicators; 32 data before bedding turning; 33 average data from different layers (0 and 20 cm); 34 they also evaluated the frequency of mastitis pathogens, associating them with bedding quality; 35 If lower t B-Dep. values were recorded during the summer than those obtained in other seasons of the year (spring and fall), as observed in the study conducted by Biasato et al [5], there was a reduction in decomposition activity.…”

“…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).…”

“…Excess of bedding moisture in CBP systems can lead to the occurrence of several problems, such as reduced composting activity, increased emission of harmful gases such as ammonia (NH 3 ), and worsening of the animals' hygiene and health conditions, as well as milk quality [13,18,34]. Excessive moisture conditions, as observed in some of the listed studies (Barberg et al [30], Giambra et al [31], Nogara et al [33], Andrade et al [4], and Oliveira et al [27]-Table 3), can be caused by several factors, such as:…”

“…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. However, until now, there is no knowledge of any systematic review on the physicochemical bedding quality in CBP systems.…”

“…Low M B conditions (<40%) are also undesirable, as they cause dehydration of the decomposer microorganisms, reduction in their populations and, consequently, limiting of decomposition activity [13,14]. Of the listed studies, low M B conditions in the aerobically active layer (depth) were observed only in those conducted by Barberg et al [30], Oliveira et al [28], Freu et al [34], and Oliveira et al [27]-Table 3. Notably, regions with low M B were observed in places with direct solar radiation and external dry air masses, which caused excessive bedding drying [27,28].…”