Cow's functional traits and physiological status and their relation with milk yield and milk quality in a compost bedded pack barn system

Roberto Kappes Deise Aline Knob André Thaler Neto Dileta Regina Moro Alessio Wagner Bianchin Rodrigues Armin Manfred Scholz Ramiro Bonotto About the authors

ABSTRACT

We aimed to determine the relationship of milk yield, milk composition, and somatic cell score (SCS) with functional traits (lameness score, udder cleanliness score, udder depth, and teat end hyperkeratosis score) and physiological status (parity and days in milk (DIM) of cows housed in compost bedded pack barn system (CBP) using multivariate analysis. Data were collected in September and October of 2017 and evaluated using factor and cluster analysis. Four factors were formed, with the first factor showing the traits responsible for altering the lactose content in milk, the second factor comprising the effect of DIM, the third factor representing the teat end hyperkeratosis score, and the fourth factor demonstrating the udder cleanliness. The cluster analysis formed three clusters. Clusters 2 and 3 differed for protein and lactose content, SCS, parity, DIM, lameness score, and udder depth. Cluster 1 differed from the others, especially due to the high milk yield. Cow conformation traits and physiological status affected milk yield and composition in CBP. There is an association between udder depth, parity, and SCS with negative impact on lactose content. Parity is also associated with higher milk yield and teat end hyperkeratosis score. Cows with lower lameness score presented dirtier udders due to increased movements on the feed parlor and water troughs areas. Special attention to the improvement of the udder conformation traits, as well as management practices that reduce hyperkeratosis, are necessary to keep high yielding, healthy, and cows with higher longevity. The cleanliness in the feed parlor and water troughs area is very important to preserve milk quality and healthy cows.

Keywords:
lameness score; somatic cell count; teat end hyperkeratosis; udder cleanliness score; udder depth

Introduction

All housing systems for dairy cattle aim at improving comfort for lactating cows, allowing expression of their natural behavior, maintaining hygiene and health, and generally improving living conditions of lactating cows and farmers ( Bewley et al., 20175 Bewley, J. M.; Robertson, L. M. and Eckelkamp, E. A. 2017. A 100-Year Review: Lactating dairy cattle housing management. Journal of Dairy Science 100:10418-10431. https://doi.org/10.3168/jds.2017-13251
https://doi.org/10.3168/jds.2017-13251...
). The compost bedded pack barn (CBP) is a type of confinement system that allows animals to move freely inside the stall, free of bays or partitions ( Janni et al., 200722 Janni, K. A.; Endres, M. I.; Reneau, J. K. and Schoper, W. W. 2007. Compost dairy barn layout and management recommendations. Applied Engineering in Agriculture 23:97-102. ). In this system, feces and urine are disposed and incorporated into the material that composes the compost bed. Through a 6-24 month of composting process, the compost bed turns into a semi-solid fertilizer ( Janni et al., 200722 Janni, K. A.; Endres, M. I.; Reneau, J. K. and Schoper, W. W. 2007. Compost dairy barn layout and management recommendations. Applied Engineering in Agriculture 23:97-102. ; Black et al., 20147 Black, R. A.; Taraba, J. L.; Day, G. B.; Damasceno, F. A.; Newman, M. C.; Akers, K. A.; Wood, C. L.; McQuerry, K. J. and Bewley, J. M. 2014. The relationship between compost bedded pack performance, management, and bacterial counts. Journal of Dairy Science 97:2669-2679. https://doi.org/10.3168/jds.2013-6779
https://doi.org/10.3168/jds.2013-6779...
). Different materials can be used as carbon source in the compost bed such as wood sawdust, wheat straw, soybean straw, flax seed, rice straw, coffee husks, and peanut shells ( Shane et al., 2010b39 Shane, E. M.; Endres, M. I. and Janni, K. A. 2010b. Alternative bedding materials for compost bedded pack barns in minnesota: a descriptive study. Applied Engineering in Agriculture 26:465–473. ). This system requires regular bedding addition, which means a new layer of material, and requires compost bed tilling at least twice a day to incorporate animal waste and to allow entry of air into the deeper layers ( Black et al., 20136 Black, R. A.; Taraba, J. L.; Day, G. B.; Damasceno, F. A. and Bewley, J. M. 2013. Compost bedded pack dairy barn management, performance, and producer satisfaction. Journal of Dairy Science 96:8060-8074. https://doi.org/10.3168/jds.2013-6778
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). This procedure allows greater microbial aerobic activity, heating and drying the compost bed, which provides a dry and fresh surface for the cows to lie down ( Shane et al., 2010a40 Shane, E. M.; Endres, M. I.; Johnson, D. G. and Reneau, J. K. 2010a. Bedding options for an alternative housing system for dairy cows: A descriptive study. Applied Engineering in Agriculture 26:659-666. https://doi.org/10.13031/2013.32062
https://doi.org/10.13031/2013.32062...
).

In the last few years, the CBP has been widely used in Brazil, especially in the south region, aiming to improve cattle comfort and longevity and to reduce somatic cell count (SCC) in milk ( Black et al., 20136 Black, R. A.; Taraba, J. L.; Day, G. B.; Damasceno, F. A. and Bewley, J. M. 2013. Compost bedded pack dairy barn management, performance, and producer satisfaction. Journal of Dairy Science 96:8060-8074. https://doi.org/10.3168/jds.2013-6778
https://doi.org/10.3168/jds.2013-6778...
), and thus improving milk yield ( Ofner-Schröck et al., 201533 Ofner-Schröck, E.; Zähner, M.; Huber, G.; Guldimann, K.; Guggenberger, T. and Gasteiner, J. 2015. Compost barns for dairy cows - aspects of animal welfare. Open Journal of Animal Sciences 5:124-131. ; Pilatti and Vieira, 201736 Pilatti, J. A. and Vieira, F. M. C. 2017. Environment, behavior and welfare aspects of dairy cows reared in compost bedded pack barns system. Journal of Animal Behaviour and Biometeorology 5:97-105. ). However, because it is a new housing system in Brazil, it still presents some challenges regarding the correct management of the compost bed, which directly and indirectly interferes in milk quality ( Pilatti and Vieira, 201736 Pilatti, J. A. and Vieira, F. M. C. 2017. Environment, behavior and welfare aspects of dairy cows reared in compost bedded pack barns system. Journal of Animal Behaviour and Biometeorology 5:97-105. ). These challenges are mostly related to the lack of new bedding material, failure to till bed for as much time as necessary, and environmental issues such as high humidity. Improper compost bed management can increase bed humidity and decrease its temperature ( Endres, 200919 Endres, M. I. 2009. Compost bedded pack barns – can they work for you ? Advances in Dairy Technology 21:271-279. ). These issues predispose the occurrence of digital lesions, as well as greater udder dirtiness by the adhesion of bedding material to the udder ( Klaas et al., 201023 Klaas, I. C.; Bjerg, B.; Friedmann, S. and Bar D. 2010. Cultivated barns for dairy cows: An option to promote cattle welfare and environmental protection in Denmark? Dansk Veterinærtidsskrift 93:20-29. ; Fávero et al., 201520 Fávero, S.; Portilho, F. V. R.; Oliveira, A. C. R.; Langoni, H. and Pantoja, J. C. F. 2015. Factors associated with mastitis epidemiologic indexes, animal hygiene, and bulk milk bacterial concentrations in dairy herds housed on compost bedding. Livestock Science 181:220-230. https://doi.org/10.1016/j.livsci.2015.09.002
https://doi.org/10.1016/j.livsci.2015.09...
; Albino et al., 20181 Albino, R. L.; Taraba, J. L.; Marcondes, M. I.; Eckelkamp, E. A. and Bewley, J. M. 2018. Comparison of bacterial populations in bedding material, on teat ends, and in milk of cows housed in compost bedded pack barns. Animal Production Science 58:1686-1691. https://doi.org/10.1071/AN16308
https://doi.org/10.1071/AN16308...
), which can increase SCC ( Albino et al., 20181 Albino, R. L.; Taraba, J. L.; Marcondes, M. I.; Eckelkamp, E. A. and Bewley, J. M. 2018. Comparison of bacterial populations in bedding material, on teat ends, and in milk of cows housed in compost bedded pack barns. Animal Production Science 58:1686-1691. https://doi.org/10.1071/AN16308
https://doi.org/10.1071/AN16308...
) and put mammary gland health at risk ( Black et al., 20147 Black, R. A.; Taraba, J. L.; Day, G. B.; Damasceno, F. A.; Newman, M. C.; Akers, K. A.; Wood, C. L.; McQuerry, K. J. and Bewley, J. M. 2014. The relationship between compost bedded pack performance, management, and bacterial counts. Journal of Dairy Science 97:2669-2679. https://doi.org/10.3168/jds.2013-6779
https://doi.org/10.3168/jds.2013-6779...
).

Physiological status may also influence the rise of SCC level in milk, such as later days in milk (DIM), through greater desquamation of mammary gland epithelial cells ( Malik et al., 201824 Malik, T. A.; Mohini, M.; Mir, S. H.; Ganaie, B. A.; Singh, D.; Varun, T. K.; Howal, S. and Thakur, S. 2018. Somatic cells in relation to udder health and milk quality-a review. Journal of Animal Health and Production 6:18-26. https://doi.org/10.17582/journal.jahp/2018/6.1.18.26
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). A greater parity number is also related to the rise of SCC level since the udder tends to become more pendulous with increasing age, which can increase the risk of traumas during locomotion as well as more dirtiness ( Pérez-Cabal and Alenda, 200235 Pérez-Cabal, M. A. and Alenda, R. 2002. Genetic relationships between lifetime profit and type traits in Spanish Holstein cows. Journal of Dairy Science 85:3480-3491. https://doi.org/10.3168/jds.S0022-0302(02)74437-8
https://doi.org/10.3168/jds.S0022-0302(0...
; Cardozo et al., 201510 Cardozo, L. L.; Thaler Neto, A.; Souza, G. N.; Picinin, L. C. A.; Felipus, N. C.; Reche, N. L. M.; Schmidt, F. A.; Werncke, D. and Simon, E. E. 2015. Risk factors for the occurrence of new and chronic cases of subclinical mastitis in dairy herds in southern Brazil. Journal of Dairy Science 98:7675-7685. https://doi.org/10.3168/jds.2014-8913
https://doi.org/10.3168/jds.2014-8913...
). Another factor related to a higher SCC level is an increasing teat end hyperkeratosis score, which may lead to a reduced ability of closing the teat sphincter, facilitating the entry of pathogenic microorganisms into the mammary gland ( Cardozo et al., 201510 Cardozo, L. L.; Thaler Neto, A.; Souza, G. N.; Picinin, L. C. A.; Felipus, N. C.; Reche, N. L. M.; Schmidt, F. A.; Werncke, D. and Simon, E. E. 2015. Risk factors for the occurrence of new and chronic cases of subclinical mastitis in dairy herds in southern Brazil. Journal of Dairy Science 98:7675-7685. https://doi.org/10.3168/jds.2014-8913
https://doi.org/10.3168/jds.2014-8913...
).

Further studies on CBP systems in Brazil are necessary, especially for the variables related to functional traits and the physiological status of lactating cows, milk quality, and the management of this confinement system. Therefore, the use of multivariate analysis is critical to evaluate multifactorial effects ( Mele et al., 201627 Mele, M.; Macciotta, N. P. P.; Cecchinato, A.; Conte, G.; Schiavon, S. and Bittante, G. 2016. Multivariate factor analysis of detailed milk fatty acid profile: Effects of dairy system, feeding, herd, parity, and stage of lactation. Journal of Dairy Science 99:9820-9833. https://doi.org/10.3168/jds.2016-11451
https://doi.org/10.3168/jds.2016-11451...
) aiming to simplify the available information ( Todde et al., 201644 Todde, G.; Murgia, L.; Caria, M. and Pazzona, A. 2016. A multivariate statistical analysis approach to characterize mechanization, structural and energy profile in Italian dairy farms. Energy Reports 2:129-134. https://doi.org/10.1016/j.egyr.2016.05.006
https://doi.org/10.1016/j.egyr.2016.05.0...
). Therefore, the objective of our study was to determine the association among milk yield, milk composition, SCC, functional traits (lameness score, udder cleanliness score, udder depth, and teat end hyperkeratosis score), and physiological status (parity and DIM) of each cow in a CBP applying a factor and a cluster analysis procedure.

Material and Methods

The experiment was carried out on a dairy farm located in Bom Retiro, Santa Catarina (27°47′50″ S, 49°29′21″ W, 890 m altitude), south of Brazil, in a subtropical humid climate region, type Cfb (C = humid sub-tropical, f = oceanic climate, without dry season, and b = with temperate summer), according to the Köppen classification ( Peel, 200734 Peel, M. C.; Finlayson, B. L. and McMahon, T. A. 2007. Updated world map of the Köppen-Geiger climate classification. Hydrology and Earth System Sciences 11:1633-1644. https://doi.org/10.5194/hess-11-1633-2007
https://doi.org/10.5194/hess-11-1633-200...
; Alvares et al., 20134 Alvares, C. A.; Stape, J. L.; Sentelhas, P. C.; De Moraes Gonçalves, J. L. and Sparovek, G. 2013. Köppen's climate classification map for Brazil. Meteorologische Zeitschrift 22:711-728. https://doi.org/10.1127/0941-2948/2013/0507
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). The farm housed approximately 280 lactating cows, with a daily production of approximately 9,000 L of milk. The herd was composed mainly of Holstein cows (about 60% of the cows) and different “blood” levels of crossbred Holstein × Simmental cows ( Figure 1 ).

Figure 1
Crossbred Holstein × Simmental cows (A) and purebred Holstein cows (B) of the farm where the research was carried out.

Lactating cows kept in the CBP were divided into three groups according to their production level; group 1 included cows in early lactation and with high milk yield, with an average of 45 L/milk/day; group 2 included cows in mid lactation, producing an average of 33 L/milk/day; and group 3 included cows in late lactation, producing an average of 22 L/milk/day. Cows were fed a total mixed ration combining corn silage, ryegrass (fresh and silage), and concentrates. The diet offered to the cows was calculated to provide 100% of the nutritional requirement ( NRC, 200132 NRC - National Research Council. 2001. Nutrient requirements of dairy cattle. 7th rev. ed. National Academy Press, Washington, D.C. ), in which the proportion of each ingredient was adjusted according to the milk yield of each group. Cows were mechanically milked three times a day (05:00, 13:30, and 20:30 h), and the individual cow milk yield (MY) was electronically recorded (DeLaval® electronically milk-recording system). Cows had access to the feed parlor right after milking, for about 2 h and 30 min (about 7.5 h/day), three times a day.

Before the beginning of milking, pre-dipping procedures were performed, by removing the first three milk jets from each teat in a strip cup with black background to diagnose changes on milk appearance such as presence of blood, watery appearance, clots, flakes, pus etc., which indicates mastitis. A disinfectant solution (Biofoam™, DeLaval) was applied in each teat right after this test, and 30 s later, each teat was dried with a disposable wipe. Immediately after milking, the post-dipping procedure was performed by applying an iodine-based solution (Della Barrier®, DeLaval).

The bedding material used for the CBP system was composed of wooden sawdust. Weekly, as a routine, a new layer of material was added to the bed. The bedding material was mixed twice a day (morning and afternoon) by using a soil cultivator that reached around 30 cm beneath ground level. Average bedding temperature was of 25° C, measured at a depth of 20 cm, and moisture content yielded 62% in September and October 2017. We evaluated the bed temperature and humidity on the same day we performed the other evaluations. For the evaluation of the bed temperature, we used a thermometer and measured the bed temperature 20 cm below the surface at six different places in each of the three divisions of the CBP, totaling 18 evaluations. Subsequently, we used the mean temperature of all measurements. To estimate the moisture content of the compost bed, we also took samples at 18 different points in the CBP. We mixed the individual samples and prepared a composed sample. The composite sample was dried in a forced-air oven at 55 °C for 72 h to determine the humidity. During the same period, the average air temperature and humidity reached 13.4-14.7 °C and 80-82%, respectively ( EPAGRI/CIRAM, 201917 Epagri/Ciram - Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina; Centro de Informações de Recursos Ambientais e de Hidrometeorologia de Santa Catarina. 2019. Monitoramento online. Available at: <http://ciram.epagri.sc.gov.br/>. Accessed on: April 22, 2019.
http://ciram.epagri.sc.gov.br/...
). The average pack area in the CBP provided at least a space of 10.5 m2 per lactating cow ( Figure 2 ).

Figure 2
Outside view (A) and inside view (B) of the compost bedded pack barn with the lactating cows of the dairy farm where the research was carried out.

The individual cow milk samples of all lactating cows were taken once a month in 40-mL bottles containing Bronopol. Samples were sent to a laboratory participating in the Milk Quality Program of Brazil for milk composition and SCC analysis. All analyses were performed by using automatic equipment. The SCC test was performed by flow cytometry (Soma Count FC), and milk composition was determined by an infrared technique (Dairy Spec FT Bentley®).

Data collection and animal evaluations were carried out once monthly during September and October 2017. Data of breed, parity, and DIM were collected from the farm records. On the same day when the milk samples were taken, we performed the evaluation of teat end hyperkeratosis score, udder cleanliness score, udder depth, and lameness score.

Teat end hyperkeratosis score was visually classified using a scale of 1 to 4 (1 - teat end without ring formation, 2 - teat end with small ring formation, 3 - teat end with rough ring formation, 4 - teat end with a very rough ring; Figure 3 ) according to the methodology described by Mein et al. (2001)25 Mein, G. A.; Neijenhuis, F.; Morgan, W. F.; Reinemann, D. J.; Hillerton, J. E.; Baines, J. R.; Ohnstad, I.; Rasmussen, M. D.; Timms, L.; Britt, J. S.; Farnsworth, R.; Cook, N. and Hemling, T. 2001. Evaluation of bovine teat condition in commercial dairy herds: 1. Non-infectious factors. In: AABP-NMC International Symposium on Mastitis and Milk Quality, Vancouver, Canada. . The scoring was performed after milking and before post-dipping procedures. After the evaluation of teat end hyperkeratosis score, the average hyperkeratosis score of each cow (average among the four teats) was calculated.

Figure 3
Teat end hyperkeratosis score, in which 1 - teat end without ring formation (A), 2 - teat end with small ring formation (B), 3 - teat end with rough ring formation (C), 4 - teat end with a very rough ring (D).

Udder cleanliness scoring was performed using a scale from 1 (clean) to 4 (very dirty) according to the model proposed by Ruegg (2002)37 Ruegg, P. L. 2002. Udder hygiene scoring chart. Chart developed with input from Dan Schreiner and Mike Maroney. 1-866-TOP-MILK. Available at: <https://milkquality.wisc.edu/wp-content/uploads/sites/212/2011/09/udder-hygiene-scoring-chart.pdf>. Accessed on: Aug. 15, 2017.
https://milkquality.wisc.edu/wp-content/...
before pre-dipping procedures. The udder depth was defined as the distance of the udder floor to the line of hock using a scale from 1 to 3 (1 = udder floor above the line of hock, 2 = udder floor on hock line, 3 = udder floor below the line of the hock; Figure 4 ) as described by Coentrão et al. (2008)13 Coentrão, C. M.; Souza, G. N.; Brito, J. R. F.; Paiva e Brito, M. A. V. and Lilenbaum, W. 2008. Fatores de risco para mastite subclínica em vacas leiteiras. Arquivo Brasileiro de Medicina Veterinária e Zootecnia 60:283-288. https://doi.org/10.1590/S0102-09352008000200001
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. The lameness score was recorded two times: the first one during the exit of the milking parlor, while animals were in locomotion, and the second one, at the feeding parlor, while cows were standing. A scale from 1 to 5 points was applied, with 1 for cows with no locomotion problems, and 5 for cows with serious locomotion problems, according to Sprecher et al. (1997)42 Sprecher, D. J.; Hostetler, D. E. and Kaneene, J. B. 1997. A lameness scoring system that uses posture and gait to predict dairy cattle reproductive performance. Theriogenology 47:1179-1187. https://doi.org/10.1016/S0093-691X(97)00098-8
https://doi.org/10.1016/S0093-691X(97)00...
.

Figure 4
Udder depth scores as the distance of the udder floor from the hock line, in which 1 = udder floor above the hock line (A), 2 = udder floor on hock line (B), and 3 = udder floor below the hock line (C).

Variables evaluated were individual cow milk yield (kg/cow/day), fat, protein and lactose contents, SCC, DIM, parity, teat end hyperkeratosis, lameness score, udder depth, and udder cleanliness. Outliers or potential errors from milk sampling were removed by data standardization. Records between 8 and 305 days of lactation, milk yields between 10 and 60 L per day, fat contents between 1.5 and 5.6%, protein contents between 2.0 and 5.3%, and lactose contents between 3.0 and 5.2% remained in the data set. In addition, cows were classified into first, second, and third or higher parities. To obtain normality, SCC data were transformed to somatic cell score (SCS) by the equation SCS=log2(SCC/100)+3 ( Ali and Shook, 19803 Ali, A. K. A. and Shook, G. E. 1980. An optimum transformation for somatic cell concentration in milk. Journal of Dairy Science 63:487-490. https://doi.org/10.3168/jds.S0022-0302(80)82959-6
https://doi.org/10.3168/jds.S0022-0302(8...
). Because the effect of the genetic group was not significant, we did not include it in the final results. All cows, independent of the genetic group, were kept and managed under the same conditions.

Data were evaluated using multivariate analysis technique (factor and cluster analysis) using the SAS® statistical software (SAS Institute 2002). Data were previously standardized by PROC STANDARD so that all variables would equally contribute to the analysis to avoid that variables with a larger numerical scale would have a greater effect than those with a smaller scale. The Factor analysis (PROC FACTOR) served as a tool to evaluate the relationships among the variables aiming at reducing the original set of variables to a smaller number of (significant) factors. To verify the suitability of the model, Kaiser-Meyer-Olkin (KMO) statistics was used. Factor loads higher than 0.40 were considered significant, and Promax rotation was used. The number of factors was defined by the eigenvalue, using all eigenvalues higher than 1. A cluster analysis was performed by PROC FASTCLUS to calculate clusters for cows with (more or less) similar characteristics and distinct differences among each other. Ward's hierarchical method was applied by using the Euclidean distance to estimate standardized means for each cluster followed by a back transformation to the original means.

A subsequent discriminant analysis (Proc DISCRIM) was performed to re-classify the data (cows) correctly for each cluster. Since a considerable proportion of data (cows) were wrongfully distributed within their respective clusters, we chose to use a non-parametric discriminant analysis using the NPAR method combined with the k-nearest neighbor (KNN) algorithm, which classified all data within the clusters. Within the discriminant analysis, the STEPWISE method using the STEPDISC procedure was used to select the variables responsible for cluster differentiation. In addition, the canonical discriminant analysis (CANDISC procedure) was used to graphically demonstrate the distances within and between clusters.

Finally, the assumptions of normality (Shapiro-Wilk test) and homogeneity of variances (Levene's test) were tested to compare the means in the clusters formed by the cluster analysis. Since the variables did not meet at least one of the assumptions, presenting a lack of normality or homogeneity of variance and/or both, we chose to perform the analysis of variance by the GLIMMIX procedure, which considers the type of distribution of the response variable for the comparison of means. If these results were significant, the least squares mean values were compared by the Tukey-Kramer test considering the 5% significance level.

Results

The descriptive analysis shows the variability of the collected data as arithmetic means and the respective standard deviations including minimum and maximum ( Table 1 ). The average SCC of 346.50 cells × 1,000/mL is below the value recommended by the Normative Instruction no. 76 ( Brasil, 20189 Brasil. 2018. Ministério da Agricultura, Pecuária e Abastecimento. Instrução Normativa n° 76, de 26 de novembro de 2018. Diário Oficial da República Federativa do Brasil, Brasília, DF, 30 de novembro de 2018. Seção 1, p.9. ).

Table 1
Descriptive statistics and standard deviation (SD) of mean milk yield and composition, somatic cell count (SCC), and individual characteristics of lactating cows in a compost barn confinement system

Factor analysis regarding the variables from individual cow milk yield (kg/cow/day), fat, protein, lactose contents, SCS, functional traits, physiological status represented by DIM, parity, teat end hyperkeratosis, lameness score, udder depth, and udder cleanliness expressed 57.6% of the total variance in the first four factors, with a KMO of 0.579 ( Table 2 ). Higher communalities show the importance of the variables within the study. The first factor shows the parameters responsible for altering the lactose content, as demonstrated by a negative relationship between SCS, udder depth, and parity with lactose content. The negative relationship between these variables is represented by the opposition of their factor loading, for example, high SCS (0.716) with low lactose content (−0.736), as shown for the first factor. The second factor comprises the effect of DIM, represented by the positive relation between DIM and milk fat as well as protein content. The third factor represents teat end hyperkeratosis score. It combines variables that affect the hyperkeratosis score, resulting from an unfavorable positive relationship between parity and milk yield and teat end hyperkeratosis score. The negative relationship among cows with the highest lameness score (more locomotion problems) and lower udder cleanliness score (udders less dirty) is defined by the fourth factor.

Table 2
Factor loads, eigenvalue, variance percentage, and communalities of each variable regarding the evaluation of the inter-relation of milk yield and composition, somatic cell score (SCS), and individual characteristics of lactating cows in a compost barn confinement system

The canonical discriminant analysis graphically demonstrates the Euclidean distances used for the separation between and within clusters ( Figure 5 ). The STEPWISE method identified the variables responsible for the differentiation of clusters, comprising the final model (P<0.0001) by order of relevance. These variables were parity, milk yield, lactose content, DIM, udder depth, SCS, teat end hyperkeratosis score, protein content, lameness score, udder cleanliness score, and fat content ( Table 3 ). All variables recorded were considered in the stepwise analysis. The partial R2 explains the impact of each variable for the differentiation of cows among the three clusters. A proportion of 69.7% of the distance among the clusters is explained by parity, followed by milk yield and lactose content.

Figure 5
Canonical discriminant analysis demonstrates the Euclidean distances between and within the clusters formed by the variables milk yield and composition, somatic cell score (SCS), and individual characteristics of lactating cows in compost barn confinement system.
Table 3
Discriminant analysis of the variables that determine the differentiation of the clusters and their respective statistical parameters for the variables that represent the inter-relation of milk yield and composition, somatic cell score (SCS), and individual characteristics of lactating cows in a compost barn confinement system

The cluster analysis formed three clusters with similar characteristics within them and distinct differences among clusters defined by the Euclidian distance ( Table 4 ). There were differences among the three clusters for lactose content, SCS, DIM, lameness score, and udder depth, while fat content did not differ among clusters. Clusters 2 and 3 did not differ for milk yield, udder cleanliness score, and hyperkeratosis scores, but differed for protein and lactose content, SCS, parity, DIM, lameness score, and udder depth. Cluster 3 is represented by younger cows with intermediate DIM (average of 146), shallow udder, and lower lameness score than cows of cluster 2, while cows of cluster 2 present a higher parity and DIM as well deeper udder and higher lameness score, producing milk with higher SCS and, therefore, lower lactose content. Cluster 1 is different from the others, especially due to high milk yield combined with low protein content and fewer DIM, representing cows with higher parity (similar to cluster 2) and higher teat end hyperkeratosis and cleanliness scores, while lactose content, SCS, udder depth, and lameness score are intermediate in comparison with clusters 2 and 3.

Table 4
Clusters formed by the variables regarding to the evaluation of the inter-relation of milk yield and composition, somatic cell score (SCS), and individual characteristics of lactating cows in a compost barn confinement system

Discussion

The physiological traits of milk yield and composition of the lactating cows at the CBP system matched all the assumptions of milk quality recommended for the Brazilian dairy farmers ( Brasil, 20189 Brasil. 2018. Ministério da Agricultura, Pecuária e Abastecimento. Instrução Normativa n° 76, de 26 de novembro de 2018. Diário Oficial da República Federativa do Brasil, Brasília, DF, 30 de novembro de 2018. Seção 1, p.9. ). The CBP system can have a positive effect on milk quality, especially regarding indicators of mammary gland health (Tables 2 and 4). The CBP potentially reduces SCS ( Black et al., 20136 Black, R. A.; Taraba, J. L.; Day, G. B.; Damasceno, F. A. and Bewley, J. M. 2013. Compost bedded pack dairy barn management, performance, and producer satisfaction. Journal of Dairy Science 96:8060-8074. https://doi.org/10.3168/jds.2013-6778
https://doi.org/10.3168/jds.2013-6778...
; Black et al., 20147 Black, R. A.; Taraba, J. L.; Day, G. B.; Damasceno, F. A.; Newman, M. C.; Akers, K. A.; Wood, C. L.; McQuerry, K. J. and Bewley, J. M. 2014. The relationship between compost bedded pack performance, management, and bacterial counts. Journal of Dairy Science 97:2669-2679. https://doi.org/10.3168/jds.2013-6779
https://doi.org/10.3168/jds.2013-6779...
), which relies on the appropriate management of the compost bed, tilling it at least two times a day and regularly adding new carbon-source materials ( Endres, 200919 Endres, M. I. 2009. Compost bedded pack barns – can they work for you ? Advances in Dairy Technology 21:271-279. ). On the other hand, an improper bed management can increase udder dirtiness by the adherence of bedding material to the udder ( Fávero et al., 201520 Fávero, S.; Portilho, F. V. R.; Oliveira, A. C. R.; Langoni, H. and Pantoja, J. C. F. 2015. Factors associated with mastitis epidemiologic indexes, animal hygiene, and bulk milk bacterial concentrations in dairy herds housed on compost bedding. Livestock Science 181:220-230. https://doi.org/10.1016/j.livsci.2015.09.002
https://doi.org/10.1016/j.livsci.2015.09...
; Albino et al., 20181 Albino, R. L.; Taraba, J. L.; Marcondes, M. I.; Eckelkamp, E. A. and Bewley, J. M. 2018. Comparison of bacterial populations in bedding material, on teat ends, and in milk of cows housed in compost bedded pack barns. Animal Production Science 58:1686-1691. https://doi.org/10.1071/AN16308
https://doi.org/10.1071/AN16308...
). The cleanliness of the lactating cows indicates the capacity of the CBP in keeping the udder clean resulting in a lower incidence of clinical and subclinical mastitis ( Eckelkamp et al., 2016a15 Eckelkamp, E. A.; Taraba, J. L.; Akers, K. A.; Harmon, R. J. and Bewley, J. M. 2016a. Sand bedded freestall and compost bedded pack effects on cow hygiene, locomotion, and mastitis indicators. Livestock Science 190:48-57. https://doi.org/10.1016/j.livsci.2016.06.004
https://doi.org/10.1016/j.livsci.2016.06...
). It is worth emphasizing that, at the time when the study was carried out, weather conditions were also challenging for the good quality of the compost bed, because of low air temperature combined with high air humidity. The combination of these two factors may help to explain why the compost bed temperature was low (around 25 °C) and the humidity high (62%).

Considering the effects of mastitis on mammary gland health, and thus its effect on milk composition, the factors related to the system that affect mastitis, represented here by the SCS, also affect milk composition. Under the conditions of this study, it can be verified that the variables of cleanliness and lameness scores do influence SCS and, indirectly, the milk composition ( Table 4 ). A higher cleanliness score is related to a higher risk of development of mastitis due to a higher exposure of the mammary gland to contaminants ( Albino et al., 20181 Albino, R. L.; Taraba, J. L.; Marcondes, M. I.; Eckelkamp, E. A. and Bewley, J. M. 2018. Comparison of bacterial populations in bedding material, on teat ends, and in milk of cows housed in compost bedded pack barns. Animal Production Science 58:1686-1691. https://doi.org/10.1071/AN16308
https://doi.org/10.1071/AN16308...
). The lameness score is also related to greater udder dirtiness. Cows with locomotion problems show longer lying times in humid environments ( Eckelkamp et al., 2016b16 Eckelkamp, E. A.; Taraba, J. L.; Akers, K. A.; Harmon, R. J. and Bewley, J. M. 2016b. Understanding compost bedded pack barns: Interactions among environmental factors, bedding characteristics, and udder health. Livestock Science 190:35-42. https://doi.org/10.1016/j.livsci.2016.05.017
https://doi.org/10.1016/j.livsci.2016.05...
; Mostafa and Mahran, 201629 Mostafa, A. S. and Mahran, H. A. 2016. Assessment of welfare and health of dairy cows under different housing and management systems. Journal of Applied Veterinary Sciences 1:56-68. https://doi.org/10.21608/javs.2016.62122
https://doi.org/10.21608/javs.2016.62122...
), especially under improper management of the compost bed, which can increase humidity and decrease the bed temperature ( Endres, 200919 Endres, M. I. 2009. Compost bedded pack barns – can they work for you ? Advances in Dairy Technology 21:271-279. ). In addition, locomotion problems decrease cow immunity due to stress caused by pain ( Eicher et al., 201318 Eicher, S. D.; Lay Jr., D. C.; Arthington, J. D. and Schutz, M. M. 2013. Effects of rubber flooring during the first 2 lactations on production, locomotion, hoof health, immune functions, and stress. Journal of Dairy Science 96:3639-3651. https://doi.org/10.3168/jds.2012-6049
https://doi.org/10.3168/jds.2012-6049...
), leading to an increased occurrence of mastitis.

In our study, lactating cows with lower lameness scores (animals with less locomotion problems) show greater udder cleanliness scores (dirtier udders), meaning that more mobile cows have dirtier udders. That is shown by the cleanliness factor ( Table 2 ). It can be concluded from cluster 1 ( Table 4 ) that cows at early lactation in combination with higher milk yield present greater udder dirtiness. The lower lameness score (1) allows cows to move more and better. That is important especially for high yielding cows with rising nutrient requirements at early lactation stages. Therefore, these animals need to increase their movement in the feed parlor area to select sites with greater amounts of feed. That way, they can meet their physiological needs of higher nutrient intake to sustain higher milk production ( Nielsen et al., 201130 Nielsen, B. H.; Thomsen, P. T. and Sørensen, J. T. 2011. Identifying risk factors for poor hind limb cleanliness in Danish loose-housed dairy cows. Animal 5:1613-1619. https://doi.org/10.1017/S1751731111000905
https://doi.org/10.1017/S175173111100090...
). Cows that moved more consequently increased udder dirtiness occurrence, due to increased contact with feces and urine accumulated in the feed parlor area ( DeVries et al., 201214 DeVries, T. J.; Aarnoudse, M. G.; Barkema, H. W.; Leslie, K. E. and von Keyserlingk, M. A. G. 2012. Associations of dairy cow behavior, barn hygiene, cow hygiene, and risk of elevated somatic cell count. Journal of Dairy Science 95:5730-5739. https://doi.org/10.3168/jds.2012-5375
https://doi.org/10.3168/jds.2012-5375...
). Furthermore, in our study, cows with lameness problems lie down immediately after reaching the compost bed, remaining cleaner compared with cows with lower lameness scores, due to greater movement of cows in water troughs area with strong accumulation of manure ( Mostafa and Mahran, 201629 Mostafa, A. S. and Mahran, H. A. 2016. Assessment of welfare and health of dairy cows under different housing and management systems. Journal of Applied Veterinary Sciences 1:56-68. https://doi.org/10.21608/javs.2016.62122
https://doi.org/10.21608/javs.2016.62122...
).

In relation to udder cleanliness, however, it is observed that cows in CBP with deeper udders have better cleanliness scores than cows with intermediate deep udders, which can be visualized in the clusters formed by cluster analysis ( Table 4 ). In this regard, clusters 2 and 3 present the best udder cleanliness score when compared with cluster 1, as cows from cluster 2 present deeper udders. However, due to an increased parity, the udder tends to become more pendular, which may increase traumas during locomotion as well as dirtiness and, thus, the SCS ( Pérez-Cabal and Alenda, 200235 Pérez-Cabal, M. A. and Alenda, R. 2002. Genetic relationships between lifetime profit and type traits in Spanish Holstein cows. Journal of Dairy Science 85:3480-3491. https://doi.org/10.3168/jds.S0022-0302(02)74437-8
https://doi.org/10.3168/jds.S0022-0302(0...
; Cardozo et al., 201510 Cardozo, L. L.; Thaler Neto, A.; Souza, G. N.; Picinin, L. C. A.; Felipus, N. C.; Reche, N. L. M.; Schmidt, F. A.; Werncke, D. and Simon, E. E. 2015. Risk factors for the occurrence of new and chronic cases of subclinical mastitis in dairy herds in southern Brazil. Journal of Dairy Science 98:7675-7685. https://doi.org/10.3168/jds.2014-8913
https://doi.org/10.3168/jds.2014-8913...
).

Higher milk yield is related to higher parity and higher teat end hyperkeratosis score, relations that were observed in the factor represented by teat end hyperkeratosis score of the factor analysis ( Table 2 ) and cluster 1 of the cluster analysis ( Table 4 ). The correlation of production and teat end hyperkeratosis is evident in cluster 1, in which cows with higher hyperkeratosis scores are those with higher milk yields. The same relation was observed by Neijenhuis et al. (2001)31 Neijenhuis, F.; Barkema, H. W.; Hogeveen, H. and Noordhuizen, J. P. T. M. 2001. Relationship between teat-end callosity and occurrence of clinical mastitis. Journal of Dairy Science 84:2664-2672. https://doi.org/10.3168/jds.S0022-0302(01)74720-0
https://doi.org/10.3168/jds.S0022-0302(0...
. It can be explained by the fact that multiparous cows have higher milk yields ( Hristov et al., 201321 Hristov, A. N.; Ott, T.; Tricarico, J.; Rotz, A.; Waghorn, G.; Adesogan, A.; Dijkstra, J.; Montes, F.; Oh, J.; Kebreab, E.; Oosting, S. J.; Gerber, P. J.; Henderson, B.; Makkar, H. P. S. and Firkins, J. L. 2013. Special Topics – Mitigation of methane and nitrous oxide emissions from animal operations: III. A review of animal management mitigation options. Journal of Animal Science 91:5095-5113. https://doi.org/10.2527/jas.2013-6585
https://doi.org/10.2527/jas.2013-6585...
), which require a longer milking time. Hyperkeratosis is also related to DIM, which affects milk yield and milking time ( Cerqueira et al., 201811 Cerqueira, J. L.; Araújo, J. P.; Cantalapiedra, J. and Blanco-Penedo, I. 2018. How is the association of teat-end severe hyperkeratosis on udder health and dairy cow behavior? Revue Médecine Vétérinaire 169:30-37. ). Blood circulation is partially interrupted by the pressure exerted by the milking machine on the teat skin. This increases local pressure and can form small cracks, leading to small deposits of keratin, causing greater resistance of teat to milking. These keratin deposits also reach the teat sphincter causing sphincter closing failure after milking and facilitating the entry of microorganisms into the mammary gland ( Mein et al., 200326 Mein, G. A.; Williams, D. M. D. and Reinemann, D. J. 2003. Effects of milking on teat-end hyperkeratosis: 1. Mechanical forces applied by the teatcup liner and responses of the teat. In: Proceedings of the 42nd Annual Meeting of the National Mastitis Council, Fort Worth, Texas, USA. ).

The negative relations of SCS, udder depth, and parity with lactose content in milk can be demonstrated with the factor lactose content ( Table 2 ) and cluster 2 in the cluster analysis ( Table 4 ). Cows with higher parity numbers have deeper udders, higher SCS, and thus lower lactose contents, opposite to the third cluster, comprised of cows with lower parity numbers and shallow udders, higher lactose contents, and lower SCS. In the first cluster, cows presented intermediary characteristics in relation to the second and third clusters. Alessio et al. (2016)2 Alessio, D. R. M.; Thaler Neto, A.; Velho, J. P.; Pereira, I. B.; Miquelluti, D. J.; Knob, D. A. and Silva, C. G. 2016. Multivariate analysis of lactose content in milk of Holstein and Jersey cows. Semina: Ciências Agrárias 37:2641-2652. https://doi.org/10.5433/1679-0359.2016v37n4Supl1p2641
https://doi.org/10.5433/1679-0359.2016v3...
found a negative relation between parity and SCS with lactose content, evaluating data of 73 dairy herds in Santa Catarina, Brazil.

Cows with higher parity present deeper udders due to a weakening of the suspensory ligaments and an increase in udder size with the advancement of lactations. Therefore, udder tends to get closer to the floor, being exposed to pathogens and increasing the risk of new and chronical intramammary infections, which also increase SCS in milk ( Ruegg and Pantoja, 201338 Ruegg, P. L. and Pantoja, J. C. F. 2013. Understanding and using somatic cell counts to improve milk quality. Irish Journal of Agricultural and Food Research 52:101-117. ; Cardozo et al., 201510 Cardozo, L. L.; Thaler Neto, A.; Souza, G. N.; Picinin, L. C. A.; Felipus, N. C.; Reche, N. L. M.; Schmidt, F. A.; Werncke, D. and Simon, E. E. 2015. Risk factors for the occurrence of new and chronic cases of subclinical mastitis in dairy herds in southern Brazil. Journal of Dairy Science 98:7675-7685. https://doi.org/10.3168/jds.2014-8913
https://doi.org/10.3168/jds.2014-8913...
). Cluster 2, however, is comprised of cows with deeper and cleaner udders in CBP, a factor that can be related to the good management of the compost bed.

The reduction of the lactose content in milk with high SCS is a consequence of the lesions in the secretory tissue of the mammary gland that lead to a reduction in the synthesis of lactose ( Coelho et al., 201412 Coelho, K. O.; Mesquita, A. J.; Machado, P. F.; Lage, M. E.; Meyer, P. M. and Reis, A. P. 2014. Efeito da contagem de células somáticas sobre o rendimento e a composição físico-química do queijo muçarela. Arquivo Brasileiro de Medicina Veterinária e Zootecnia 66:1260-1268. https://doi.org/10.1590/1678-7616
https://doi.org/10.1590/1678-7616...
; Alessio et al., 20162 Alessio, D. R. M.; Thaler Neto, A.; Velho, J. P.; Pereira, I. B.; Miquelluti, D. J.; Knob, D. A. and Silva, C. G. 2016. Multivariate analysis of lactose content in milk of Holstein and Jersey cows. Semina: Ciências Agrárias 37:2641-2652. https://doi.org/10.5433/1679-0359.2016v37n4Supl1p2641
https://doi.org/10.5433/1679-0359.2016v3...
). Another factor that causes lactose reduction is its passage to the blood. Lesions in the tight junctions caused by the endotoxins released by the microorganisms and inflammatory mediators can increase the vascular permeability, raising lactose levels in the blood and urine ( Stelwagen et al., 199843 Stelwagen, K.; McLaren, R. D.; Turner, S. A.; McFadden, H. A. and Prosser, C. G. 1998. No evidence for basolateral secretion of milk protein in the mammary gland of lactating goats. Journal of Dairy Science 81:434-437. https://doi.org/10.3168/jds.S0022-0302(98)75594-8
https://doi.org/10.3168/jds.S0022-0302(9...
). Lactose is used as a substrate by pathogenic bacteria ( Blum et al., 20088 Blum, S.; Heller, E. D.; Krifucks, O.; Sela, S.; Hammer-Muntz, O. and Leitner, G. 2008. Identification of a bovine mastitis Escherichia coli subset. Veterinary Microbiology 132:135-148. https://doi.org/10.1016/j.vetmic.2008.05.012
https://doi.org/10.1016/j.vetmic.2008.05...
; Alessio et al., 20162 Alessio, D. R. M.; Thaler Neto, A.; Velho, J. P.; Pereira, I. B.; Miquelluti, D. J.; Knob, D. A. and Silva, C. G. 2016. Multivariate analysis of lactose content in milk of Holstein and Jersey cows. Semina: Ciências Agrárias 37:2641-2652. https://doi.org/10.5433/1679-0359.2016v37n4Supl1p2641
https://doi.org/10.5433/1679-0359.2016v3...
). The reduction in lactose levels can also be a consequence of the increase in parity, regardless of the SCS levels ( Miglior et al., 200728 Miglior, F.; Sewalem, A.; Jamrozik, J.; Bohmanova, J.; Lefebvre, D. M. and Moore, R. K. 2007. Genetic analysis of milk urea nitrogen and lactose and their relationships with other production traits in Canadian Holstein cattle. Journal of Dairy Science 90:2468-2479. https://doi.org/10.3168/jds.2006-487
https://doi.org/10.3168/jds.2006-487...
).

The positive relation of DIM with fat content and especially with the milk protein content can be demonstrated by the factor effect of DIM within the factorial analysis ( Table 2 ), and with cluster 2 for the cluster analysis ( Table 4 ). An increase in the milk protein content was observed with advancing DIM, while the fat content did not present differences for the clusters formed. This observation can be related to a lower milk yield at late lactation combined with a higher concentration of milk solids components ( Miglior et al., 200728 Miglior, F.; Sewalem, A.; Jamrozik, J.; Bohmanova, J.; Lefebvre, D. M. and Moore, R. K. 2007. Genetic analysis of milk urea nitrogen and lactose and their relationships with other production traits in Canadian Holstein cattle. Journal of Dairy Science 90:2468-2479. https://doi.org/10.3168/jds.2006-487
https://doi.org/10.3168/jds.2006-487...
; Smith et al., 201341 Smith, D. L.; Smith, T.; Rude, B. J. and Ward, S. H. 2013. Short communication: Comparison of the effects of heat stress on milk and component yields and somatic cell score in Holstein and Jersey cows. Journal of Dairy Science 96:3028-3033. https://doi.org/10.3168/jds.2012-5737
https://doi.org/10.3168/jds.2012-5737...
).

According to the literature, the use of the CBP system enables better housing conditions, promoting an increase in the welfare of lactating cows. The housing system is one of the factors that have an impact on milk and solids production, once improvements to the welfare of lactating cows increase milk and solids yield after the reduction or elimination of stressors that negatively influence milk yield and quality. The lameness score, for example, might be improved by a reduction of digital lesions, and a better udder cleanliness score would lead to an improved milk quality ( Fávero et al., 201520 Fávero, S.; Portilho, F. V. R.; Oliveira, A. C. R.; Langoni, H. and Pantoja, J. C. F. 2015. Factors associated with mastitis epidemiologic indexes, animal hygiene, and bulk milk bacterial concentrations in dairy herds housed on compost bedding. Livestock Science 181:220-230. https://doi.org/10.1016/j.livsci.2015.09.002
https://doi.org/10.1016/j.livsci.2015.09...
; Albino et al., 20181 Albino, R. L.; Taraba, J. L.; Marcondes, M. I.; Eckelkamp, E. A. and Bewley, J. M. 2018. Comparison of bacterial populations in bedding material, on teat ends, and in milk of cows housed in compost bedded pack barns. Animal Production Science 58:1686-1691. https://doi.org/10.1071/AN16308
https://doi.org/10.1071/AN16308...
). The last one, apart from facilitating milking procedure, is also related to improvements of the immunity of lactating cows, reducing the SCS as a variable that has a significant economic impact on the dairy production chain ( Black et al., 20136 Black, R. A.; Taraba, J. L.; Day, G. B.; Damasceno, F. A. and Bewley, J. M. 2013. Compost bedded pack dairy barn management, performance, and producer satisfaction. Journal of Dairy Science 96:8060-8074. https://doi.org/10.3168/jds.2013-6778
https://doi.org/10.3168/jds.2013-6778...
; Ruegg and Pantoja, 201338 Ruegg, P. L. and Pantoja, J. C. F. 2013. Understanding and using somatic cell counts to improve milk quality. Irish Journal of Agricultural and Food Research 52:101-117. ; Black et al., 20147 Black, R. A.; Taraba, J. L.; Day, G. B.; Damasceno, F. A.; Newman, M. C.; Akers, K. A.; Wood, C. L.; McQuerry, K. J. and Bewley, J. M. 2014. The relationship between compost bedded pack performance, management, and bacterial counts. Journal of Dairy Science 97:2669-2679. https://doi.org/10.3168/jds.2013-6779
https://doi.org/10.3168/jds.2013-6779...
; Cardozo et al., 201510 Cardozo, L. L.; Thaler Neto, A.; Souza, G. N.; Picinin, L. C. A.; Felipus, N. C.; Reche, N. L. M.; Schmidt, F. A.; Werncke, D. and Simon, E. E. 2015. Risk factors for the occurrence of new and chronic cases of subclinical mastitis in dairy herds in southern Brazil. Journal of Dairy Science 98:7675-7685. https://doi.org/10.3168/jds.2014-8913
https://doi.org/10.3168/jds.2014-8913...
; Eckelkamp et al., 2016a15 Eckelkamp, E. A.; Taraba, J. L.; Akers, K. A.; Harmon, R. J. and Bewley, J. M. 2016a. Sand bedded freestall and compost bedded pack effects on cow hygiene, locomotion, and mastitis indicators. Livestock Science 190:48-57. https://doi.org/10.1016/j.livsci.2016.06.004
https://doi.org/10.1016/j.livsci.2016.06...
). Therefore, the CBP has a high potential to provide comfort and welfare to dairy cows. It is necessary, however, to perform a well-organized management of the compost bed ( Pilatte and Vieira, 201736 Pilatti, J. A. and Vieira, F. M. C. 2017. Environment, behavior and welfare aspects of dairy cows reared in compost bedded pack barns system. Journal of Animal Behaviour and Biometeorology 5:97-105. ).

Conclusions

Udder conformation and physiological status influence milk quality in a compost bedded pack barn housing system, through the association of depth udders and udder health, older cows with higher somatic cell score, and the consequent lower lactose content. As higher parity is also associated with higher milk yield and teat end hyperkeratosis score, special attention to the improvement of the udder conformation traits, as well as management practices that reduce hyperkeratosis, are necessary to keep high yielding, healthy, and cows with higher longevity.

As cows without locomotion problems have dirtier udders in compost barn confinement system because of their greater movement, the cleanliness in the feed parlor and water troughs area is very important to preserve milk quality and healthy cows.

Acknowledgments

We would like to thank the dairy farmer that kindly collaborated in this research. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001.

References

  • 1
    Albino, R. L.; Taraba, J. L.; Marcondes, M. I.; Eckelkamp, E. A. and Bewley, J. M. 2018. Comparison of bacterial populations in bedding material, on teat ends, and in milk of cows housed in compost bedded pack barns. Animal Production Science 58:1686-1691. https://doi.org/10.1071/AN16308
    » https://doi.org/10.1071/AN16308
  • 2
    Alessio, D. R. M.; Thaler Neto, A.; Velho, J. P.; Pereira, I. B.; Miquelluti, D. J.; Knob, D. A. and Silva, C. G. 2016. Multivariate analysis of lactose content in milk of Holstein and Jersey cows. Semina: Ciências Agrárias 37:2641-2652. https://doi.org/10.5433/1679-0359.2016v37n4Supl1p2641
    » https://doi.org/10.5433/1679-0359.2016v37n4Supl1p2641
  • 3
    Ali, A. K. A. and Shook, G. E. 1980. An optimum transformation for somatic cell concentration in milk. Journal of Dairy Science 63:487-490. https://doi.org/10.3168/jds.S0022-0302(80)82959-6
    » https://doi.org/10.3168/jds.S0022-0302(80)82959-6
  • 4
    Alvares, C. A.; Stape, J. L.; Sentelhas, P. C.; De Moraes Gonçalves, J. L. and Sparovek, G. 2013. Köppen's climate classification map for Brazil. Meteorologische Zeitschrift 22:711-728. https://doi.org/10.1127/0941-2948/2013/0507
    » https://doi.org/10.1127/0941-2948/2013/0507
  • 5
    Bewley, J. M.; Robertson, L. M. and Eckelkamp, E. A. 2017. A 100-Year Review: Lactating dairy cattle housing management. Journal of Dairy Science 100:10418-10431. https://doi.org/10.3168/jds.2017-13251
    » https://doi.org/10.3168/jds.2017-13251
  • 6
    Black, R. A.; Taraba, J. L.; Day, G. B.; Damasceno, F. A. and Bewley, J. M. 2013. Compost bedded pack dairy barn management, performance, and producer satisfaction. Journal of Dairy Science 96:8060-8074. https://doi.org/10.3168/jds.2013-6778
    » https://doi.org/10.3168/jds.2013-6778
  • 7
    Black, R. A.; Taraba, J. L.; Day, G. B.; Damasceno, F. A.; Newman, M. C.; Akers, K. A.; Wood, C. L.; McQuerry, K. J. and Bewley, J. M. 2014. The relationship between compost bedded pack performance, management, and bacterial counts. Journal of Dairy Science 97:2669-2679. https://doi.org/10.3168/jds.2013-6779
    » https://doi.org/10.3168/jds.2013-6779
  • 8
    Blum, S.; Heller, E. D.; Krifucks, O.; Sela, S.; Hammer-Muntz, O. and Leitner, G. 2008. Identification of a bovine mastitis Escherichia coli subset. Veterinary Microbiology 132:135-148. https://doi.org/10.1016/j.vetmic.2008.05.012
    » https://doi.org/10.1016/j.vetmic.2008.05.012
  • 9
    Brasil. 2018. Ministério da Agricultura, Pecuária e Abastecimento. Instrução Normativa n° 76, de 26 de novembro de 2018. Diário Oficial da República Federativa do Brasil, Brasília, DF, 30 de novembro de 2018. Seção 1, p.9.
  • 10
    Cardozo, L. L.; Thaler Neto, A.; Souza, G. N.; Picinin, L. C. A.; Felipus, N. C.; Reche, N. L. M.; Schmidt, F. A.; Werncke, D. and Simon, E. E. 2015. Risk factors for the occurrence of new and chronic cases of subclinical mastitis in dairy herds in southern Brazil. Journal of Dairy Science 98:7675-7685. https://doi.org/10.3168/jds.2014-8913
    » https://doi.org/10.3168/jds.2014-8913
  • 11
    Cerqueira, J. L.; Araújo, J. P.; Cantalapiedra, J. and Blanco-Penedo, I. 2018. How is the association of teat-end severe hyperkeratosis on udder health and dairy cow behavior? Revue Médecine Vétérinaire 169:30-37.
  • 12
    Coelho, K. O.; Mesquita, A. J.; Machado, P. F.; Lage, M. E.; Meyer, P. M. and Reis, A. P. 2014. Efeito da contagem de células somáticas sobre o rendimento e a composição físico-química do queijo muçarela. Arquivo Brasileiro de Medicina Veterinária e Zootecnia 66:1260-1268. https://doi.org/10.1590/1678-7616
    » https://doi.org/10.1590/1678-7616
  • 13
    Coentrão, C. M.; Souza, G. N.; Brito, J. R. F.; Paiva e Brito, M. A. V. and Lilenbaum, W. 2008. Fatores de risco para mastite subclínica em vacas leiteiras. Arquivo Brasileiro de Medicina Veterinária e Zootecnia 60:283-288. https://doi.org/10.1590/S0102-09352008000200001
    » https://doi.org/10.1590/S0102-09352008000200001
  • 14
    DeVries, T. J.; Aarnoudse, M. G.; Barkema, H. W.; Leslie, K. E. and von Keyserlingk, M. A. G. 2012. Associations of dairy cow behavior, barn hygiene, cow hygiene, and risk of elevated somatic cell count. Journal of Dairy Science 95:5730-5739. https://doi.org/10.3168/jds.2012-5375
    » https://doi.org/10.3168/jds.2012-5375
  • 15
    Eckelkamp, E. A.; Taraba, J. L.; Akers, K. A.; Harmon, R. J. and Bewley, J. M. 2016a. Sand bedded freestall and compost bedded pack effects on cow hygiene, locomotion, and mastitis indicators. Livestock Science 190:48-57. https://doi.org/10.1016/j.livsci.2016.06.004
    » https://doi.org/10.1016/j.livsci.2016.06.004
  • 16
    Eckelkamp, E. A.; Taraba, J. L.; Akers, K. A.; Harmon, R. J. and Bewley, J. M. 2016b. Understanding compost bedded pack barns: Interactions among environmental factors, bedding characteristics, and udder health. Livestock Science 190:35-42. https://doi.org/10.1016/j.livsci.2016.05.017
    » https://doi.org/10.1016/j.livsci.2016.05.017
  • 17
    Epagri/Ciram - Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina; Centro de Informações de Recursos Ambientais e de Hidrometeorologia de Santa Catarina. 2019. Monitoramento online. Available at: <http://ciram.epagri.sc.gov.br/>. Accessed on: April 22, 2019.
    » http://ciram.epagri.sc.gov.br/
  • 18
    Eicher, S. D.; Lay Jr., D. C.; Arthington, J. D. and Schutz, M. M. 2013. Effects of rubber flooring during the first 2 lactations on production, locomotion, hoof health, immune functions, and stress. Journal of Dairy Science 96:3639-3651. https://doi.org/10.3168/jds.2012-6049
    » https://doi.org/10.3168/jds.2012-6049
  • 19
    Endres, M. I. 2009. Compost bedded pack barns – can they work for you ? Advances in Dairy Technology 21:271-279.
  • 20
    Fávero, S.; Portilho, F. V. R.; Oliveira, A. C. R.; Langoni, H. and Pantoja, J. C. F. 2015. Factors associated with mastitis epidemiologic indexes, animal hygiene, and bulk milk bacterial concentrations in dairy herds housed on compost bedding. Livestock Science 181:220-230. https://doi.org/10.1016/j.livsci.2015.09.002
    » https://doi.org/10.1016/j.livsci.2015.09.002
  • 21
    Hristov, A. N.; Ott, T.; Tricarico, J.; Rotz, A.; Waghorn, G.; Adesogan, A.; Dijkstra, J.; Montes, F.; Oh, J.; Kebreab, E.; Oosting, S. J.; Gerber, P. J.; Henderson, B.; Makkar, H. P. S. and Firkins, J. L. 2013. Special Topics – Mitigation of methane and nitrous oxide emissions from animal operations: III. A review of animal management mitigation options. Journal of Animal Science 91:5095-5113. https://doi.org/10.2527/jas.2013-6585
    » https://doi.org/10.2527/jas.2013-6585
  • 22
    Janni, K. A.; Endres, M. I.; Reneau, J. K. and Schoper, W. W. 2007. Compost dairy barn layout and management recommendations. Applied Engineering in Agriculture 23:97-102.
  • 23
    Klaas, I. C.; Bjerg, B.; Friedmann, S. and Bar D. 2010. Cultivated barns for dairy cows: An option to promote cattle welfare and environmental protection in Denmark? Dansk Veterinærtidsskrift 93:20-29.
  • 24
    Malik, T. A.; Mohini, M.; Mir, S. H.; Ganaie, B. A.; Singh, D.; Varun, T. K.; Howal, S. and Thakur, S. 2018. Somatic cells in relation to udder health and milk quality-a review. Journal of Animal Health and Production 6:18-26. https://doi.org/10.17582/journal.jahp/2018/6.1.18.26
    » https://doi.org/10.17582/journal.jahp/2018/6.1.18.26
  • 25
    Mein, G. A.; Neijenhuis, F.; Morgan, W. F.; Reinemann, D. J.; Hillerton, J. E.; Baines, J. R.; Ohnstad, I.; Rasmussen, M. D.; Timms, L.; Britt, J. S.; Farnsworth, R.; Cook, N. and Hemling, T. 2001. Evaluation of bovine teat condition in commercial dairy herds: 1. Non-infectious factors. In: AABP-NMC International Symposium on Mastitis and Milk Quality, Vancouver, Canada.
  • 26
    Mein, G. A.; Williams, D. M. D. and Reinemann, D. J. 2003. Effects of milking on teat-end hyperkeratosis: 1. Mechanical forces applied by the teatcup liner and responses of the teat. In: Proceedings of the 42nd Annual Meeting of the National Mastitis Council, Fort Worth, Texas, USA.
  • 27
    Mele, M.; Macciotta, N. P. P.; Cecchinato, A.; Conte, G.; Schiavon, S. and Bittante, G. 2016. Multivariate factor analysis of detailed milk fatty acid profile: Effects of dairy system, feeding, herd, parity, and stage of lactation. Journal of Dairy Science 99:9820-9833. https://doi.org/10.3168/jds.2016-11451
    » https://doi.org/10.3168/jds.2016-11451
  • 28
    Miglior, F.; Sewalem, A.; Jamrozik, J.; Bohmanova, J.; Lefebvre, D. M. and Moore, R. K. 2007. Genetic analysis of milk urea nitrogen and lactose and their relationships with other production traits in Canadian Holstein cattle. Journal of Dairy Science 90:2468-2479. https://doi.org/10.3168/jds.2006-487
    » https://doi.org/10.3168/jds.2006-487
  • 29
    Mostafa, A. S. and Mahran, H. A. 2016. Assessment of welfare and health of dairy cows under different housing and management systems. Journal of Applied Veterinary Sciences 1:56-68. https://doi.org/10.21608/javs.2016.62122
    » https://doi.org/10.21608/javs.2016.62122
  • 30
    Nielsen, B. H.; Thomsen, P. T. and Sørensen, J. T. 2011. Identifying risk factors for poor hind limb cleanliness in Danish loose-housed dairy cows. Animal 5:1613-1619. https://doi.org/10.1017/S1751731111000905
    » https://doi.org/10.1017/S1751731111000905
  • 31
    Neijenhuis, F.; Barkema, H. W.; Hogeveen, H. and Noordhuizen, J. P. T. M. 2001. Relationship between teat-end callosity and occurrence of clinical mastitis. Journal of Dairy Science 84:2664-2672. https://doi.org/10.3168/jds.S0022-0302(01)74720-0
    » https://doi.org/10.3168/jds.S0022-0302(01)74720-0
  • 32
    NRC - National Research Council. 2001. Nutrient requirements of dairy cattle. 7th rev. ed. National Academy Press, Washington, D.C.
  • 33
    Ofner-Schröck, E.; Zähner, M.; Huber, G.; Guldimann, K.; Guggenberger, T. and Gasteiner, J. 2015. Compost barns for dairy cows - aspects of animal welfare. Open Journal of Animal Sciences 5:124-131.
  • 34
    Peel, M. C.; Finlayson, B. L. and McMahon, T. A. 2007. Updated world map of the Köppen-Geiger climate classification. Hydrology and Earth System Sciences 11:1633-1644. https://doi.org/10.5194/hess-11-1633-2007
    » https://doi.org/10.5194/hess-11-1633-2007
  • 35
    Pérez-Cabal, M. A. and Alenda, R. 2002. Genetic relationships between lifetime profit and type traits in Spanish Holstein cows. Journal of Dairy Science 85:3480-3491. https://doi.org/10.3168/jds.S0022-0302(02)74437-8
    » https://doi.org/10.3168/jds.S0022-0302(02)74437-8
  • 36
    Pilatti, J. A. and Vieira, F. M. C. 2017. Environment, behavior and welfare aspects of dairy cows reared in compost bedded pack barns system. Journal of Animal Behaviour and Biometeorology 5:97-105.
  • 37
    Ruegg, P. L. 2002. Udder hygiene scoring chart. Chart developed with input from Dan Schreiner and Mike Maroney. 1-866-TOP-MILK. Available at: <https://milkquality.wisc.edu/wp-content/uploads/sites/212/2011/09/udder-hygiene-scoring-chart.pdf>. Accessed on: Aug. 15, 2017.
    » https://milkquality.wisc.edu/wp-content/uploads/sites/212/2011/09/udder-hygiene-scoring-chart.pdf
  • 38
    Ruegg, P. L. and Pantoja, J. C. F. 2013. Understanding and using somatic cell counts to improve milk quality. Irish Journal of Agricultural and Food Research 52:101-117.
  • 39
    Shane, E. M.; Endres, M. I. and Janni, K. A. 2010b. Alternative bedding materials for compost bedded pack barns in minnesota: a descriptive study. Applied Engineering in Agriculture 26:465–473.
  • 40
    Shane, E. M.; Endres, M. I.; Johnson, D. G. and Reneau, J. K. 2010a. Bedding options for an alternative housing system for dairy cows: A descriptive study. Applied Engineering in Agriculture 26:659-666. https://doi.org/10.13031/2013.32062
    » https://doi.org/10.13031/2013.32062
  • 41
    Smith, D. L.; Smith, T.; Rude, B. J. and Ward, S. H. 2013. Short communication: Comparison of the effects of heat stress on milk and component yields and somatic cell score in Holstein and Jersey cows. Journal of Dairy Science 96:3028-3033. https://doi.org/10.3168/jds.2012-5737
    » https://doi.org/10.3168/jds.2012-5737
  • 42
    Sprecher, D. J.; Hostetler, D. E. and Kaneene, J. B. 1997. A lameness scoring system that uses posture and gait to predict dairy cattle reproductive performance. Theriogenology 47:1179-1187. https://doi.org/10.1016/S0093-691X(97)00098-8
    » https://doi.org/10.1016/S0093-691X(97)00098-8
  • 43
    Stelwagen, K.; McLaren, R. D.; Turner, S. A.; McFadden, H. A. and Prosser, C. G. 1998. No evidence for basolateral secretion of milk protein in the mammary gland of lactating goats. Journal of Dairy Science 81:434-437. https://doi.org/10.3168/jds.S0022-0302(98)75594-8
    » https://doi.org/10.3168/jds.S0022-0302(98)75594-8
  • 44
    Todde, G.; Murgia, L.; Caria, M. and Pazzona, A. 2016. A multivariate statistical analysis approach to characterize mechanization, structural and energy profile in Italian dairy farms. Energy Reports 2:129-134. https://doi.org/10.1016/j.egyr.2016.05.006
    » https://doi.org/10.1016/j.egyr.2016.05.006

Publication Dates

  • Publication in this collection
    20 July 2020
  • Date of issue
    2020

History

  • Received
    11 Nov 2019
  • Accepted
    10 Apr 2020
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