New Strategy to Reduce Water Consumption and Waste Generation During the Mechanical Milking Process in a Small Cattle Sector

Dairy cattle farming is an activity of great economic importance in Brazil; however, this activity presents high water consumption and volume of waste generated. The objective in the present work was to measure water consumption and waste generation during mechanical milking, in order to promote rational initiatives for the process. The farm property showed the consumption of 64.76% of the whole used water per day and generation of 35.24% of waste-water in the milking process. After orientation, the average coefficient of water consumption in the cattle sector decreased to 3.2 liters with a daily production of approximately 550 liters of milk and an average water consumption of 1,764.83 liters per day. The implementation of equipment and adoption of mitigation measures was associated with a significant reduction in water waste.


Introduction
Water is important for the emergence and support of life on the planet. Although the amount of water remains in constant dynamic circulation, it is vulnerable to changes in climatic conditions. In addition, local and global impacts and changes over the course of a hydrological year are factors that also change the distribution of water over time and space (Westall & Brack, 2018).
Rationalizing the use of water is one of the main alternatives of a water resources management program, and it is essential to determine the quantity and quality level of water necessary for each use. The measures to reduce water consumption include the modification of procedures and exchange of equipment that consumes a large amount of water and that are already installed on the production line, as well as the search for new technologies and production procedures (Cambrainha & Fontana, 2018).
Worldwide, Brazil is the second largest producer of beef and the sixth largest producer of milk and also has the largest commercial herd, with about 200 million animals involved in all this production (USDA, 2014). Milk is one of the most important agricultural products in the country, with an annual production of approximately 32 billion liters, representing about 5.0% of world production (SEBRAE, 2014).
Livestock farming, especially in the case of intensive animal production systems, is potentially impacting the environment, as it generates a large amount of waste in the soil (Teston, 2010). The maintenance of equipment and utensils as well as the daily cleaning of the milking parlor are essential requirements for the hygienic production of milk. At the end of the milking process, it is recommended to remove feces and other residues such as the remains of feed and milk, among other residues that are carried out in a wet manner using water (Carvalho & Ribeiro, 2002).
Milk production is responsible for generating a large volume of wastewater with a high polluting potential. When water management is performed inappropriately and in the absence of prior treatment before disposal, nutrients accumulate in the soil that can lead to eutrophication of water courses. The return of water from cleaning facilities to the environment is a problem that requires alternatives to reduce the environmental impacts that are generated in milk production (Decezaro, 2013). Willers et al. (2014) analyzed indirect water consumption in the milking process on a small farm in the state of Bahia (Brazil) and identified a high environmental impact associated with indirect water consumption throughout milk production (from milking to when the milk is sent to the dairy industry). The water consumption coefficient in the milking sector averaged 3.4 L/L for milk produced (541 L of water consumed for 160 L of daily milk produced). The authors reported that the professionals who work in the milking and cleaning activities have little or no instructions on the proper use of water. In another study, Shine et al. (2018) analyzed the direct water consumption in 58 Irish dairy farms during 2014 and 2016, and observed a water consumption of 13.42 L water/L milk.
In view of the current scenario of intense population growth, concomitant with the great demand for water for public and industrial supply, it is necessary to promote rational and sustainable initiatives for the management of water resources, paying attention to preventive measures to rationalize and properly dispose of wastewater from traditional activities, such as dairy cattle. Thus, the present study aimed to measure water consumption and waste generation in mechanical milking on a rural property (Itarumã, Goias, Brazil), in order to promote rational initiatives to reduce water consumption and waste generation.

Method
The research was carried out in the dairy cattle sector on a rural property, located in the municipality of Itarumã (Goias, Brazil) (18°43'58'' latitude South, 51º26'16'' longitude West), in January 2014. The property employed three employees in the milking sector and had a dairy herd content of 55 lactating Girolando animals, which were subjected to two daily milkings.
Water storage in the sector was carried out in a 200-liter drum ( Figure 2), which was used to dilute the animals' feed (5 liters) and to clean the milking parlor. In the milking time, the animals were transferred from the sector (18 m long x 12 m wide, 216 m² area) to the milking parlor (15 m long by 8 m wide, 120 m² area).
The first stage of the present work was the description of the environments, procedures performed, and indication of the points where there was consumption and waste of water. The second stage of the present work was the determination of the volume of water consumed and wasted in the environment for observation over 15 days, totaling 30 milking processes. For this, the cubing method was used (Giordano, 2004). Briefly, the time it took the water to fill the 40-liter container was timed and using these data the flow (volume/time) was calculated. The water consumption was characterized by opening and using the connection of water in milking parlor (milking process on) and the waste generation was characterized by opening and unused the connection of water in milking parlor (milking process off).
The third stage was guidance on water consumption and waste generation. An orientation meeting lasted an hour and all employees (including the owner of the property) were present for a proposal to implement mitigating measures, reduce consumption, or wastewater. Mitigation measures included: using a Mac Loren revolver at the end of the water connection; changing the wet cleaning of the milking parlor (removal of animal feces) for dry cleaning with the use of shovels; using exclusive water washing for scraping the bays of the animals in the milking parlor; and cleaning when there is a significant accumulation of residue. Also, basic information about the correct use of water and its importance as a natural resource were taught for the whole team.
To assess the effectiveness of using the recommendations, the same determination was made for the second stage after 15 days, totaling 30 milking process (2 per days).
For the statistical analysis of the data, the t-test using statistical software SPSS 20.0 was performed to compare the means before and after the intervention.

Description of the Environment and Activities Evaluated
In the evaluated environment, water was used to: 1) clean the dirty animal when it entering the milking parlor; 2) wash the udder to remove dirt before milking with the liners; 3) clean feces if the animal defecated while milking occured.
Before the milking process, the test for the detection of clinical mastitis was performed, aiming to detect clinical mamitis in the first milk samples. Figure 1 shows the internal view of the milking parlor with drum in the foreground. Throughout the milking procedure, an unused stream of water remained open.
After milking, the equipment, milking parlor, the gallons that stored the milk, the equipment, utensils that were used during the process, and the milk and feces on the floor were cleaned with water and liquid detergent. These activities were carried out by any of the sector's employees using continuous water flow. jms.ccsenet

Assess
Water con After train liters/340 s Water is used for various purposes in dairy production such as washing floors, walls, equipment, and utensils containing impurities (Saraiva, 2008). The dairy industry demands large volumes of water for the production and cleaning process, resulting in significant flows of liquid effluents (ranging from 1 to 7 m 3 effluent/m 3 processed milk) containing nutrients, infectious agents, and persistent organic substances. Machado et al. (2006) emphasize the importance of implementing and optimizing wastewater treatment systems in conjunction with the identification of critical points that generate liquid waste in the production process.
According to Paiva et al. (2009), it is possible to promote a 75% reduction in water consumption when washing equipment on dairy cattle properties by replacing hoses with buckets. The lack of training and awareness of employees regarding good environmental practices is a factor justifies the deficiencies in the production lines that result in wasted water and the lack of standardization of cleaning methods (Castro, 2007).
Although the recommended measures have been effective, it is necessary to continue using the proposed recommendations of this program, so that the quantity and quality of water on the property can be preserved.