By Katelyn Zeamer, Crystal Levesque and Bob Thaler; South Dakota State University, Animal Science Department
Water is one of the six essential nutrients, along with protein, carbohydrates, fats, minerals and vitamins, which are needed to sustain life and normal chemical processes in both humans and pigs. Considerably more effort is routinely expended to assess diet nutrient profile and accessibility compared to water. Understanding the importance of water in pork production, measurement of water quality and water flow is essential because water intake is an important factor in feed intake and growth performance (Patience, 2012).
Water intake can be influenced by a variety of factors such as environment, stress and diet composition (Nyachoti and Kiarie, 2010). Poor water quality, limited water flow and reduced access to water (i.e. high pig to waterer ratio) may inhibit the pig’s desire to drink and hence impact water intake and subsequent growth performance.
To provide producers with benchmarks of production parameters in their geographical region, a finishing barn survey was conducted throughout the state of South Dakota. This survey consisted of a one-time visit to the producers’ barns where parameters consistent with a PQA Plus site assessment were collected, as well as a feed sample and in-barn temperature fluctuations over seven days. For the purpose of this article, only the water assessment will be presented.
Twenty-three finishing barns were surveyed, with 22 water samples collected from a central water source in each of the barns. Approximately 60% of the barns were supplied from a rural water source; the others accessed well water sources. Water samples were analyzed at the Water & Environmental Engineering Research Center on the SDSU campus for pH, total dissolved solids, total hardness, calcium hardness, E. coli coliforms and total coliforms. Water flow and pig to waterer ratio at each barn was determined, with measurements taken from at least 25% of the pens in the barn. Water flow was measured to determine an average flow in cups per minute for each barn. The pig to waterer ratio was calculated as the number of pigs in the pen divided by the number of waterers in the pen and calculating an average for the barn.
The National Research Council suggests 6.5-8.5 as an acceptable pH range of water in barns, but notes limited impact to pigs when pH falls outside of that range (NRC, 2012). Between the rural and well water sources, there was no difference in the water pH (Table 1; P > 0.05) with an average pH of 7.7. Total dissolved solids measures the amount of minerals within the water and well water had significantly higher TDS (Table 1; P < 0.05) compared to rural water sources. When the TDS level becomes higher than 6000 mg/L, the instance of diarrhea can increase as well as an increase in the amount of water intake, due to the high level of salts (NRC, 2012). However, in this study, all facilities were well below this upper limit.
Total hardness is a measure of calcium and magnesium cations and water is defined as soft (less than 60 ppm) or hard (greater than 120 ppm) (NRC, 2012). There is no impact of water hardness on the health of the pigs, but harder water can increase the deposits accumulating in the water lines (NRC, 2012). An excess of deposits in the water lines can limit water flow and, ultimately, pig water accessibility. According to Brumm (2010), Menegat et al. (2019) and National Pork Board (2019), water flow for pigs <60 pounds should be 1-2 cups/min and 2-4 cups/min for pigs >60lbs. Of the 19 barns where average pen water flow rate could be determined, survey results indicate a range of 3.3 cups/min to 17.2 cups/min, with an average of 6.2 cups/min. When compared to recommended flow rates, only two barns had ≥50% of the pens meeting recommendations. Average pig to waterer ratio was 13.1 with one barn as low as 7.8 and one as high as 16.6. Menegat et al. (2019) suggests there should be one waterer for every 10 to 15 pigs. Although most barns are meeting or exceed that requirement, there are some that are well below the lower limit of 10 pigs. With a lower amount of waterer space available, growth performance may be impacted. There was no difference in the total hardness or calcium hardness between rural and well water sources (Table 1; P > 0.05) and thus water accumulation in the lines may not be currently impacting water flow in these barns, but long-term hardness may be an influencer in the future. Instead, the water flows observed during the barn visits could be related to water pressure and flow rate not being routinely checked.
The E. coli test measures the number of E. coli coliforms found in the water whereas total coliforms evaluates the total number of bacteria found in the water samples. There was no significant difference between rural and well water in the amount of E. coli coliforms or total coliforms (Table 1; P > 0.05). Total coliforms should not exceed 5000 CFU/100ml. However, this level is only a recommendation, because there are some bacteria that can be more harmful than others (NRC, 2012). In the present study, there was no current concern with the coliform levels. Conversely, if levels were found to be higher, treatment of the water, such as chlorination, may be necessary to reduce the bacteria (Nyachoti and Kiarie, 2010).
In conclusion, adjustments to water flow rate in the barns surveyed may improve pig performance, or at minimum, reduce water wastage. While there were not any extreme concerns with the water summary of this survey, it is still essential to be checking your water quality and water flow on a regular basis. The water quality of the well water may not change frequently but rural water can be variable depending on the season (Nyachoti et al., 2005). While waterers should be checked daily for maintenance (National Pork Board, 2018), a monthly or quarterly water flow check may improve pig performance and water utilization.
This survey was completed by Katelyn Zeamer, a swine nutrition graduate student at South Dakota State University, under the guidance of Bob Thaler and Crystal Levesque. The authors would like to thank all the producers who let us enter their barns and collect this data. Extended data from this survey will be published at a later date.
Brumm, M. C. 2010. Water recommendations and systems for swine. Pork Information Gateway
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