Impact of water flow rate on finishing pig performance

Abstract

A survey of 23 South Dakota pork producers in 2019 reported that 68% of the waterers in finishing barns had water flow rates above the recommended rate of 500-1,000 mL/min. The objective of the two studies was to determine the impact of water flow rate on finishing pig performance in the summer months. Study 1 used a total of 396 pigs in two groups in a 77-day trial (35.0 to 104.3 kg BW) with 6 pigs/pen and 1 cup waterer/pen. Study 2, conducted in a commercial style barn, used a total of 1,227 pigs in an 84-day trial (60.9 to 117.4 kg BW) with 26 pigs/pen and 2 cup waters/pen. Pens were assigned to one of three water flow rates (high, medium, low) based on the 3-hole settings of the water nipples (2.0, 1.0, and 0.8 mm; n = 22 and 16 pens/treatment for Study 1 and 2, respectively). Room temperature, outside temperature and relative humidity were recorded daily for both studies. In Study 1, water disappearance was recorded daily, and individual pen water flow rates were recorded every two weeks. At every diet phase change (26 ± 2.6 days), feed disappearance and individual pig body weights were recorded. Water flow rates averaged 1856 ± 188, 906 ± 214, 508 ± 100 mL/min for high, medium, and low flow settings, respectively. In Study 2, individual pen water flow rate, water disappearance, BW, and feed disappearance were recorded every two weeks. Water flow rates averaged 1115 ± 98, 906 ± 209, and 605 ± 203 mL/min for high, medium, and low flow settings, respectively. In both studies, there were no differences in final BW, cumulative ADG, or G:F. Due to the variability of water flow rate within a setting, data was further analyzed using regression with flow rate as the independent variable. Apart from average daily water disappearance (adj. R ² = 0.87), there was a low relationship between pig performance and water flow rate (adj. R ² < 0.09). The low R ² values associated with pig performance and the high association with water disappearance suggests that water flow rate above current recommendations has little impact on finishing pig performance but does contribute to water wastage and its associated costs.

Keywords: finishing pigs; summer; water flow rate.

Figure 1.

Dimensions of the water nipple and water cup.

Figure 2.

Size comparison of water nipple setting orifice diameter.

Figure 3.

Average daily water disappearance per kg BW and high room temperature over time in Study 1.

Figure 4.

Regression of water usage per pig on the high, medium, and low water settings against daily high room temperature in Study 1.

Figure 5.

Regression of cumulative pig performance vs waterflow rate during Study 1. A = final body weight; B = cumulative average daily and feed intake; C = gain:feed ratio. Barn temperature ranged from 15.4 to 34.8 °C. High barn temperature averaged 29.0 °C for the entire trial period. Linear regression: body weight, P = 0.05, R² = 0.04; average daily gain, P = 0.041, R² = 0.05; average daily feed intake, P = 0.007, R² = 0.09. Cubic regression: gain:feed ratio, P = 0.190.

Figure 6.

Regression of cumulative pig performance vs waterflow rate during Study 1. A = final body weight; B = cumulative average daily and feed intake; C = gain:feed ratio. Barn temperature ranged from 18.3 to 38.2 °C. High barn temperature averaged 28.5 °C for the entire trial period. Linear regression: body weight, P = 0.11; average daily gain, P = 0.01, R² = 0.09; average daily feed intake, P = 0.05, R² = 0.06. Cubic regression: gain:feed ratio, P = 0.79.

Figure 7.

Regression of cumulative water disappearance in liters/pig/day. Quadratic regression, P < 0.0001, R² = 0.87.