Abstract
A survey of South Dakota pork producers in 2019 reported that 68% had water flow rates above the recommended rate of 500-1,000 mL/min. The objective of this study was to determine the impact of water flow rate on finishing pig performance during from June to September in a commercial barn. A total of 1,227 mixed sex pigs (61 ± 4.38 kg) at 8-weeks post-wean were utilized in an 84-d trial with 26 pigs/pen and 2 cup waterers/pen. Pens were assigned to 1 of 3 water flow rates (high, medium, low) based on the 3-hole diameter of the water nipples (2.0, 1.0, 0.80 mm; n = 16 pens/setting). Individual pen water flow rate, water disappearance, BW, and feed disappearance were recorded every 2 weeks. Carcass data was collected at the conclusion of the trial. Water flow rates averaged 1,565±96, 1,115±265, and 605±203 mL/min for high, medium, and low flow rates, respectively. Ambient temperature ranged from 4 to 37 °C. There was no difference in growth performance based on means separation test. Due to variability of water flow rate within a setting, data was further analyzed using regression with flow rate as the independent variable. There was a positive quadratic relationship (P < 0.05) for daily water disappearance (adjR(2) =0.87) and daily gain (adjR(2) =0.11) with water flow rate and a tendency for positive linear relationship between final BW (P = 0.07, adj. R(2) = 0.06) and flow rate. Feed conversion had a negative cubic relationship with water flow rate (P < 0.05, adj. R(2) = 0.20) and no relationship between hot carcass weight or average daily feed intake and water flow rate. The low R(2) values associated with pig performance and high association with water disappearance suggest that excess water flow rate has a low impact on finishing pig performance but contributes to water wastage and its associated costs.