Water intake and wastage at nipple drinkers by growing-finishing pigs.

Three experiments were conducted to assess water intake, water wastage, and a means to decrease water wastage by growing-finishing pigs from nipple drinkers. In Exp. 1, 48 pigs were studied during two periods (average BW = 53 and 72 kg for Period 1 and 2, respectively). Water disappearance and wastage were determined for 4 d, while nipple drinkers were set at 50 mm above the shoulder height of the smallest pig in the pen (recommended heights), with flow rates at 700 mL/min during Period 1, and 1,000 mL/min during Period 2. Water intake rate was assessed at two nipple flow rates, approximately 650 and 1,300 mL/min during the Period 1, and 1,000 and 2,000 mL/min during the Period 2. The average water intake was 4.01 and 5.38 +/- 0.19 L.pig(-1).d(-1) during Periods 1 and 2, respectively (P < 0.01). Water wastage as a percentage of water disappearance was similar between the two periods (25.8 and 27.0 +/- 1.9% for Periods 1 and 2, respectively). Water intake rate was 467 and 795 mL/min (+/-34.2; P < 0.01) during Period 1, and 722 and 1,422 mL/min (+/-80.0; P < 0.01) during Period 2, at the lower and higher flow rates, respectively. In Exp. 2, 32 pigs were used in a 2 x 2 factorial design to determine effects of nipple heights (recommended vs. unadjusted = 330 mm) and flow rates (500 vs. 1,000 mL/min) on water intake and wastage. Water wastage was increased (P < 0.01) on the unadjusted vs. recommended nipple height, and the higher flow rate also resulted in greater wastage (P = 0.03) compared with the lower rate. In Exp. 3, water disappearance and manure output in 16 pens of 18 pigs per pen were monitored for 12 wk (average initial BW = 32 kg) using four drinker treatments (bowl drinker, nipple drinker at recommended heights, an unadjusted nipple set at 480 mm, and high nipple drinker height of 730 mm with a step underneath). For pigs on the high nipple drinker, the average water disappearance and manure output did not differ from those of the pigs on the recommended nipple heights and bowl drinker, but these measurements were 15 and 12% lower, respectively, than for the pigs on the low nipple drinker. The results indicate that growing-finishing pigs can maintain adequate water intake from a variety of drinker types and management. Water wastage can be controlled through drinker management.

Hydrogen sulfide assessment in shallow-pit swine housing and outside manure storage.

In Saskatchewan, some recent incidents have lead us to believe that certain manure management activities can potentially release high concentrations of H2S into the atmosphere of shallow-pit barns. The objectives of the monitoring project reported here were to evaluate worker exposure to H2S during the completion of the following tasks: emptying of in-barn shallow manure pits, power washing of barn rooms, and agitation and emptying of outdoor manure storage facilities. In-barn monitoring was performed in gestation, farrowing, nursery, and grow-finish sections in the summer of 2001 and the winter of 2002 on four different farms. Plug pulling can generate very high concentrations of H2S. The maximum values recorded during some of the monitored events reached 1,000 ppm. The H2S released as a plug is being pulled does not follow a predictable pattern when considering the level that will be reached, the concentration variations during the event, and the time at which the peak concentration will be observed. Power washing generated lower H2S concentrations than plug pulling. However, as the task to be performed generally takes time, the 15 min time-weighed average of 15 ppm (STEL) can be reached after the task started and can be exceeded for a long period of time, which for some of the monitored events was more than 30 min. Finally, monitoring at the storage facilities showed that the risks of exposure to excessive H2S concentrations during the agitation and emptying of outside manure storage facilities were very limited. Results from this study suggest that pig production buildings involving short-term storage of liquid manure may present H2S exposure risks that have been underestimated until now. All workers should be provided with an H2S monitor and safety equipment to ensure that workers are protected when the H2S concentration rises. As well, engineering controls have to be developed to prevent H2S formation in the manure or H2S emission into the worker/pig space.