Tests over a nine-month monitoring period evaluated the effect of canola oil sprinkling and low crude protein diet on ammonia (NH3) and respirable dust concentrations.

The test was conducted in six swine grow-finish rooms with partially slatted floor; each 5.49 × 14.63 metre room has six pens with a total capacity of 72 pigs.

Dr Y. Jin and Dr B. Predicala

Each treatment, namely canola oil-sprinkling, low crude protein diet, and control (no measures), were applied to two rooms each. (No changes from typical production).

Pigs were moved into the rooms from nursery at about 20kg and were taken to market weight of about 120 kg after 14 to 15 weeks. Except for the two rooms given the experimental low crude protein diet, all pigs were fed identical diets.

A variable sprinkling schedule was followed from the same day of admission of pigs into the rooms: 40ml per square metre per day for the first two days, 20ml per square metre per day for the third and fourth days, and 5ml per square metre per day for the succeeding days. Dietary crude protein was reduced by adding supplemental amino acids to the normal diet such that the amino acid requirement of the pigs were achieved with concomitant reduction in dietary nitrogen.

Each trial was run for 16 weeks, which includes two weeks of animal and room preparation at the start of each trial and 14 weeks of data collection.

Ammonia and respirable dust concentration were measured by area sampling according to National Institute of Occupational Safety & Health (NIOSH) 6015 and 0600 methods (NMAM, 1994), respectively. Ammonia concentration was also measured using commercial gas monitors (GasBadge Pro, Industrial Scientific). The pigs were weighed at the start (week 0), middle (week 6) and end (week 12) of each trial to determine the average daily gain. Ammonia and dust concentration were measured every three weeks (week 2, 5, 8, 11 and 14) for two consecutive days.

The results plotted in Figure 1 shows that the respirable dust concentration in the room sprinkled with canola oil (mean = 0.18mg per cubic metre, SD=0.19) is significantly lower (P=0.036) than in the control room (mean = 0.33mg per cubic metre, SD=0.39). This was expected based on previous tests.

The ammonia concentrations measured using the NIOSH method in the room given low crude protein diet (mean = 4.2ppm, SD=2.3) were significantly lower (P<0.01) than the control (mean = 6.3ppm, SD=2.0) (Figure 2).

Figure 1. Respirable dust concentrations measured in the control and experimental rooms

Figure 2. Ammonia concentrations measured in the control and experimental rooms (NIOSH method).

The Bottom Line

Canola oil sprinkling and use of low crude protein diet resulted in significantly lower respirable dust and ammonia concentrations, respectively. The findings from this study would aid pork producers in implementing these measures to improve the barn environment for animals and workers.

Acknowledgement: Project funding was provided by Manitoba Livestock Manure Management Initiative. Strategic program funding provided to Prairie Swine Centre Inc. by the Saskatchewan Pork Development Board, Alberta Pork, Manitoba Pork Council and Saskatchewan Ministry of Agriculture is also acknowledged.

April 2011