Martine Laitat

Gaseous emissions during the fattening of pigs kept either on fully slatted floors or on straw flow.

The aim of this study was to compare the environmental impact of the straw-flow system for fattening pigs with the slatted-floor system by measuring pollutant gas emissions such as ammonia (NH3), nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2), manure nitrogen (N) content and emissions of water vapour (H2O). Three successive batches of 32 pigs were fattened. For each batch, pigs were allotted to two groups raised in separated rooms fitted either with a concrete totally slatted-floor system (0.75 m2 per pig) or with a straw-flow system (0.79 m2 per pig). With this last system, pigs were kept on a sloped floor, straw being provided daily at the top of the pen. Throughout the fattening period, about 34.4 kg of straw were supplied per pig. The straw, mixed with dung, travelled down the slope by pig motion and went out of the pen to a scraped passage. The solid fraction was scraped every day, stored in a heap in the room and removed every month, 1 week before each period of gaseous emission measurement. The liquid fraction was automatically pumped from the scraped passage into a hermetic tank, which was emptied at the end of each fattening period. Rooms were ventilated mechanically in order to maintain a constant ambient temperature. Once a month, the emissions of NH3, N2O, CH4, CO2 and H2O were measured hourly for 6 consecutive days via infrared photoacoustic detection. Mean daily emissions per pig fattened on the slatted floor or on the sloped floor were, respectively, 4.98 and 13.31 g NH3, 0.67 and 0.68 g N2O, 15.2 and 8.88 g CH4, 548 g and 406 g CO2 equivalents, 1.61 and 1.77 kg CO2 and 2.33 and 2.95 kg H2O. Except for N2O emissions, all the differences were statistically significant (P < 0.001). From the slatted-floor system, the amount of slurry removed per fattening period was on average 256 kg per pig. From the straw-flow system, solid manure amounted on average to 209 kg per pig and liquid manure to 53 kg per pig. The total N-content of the manure was 2.23 kg N per pig with the straw-flow system (solid and liquid manure) v. 3.26 kg N per pig for slurry from the slatted-floor system. This reduction of 30% observed with the sloped floor was mainly explained by the higher level of NH3-N emissions.

Comparison of feeding behaviour and performance of weaned piglets fed with two types of dry feeders with integrated Drinkers

Performance of 80 (tests 1 and 2) or 60 (tests 3 and 4) weaned pigs were compared when using ‘Tubetype’ feeder (T), allowing the animals to mix meal and drinking water, or another type (V) where drinking and eating places are separated. The difference in growth rate was not significant but the mean daily water consumption (1 per pig per day) was higher with T than with V in each test but significantly only in tests 1 and 3 (1·84 v . 1·40, and 2·11 v . 1·26, P Feeding behaviour was assessed during tests 2 and 4. Multifactor analysis of variance revealed effects ( P v . 21·5 per 24 h and 4·5 v . 3·7, P P P

Comparison of performance, water intake and feeding behaviour of weaned pigs given either pellets or meal

Performance, water intake and feeding behaviour of two groups of 30 (trial 1), 40 (trial 2) or 50 (trial 3) weaned pigs offered either pellets or meal of the same formulation were compared. Average daily weight gains (ADG) were higher for pigs given pellets rather than meal in trials 2 (413 v. 363 g/day, P The occupation time (ОT) and the number of animals using the feeder simultaneously (N) were higher when pigs were given meal rather than pellets, whatever the animal density: trial 1: 82·6 v. 69·9% (P = 0·05) and 3·8 v. 2·3 (P 0·05) and 5·2 v. 3·1 (P The greater the group size, the lower were ADG (both diets) and DWI (only with meal) and the higher were ОT and N (both diets). Furthermore, significant linear and curvilinear regressions of DWI, ОT and N according to time were calculated. In conclusion, pigs need more time to eat meal than to eat pellets. Thus the number of pigs per feeder has to be adapted to the food presentation. Too high a number of pigs per feeder impairs feeding behaviour and eventually welfare, by preventing preferential diurnal feeding activity and this may affect productivity.

Floor slat openings impact ammonia and greenhouse gas emissions associated with group-housed gestating sows

According to EU legislation, group-housed gestating sows must have a minimum of 2.25 m2 floor area per sow with at least 1.3 m2 of continuous solid floor of which a maximum of 15% is reserved for drainage openings. The aim of the experiment was to quantify the impact of different drainage openings on ammonia and greenhouse gas emissions. Three successive batches of 10 gestating sows were used. Each batch was divided into two groups kept separately in two identical rooms with similar volume and surface. The solid part of the floor presented 15% drainage openings in the first room and 2.5% in the second room. The gas emissions (ammonia (NH3), methane (CH4), nitrous oxide (N2O), carbon dioxide (CO2) and water vapour (H2O)) were measured three times during 6 consecutive days. Gaseous emissions were significantly lower with 15% drainage openings with reductions of 19% for NH3 (12.77 v. 15.83 g/day per sow), 15% for CH4 (10.15 v. 11.91 g/day per sow), 10% for N2O (0.47 v. 0.52 g/day per sow), 9% for CO2 (2.41 v. 2.66 kg/day per sow) and 13% for H2O (3.25 v. 3.75 kg/day per sow). This trial showed the advantage, in an environmental point of view, to use 15% drainage openings on the solid part of partly slatted floors in pens for group-housed gestating sows.