Lactating sows require high feed intake in order to produce milk for their piglets and to maintain their body condition. Ad-lib feeder can allow sows to eat feeds as much as they want. The objectives of the present study was to assess the effect of ad-lib feeder to lactating sows on feed intake and subsequent productivity. The present study was conducted on a commercial farm having 350 crossbred sows between Large White and Landrace. Nineteen sows farrowed during Sep. 11 to 13, 2014 were used and randomly assigned to two groups: ad libitum feeding groups (n＝10) and conventional feeding groups (n＝9). Ad libitum feeding was applied during 17 days from study start date (day 4 after farrowing) to study end date (day 20 after farrowing). Piglet weight at weaning and weaning-to-first-mating interval was used as production performance. Total amount of feed intake during 17 days of the study period (±SEM) was 105.0±4.8 kg, and ad libitum feeding group tended to have higher amount than conventional feeding group (111.5±7.6 vs. 97.9±4.8 kg;P＝0.16). Statistical power of this analysis was 0.235. Ad libitum feeding group had higher piglet weight at weaning (9.1±0.1 kg vs. 7.8±0.1 kg;P<0.05) and shorter weaning-to-first-mating interval (4.8±0.1 vs. 5.4±0.2 days;P<0.05) than conventional feeding group. The present study indicated that ad-lib feeder can increase feed intake of lactating sows and subsequently increase production performance.
We tried to recover and utilize heat of exhaust from the enclosed vertical type composting facility (Compo) as heating source of air with the plate fin type heat exchanger. As a result, the temperature of the warmed air after heat exchange between exhaust gas of Compo (52.2°C, 210m3/h) and air (11.3°C, 153m3/h) reached 40.8°C, and its heat quantity was 4.5MJ/h. The heat exchange efficiency converged upon approximately 69% under these conditions, and the overall heat transfer coefficient was 90W/m2·K. The volume of warmed intake air of facility decreased from 180m3/h to 144m3/h by passing along a heat exchanger. Fermentation was maintained by using for an air intake of facility the warm air obtained by heat exchange, there was no negative influence on a dry matter decomposition. We are using warm air for the air intake to facility, compared with the heater, amount of used electricity became half and electric cost has reduced about 115,000 yen per year.