The impact of gestation sow housing system (individual vs. group) on the reproductive performance of sows & the effect of farrowing pen size on pre-weaning mortality
Section 1: The effect of gestation sow housing system on sow performance was evaluated in a study carried out on a commercial breed-to-wean facility. A Randomized Complete Block Design was used to compare 2 treatments, Individual and Group (8 females/pen) housing. The experimental unit was individual animal and a replicate was 16 females (1 group of 8 and 8 individually-housed). A total of 1325 females were allotted to treatment to produce 1695 individual records. Data was recorded for parity 0 and parity 1 females from allotment into gestation housing treatment (approximately day 35 of gestation) until assigned back into the respective housing treatment. Sow litter performance, reproductive traits, body weight and body condition score did not differ (P > 0.05) between Gestation Housing treatments. However, females housed in groups had a lower (P < 0.05) farrowing rate (3.9 percentage units), and a higher (P < 0.05) piglet pre-weaning mortality (1.2 percentage units) and sow removal rate (5.7 percentage units) than those housed in individual stalls. This study will follow females through the 5th parity and the additional data will help understand the effect of housing treatment over time on litter performance, reproductive traits, BCS, and body weight variables. Section 2: The effect of farrowing pen size (in pens with farrowing crates) on pre-weaning mortality was evaluated in a study carried out on a commercial breed-to-wean facility. This study used animals that were part of the gestation sow housing study (Section 1 above). A Randomized Complete Block Design was used to compare 2 treatments, Standard (pen width = 1.52 m) and Increased (pen width = 1.68 m) pen size. The experimental unit was individual sow and litter and replicate was equal to 2 sows with litter. A total of 526 bred females were allotted to treatment. Data were recorded on litter performance variables. The Increased pen size treatment had a greater (P < 0.05) total number of piglets born per litter (0.5 piglets) and showed a tendency for a greater (P < 0.10) litter size after cross-fostering (0.4 piglets). The Increased pen size had a greater (P < 0.05) number of piglets weaned per litter (0.4 piglets). Ideally litter size would be similar across the 2 treatments to make it relatively easy to interpret any treatment effects on piglet mortality and the number weaned per litter. Pre-weaning mortality would be the best variable to evaluate the effect on farrowing pen size treatments and this was not different (P > 0.05) between the two treatments which suggests that there was no benefit for the increased farrowing pen size. The study was carried out with relatively young (mainly parity 0 and 1) and relatively small animals and the study is on-going to collect data on older and bigger animals to evaluate the effect of farrowing pen size on pre-weaning mortality over time.
sow housing, grouping, gestation stall, sow performance
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign