Signe Lovise Thingnes

This 2 × 2 factorial study examined the welfare and performance of finishing pigs at two group sizes (9 or 18 pigs) over 12 weeks. For each set of groups of either 9 or 18 pigs, half of the pigs in each group size were fed ad libitum, while the others received a mildly restricted ration. Treatments were assigned to 16 partially slatted floor pens in a randomized block design, with a floor space of 1.15 m²/pig. Except in Week 1, there were proportionally fewer pigs with ear (p = 0.020) and tail (p < 0.0001) bite marks in groups of 18 than in groups of 9. Ear bite marks declined over time in both group sizes (p < 0.0001). There was also a significant interaction between group size and week regarding severe bite marks on the ears (p < 0.0002). Tail bite mark prevalence increased over time in the smaller groups but decreased in the larger groups (interaction: p < 0.001). A higher proportion of pigs in smaller groups sought human contact in Weeks 1 and 6, but this measurement equalized by Week 10 (interaction: p = 0.008). There were proportionally more pigs with tucked tails in the smaller groups in Week 1 but not in later weeks (interaction: p < 0.0001). Group size did not influence pig cleanliness or locomotion disorders. Ad libitum (vs. restricted) feeding increased average daily gain (p < 0.001), feed intake (p = 0.002), and slaughter weight (p = 0.030). Results suggest better welfare in the larger than in the smaller groups.

The presented study investigated the long-term effects of four different gilt development strategies on sow lifetime performance and longevity. Five hundred Norwegian Landrace x Yorkshire animals were offered two dietary energy levels during rearing: 13.2–29.0 MJ NE/d (High) or 10.6–22.9 MJ NE/d (Norm), and two dietary energy levels during mid-gestation (day 42–94); 27.3 MJ NE/d (High) or 22.3 MJ NE/d (Norm). Dietary treatments were only imposed in parity one. While no clear long-term effect was found on lifetime weight and backfat development, the survivability in lower parities was higher among sows offered the highest dietary energy levels during parity one. These sows also had the numerically highest number of produced piglets per sow lifetime. This study provides insight into how different gilt development strategies influence development and lifetime performance of a modern genotype sow, in a commercial setting.

"The effect of different dietary energy levels during rearing and mid-gestation on gilt performance" published on 28 Nov 2014 by Wageningen Academic.

"The effect of dietary energy levels during rearing and first gestation on sow lifetime performance" published on 28 Nov 2014 by Wageningen Academic.