30 www.pigchamp.com Spring 2025 removed from the farrowing crate. Fall-behind pigs were any pigs identified as being gaunt in appearance with evidence of ribs and backbone becoming visible and empty bellies. Removals and mortalities were not replaced in the litter. The results showed that the percentage of removals and mortality increased as litter size relative to functional teat count increased. However, it did so at a diminishing rate, which means that the increase in removals and mortality when moving from 0 to +1 sows was smaller than the increase when moving from -1 to 0 sows. Also, the increase in removals and mortality did not happen at the same rate as the starting litter size increased. This means that even though there was an increase in removals and mortality, there was still an increase in litter size at weaning as litter size relative to functional teat count increased, with litter size at weaning increasing from 12 pigs in -1 sows to 13.5 pigs in +2 sows. As expected, piglet average daily gain decreased as litter size relative to functional teat count increased, which translated to a reduction in average piglet weaning weight. Average weaning weight decreased from 14.4 lbs. in -1 sows to 13.6 lbs. in +2 sows. However, it should be emphasized that all four treatments still weaned pigs that were heavier than 13.5 lbs. on average. Even though -1 sows weaned a heavier pig, the difference in weaning weight was not enough to make up for differences in litter size at weaning. Thus, litter weaning weight increased as litter size relative to teat count increased, with +2 sows weaning litters that were 11.5 lbs. heavier on average than litters weaned by -1 sows. We discussed litter size relative to teat count at the beginning of the trial, but how many pigs did sows wean relative to teat count? Figure 1 shows the proportion of the litters in each treatment that weaned at different pig counts relative to teat count. The green bars are those sows that weaned above the teat count, the yellow bars are sows that weaned at the teat count, and the orange and red bars are sows that weaned below the teat count. In total, 47% of the -1 sows weaned at three or more pigs below the teat count. The percentage of sows that weaned at three pigs below teat count or worse decreases as you increase the starting litter size relative to teat count, with only 15% of +2 sows weaning three or more pigs below teat count. Conversely, 48% of the +2 sows weaned at a teat count or above. That means that almost half the +2 sows were utilizing all functional teats throughout the entire lactation period. The percentage of sows that weaned at teat count or above decreases as you decrease starting litter size relative to functional teat count, with none of the -1 sows weaning at teat count or above because none of the sows in this treatment even started at teat count. As you would expect, sow body weight loss increased as the number of pigs nursing relative to functional teat count increased. However, the difference in sow body weight loss between the -1 and +2 treatments was only eight lbs. We saw a similar trend in sow caliper score and backfat depth change over lactation, where there was an increase in sow body condition loss over lactation with more pigs nursing relative to functional teat count, but the differences between the treatments were relatively small. Effect of pigs placed relative to teat count on the proportion of litters weaned relative to teat count (Jenkins et al. 2025). Figure 1
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