Recent research has demonstrated that a BMD® sow program (fed from 2 weeks before farrowing through 3 weeks of lactation) can help reduce piglet variability at weaning. The extensive study investigated if the relative size of a piglet at birth influenced its response to BMD in sow lactation diets in a production system where partial and early weaning was common.

Results showed that piglets weighing under 2 lb at birth achieved weaning age 6.3 days sooner (25% improvement; P < 0.05) when reared by sows fed BMD. Furthermore, these animals produced adjusted 21-day weaning weights 3 lb heavier (55%
improvement; P < 0.05) than piglets in the control group.  Similar results were seen for piglets with birth weights of 2 to 3 lb.

These results suggest that BMD supplementation of sow diets helps smaller pigs achieve marketable size (8-lb target) within a 21-day window.

The ramifications of variable weights in nursery pigs can be economically significant, so producers have become very interested in decreasing piglet variability and minimizing the number of light-weight animals.

The best predictor of nursery performance is the quality of weaned pigs entering the nursery. A number of different factors impact piglet quality, such as body weight, gender, and sow parity. If light-weight pigs enter the nursery, they typically have a much higher likelihood of dying or continuing to be light-weight pigs when leaving the nursery, and they increase the risk for disease outbreaks in the other nursery pigs.

Several factors can help reduce body weight variability, such as decreasing litter size (larger litters are at greater risk for variable piglet weights). Older sows can also contribute to variable piglet weights. Although they may produce sizable litters, they may not produce consistent pigs at weaning. Conversely, Parity 1 sows typically generate more light-weight pigs as well. Yet another factor is the relationship between birth weight and weaning weight. If any restriction on the availability of milk is experienced by nursing piglets (e.g., through litter size, low feed intake, or even heat), light-weight pigs at birth are more likely to remain light-weight pigs at weaning, widening the degree of variation during the lactation period.

But that's not all. Feed additive antimicrobials like BMD® have been demonstrated to have positive effects on the body weights of pigs at weaning, reducing the number of light-weight pigs that leave the nursery.