Interpretive Summary: Effects of feeding diets containing low crude protein and coarse wheat bran as alternatives to zinc oxide in nursery pig diets
By Caitlin Vonderohe
The weaning process is considered the most stressful even in a pig’s life; the abrupt changes in diet and environment result in reduced feed intake and increased disease stress, which in turn results in a postweaning lag in growth. Multiple strategies have been used to try to improve growth and reduce post-weaning diarrhea, including pharmacologic levels of Zinc and reducing dietary crude protein levels. However, there are increasing regulations affecting the availability and utility of Zn as an additive, and the reduction of crude protein may reduce growth performance. Other authors have also added fermentable fiber to these diets to promote growth of beneficial bacterial species and reduction in the adhesion of intestinal pathogens. A recent paper published in the Journal of Animal Science by Batson et al., “Effects of feeding diets containing low crude protein and coarse wheat bran as alternatives to zinc oxide in nursery pig diets” to describe how the addition of fermentable fiber (wheat bran) and synthetic amino acids, and reduction of crude may reduce post-weaning growth lag and diarrhea incidence in piglets.
The experiments described by Batson et al. demonstrated, as expected, inclusion of Zinc in post-weaning diets improved growth performance, when amino acid levels were consistent. However, when SID Lysine and crude protein were reduced, and wheat bran was added, there were reductions in diarrhea but no improvements in growth performance. In fact, reducing dietary crude protein resulted in poorer performance, but the inclusion of non-essential amino acids to these diets improved growth, indicating that some of the observed differences were due to a shortage of indispensable amino acids when dietary crude protein was reduced. Overall, these results demonstrate that more research needs to be done to further explore the potential utility of reducing crude protein and Zn inclusion in post-weaning diets.
The full paper can be found on the Journal of Animal Science webpage.