July 26, 2018

Interpretive Summary: Ileal digestibility of amino acids in selected feed ingredients fed to young growing pigs

Interpretive Summary: Ileal digestibility of amino acids in selected feed ingredients fed to young growing pigs.

By: Surely Wallace

In a June 2018 article published in the Journal of Animal Science, researchers studied the standardized ileal digestible (SID) crude protein (CP) and amino acids (AAs) of ten different common feed ingredients, in young growing pigs. Their purpose was to determine protein digestibility in common pig feed ingredients specific to post-weaning pigs, in order to provide needed data to help determine optimized feed for young growing pigs.

The ileal digestibility of AA and CP in young growing pigs (weight <20 kg) may not be as efficient as in mature pigs (weight 20-100 kg). Many ingredients in pig feed are byproducts of the grain and oilseed industry, but included in different formulations in pig feed.  There is data to help determine optimal feed composition based on SID AA and CP in mature pigs, however, there is a lack of data on SID CP and AA in younger, post-weaning pigs.

A total of 22 barrow pigs (weight: 14.09 ± 1.48 kg) surgically fitted with ileal T-cannula were studied. The experimental feeding period lasted 7 days. There were 10 separate treatment diets formulated in this study, with protein sourced exclusively from the following feed ingredients in each, respectively: brewers rice, full-fat rice bran (FFRB), defatted rice bran (DFRB), peanut meal, sesame meal, rapeseed meal, rapeseed expellers, soybean expellers, cassava meal, and bakery meal. An additional eleventh nitrogen-free diet was used to determine basal losses of CP and AA. Ileal digesta was collected through the T-cannula on days 6 and 7 of the study.

In this study, peanut and sesame meal had the highest SID CP (452.38 and 482.32 g/kg DM, respectively) and SID AA, with the exception of the essential AA lysine. Lysine (g/kg DM) in peanut meal (14.55) and sesame meal (11.51) was greater than in brewers rice (2.71), FFRB (5.31), DFRB (5.80), cassava (0.39) and baker’s meal (1.77), but less than in rapeseed meal (16.11), rapeseed expellers (16.17) and soybean expellers (22.98). The SID CP (g/kg DM) of rapeseed meal (286.64), rapeseed expellers (262.74) and soybean expellers (351.33), although less than peanut and sesame meal, were superior compared to brewers rice (73.87), FFRB (112.19), DFRB (119.50), cassava (6.93) and baker’s meal (76.63). In this study, cassava meal had the lowest SID CP, while peanut and sesame meal had the highest.

Overall, the data provided in this study strongly suggests that feed source type affects SID CP and AA in young growing pigs. This data should be useful to help better understand how to formulate optimal diets for growing pigs. Larger and more in-depth studies characterizing the effects fiber and fat content of these different feed sources may have on SID CP and AA in growing pigs may also be warranted.  

To view the full article, “Ileal digestibility of amino acids in selected feed ingredients fed to young growing pigs,” visit the Journal of Animal Science.