There is concern that current demands for fish, and its resultant by product fishmeal (FM), are at unsustainable levels, as such, efforts are being placed on finding alternatives sources of quality protein for pig diets. Microbially-converted soybean meal (MCSBM), developed at South Dakota State University, can be used as an alternative for FM in fish diets and may have
potential as a locally grown alternative protein source in diets for young pigs. This study was conducted to evaluate the nutrient digestibility content of MCSBM and its suitability as a replacement for fishmeal in early weaned pig diets. A total of 37 pigs (6 at 30.0 ± 1.6 kg bodyweight and 31 at 9.8 ± 1.2 kg bodyweight) were used to determine the crude protein and amino acids digestibility of MCSBM and FM. A 35d performance trial using 336 weaned pigs (21 ± 1d of age) were used to assess the suitability of MCSBM as a replacement for FM in nursery pig diets. Determined digestibility of MCSBM and FM were used to formulate experimental diets such that all performance study diets contained equivalent nutrient levels. Experimental diets were fed in Phase I (d0-7) and Phase II (d8-21) in a 3-phase feeding program. All pigs received a common Phase III diet (d22-35). Pig growth performance was measured weekly and at d7 and 21 intestinal tissue and digesta were collected from 1 pig/pen (n=8/treatment) to assess gut health. Digestibility of lysine, methionine, threonine, isoleucine and leucine was greater in FM compared to MCSBM but when nursery pig diets were formulated to contain equivalent amounts of dietary nutrients, use of MCSBM did not negatively impact pig performance. Pig age affected digestibility of lysine, methionine, and alanine in FM but did not affect digestibility values in MCSBM. Inclusion of dietary acidifier did not provide additional benefit in nursery pig performance but did lower pH in the upper intestinal tract. MCSBM holds promise as high quality protein source for young pigs.
potential as a locally grown alternative protein source in diets for young pigs. This study was conducted to evaluate the nutrient digestibility content of MCSBM and its suitability as a replacement for fishmeal in early weaned pig diets. A total of 37 pigs (6 at 30.0 ± 1.6 kg bodyweight and 31 at 9.8 ± 1.2 kg bodyweight) were used to determine the crude protein and amino acids digestibility of MCSBM and FM. A 35d performance trial using 336 weaned pigs (21 ± 1d of age) were used to assess the suitability of MCSBM as a replacement for FM in nursery pig diets. Determined digestibility of MCSBM and FM were used to formulate experimental diets such that all performance study diets contained equivalent nutrient levels. Experimental diets were fed in Phase I (d0-7) and Phase II (d8-21) in a 3-phase feeding program. All pigs received a common Phase III diet (d22-35). Pig growth performance was measured weekly and at d7 and 21 intestinal tissue and digesta were collected from 1 pig/pen (n=8/treatment) to assess gut health. Digestibility of lysine, methionine, threonine, isoleucine and leucine was greater in FM compared to MCSBM but when nursery pig diets were formulated to contain equivalent amounts of dietary nutrients, use of MCSBM did not negatively impact pig performance. Pig age affected digestibility of lysine, methionine, and alanine in FM but did not affect digestibility values in MCSBM. Inclusion of dietary acidifier did not provide additional benefit in nursery pig performance but did lower pH in the upper intestinal tract. MCSBM holds promise as high quality protein source for young pigs.
Key Findings:
• Digestibility of lysine, methionine, threonine, isoleucine, and leucine are greater in FM than MCSBM.
• Digestibility of lysine, methionine, and alanine in FM was greater in growing pigs compared to weaned pigs but pig age did not affect digestibility of protein or amino acids in MCSBM.
• Inclusion of dietary acidifier reduced pH of the upper intestinal tract but did not impact pig performance.
• MCSBM did not negatively impact pig performance when used as a substitute for FM in nursery pig diets formulated to contain equivalent dietary nutrients.
