The USDA released an amino acid soybean digestibility study on growing pigs to determine the standardized ileal digestibility (SID) of amino acids (AA) and to calculate net energy (NE) for micronized regular full-fat soybean (R-FFSB) and low stachyose and raffinose full-fat soybean (LSR-FFSB).
Six ileal-cannulated barrows weighing 31.4 kg were fed six diets in a 6 × 6 Latin square. The six diets were cornstarch-based with soybean meal (SBM), R-FFSB, LSRFFSB, or lentil as the sole source of protein; N-free diet (NFD); and enzymatically hydrolyzed casein diet (EHC). Energy digestibility in SBM, R-FFSB and LSR-FFSB was determined difference from the NFD and the SID of AA for SBM and test ingredients was calculated using NFD or EHC.
Results indicated that the SID of AA for feedstuffs was similar between two methods (NFD vs. EHC). The SID of lysine for SBM (93%) was higher (P < 0.05) than that for R-FFSB or LSR-FFSB, which were similar in SID of lysine (76 vs. 79%). The SID of other indispensable AA for SBM was also higher (P < 0.05) than that for R-FFSB or LSR-FFSB, which were similar in SID of the same AA.
The NE value for SBM was estimated to be 2.62 Mcal/kg of DM. However, SBM had lower (P < 0.05) NE content than R-FFSB or LSR-FFSB, which were similar in NE content (2.96 vs. 3.07 Mcal/kg of DM). The researchers concluded that FFSB (regular vs. LSR) may not affect the NE and SID of AA for micronized FFSB fed to pigs. Micronized FFSB (regardless of seed characteristic) is a better source of dietary energy, but not AA compared to SBM.
Nutritional value of low oligosaccharide soybean meal
An experiment was conducted to determine the effect of replacing conventional soybean meal (SBM, 46.55 % crude protein) with low oligosaccharide soybean meal (LOSBM, 53.16 % crude protein) on growth performance, blood urea nitrogen (BUN), intestinal morphology and digesta viscosity of early-weaned pigs. Thirty-two 19-day old pigs weighing about 6.9kg were assigned to individual pens based on a randomized complete block design. Four iso-nitrogenous nursery diets were fed ad libitum for the 14-day experimental period.
The treatments had no effect on average daily gain, daily feed intake, organ weights, intestinal length, ileal and jejunal crypt depths, or ileal villi height. However, jejuna villi height was greater (P = 0.01) in SBM diet and the concentration of BUN was higher (P = 0.01) in pigs fed LOSBM diet compared to the pigs fed diets containing SBM. Replacing SBM with LOSBM reduced (P =0.01) the viscosity of intestinal content. The researchers concluded that LOSBM was a suitable substitute for SBM, with no negative effects and improved digesta viscosity.
The DE and ME values were measured in grower pigs weighing about 51 kg and finisher pigs weighing about 95 kg. Barrows were randomly assigned by weight to a treatment consisting of either a basal diet (97.28% corn), or the basal diet with 30% of either SBM or LO-SBM added at expense of corn. Each treatment was fed to eight replicates. All diets included a phytase (500 FTU/kg of diet) without consideration of energy or nutrient contribution. Feed was set to provide 2.5 times their energy maintenance requirement; that calculation assumed LO-SBM to have 10% more energy than the SBM diet, thus reducing feed offered by 3% as compared to pigs fed SBM diet. Pigs were placed in metabolic cages and allowed fourteen days of adaptation, followed by four days of total collection of feces and urine. The DE and ME values of the various feed ingredients were calculated by difference.
Results indicated that both the DE and ME values measured in corn were 3% less than book values (Nutrient Requirements of Swine, 2012). The ME measured value in SBM was 13 and 6% less in grower and finisher pigs, respectively, than its book value (Nutrient Requirements of Swine, 2012).
In grower pigs, LO-SBM had 550 kcal of either DE or ME/kg of DM more than the conventional SBM (P<0.05). In finisher pigs, LO-SBM had 399 kcal of DE and 293 kcal of ME/kg of DM more (P<0.05) than SBM ingredient. In conclusion, LO-SBM had about 16.5% more energy in grower pigs and about 9.6% more energy in finisher pigs than conventional SBM.
To read more findings on the USDA finishing pig soybean meal study, see http://www.communication-insight.com/client/infosource/may13/index.html