Soybean meal (SBM) is the most widely used protein source as it represents an excellent source of essential amino acids. However, the anti-nutritional factors and immunogenic components in SBM have been reported to impair performance. A joint strategy is reducing SBM in early diets through implementing non SBM protein sources. Nevertheless, non SBM protein sources are often variable in nutritional content, can produce enteric disruptions, and many don’t reduce inclusion of SBM at appreciable rates. As popularity of vegetarian diets increase, evaluating cost effective, consistent veg. protein sources that reduce inclusion of conventional SBM in early diets is necessary. An experiment was conducted to evaluate economic and live performance of enzymatically processed soy protein (EPSP) relative to common non SBM protein sources. Eight hundred and fifty day old Ross 708 males were placed in 50 pens (17 birds/pen; 0.27 m2/bird). A completely randomized block design was utilized and pen replicates were assigned to 1 of 5 dietary treatments: 3%, 5% EPSP, 3% corn gluten meal (CGM), 3% dried distiller’s grain with solubles (DDGS), or 3% meat bone meal (MBM). Broilers were fed a 3 phase program consist- ing of a starter (0-14d), grower (14-28d), and finisher (28-42d). Dietary treatments in each phase were iso-energetic and contained similar amino acid ratios relative to dig. LYS. At 35 days of age, body weight gain (kg/ bird) in EPSP was significantly higher than CGM fed birds (P<0.05). BW adjusted feed to gain was significantly lower in EPSP compared to the CGM treatment (P<0.05). EPSP numerically reduced BW adjusted feed to gain in comparison to DDGS (-3.4). Treatment BW variation was reduced 2.50, 1.44, 1.35 fold when EPSP was equated to MBM, DDGS, and CGM, respectively. At 42 days of age, body weight gain (kg/bird) was significantly higher in EPSP versus CGM (P<0.05). BW adjusted feed to gain was numerically reduced in EPSP treatments in relation to DDGS and CGM (-2.5, -3.4). Treatment BW variation was reduced 2.89, 1.89, 1.58 fold when EPSP was fed versus MBM, CGM, and DDGS. EPSP, DDGS, and CGM were evaluated for their return on investment (cost and performance).
In the present study, EPSP provided the greatest return on investment of the vegetarian protein sources.