Substitution of peanut skins for soybean hulls in steer finishing diets containing recommended and elevated crude protein levels

A 0.0.steer finishing trial was conducted to study the substitution of peanut skins (PS) for soybean hulls (SH) when included at three levels (0, 7.5, or 15%) in diets containing recommended (10.5% = RP) or elevated (15.5% = HP) levels of CP. Average daily gain, DMI, and gain:feed ratios decreased linearly (P 0.01) when steers were fed RP and increasing levels of PS. Average daily gain and DMI increased linearly (P 0.05) when steers were fed HP and increasing levels of PS. Carcass quality grades were greater (P 0.05) for steers fed the HP-15% PS diet than for steers fed either the RP-15% SH or HP-15% SH diets. Ruminal fluid ammonia concentrations were greater (P 0.05) for HP diets and decreased linearly (P 0.05) with increasing levels of PS at both RP and HP. Nutrient fractions of the HP diets were more (P 0.05) digestible for CF, NDF, and ADF than for the RP diets. In general, the HP-7.5% SH/PS diet was more digestible than the other diets in the comparison. When SH are fed as 15% of the diet, PS can be substituted for SH up to 7.5% of the diet at RP levels and can be used to completely replace SH at HP levels