Nutritional value of an extruded spent hen-soybean meal blend for pigs andruminants

Two studies were conducted to determine the feeding value of an extruded sp ent hen meal-soybean meal (SHSB) blend (50:50 spent hen/soybean meal) for p igs and ruminants. In the first trial, 60 crossbred pigs were assigned to o ne of five dietary treatments in which 0, 25, 50, 75 or 100% of soybean mea l was replaced by the SHSB blend as a protein source. Total tract nutrient digestibility coefficients (obtained using the indicator method) were deter mined using six barrows per treatment. Results showed that digestibility co efficients for dry matter, crude protein (CP) and gross energy were not aff ected (P > 0.05) by the inclusion of the SHSB blend in the diet and average d 75.3, 74.3 and 74.0% respectively. Average daily gain during the growing period (22-54 kg) increased (P < 0.05) as the level of the SHSB blend incre ased to 50% of the supplementary protein. However, higher replacement level s reduced the average daily gain of growing pigs (quadratic effect P = 0.03 7). Inclusion of the SHSB blend had no effect on average daily gain during the finishing period (54-76 kg). Feed intake decreased linearly (P=0.042) a s the level of the SHSB blend in the diet increased. Consequently, feed con version improved linearly (P = 0.001) in response to increased levels of th e SHSB blend. Two ruminally fistulated cows were used in the second trial t o determine the ruminal degradability of the SHSB blend relative to meat me al, canola meal and brewers' grains. Effective ruminal CP degradability of the SHSB blend was similar to brewers' grains, lower (P<0.05) than canola m eal and higher (P<0.05) than meat meal. The estimated ruminal undegraded pr otein value for the SHSB blend, meat meal, canola meal and brewers' grains was 547, 593, 417 and 5468 kg(-1) of CP, respectively. It was concluded tha t the SHSB blend could replace 50% of soybean meal during the growing perio d and 100% during the finishing period with no adverse effects on pig perfo rmance. The SHSB blend could serve as a source of both ruminal degraded and undegraded protein for ruminants. (C) 2000 Society of Chemical Industry.