The value of soybean hulls as a replacement for corn in beef cattle diets formulated with or without added fat.
One hundred twenty crossbred yearling steers (average weight = 445 +/- 32 kg) were used in an 84-d randomized complete block design experiment to determine the value of soybean hulls (SH) as a replacement for corn in concentrate diets formulated with or without added fat (lard). The steers were blocked by weight and alloted to one of eight treatments in a 4 x 2 factorial arrangement of treatments. The main factors were amount of SH (0, 20, 40, or 60% of diet DM) and amount of added fat (0 or 5% of diet DM). The basal diet without added fat or SH contained cracked corn (80%), a urea-based protein supplement (15%), and ground corn cobs (5%). Replacing corn with SH linearly (P = .03) decreased ADG, increased DMI (linear, P = .003; quadratic, P = .06), and linearly (P < .001) decreased gain efficiency. Fat addition tended (P = .08) to improve efficiency; ADG and DMI were unaffected (P > .05) by fat addition. Similar diets were fed to 16 wethers (average weight = 47 +/- 2.3 kg) in a randomized complete block design experiment to determine digestibility of NDF and dietary concentration of DE. Replacing corn with SH linearly increased DMI (P = .001) and NDF (P < .001) and linearly decreased (P < .001) the digestibility of DM. The digestibility of NDF tended to increase with increased SH. The digestibility of energy linearly (P = .0001) decreased with increased SH. The amount of fat had no effect (P > .05) on DMI or intake of NDF or digestibilities of these nutrients. The addition of fat tended (P = .07) to improve the intake of DE.(ABSTRACT TRUNCATED AT 250 WORDS)
Ludden
P A
PA
Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA.
Cecava
M J
MJ
Hendrix
K S
KS
D000818:Animals; D002417:Cattle / Q000254:growth & development* / Q000502:physiology; D004041:Dietary Fats / Q000008:administration & dosage*; D004063:Digestion / Q000502:physiology; D004734:Energy Metabolism; D008297:Male; D009753:Nutritive Value; D014674:Plant Proteins, Dietary / Q000592:standards*; D011897:Random Allocation; D030262:Soybean Proteins; D013025:Glycine max / Q000592:standards*; D003313:Zea mays / Q000592:standards*
D004041:Dietary Fats; D014674:Plant Proteins, Dietary; D030262:Soybean Proteins