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The effects of Cellulo-Gest supplement on forage digestibility and feedlot performance for growing steer calves
An 84d growing trial evaluated the performance and feed efficiency of weaned crossbred beef steers (n = 172; BW = 278 ± 2.3 kg) consuming growing diets with or without the commercially available natural feed supplement Cellulo-Gest (CGS; Old Mill Troy, North Troy, VT). CGS is comprised of calcium carbonate, fermentation extracts of Aspergillus oryzae and Aspergillus niger, dextrose, lactose, cobalt carbonate, mineral oil, and natural flavorings. A common diet (13% CP and 1.15 Mcal/kg NEg) was formulated with 23% dry-rolled corn, 13% dry-rolled barley, 21% corn distillers grains, 12% chopped switchgrass hay, 28% corn silage and 2.5% vitamin-mineral-ionophore supplement and was supplemented with 4g/hd/d of CGS or not supplemented(CON). Steers were consigned by 40 different ranchers in North Dakota, vaccinated and implanted with Ralgro prior to delivery to the feedlot. Steers were blocked by weight (n=4) and allotted to identical pens (n= 16) with dietary treatments (n=2) randomly assigned to pen within block. Data were analyzed using the mixed procedures of SAS for a randomized complete block with replication within block. Dry matter intake was similar between treatments (P = 0.73; 10.7 and 10.6 ± 0.19 kg/hd/d for CGS and CON respectively). However, ADG tended to improve (P = 0.09) for CGS fed steers at 1.83 vs. 1.75 kg/hd/d; respectively for CGS and CON treatments. Feeding CGS did not affect final BW (P = 0.41). CGS tended (P = 0.12) to improve feed efficiency (5.17 vs 5.40 kg feed/kg gain for CGS and CON treatments respectively. The cost to feed CGS at the recommended rate of 4g/hd/d is $0.04 with a net return in this study of $0.17 per hd daily based on improved gain. These data indicate feeding CGS to calves consuming high forage growing diets may enhance rate of gain and improve efficiency in the feedlot. An in vitro laboratory test was conducted with rumen fluid from fistulated steers fed CON or CGS to evaluate effects on digestibility of nine high fiber feeds and forages. DM disappearance at 24 hr was greater (P<0.01) for CGS vs. CON (63.4 vs. 59.85% ± 0.58%) with the greatest percentage improvement for CGS over CON in corn stover (18.26%), mixed grass hay (12.35%) and wheat straw (12.27%). CGS appears to be useful when lower quality forages and crop residues are fed.
Keywords:
beef, digestibility, forage, supplement