Volume 67, Issue 2, March 2014, Pages 219–223
Research Articles
Knapweed Hay as a Nutritional Supplement for Beef Cows Fed Low-Quality Forage
Abstract
Advancing
our ability to use invasive plants for producing commodities is central
to the agricultural industry. Our objective was to evaluate Russian
knapweed (Acroptilon repens [L.] DC.) as a winter feed
supplement for ruminant livestock. In Experiment 1, we utilized three
ruminally cannulated steers in a completely randomized design to compare
the ruminal degradation characteristics of alfalfa and Russian
knapweed. In the second experiment, Russian knapweed and alfalfa were
compared as protein supplements using 48 midgestation, beef cows
(530 ± 5 kg) offered ad libitum hard fescue (Festuca brevipila
Tracey) straw in an 84-d study. Treatments included an unsupplemented
control and alfalfa or Russian knapweed provided on an iso-nitrogenous
basis. In Experiment 1, the rate and effective degradability of neutral
detergent fiber was greater for alfalfa compared with Russian knapweed (P ≤ 0.02). Ruminal lag time for NDF (period before measurable disappearance began) was greater for knapweed (P
= 0.03). Soluble nitrogen, rate of N degradation, rumen degradable N,
and effective degradability of N were all greater for alfalfa compared
with Russian knapweed (P &spilt; 0.01). In Experiment 2, supplementation increased (P
&spilt; 0.01) cow weight gain and BCS compared to the unsupplemented
control with no difference between alfalfa and Russian knapweed (P = 0.47). There was no difference (P
= 0.60) in the quantity of straw offered between the unsupplemented cows
and supplemented groups, but alfalfa fed cows were offered
approximately 11% more (P = 0.03) than Russian knapweed-fed cows. Total DM offered to cows was greater (P
&spilt; 0.01) for supplemented compared with unsupplemented cows
with no difference noted between alfalfa and Russian knapweed (P
= 0.79). Russian knapweed is comparable to alfalfa as a protein
supplement for beef cows consuming low-quality forage. Using Russian
knapweed as a nutritional supplement can help solve two major production
problems; managing an invasive weed, and providing a feedstuff that
reduces an impediment in livestock production systems.
Key Words
- digestible protein;
- invasive weeds;
- livestock feed;
- Russian knapweed
Copyright © 2014 The Society for Range Management. Published by Elsevier Inc. All rights reserved.