I think that may be the case, IaJewel. I had a link to another study about fodder trees... If I find it I will come back and post it.
Here's a couple:
http://www.fao.org/ag/AGP/AGPC/doc/p...ngs/willow.pdf
http://www.grahamandrews.com/fodder_trees.htm
And here's a report I wrote up a couple years ago about feeding willow and poplar to rabbits:
Willow And Poplar
Report on Willow (Salix spp.) and Poplar (Populus spp.) as livestock fodder.
There are about 90 species of native North American willow (Salix) plus many more that have become naturalized here and about 35 species of poplar, plus a number of natural hybrids. Poplar is a member of the huge willow family (Silicaceae). Willow bark has been used for millennia for easing pain and aspirin has much the same chemical composition.
As far as I have been able to determine, all willows and poplars are safe to feed to rabbits; however, specific information relating to feeding willow and poplar to rabbits is hard to find. I feed both of these to my rabbits, willow regularly and poplar occasionally (merely because the poplar trees are further from the rabbitry and house) and have found that the rabbits eat both the bark and leaves eagerly. Willow, in particular, is among their top ten favourite plants.
Using trees as fodder for livestock is an idea that is gaining ground quickly, particularly in areas of the world where seasonal drought results in unreliable grass and legume supplies during the dry months. Because trees have a much deeper root system, they are better able to provide sustained production in dry conditions. Australia, New Zealand and Bhutan all have well-established usage of willow as feed for cattle and sheep.
It was a pleasant surprise to me to learn that willow and poplar compare favourably with alfalfa as a source of protein. Crude protein content varies with the seasons, from a low of about 11% to a high of 25%. Crude fibre varies from 12 to 22%. Poplar has similar levels. Willows grown in Canada, for reasons unspecified, generally have only about 16% protein, but that is about the same as many commercial feeds.
There is a lot of information about feeding willow to cattle and sheep. See the sources at the end of this report for more information. One experiment with cattle found that lactating cows fed entirely on willow maintained their milk supply at a level equal to the period preceding willow feeding – and that milk supply dropped when the willow was discontinued.
Here, we are fortunate in having a huge weeping willow tree providing shade for our summer rabbitry. Salix babylonica is the preferred species of willow as tree fodder in Bhutan and we make good use of it here as well. From spring until late autumn we feed the leaves and tender branches to our rabbits several times a week. We also dry large quantities for winter use and sometimes feed the bare frozen whips as well. It is easy to harvest for drying and can simply be tied in convenient-sized bundles and hung up on nails on the walls of the winter rabbitry until needed.
The use of trees and shrubs as a source of feed for livestock is not new. Plato, in his Critias and Timaeus, noted that: “...there were also many other lofty cultivated trees which provided unlimited fodder for beasts.”
In England and parts of northern Europe, elms were used as a source of fodder until the mid-1800s. They formed an integral part of the farming system (Lamb 1979). The elm's large volume of canopy contains much needed proteins, carbohydrates and minerals sought by livestock. This small digression is simply to point out that other trees besides willow and poplar can be used for animal fodder.
Some of the species that are used world-wide are:
Ø Tagasaste: Chamaecytisus proliferus
Ø Carob: Ceratonia siliqua
Ø Honey Locust: Gleditsia triacanthos
Ø Willows: Salix spp, especially the weeping willow, Salix babylonica, and the hybrid Salix matsudana x alba
Ø Poplars: Populus spp
Ø Leucaena: Leucaena leucocephala
Ø Chenopods: particularly Atriplex nummularia.
Willows are valued for their spring and summer foliage. They are fast growing, long-lived, and easily propagated from cuttings. They yield copious foliage after just two or three years, up to 200 kgs (about 440 pounds) per tree per year. The foliage contains an average 17% protein.
Willows coppice readily, even when cut right back. Trees are kept low to be grazed directly by cattle or more easily cut for other livestock. Willows are drought tolerant and frost resistant and are ideal for soil stabilisation.
Poplars (Populus spp) are grown under conditions similar to willows. They are deciduous, providing foliage in spring and summer. Like willow, they are fast growing and tolerate dry periods well. Yields are increased by keeping them well grazed and small. The trees should be well spaced and can be grazed within their first two or three years. Propagation is from cuttings or suckers. Yields of five to seven tonnes dry matter per hectare per year on first cutting; second browsing should double this.
Willow and poplar have been fed successfully to livestock in many parts of the world for many years. At first, it was
used during periods of drought for animal maintenance; however, after much studying, hands-on experience, and high level testing, it was determined that these trees, and others, could be fed to livestock on a regular basis.
Furthermore, it was proven that the (RFV) Relative Feed Value and protein levels equate favourably to those of alfalfa, hay, and other forage. Once planted, the trees offer an available feed source for many years without concern for watering, fertilizing, or crop rotation.
Depending on your method of planting, this feed source will yield between 100 to 400 tons of (DM) Digestible Material, per acre, per year.
Summary:
All this information is useful to livestock farmers, but for the small homestead or backyard rabbitry, what is the bottom line?
In my opinion, willow and poplar of all types may be fed with confidence to rabbits as a good source of protein and other valuable nutrients.
In addition to their nutritive qualities, there is considerable evidence that willow acts as a natural wormer and coccidiostat.
Given the ease of propagation and the ubiquitous nature of these trees, establishment of a stand can only be a good thing for the smallholder and homesteader.
