Species Characteristics

Species characters are given for two specific situations:

- Feeding characteristics of livestock species and potential impact on the environment, and
- Feed digestion characteristics of livestock species and related methane emission and quality of excreta

Feeding Characteristics

The matrix presents some principal characteristics of the most common livestock species. The Natural feed resources refers to the feed the animal will eat under natural conditions. Specific abilities refer to the anatomy and abilities in relation to feeding resulting in specific feed intake behaviour. The table also presents the Impact on the environment of feed intake and behaviour by species in general and the Impact that can be expected after prolonged exposure.

A high animal density of poultry or pigs in general only appears on-farm. The situation with “grazers” is different. It is well known that grazing natural vegetation with a mix of species is more sustainable then grazing by only one species. Also wildlife can contribute to maintaining a desirable vegetation composition and are not necessarily in competition with livestock. Problems with overgrazing as mentioned under both grazing and mixed systems can also result from an inapropriate species composition rather than from too many animal units per area.

Sheep and cattle are both grazers but with different abilities. Sheep can feed themselves when the availability and density of consumable fodder is relatively low. This explains how sheep can survive where cattle are unable to, for example:

- at the onset of the rainy season when feed density is still very low
- on moors and mountains with marginal grass growth
- on fallow land where density of palatable species is low
- on aftermath from grass cutting or crop harvesting

Goats are often “scapegoats”, considered to be responsible for environmental degradation. Goats do reduce the regeneration of bush and tree vegetation through browsing seedlings. However, under free grazing they will not eliminate adult shrubs and trees. If degradation appears, then it is often due to a combination of deforestation, crop cultivation and inapropriate grazing practices. Goats are often still around when degradation appears and are as a result blamed for it. Efforts in Namibia to reduce a standing shrub vegetation on a pasture for cattle by intensive browsing by goats failed. It only stopped further bush encroachment. Similar results were obtained in trials in Tanzania. In this example, in a block of savannah that had been “grazed” by goats for five years, mature shrubs and trees had survived but no further encroachment had taken place.

In the case of reforestation reforestation and tree planting, goats can cause considerable damage and measures are required to keep goats under control (i.e. tethering) or to protect the seedlings against browsing (i.e. branches of thorn bushes). A ban on goat or other livestock is often counter-productive. Farmers’ participation in reforestation or tree planting in general requires short-term returns. One of the most feasible options is to pass on to them well regulated rights to harvest tree leaves and cover vegetation for their goats or other livestock. On farm research in Indonesia on the island of Bali so resulted in a successful land rehabilitation system based on three strata of plant-shrub-tree vegetation on the boarder of fields in combination with the keeping of goats (smaller farms) or Bali cattle (larger farms). Shrubs and trees protect the soil against erosion and provide fodder for animals producing manure for crop cultivation and income through sales. Branches are firewood for home consumption and sales. In many other agro forestry, alley and mixed farming systems, shrubs and trees play similar roles in combination with livestock.

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