Dr Axel Rothauge consults farmers on grazing (Part 1 of 2)

20 Oct 2017

Heavy rain in several parts of the country is always a delight for both livestock and crop farmers. Given that the rainy season is upon us, let us briefly review how grazing degrades.

To livestock farmers, grass grows once again after months of dry weather. However, along with the rain come challenges for farmers as the young, fresh fodder can cause several problems for animals.

Normally fodder is watery and does not have enough fibre, which leads to improper digestion. Therefore, the animal does not chew cud the required 55 to 70 times.

What is degraded grazing?                                    

This is when the dominant species of grass in the rangeland changes from edible perennial (also called “climax”) to less edible perennial (“sub-climax”) to pioneer (mostly “annual”) grasses or, in the worst case, to bare ground.

According to Dr Axel Rothague, founder and consultant of AgriConsult Namibia and former agriculture lecturer at the University of Namibia (Neudamm campus), a degraded grass pasture offers less nutrition to animals in the form of quality (amount of energy and protein in the veld), dependability (annuals are less reliable than perennials) and commonly also lower carrying capacity (quantity). Another general sign of grazing degradation is bush encroachment beating back the grasses.

In recent times, the most frequent cause of grazing degradation is the inability of farmers to control the selective grazing of their livestock. All animals eat selectively.

Cattle and sheep in Namibia generally prefer only a handful of climax grass species. If poorly controlled, animals will graze these palatable grasses into oblivion. Thereafter they tackle the next-most palatable grass until it too is finished, then the next one and so on down the ladder of palatability until only the least palatable, least dependable and most variable grass species remain.

A perennial grass cannot survive being grazed all the time. After every grazing-down, it needs time to recover, grow new leaves and roots and recuperate its vigour.

“Generally, a grass has recovered from a previous grazing when it has grown to the point of making seeds. It is now very leafy and can be grazed again with minimal danger to its survival. Obviously, such recovery can only happen in the rainy season. In winter, all grasses are dormant (do not re-grow) due to low soil moisture and night-time temperatures,” Rothauge says.