It’s time for winter lick: Minerals

• AXEL ROTHAUGEIMPLEMENTING research and development projects for the livestock activity of the Millennium Challenge Account Namibia (MCA-N) in the northern communal areas (NCA) was a real privilege because we learnt so much about the northern part of our own country, long neglected in terms of agricultural research and extension.

Amongst others, I had the unique experience of supplementing cattle and goats that had never in their lives before received a commercial lick supplement, with rock salt and a mineral lick block. The scramble to get to the lick was unbelievable, as illustrated in the picture. Individual animals fought each other for access to lick. It reminded me of the struggle in our school hostel on Sundays, when we used to get a small piece of steak for lunch!

Interestingly, cattle and goats would take a few sniffs of the phosphate (P)-containing, molasses-based but urea-free lick block and move on to the salt rock. For the first 2-3 weeks, they would only take salt. Only then would they start consuming the lick block, which also contained salt. Obviously, their salt hunger was overwhelming and they stilled it first before advancing to supplement their mineral intake. This clinched the argument for me: our livestock animals in the sub-tropics experience a severe salt hunger and need free access to salt irrespective of the lick being fed. If they get supplied with lick only (which nearly always contains salt as well), they will eat more lick than is necessary to still their mineral requirement due to their craving for salt.

This is wasteful and costly for the farmer (minerals are many times more expensive than salt) and the animals excrete the excess minerals taken in (which can be a potential source of pollution).

I would therefore advise commercial farmers to always feed rock salt in addition to whatever lick they are supplementing. When livestock are moved to another camp, the lick can follow them but the salt rock should stay behind, for the benefit of wild game animals. Obviously, some feed manufacturers may be upset by this advice because it is more profitable for them if farmers do away with feeding rock salt.

We also tried to determine the economics of lick provision in the NCA. This was difficult as it was a huge trial, held over all of the NCA except the Caprivi region, held on several farms with poor control over many variables.

On-farm trials are always messy and crude compared to on-station trials, so I am not sure if the figures supplied below are absolutely correct, but they do illustrate the severity of the cost involved. To supplement cattle year-round with a mineral-containing, molasses-based, urea-free lick block cost 38 cents per cow per day while cattle also consumed 12 cents worth of rock salt per cow per day. For in total 50 cents per cow per day, a farmer can already meet the basic mineral requirement of his cattle! This is very cheap indeed; the cost of a Wilson’s toffee or a bubble-gum per cow per day! If you cannot afford this investment, why are you farming? On the other hand, if your lick bill is very much more than this, you either have very poor veld, poorly adapted cattle or are substituting (cheap) veld fodder with (expensive) lick supplement.

In return, supplemented cattle maintained higher body weights and better body condition throughout the year and lactating cows had more milk.

Cattle appeared healthier and had less mortality than before, when they were not supplemented. Project requirements limited the lick pilot trial to 12 months only, so it was impossible to measure the effect of lick on fertility and reproduction, but farmers reported that more calves survived to adulthood and were themselves in better health, even though they were not supplemented, only their mothers.

The ultimate proof of the benefit of lick supplementation, however, was the NCA farmers: many are continuing with lick supplementation at their own expense now that the project is over.

The principle of the above is not news to students of agriculture, although some of the detail amazes.

If development is to come to Namibia’s communal farmers, lick supplementation would certainly be one of the first steps to take! For the inexperienced farmer, a hard lick block is safer and easier to use than meal-type, bagged lick and doesn’t require feed-out infrastructure. Lick and salt should be fed in overnight kraals and be always available, with as little interruption as possible.

The less the knowledge or management inputs, the more important it is to stick to the basics: a P-containing, molasses-based, urea-free lick block and rock salt throughout the year with two injections of micro-minerals, which will be discussed next time.

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