Is your beef herd’s weaning percentage perhaps lower than usual or are you perhaps weaning lighter calves? The reason for that is probably that the cows’ nutritional needs are not properly met during late pregnancy and lactation. This is the period that currently causes issues for most herds, and if small corrections are made the above problem can be successfully solved.

From Table 1 below, it is clear that cow’s protein and energy requirement begin to increase rapidly in September as the greater part of foetal growth occurs during the last third of the gestation period.  Although pasture regrowth is starting to take place, the protein content of available pasture during this time is usually still low.

Table 1

It is therefore important to continuously provide a protein lick such as Winter Lick 40 which, among other things, provides degradable protein so that there is sufficient nitrogen available in the rumen to digest low-digestible fibre in available pasture. In addition, essential macro-minerals such as phosphorus, trace minerals and vitamins are also supplemented.

With the start of the calving season in October, the nutritional needs of the cow begin to rise drastically and although the nutritional value of the grazing slowly begins to improve, it is not nearly sufficient to meet the nutritional needs for lactation (Table 1).

Milk production of the cow usually peaks after two months (Table 1) which means that her nutritional needs will be the highest during November/December. It therefore becomes important to switch to Production Lick 20 to supplement energy, protein and minerals. This practice should be continued until it has rained sufficiently.

From January the protein content of pasture rises rapidly. A decrease in NDF (fibre) and lignin content also occurs, resulting in more energy being available for milk production. In addition, milk production begins to decline gradually (Table 1).

The net result of these changes is that natural pasture can usually now meet the nutritional needs of lactating cows, except for salt and phosphate. It is therefore now advisable to switch from Sernick Production Lick 20 to Soutfos 6.

It is important to note that phosphorus is essential for energy utilization and together with calcium is also essential for bone formation. It has also been proven under South African conditions that phosphate supplementation can dramatically increase fertility of cows in areas where natural pasture is phosphate deficient.

If cattle have a phosphate deficiency, they will tend to pick-up bones during grazing (Pika). This can lead to botulism ‘lamsiekte’ disease.

It is calculated that lactating cows’ phosphorus intake during lactation can be as low as 11g per day, while the phosphate requirement of lactating beef cows is in the order of 22g per day (Table 1). It therefore goes without saying that phosphorus must be supplemented during the summer. 

In addition to phosphate  supplementation, salt phosphate licks are also essential to supplement salt (NaCl). Salt is an essential dietary component that helps to maintain water balance in the animal’s body. Salt requirement is increased in summer as salt is lost in the form of sweat.

In summary, it must be emphasised that the milk production of the cow is the most important factor that determines weaning weight and can be managed through strategic supplementation.

Future conception, and consequent calving percentage, is largely determined by the condition of the cow and can likewise be optimised with lick supplementation. Mineral supplementation can also have a significant positive effect on conception.

The choice of lick is determined by a large variety of factors, of which the grazing and animals’ condition are the most important. Feel free to contact your local Sernick technical advisor for specific recommendations.