Pastures in Northern Australia and their Impact on Nutrition

Northern pastures rarely meet the nutritional needs of ruminants. Yet pasture is the cheapest feed available.

With large distances to transport supplements and distinct wet and dry seasons, meeting the nutritional demands of cattle in an efficient and cost effective manner is a challenge.

Selecting an appropriate Rumevite product will allow your cattle to gain maximum benefit from available pasture. Correcting nutrient deficiencies can increase the consumption of mature grasses, improve the digestibility of dry stubble and fibrous plants (including wire grass, spinifex and scrub), and encourage more even grazing patterns.

Dry Season		High Quality Pasture
Protein is needed for tissue maintenance, growth and milk production.  Tropical grasses provide adequate levels of protein and energy for less than three months of the year.  After that, levels of protein and energy decline rapidly, leading to losses in live weight. Early in the dry season, when green pasture remains available, products with lower levels of total crude protein may be used.
Dry Season		Moderate Quality Pasture
As pastures mature, digestibility falls and protein levels become negligible.  Using microbes in their rumen, cattle can produce protein from poor quality feed sources - but only when there is adequate nitrogen, sulphur and energy available. Urea serves as a nitrogen source for mature cattle and molasses or grains provide energy for protein production.  Additional nutrition should be introduced before cattle begin to lose weight.
Dry Season		Low Quality Pasture
By the end of the dry season, plant growth has ceased.  In many cases, cattle will be feeding on stubble and foraging in scrub. To utilise this poor quality feed, cattle require a source of nitrogen and fast acting energy (such as molasses or grain). If phosphorus is also deficient, the effect of declining feed intake will be more serious.  Phosphorus supplementation for all cattle should be maintained year round in severely deficient areas.
Wet Season
Serious productivity losses occur during the wet season, ironically due to poor nutrition.  Tropical grasses have a low leaf to stem ration and a high fibre content even when they are growing rapidly following wet season rains.  A bulky diet makes the cattle feel full, which can impact the ability of young cattle in particular, to consume enough quality nutrients for growth and production.

Plant growth depletes soil minerals and nitrogen; pastures become dull and begin turn yellow. As protein levels fall and the plants become less digestible, feed intake declines. Supplementation with a source of nitrogen can maintain feed intake. Breeding cows, growing cattle (including replacement heifers) and weaners can benefit from wet season supplementation with protein, sulphur and phosphorus.

Supplementation can improve conception and branding rates. It leads to a tighter and earlier calving pattern. Breeders that calve early in the season are more likely to finish the wet season in better condition and are therefore at less risk during the dry.

Supplemented cows are also more likely to produce a heavier and more uniform line of calves at branding. By comparison, out-of-season calves often cannot "do" as well because their mother's milk dries up before the onset of the wet.

One study found that 70% of supplemented weaners reached live export weights as yearlings in situations where previously it would have taken two or three years to achieve the same weight.

Phosphorus-deficient regiosn of northern Australia will require supplementation during the wet season. Weather-resistant blocks have been developed for use in areas which may become waterlogged and isolated.