By Vincent Posada – Consulting Nutritionist to Goldmix Stockfeeds
As weather warms up and increasing rain comes along, tropical grasses tend to grow faster and mature quickly. Grass species such as Setaria, Kikuyu and Rhodesgrass try to capture as much sunlight as possible by generating longer leaves to convert energy into sugars, through photosynthesis. To ensure reproduction and survival of species, these grasses soon put up seed heads which can appear as quickly as 10 to 15 days from previous grazing or cutting. Unfortunately the quality of the feed available to stock decreases rapidly after seeding. However it is possible to minimise its effect on cattle’s nutrition through better grazing management and adequate pasture supplementation.
Grazing management is closely linked to forage quality and it includes setting stocking rates and defining how much time paddocks are grazed and rested. Regardless of grazing system used on farm (continuous, rotational, cell or strip grazing), maintaining conservative stocking rates (animal units/ha) has the greatest impact on feed quality and availability over the longer term. However on a short term basis, adequate time allocation of tropical grass’ paddocks can greatly improve feed quality. There are three rules to follow: 1) start grazing cattle in each new paddock preferably before grasses reach the seeding stage - this may be as soon as 12-15 days from last grazing; 2) take cattle out of paddock before they start re-grazing an area grazed 2-3 days before – this prevents the pasture from losing vigour from continuous drainage of sugar reserve in its roots and it also allows grass to better respond to moisture and fertilizer application; and 3) increase or decrease the number and/or area of paddocks being grazed to meet the above two rules. If grasses are growing fast, there will be paddocks with excellent pasture that will not be grazed in time. These excess grass paddocks should be harvested into hay/silage at pre seeding stage, or allowed to mature and stockpile for later grazing in winter season.
Pasture supplementation are also very important as spring and summer approach. If the season is very wet and grass is fairly green, phosphorus supplementation through a loose lick is extremely beneficial to cattle grazing on phosphorus deficient country. This is the case in most of our coastal or light hilly country. Phosphorus is required by the rumen microbes to convert feed into useful energy in order to multiply and be able to consume high level of pasture. If not supplemented, it becomes the limiting nutrient for cattle performance. Sulphur is another mineral that can help cattle during summer by reducing the incidence of ticks and flies. Cattle will eat and perform much better when ticks and flies are controlled with the help of sulphur. Finally, protein supplementation in the form of urea and a slow rumen degradable protein source such as cottonseed meal should definitely be considered when the season turns dry and pasture protein level falls below 8%. The extra protein in the supplement, allows the rumen microbes to multiply and increase pasture intake this improving cattle performance. Goldmix Stockfeeds and your local Norco Rural Store can help you select the correct paddock supplement that will improve the quality of diet consumed by your cattle.