Green Drought

green1There is a significant risk to stock during the immediate period following enough rain to generate a short green pick. This situation can be harder on your stock than the actual 'dry' drought. Several issues arise in a green drought.

 

Green Drought & Early Weaning Strategies

After extended periods of drought it is great to have more moisture in the atmosphere and to hear of showers, rain and storms.  The next few weeks can be particularly challenging especially if you have been feeding livestock for a while.  Any green feed that starts to come away is going to prove a real temptation for cattle and they will chase the green pick leading to a number of problems.  Cattle won't be able to eat enough green pick to meet their daily energy needs and they will use up a lot of energy chasing the new growth.

 

If the drought is starting to break on the entry of calving season, a green drought may still require early weaning. Drastic times call for drastic action but early weaning has a silver lining and the benefits can be significant.

 

Because the energy requirement of your breeders is halved when the calf is weaned the cost of feeding or supplementing a cow and calf as a unit is more than twice that of the cow once the calf is weaned.

 

For instance, a 500kg cow during early lactation requires approximately 92 mega joules (MJ) of energy per day as compared to 48 MJ per day once the calf is weaned. During a drought (green or dry) the pasture has no chance of meeting the requirements of a lactating cow.
It is the next year after a drought that will hit harder if no calves are on the ground, so getting cows back in calf is the priority. In feed shortage times, prior to weaning, less than 20% of your breeders are likely to be cycling.

 

With early weaning (as low as a 60kg calf) trials have proven that within 4 weeks, 90% of breeders may be cycling, equivalent to the level of cycling expected of your breeders in a ‘good’ year under normal weaning programs.

 

A simple ration is all that is required for early weaned calves, and breeders can then be run on drought affected pastures with minimal supplementation and minimal costs compared with trying to sustain the cow and calf as a unit.

 

Though there is a cost of feeding a ration to early weaned calves, their intake is very low (2% of bodyweight), again a lot less than feeding a cow and calf in the paddock.

 

AgSolutions free ration formulation service has assisted many producers with early weaning and backgrounding rations using simple, least cost ration formulations designed to utilise those feedstuffs available to you and also advising on other inputs as required.
A source of roughage, grain, protein meal and MegaMin Feedlot Enhancer forms the basis of a simple ration.

 

Protein is important for younger calves so calf rations are targeted to include 16-18% protein. Putting condition on cows with a basic ration can be quick and very cost effective and allow direct selling to abattoirs where fat cow prices are attractive.
Cow rations are very economical because protein and starch requirements are minimal and the power of compensatory weight gains in cows that were in store condition is enormous.

 

To maximise returns on feeding store cows, only feed for a maximum of 45 days then cull regardless of weight and price as compensatory weight gains reduce after this period, greatly reducing feed conversion and returns.

 

Negative Impacts of a Green Drought

Managing stock during the period following rain when pastures are growing rapidly on a daily basis and herbage mass is starting to build up can be risky. This situation can be harder on your stock than the actual 'dry' drought and follwing are a few tips worth considering as you start to use this pasture growth for livestock production.

 

Cattle and sheep madly chase this green pick and yet lose condition.  The reason is due to high moisture and lack of fibre in the green shoot and stock can’t consume enough feed or bulk to meet their daily dry matter (DM) requirements. In addition, lush green fodder passes too quickly through the rumen causing scours and also reducing the absorption of adequate magnesium, which can lead to Grass Tetany.

 

Fresh, green grass is also high in sugars and has the potential to cause an ‘acidosis’ type scenario resulting in a decrease in rumen pH, similar to when ruminants consume grain without adequate fibre. This can result in scouring and loss of appetite.

 

To maximise the benefits of green fodder, it is important to provide a source of fibre (any available standing roughage, by-products high in fibre such as whole cottonseed or hay/straw). The manure will always tell you if there is enough fibre (or too much) in the diet.

 

Phosphorus and magnesium are often limiting factors for stock grazing lush green pastures so providing a broad spectrum mineral supplement that includes phosphorus, magnesium and trace minerals can assist to ensure that stock achieve maximum weight gains.

 

MegaMin Extra Magnesium (which contains phosphorus) will cost around 12-15c per head per day for cattle, and for stock grazing forage sorghum, MegaMin Extra Sulphur (contains phosphorus and magnesium) is recommended.