72
Beef Breeder MANUAL
P levels in the diet can be increased in two ways: 1. Fertilising the forage with phosphatic fertiliser. While
this method will usually increase the amount of improved forage produced, as well as increasing the
P level in the forage, it is a relatively expensive way of improving dietary P levels.
2. Feeding supplementary P using products including mono-ammonium phosphate MAP, di-ammonium
phosphate DAP and dicalcium phosphate DCP. MAP and DAP have the advantage of providing some
additional non-protein nitrogen that can be converted to protein. Rock phosphate is not recommended
as it contains less available phosphorus than the alternatives, is insoluble in water and is relatively
unpalatable. Some sources also contain potentially toxic impurities such as luorine and cadmium. Care
should be taken to maintain the appropriate balance between dietary phosphorus and calcium if using
these supplements.
Sodium Na Sodium or salt deiciency is relatively common in animals
fed grass and legume forage, since many species have inherently low levels in their tissues. Provision of salt
licks can greatly improve performance of animals on pastures low in Na.
3.3.4. Vitamins
Cattle obtain the majority of their vitamin requirements from the feed consumed, with the exception of Vitamin
D, which is synthesized in the skin on exposure to the ultra violet light in sunlight. During periods when cattle
are on pasture, vitamin deiciencies are generally rare. However, when fed fully prepared rations, attention
must be paid to ensure that daily vitamin requirements are addressed.
Grains contain little or no vitamins, and conserved forages and silage contain highly variable levels of
vitamins. When rations based on conserved forages and grain supplements are fed to cattle during winter,
the addition of a vitamin supplement to the ration will address their daily requirement. Many common
sources of vitamin supplements are available to assist in balancing the ration, and typically these will provide the
key vitamins A, D and E.
3.3.5. Nutrient Balance
The balance of nutrients consumed by animals greatly afects their performance. In conined feeding situations
where rations are prepared for animals on a daily basis, supplying and maintaining a balanced diet is a
comparatively simple task. With the aid of feed tests to determine the nutrient content of the feed, and a ration
formulating program such as Cowbytes©, Grazfeed™ or others, balanced diets that meet the physiological
needs of cattle can be easily prepared.
However, in grazing situations the ideal balance of nutrients required to achieve maximum performance
rarely occurs, and identifying the primary limiting nutrients and providing supplements can signiicantly
improve productivity. However, this is not always economical or practical. In all circumstances, the health
and welfare of the animal is the overriding consideration in meeting its nutrient requirements.
In ensuring that animals receive a balanced diet, producers should consider the hierarchy of supply and
availability of the essential nutrients; energy, protein, macro minerals, micro minerals and vitamins. Substantive
dietary deiciencies can then be addressed by basing management decisions such as supplementation on the
most critical limiting nutrients irst.
3.4. Water
