FEEDING FOR PRODUCTION 

Dry Matter
i.e. feed with no water - why?

Water requirements  - 5 - 8% body weight in water daily.

Functions of Macronutrients

• Energy - drives all metabolic processes.
• Protein - cellular structure and enzymes for metabolic processes.
• Fats - a way of storing energy, and some cell elements.
• Macrominerals: (eg Ca and P, Fe) structural - bone, blood.

Micronutrients: Vitamins, Magnesium, Zinc, Copper, Cobalt, Selenium.  Metabolic function co factors and enzymes.

Energy - measured in MJoules Metabolizeable Energy i.e. MJ ME/kg.  Comes from starch or sugars in forage or supplemented feed.  Soluble sugars (those which make the feed taste sweet) are very rapidly fermented by microbes. Stored plant cell starch is fermented readily also.  Cell wall starches take much longer to be digested by them and tend to produce a slower release of VFA’s.

Crude Protein - calculated assuming all nitrogen in the diet is incorporated in protein.  Works because microbes mainly ensure that this is the case, but doesn’t account for NDP.

Different productive states:

1.  Maintenance.
Mature animals, usually gelded or batchelor males.

• Require 1.4 - 1.8% body weight intake of DM.
• Require 8-10% Crude Protein in the diet.
• Require 8 - 9 MJ ME/kg

2. Early Pregnancy, Juveniles > 12 months.
The first 8 - 9 months of pregnancy, and the later stages of growth.

Can still consume no more than about 2% body weight in DM, so need:

• 10 - 12% Crude Protein
• 9 - 10 MJ ME/kg

3.  Late Pregnancy and Juveniles 6 - 12 months old.
Last 2-3 months of pregnancy during which the foetus does 85% of its growing.  The female needs to gain 12 - 15 % body weight.  She needs between 1.5 and 2 times her maintenance requirements, but can’t consume any higher volume because the pregnancy is occupying too much space in her abdomen.  The crias are still growing fairly quickly but have not yet attained their full fermenting capacity.  Therefore their diets need to contain:

• 12 - 14 % Crude Protein
• 10 MJ ME/kg

4.  Lactation
Females need at least twice, and up to two and a half times their maintenance requirements.  They can cope with higher bulks, though and their DM intakes may increase to 2.5% body weight, sometimes increasing by two thirds.  This feed should contain:

• 13 - 15% CP
• 10.5 MJ ME/kg

5.  Crias < 6 months.
The digestive system is not fully functional, and the C1, C2 fermenting capacity not fully developed, but the cria is growing rapidly. Its diet should contain:

• 14 - 16% CP
• 10.5 - 11 MJ ME/kg