15.1 Feed Conversion

The advantage of using dairy breed cattle is that they are capable of converting a higher percentage of the feed that they consume into milk. A heifer that reaches her target weight of 350 kg at mating has the best chance of reaching her potential life times production. Not just any cow, can fulfil her owners wishes of high production, purpose bred dairy cattle are needed, as they when well managed have special advantage.

Dairy breed cows have a superior ability to utilise body reserves.

A farmer will notice that it is in mid lactation that the cows appetite reaches its highest, this is after the period of highest milk production. This is because a good dairy bred cow will use her own body reserves (fat) to produce milk.

Figure 15. Partition by the cow of feed in early lactation

During the mid to late period of lactation the cow will produce less milk and begin to build up her body reserves. This build up of reserves enables her to care for her new calf

Figure 16. Partition of feed by the cow in mid-late lactation

Source of figs 15 &16: Balch, C.C. 1988 - Meeting the dietary needs. A high producing cows in intensively farmed pen - urban areas.

The characteristics of a high quality cow are

1. Well grown at first calving

2. Ability to produce calves at regular intervals

3. Good appetite

4 Ability to utilise body reserves.

15.2 Body Condition Scoring

In managing a cow the farmer should be constantly checking the body condition of a cow. A useful method is the NIRD body condition score system [below].

Figure 17.

source. Balch, C.C. - Dairy Cattle Feeding and Nutrition.

These diagrams represented the shape, skin and fat thickness of the cow just in front of the tail.

In the simplest terms a cow of

Score 4: is too fat and probably has not been in calf for a long time, care should be taken to ensure she gets in calf

Score 3: A cow in good condition

Score 2: This cow has probably used some of her reserves to produce milk

Score 1: This cow is excessively thin and will probably require extra feeding and time before she can produce a calf again.