Method of Obtaining Replacements

Producing replacement females may require the commitment of 40 to 60% of the cow herd. However, that proportion of the herd need not be dedicated to producing replacement females if replacements are purchased. This enables a greater proportion of cows to be bred to a terminal sire. Scarcity of consistent, reliable, and affordable sources for replacement females may make

Table 1 Resource and managerial requirements of crossbreeding systems

Pastures

System

No.

Sizes

Sorting of cows

Herd sizea

Straightbred

1

None

vs

Composite breed

1

None

vs

Two breed rotation

2

1:1

Sire

sm

Terminal sire on:

Straightbred

2

1:1

Age

sm

Composite breed

2

1:1

Age

sm

Three breed rotation

3

1:1:1

Sire

md

Terminal sire on two breed rotation

3

2:1:1

Sire, age

lg

Four breed rotation

4

1:1:1:1

Sire

lg

Terminal sire on three breed rotation

4

3:1:1:1

Sire, age

vl

aA very small (vs) herd implies one bull, a small (sm) herd implies two bulls, a moderate (md) herd implies three bulls, a large (lg) herd implies four bulls, and a very large (vl) herd implies six bulls.

aA very small (vs) herd implies one bull, a small (sm) herd implies two bulls, a moderate (md) herd implies three bulls, a large (lg) herd implies four bulls, and a very large (vl) herd implies six bulls.

purchasing them an unattractive option in many cases. However, producing first-cross females to market as commercial replacement heifers represents a significant niche market.

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