Wool Sheep Production Plan

All successful wool sheep enterprises work according to some form of wool sheep production plan.  The following is a crisp reference to management practices during the different production stages that may have an influence on the profitability of wool sheep farming.  Consider them, identify possible risk areas, structure a plan and away you go!

Ewes - Conception criteria

Maximum ovulation occurs during the autumn mating season when ewes show natural heat.

The heat cycle of ewes is 16-17 days with the result that a mating period of 34 days is sufficient.

Flushing has little effect if applied longer than four weeks before mating.

The condition of the ewes at the time of mating is considered the most important factor in achieving high ovulation rates, regardless of how it is achieved.

Extremes in nutrition during the mating period should be avoided and ewes should, in the first month of pregnancy, be kept at a constant feeding level.

Embryos in the pre-implantation phase (from conception to day 15) may be lost in ewes that are in a poor condition or when subjected to extremes of under- or over-nutrition.

The same applies during the implantation phase. (Day 15-16 to day 30 after conception)  Losses during this period have a wider range of effects on pregnancy.

These effects include:

o    Increases in the proportion of ewes which return to the ram at more than 19 days after mating

o    A reduced lambing percentage

o    Small lambs

Mid and late pregnancy

Fetal growth during the second and third months of pregnancy is slow with rapid gains in the last trimester

The feed intake of ewes is normally adequate in late pregnancy.  Ewes mobilize their own body reserves for utilization by the fetus.

o    As the number of fetuses with extra nutritional demand increases, ewes will find it difficult to compensate by increased voluntary intake.

o    Under-nutrition of ewes, in late pregnancy can reduce weight at birth, particularly in the case of twins.  It is therefore advisable to scan ewes for twin identification 42 days after ram withdrawal.

A low birth weight disadvantages lambs in almost every way.  70 % of the unborn lamb’s development takes place during the last six weeks of pregnancy.  Such ewes should have a weight increase of between 15 and 20% (150 – 250 g/day for ewes with a single fetus and 250-350g/day for ewes with twins is advisable).

The following results can be expected:                                                       

Energetic lambs (birth weight 3,5 – 5,5 kg)

Optimum udder development for maximum wool production is secured

Less tender wool

Pregnancy disease is prevented

Lactation

Optimum lambing percentage is achieved by lambing in smaller groups and camps.

Ewes carrying twins should lamb in groups of no more than 30 while single-lamb groups can be increased to between 50 and 80 ewes.

It has been found that lamb mortality increases by 7,5 percent whenever the flock numbers increases by 50 ewes.

Lactating ewes should never lose more than 25-50g (singles) and 60-100g (twins) body mass per day.

In the first month of lactation a ewe requires considerably greater amounts of energy and protein than the amounts needed in late pregnancy.

Proper feeding will result in:

o    Maximum weight gain by twin lambs – during the first three weeks of lactation, lambs are completely dependent on milk.

o    Maximum milk production.

o    Ewes are in a good condition when egg-cells are formed. An egg-cell formed today will be ready to be fertilized 180 days later.

o    The development of wool follicles for a stable wool production is supported.

 

Lactating ewes in a good condition can be mated with great success.

Weaning

Milk production peaks approximately 3 to 4 weeks after birth.  Keeping this in mind it is often, during adverse conditions, cheaper to feed the lamb only instead of both the lamb and the ewe.

Wean lambs in camps to which they are familiar.  A few older ewes retained with newly weaned lambs should reduce stress.

During periods of drought lambs can be weaned as soon as they have intake of between 200g and 250g creep feed per day.

The proper feeding of young sheep, especially during their first 6 months is advisable – grow them out well!  Their future ability to produce is increased by this practice.

Flock composition and selection practices

In order to maintain a high quality standard throughout the flock it is important that selection practices and the composition of the flock be addressed as a unit.

A breeding flock must be replaced annually by between 30 and 35% maiden ewes.  If certified pregnant a 25% replacement will be sufficient to maintain a flock.

To explain this, one must note that in theory any flock should have 5 age groups of 20% each.  In practice you will experience losses with the result that the oldest group in a flock seldom retains more than 16% of the original input.

First selection

This practice allows the replacement of ewes 6 years and older.  These ewes are normally less productive and tend to experience more udder and foot problems.  It is impossible to identify these ewes by their teeth only.  The use of color tags to mark the different age-groups is practical.  Age groups can also be identified by earmarks at a labour cost only.

Second selection

Examine all lactating ewes when the lambs are docked to identify those who lost their lambs as well as those with udder abnormalities.

The wet & dry selection method can be applied.

This inspection should be carried out at approximately 4 to 6 weeks after lambing.  It entails that udders be examined and that ewes with dirty teats be culled.  Mistakes can be made. It is a good practice to identify the presumably skipped ewes and to leave them in an adjoining camp while retaining the lambs close by. Your mistakes or the ewes with the lambs will not wander off too far.

If this method is followed correctly, you should, in 10 years time, have increased your weaning percentage by 20%.

This selection practice means money and ensures a healthy flock composition.

 Third selection

Eventually you should have excess ewes and numbers to play with.  In such a case a good practice will be leaving the runts in the flock at weaning.  Wet & Dry these ewes in a week's time and cull both ewe and lambs – this time the ewes with clean teats.

Fourth selection

Identify and discard maiden ewes with sub-standard wool and conformation problems.  This fourth selection method applies when your flock counts are sustainable.