The timing and nature of joining programs should be determined by the breeding objective.
A well planned joining will maximise the number of does that become pregnant and the number of kids that will potentially meet market specifications according to the breeding objective.
To maximise the percentage of does becoming pregnant, joining periods should be timed to coincide with the time when does are most fertile - February to July (a result of a hormonal response to shortening day length). Goats can breed all year depending on rainfall, nutrition and feed supply. Some producers are even able to successfully kid three times in two years.
Maiden does begin cycling when they reach puberty.
- At about 40% of mature body weight.
- As early as 3.5 months of age but usually at about 7 months of age.
A boost in nutrition (or a rising plane of nutrition) at joining increases ovulation rates and encourages multiple births. Increasing the quality and quantity of available feed leading up to the joining period will provide a raising plane of nutrition. Joining over-fat does should be avoided as this can lead to kidding problems and pregnancy toxaemia.
In enterprises aiming to kid three times in two years, feed supply must be managed carefully. If feed supply is sufficient, does can return to oestrus five days after giving birth.
Buck performance is critical to ensuring high pregnancy rates and a tight kidding pattern. As the buck has a significant influence over the next generation's genetics, only bucks that suit the breeding objective should be used.
Common buck management practices used prior to joining include:
- Selecting bucks that meet the enterprise breeding objective and culling for undesirable characteristics.
- Testing bucks for fertility, health and physical (feet, teeth and testicles) soundness. All such checks and culling should be completed two months prior to joining to allow time for corrective actions or replacement if required.
- Managing nutrition to ensure that bucks are in good condition prior to the start of the joining period; aim for condition score 3. Bucks should be monitored and replaced if they become unfit.
- Use the appropriate ratio of bucks to does. This may be as low as 1.5% in small paddocks and up to 5% in extensive systems. More bucks should be used if the bucks are young and on their first joining.