The trial investigated a number of issues including the optimal age to introduce bucks into pastoral areas, acclimatisation and the effect of implementing a managed joining program.
The trial commenced in February 2005, when 154 Boer bucks donated from 12 different studs across eastern Australia were introduced to ‘Bushley’. The bucks ranged in age from four to 20 months and had been weaned for a least one month.
The bucks were acclimatised, without being joined until March 2006. The practices used for acclimatisation included:
- studs’ drenching and vaccinating bucks;
- managing the bucks to ensure they maintained adequate feed in their rumen and introducing them onto hay and water as soon as possible after arrival, to assist rumenal microflora adapt to the new pasture conditions;
- settling the bucks in a small holding paddock for 48 hours on water and
- releasing them into a small paddock (400ha) where they could be easily monitored.
The practices used to introduce the bucks were successful, as the bucks on average gained weight during the first three months at ‘Bushley’ in extremely dry conditions.
“One surprise was how readily bucks from the ‘inside’ country took to the chenopod and other shrubs and herbages of pastoral country, plants they’d never seen before,” said Greg Curran, DPI’s Western Division-based Senior Regional Animal Health Manager.
A single major mortality event occurred over four days in July 2005. An intensive investigation of the cause of these mortalities was undertaken.
“The mortality was related to the bucks being affected by a complex interaction of phosphorus and cobalt deficiencies, teeth abnormalities, worm burdens, and exposure to cold, wet conditions,” Mr Curran explained.
“The two mineral deficiencies had led to illthrift, reduced appetite and wasting, made worse by a mild worm burden. These problems made breaking new teeth and gum disease worse, and these in turn made feeding and chewing efficiently more difficult.
“The soft green pick available from the June/July rain had diluted nutrients further. The combination of trouble feeding, wasting, and reduced appetite had run some bucks’ energy reserves down to the point where they were unable to withstand cold, wet windy conditions.
“The lack of any significant mortality in rangeland goats run under the same conditions suggested that producers bringing Boer bucks into pastoral areas need to be aware that Boer bucks may be more susceptible to certain nutritional deficiencies and teeth and mouth problems, and perhaps worms than rangeland goats, as worm egg counts increased rapidly in the Boer bucks after effective drenching.
“These risks can be managed. Regular worm tests of introduced bucks are appropriate. Cobalt, phosphorus and some other mineral deficiencies can make the effects of worms worse. If introducing young bucks into pastoral country, their condition should be monitored closely when they are cutting their 2 and 4 teeth”.
Mr Curran recommended that goat buyers and breeders be aware that the ‘Bushley’ trial suggested that Boer bucks may be more susceptible to mineral and other deficiencies and to worms than rangeland goats.
If this is the case, Boer goat owners will need to check more frequently for signs of these deficiencies and for worms than for rangeland goats.
He also recommended that Boer goat studs aim to breed goats that are more resistant to worms and to mineral and other deficiencies.
“Overall, the Boer goats adapted and performed remarkably well during the trial, and especially at the business end (mating) except for the short period where the specific but complex disease issues conspired,” Mr Curran said.
After this event with treatment, management and improved pasture condition, the surviving bucks performed well. From August to November the average weight gain of all bucks was 23.3 kg. The majority of teeth abnormalities improved markedly as well.
The weight and the age of the bucks when they were introduced had an effect on survivability, with the heavier and older goats generally being more at risk.
However, this relationship is complicated because the breeders (or where the goats were sourced from) had an influence on the predicted survivability. Hence, it is difficult to make judgment about the impact of the individual factor on survivability.
“I think we have to bring bucks into pastoral country young and let them grow out here” Mr Church said.
The trial highlighted the importance of bucks having sound confirmation.
“It is essential that bucks going into pastoral areas have sound mouths, legs, hooves, shoulders. Any faults such as undershot or misaligned jaws, bad pasterns, over grown hooves and devils grip affect the bucks performance when they have to walk long distances to forage and keep up with mobs of rangeland does” Mr Church said.
The trial also investigated the impact of implementing a managed joining program by comparing two joining treatments (managed and unmanaged).
The managed treatment joined the bucks at 5% to approximately 500 rangeland does in a smaller paddock (800 ha). Feral bucks were also actively managed. The unmanaged treatment joined the bucks at 5% to approximately 500 rangeland does in a larger paddock (3200 ha).
Both the managed and unmanaged mobs had similar marking percentages of around 140%. However, the managed treatment had a far higher proportion of Boer sired progeny (approximately 88%) compared to unmanaged group (approximately 36.5%).
“We need to concentrate our joining and control feral bucks,” Mr Church said.
“Joining in smaller paddocks increases doe and buck contact and it is also easier to manage feral bucks in smaller paddocks.”
The trial culminated in a goat industry field day held at ‘Bushley’ in November last year, which attracted visitors from across Australia.
The field day was an opportunity for people interested in the goat meat industry to exchange knowledge and information, and hear the trial’s results presented on the day.
“Introducing Boer goats can expand your goat marketing opportunities. The field day showcased how we are using Boers in our enterprise to capitalise on these marketing opportunities” Mr Church said.