1998 December

Further Developments in Reproduction Work

The DRDC has funded an ongoing program into research, development and extension of programs to improve the reproductive performance of the Australian Dairy herd. This year, Dr Jock McMillan, formally a researcher at Ruakura in New Zealand, was appointed at the University of Melbourne with funding from DRDC to head a research team.

To facilitate the effective use of funds, a project management committee was set up to oversee this program and assist with prioritising areas of most importance. I was appointed to this board which has met on several occasions this year. It is also represented by researchers, farmers and John Morton, the coordinator of the National Dairy Herd Fertility Project (NDHFP).

To priortise areas of importance, the collective input from committee members using estimates of the likely improvement in such parameters as conception rate or not in calf percentage has been backed up by use of data from the NDHFP much of which was collected from our local farmers. Once these areas have been elucidated it is planned to develop extension or research programs to begin to improve performance of the national herd. In the case of research, this may involve some on farm trial work such as use of CIDRs prior to mating start date to increase the submission rate. Extension work may involve a program for farmers to monitor performance and set targets.

The areas which the project management committee has identified as high priority are:

Repeat breeder cows.
Use of efficient synchronising programs to improve submission rate and decrease not in calf rate.
Develop an extension program to improve the uptake of already well recognised areas of importance eg. growing heifers well.
Improve conception rate in cows not calving in the first six weeks.
Reduce the prevalence of missed heats in herds with a priority to labour saving.

Along with a list of approximately 30 other areas, the group will assess the need for research or extension and plan a program for the DRDC for future use.

Is It Worth Chasing Milk Quality?

All the factories in this region have milk quality penalties for milk which does not achieve the highest standards. For all except BMCC's, the requirements in cost and effort to reach these standards on most farms are not high compared with the penalty for non-achievement.

However, the BMCC is a much more difficult quality parameter to influence in the short term. There are many farmers now who have milk bordering on falling into a lesser quality band due to the rising BMCC. In some herds it will be feasible and economic to maintain that higher quality standard and in others it will be frustrating and difficult to maintain that level into late lactation.

The typical 200 cow herd supplying one of the major dairy cooperatives would be faced with the following situation till drying off.

Period:

1st Dec 98 to 31 Mar 99 (125 days)

Production Average:

Fat 0.65 kg/day
Protein 0.52 kg/day

Typical margins paid to increase the quality standard from second to first premium:

Fat 6c per kilogram * 0.65 kg * 200 cows * 125 days = $975
Protein 12c per kilogram * 0.52 kg * 200 cows * 125 days = $1560
Each cow producing at herd average will be earning $3.50 per day less feed and milking costs ($0.50)
The net of $3 per day for 125 days = $375
Only four cows produce enough milk to make up the difference between supplying at one lesser quality standard.

In this herd, a cow with a cell count of 2 million that is producing herd average, will drop the BMCC by 10,000 if removed from the herd. As production of the herd drops in late lactation, the cell count goes up in proportion since less milk is available to dilute the cells produced. Therefore the number of cows that need to be removed from the herd continues to rise as the season progresses.

In most herds it is going to be more productive to stop new infections occurring and accept the higher cell count for the remainder of the year. It is then that appropriate steps can be taken to cull chronic carriers and treat the remainder of the herd with dry cow therapy.

Blackleg

Blackleg is a highly fatal disease of cattle. It is most commonly seen in the warmer months of the year and most commonly affects cattle aged 6 months to 2 years of age. Calves are often found dead with little signs of struggle, or are observed suddenly lame and die quietly in 12 to 24 hrs, they bloat quickly and develop gas under the skin.

The disease is caused by a bacteria which is found on the ground. Spores are ingested, the bacteria then get into the bloodstream and travel to the muscles where they lodge and remain virtually undetectable.

When the disease occurs it usually affects a number of animals over a few days. The disease is initiated by trauma to the muscles where the spores are lodged, the muscle damage stimulates the bacteria to multiply rapidly, calves are lame, running a high temperature, and the affected area is hot and painful. As the bacteria proliferate a powerful toxin is produced which rapidly kills the surrounding tissue, producing gas and causing more muscle damage and further activation of bacteria. The calves are now quite depressed and the affected area is cold, painless and may have gas under the skin. The bacteria continue to proliferate, the toxin is absorbed into the bloodstream and the calves die soon after from toxic shock.

Usually 10% to 20% of the group will be affected but some losses may exceed 50%. It is common to observe that the biggest and healthiest animals are affected first. Treatment of affected calves is usually unsuccessful due to the rapid progression of the disease, however high doses of penicillin in the very early stages of the disease may help.

Adequate vaccination is very effective in preventing blackleg. In most situations, the common practice of vaccinating calves at weaning, again one month later and again at 12 months is adequate. However calves will not be fully protected until 2 weeks after the second injection. In areas where blackleg has occurred recently calves should be fully vaccinated before weaning, this may mean giving the first injection at 4 weeks of age and another 3-4 weeks later. An extra shot at 6 months of age is also recommended in high risk areas.

Bracken Poisoning

One of the other serious illnesses in young stock we are seeing at the moment is Bracken poisoning.

While adult cattle are occasionally affected, the majority of cases we see are in young stock from three to twelve months of age, probably a reflection of their size and inquisitive nature. I have often made the observation that paddocks with bracken only along fence lines are associated with poisoning. This could be due to calves tendency to camp in groups close to the fence seeking shelter, bringing them into close contact with something that seems interesting to chew on.

Signs of illness occur after calves have had access to bracken from 2-8 weeks. It is possible for animals to show signs of poisoning for up to 6 weeks after removal from bracken although we rarely see new cases after the first week away from the infested paddocks.

The underground roots and the new curly fronds have up to five times the amount of toxin as the mature plant but it appears that in our area at least, most poisonings are from ingestion of the mature leaves.

The toxin affects the blood causing a reduction in platelets, which are essential for blood clotting and a reduction in the cells that fight infection. The clinical signs that are seen are a manifestation of these two main mechanisms.

Bleeding is seen as blood in the eye, from the nose or in the faeces. The most common sign in heifers is small haemorrhages visible inside the lips of the vulva.

The inability to fight infection results in various overwhelming bacterial infections, such as pneumonia and peritonitis leading to elevated temperatures and severe weakness.

The vast majority of affected animals die, although some do respond to treatment with antibiotics.

The method of control is to avoid the opportunity to graze bracken. This may mean a hot wire in from the fence line and a planned eradication program using spray such as Brush Off.

Financial Assistance

The Commonwealth Government has made provision through the Farm Family Restart Scheme for support to farmers who are experiencing financial hardship.

The scheme is implemented through Centrelink and provides income support to low income families who cannot borrow further against their assets. Up to $500 per fortnight is provided for a maximum of 12 months as well as payment of up to $3,000 over one year for professional advice on the viability of their business and future options if they decide to leave the industry.

To qualify for assistance farmers need to provide tax returns showing their low income and a letter from a financial institute indicating their unavailability of credit.

One of the requirements of the scheme is to seek professional advice on the viability of the business. This can be obtained from a number of different sources including agricultural consultants, accountants, financial planners, lawyers and psychologists. This advice can be ongoing over 12 months to assist farmers to put into place an action plan for the future.