FMG BULL EVALUATION UNIT REPORT

The 2009 - 2010 season is underway. A report will appear here later in the season.

2006 - 2007

Bull Breeding Soundness

John delivered a fascinating presentation on bull breeding soundness, conceding that most bull buyers are familiar with the structural aspects of soundness, but far fewer were aware of the equally important factors that can’t be seen, but which can lead to poor in-calf rates.
Bulls can be classed as:

• Fertile
• Sub fertile
• Infertile

There are relatively few totally infertile bulls, therefore the majority of problem bulls fall into the sub fertile class. The challenge is to identify those bulls that are likely to sire an unacceptable number of calves in a restricted mating period and remove them from the bull team.
John described a reproductively sound bull as:

• being structurally sound
• having satisfactory sperm production and quality
• having good libido and ability to serve
• being free from reproductive diseases
• having acceptable temperament

and stressed that no single trait will consistently predict calf output. His trials involving multiple-sire matings in Northern Australia demonstrated that a number of different traits influence calf output and he stated that he had no reason to believe that this would not also be the situation in N.Z.
He mentioned the bull breeding soundness evaluation certificate the Australian cattle vets had introduced to their beef industry. This included a check list involving:

• a bull’s scrotal size and tone
• a physical examination of the penis and sheath contents
• an assessment of the legs, feet and eyes
• a crush-side assessment of the semen
• a full morphology examination of the semen by an accredited technician
• a serving capacity test to assess mating ability and behaviour

He went on to discuss various penile abnormalities, most of which he suggested were influenced by an animal’s genetics and will therefore respond to selection and in dealing with the subject of scrotal size, stated that not only should the scrotal size be greater than the minimum acceptable value but the testicles should be of good tone. He stressed however that a bull with acceptable scrotal size and tone could still be sub fertile and there were also a few bulls, which had unacceptably small testicles that achieved satisfactory in-calf rates, but these were the exception rather than the rule.
In discussing the subject of semen evaluation, John stated it was important to follow up the normal crush-side evaluation (gross motility, colour etc) with a full morphology (semen soundness) examination in the laboratory by an accredited technician, especially if the risk situation was likely to be high e.g. single-sire mating and/or a short mating period. He reinforced this point by quoting trial work he had undertaken, using hundreds of bulls in multiple-sire mating groups, which demonstrated that if everything else was satisfactory reproductively but semen morphology was poor, the in-calf rate would also be poor.
The serving capacity test provided an ideal opportunity to observe structural problems in the legs, feet, sheath and penis as well as assessing an animal’s willingness and capability to mate. Again John provided research information which demonstrated that if all other reproductively related traits were satisfactory, those bulls that showed a greater overall willingness to mate (a combination of interest, mounts and serves) achieved higher in-calf rates.
John ended his presentation by commenting on the effect that prolonged stress (4-5 days) can have on semen morphology (soundness). He cited trials in which bulls were exposed to a period of prolonged cold (snow), to foot abscesses and dehorning and how the percentage of normal sperm dropped from being perfectly acceptable to disastrously low in a matter of a few days, and how it took about 6-8 weeks for the percentage of normal sperm to return to acceptable levels. He made the point that if the stress occurred just prior to mating or early in this period and the mating interval was confined to 6-8 weeks, the number of calves the bull would be likely to sire would be very low.
The fact that a bull’s semen quality (morphology) has the ability to recover after a setback means bulls should ideally be retested after a period of 6-8 weeks, if they fail an initial morphology test.

The Beef Cooperative Research Centre

With its headquarters at the University of New England, Armidale, New South Wales, the Cooperative Research Centre (CRC) for Cattle and Beef Quality was established in 1993 with a team of geneticists, rumen nutritionists, meat scientists and economists drawn from the Commonwealth Scientific and Industrial Research Organisation (CSIRO), the University of New England, New South Wales Agriculture and the Queensland Department of Primary Industries. As part of the largest integrated beef research project in Australia’s history, the scientists are contracted to work together to identify the key genetic and non-genetic factors influencing beef eating quality.
Supportin g participants come from institutions in Victoria, South and Western Australia and a large number of valued industry sponsors are involved. Overseas involvement comes from N.Z., Korea and the United States
The CRC is governed by a board of people representing the core parties, pastoral companies, producers, processors, feedlot and commercial beef producers. They ensure the research is relevant and important.
The CRC’s initial charter (CRC I) was to develop Australia’s ability to meet the specifications of the emerging markets for high quality beef, particularly in Japan. As a result Australia is in a much better position to capitalise on these growing markets. Local consumers had also been demanding a more consistent quality product. The CRC was instrumental in defining the critical factors determining beef eating quality under Australian conditions, enabling Meat Standards Australia to develop the world’s most advanced consumer grading system for beef.
Using state-of-the-art genetic technology, researchers have conducted a large meat quality sire evaluation programme. 12,000 progeny were drawn from pedigree herds of Hereford, Angus, Shorthorn, Murray Grey, Brahman, Belmont Red and Santa Gertrudis breeds, and crossbred progeny out of 1100 Brahman cows donated by beef industry producers. 1.6 million pieces of information were collected on these 12,000 animals both while they were alive and when they were slaughtered.
The cattle breeding programme has identified sires that will produce cattle which:

• Excel in traits which directly affect profitability : growth, carcass quality, boning room yield and beef quality;
• Perform in specific environments (north and south) under different production systems (pasture or feedlot) for specialist markets (Domestic, Japanese or Korean).
• Achieve eating quality excellence.
All breeds now benefit from more accurate and complete genetic evaluation of growth, carcass and meat quality traits by Breedplan, which has been greatly extended and strengthened by the knowledge gained.

A new phase of the CRC (CRC II) began in 1999, with broader involvement across the beef producing regions around Australia, including network sites in Queensland, South Australia, Western Australia, Victoria and New South Wales. This phase of the CRC was involved with further research on meat quality issues but extending these to beef supply chains and businesses as well as well as delivering the findings to end users. Studies to be completed by 2006 from CRC II include:

• How muscle cell growth and development affects eating quality
• How the deposition and expression of marbling is regulated
• Studies of how genes are influenced by nutrition to produce different beef quality results
• Identifying new gene markers for beef quality
• Improving efficiency of feed utilisation
• How to manage pre-slaughter stress to improve beef quality
• On-farm strategies to reduce the risk of pathogens entering our food
• Broadening the understanding and adoption of best practice, to improve eating quality of beef
• Further strengthen the meat quality practices in the Meat Standards Australia grading scheme
• Regional strategies to optimise genetics, nutrition and management to achieve high market compliance and guaranteed beef eating quality across Australia.

The third phase of the CRC (CRC III) is just getting underway and will be largely concerned with finding gene markers that control economically important traits. There are five programmes involved:

1. High quality beef for global consumers
2. Feed efficiency, maternal productivity and responsible resource use
3. Adaptation, parasite resistance and cattle welfare
4. Improving female and male reproductive performance
5. Integrated information delivery strategies
The total cost of the three CRC projects is in the region of $220 million of which Meat & Wool New Zealand is contributing a little over $2 million, thereby giving it access to all the outcomes.

Rob Wylie