The Meat and Wool NZ Manawatu Monitor Farm Finishing programme kicked off with a Beef Finishing seminar last November.
Jim Gibbs from Lincoln University spoke about normal rumen function where plant carbohydrates are converted to acids which are buffered and absorbed or flushed through the body. High-quality pasture can have high levels of water-soluble carbohydrates. In excess, these overwhelm the rumen with acid, so they cannot be buffered or excreted. This creates a low rumen pH, which results in lameness, liver abscesses and metabolic deaths.
Gibbs' research shows that NZ pasture-fed animals have a normal daily fluctuation of rumen pH from 5.6-6.5. Acidosis has previously been defined as a rumen pH <5.5-6.0. Acidosis found on improved pasture differs from that seen on grain-fed diets and does not appear to affect our cattle. However, half of NZ's manufacturing beef comes from pasture-fed bulls of which 10% have liver abscesses.
It's proposed that damage to the rumen lining allows bacteria to spill into the bloodstream and seed into the liver, causing abscesses. This may reduce liveweight (LW) gain and even cause death. The incidence of liver abscesses in NZ beef bulls seems to be increasing and is similar to that of grain-fed cattle.
Steve Morris, from Massey University said fast-growing animals are the most efficient. To improve efficiency, the output of beef for a given unit of feed needs to be maximised. In general, animals with a higher mature LW grow faster but have greater maintenance requirements. If these animals are fed well, a greater proportion of feed is partitioned towards LW gain.
Angus Mabin, a bull farmer from Waipukarau demonstrated how technosystems had been implemented on his farm and their gradual adaptation to his farming system. This fencing system is flexible enough to change between seasons or within different blocks on the farm. Angus provided practical concepts for improving the efficiency of technosystems, some of the downfalls and many of the benefits.
Lindsay Rowe, Totally Vets' Intelact consultant, advised on managing pasture. The ryegrass tiller produces only three leaves before the oldest leaf dies and a new leaf emerges. The time between new leaf appearance is determined by soil temperature and moisture. It is best to graze at 2.5 leaves/tiller to optimise plant quality, re-growth, and survival. Grazing management should focus on rotation length, grazing intensity (residual pasture covers) and duration.
Trevor Cook outlined some major animal health issues in cattle finishing systems and highlighted the importance of purchasing stock with a good health status - i.e. know your rearer.
Quarantine drenching is important. Create a customised parasite control and trace element monitoring programme with Totally Vets. Planning includes targets and monitoring with fixed timelines. Optimising animal health will allow maximum LW gains to be achieved.
Totally Vets has copies of the Finishing Seminar presentations and would be pleased to speak with you about any of these issues.
