Calculating and monitoring breeder mortality rates is essential for maintaining the health of your herd and your business. Breeder mortality is accepted by industry as one of the greatest challenges to individual property profitability and how the wider community perceives the industry’s ability to maintain high animal welfare standards. A number of factors can lead to breeders dying in the paddock, or being in poor condition and requiring euthanasia. With forward planning and good management, breeder cattle should exit the herd as strong and healthy cull cows – converting an opportunity cost into an animal welfare and financial gain.
In this article, we explore the effect of breeder mortality on productivity, calculating mortality and strategies to reduce breeder mortality.
The next step
After calculating your breeder mortality, the next step is to consider which strategic intervention will be the most beneficial and cost effective to your business. Online programs that are designed to assist in this type of decision making include BRICK and Breedcow, which are available for free on the FutureBeef website. These programs can be tricky to use, however the FutureBeef extension officers, in conjunction with Department agricultural economists, are here to help.
If you would like assistance using these programs, head on over to the FutureBeef contact page or contact your trusted agricultural economist.
Further reading and references
Jubb, T, Vassallo, R, & Annand, T 1996 ‘Estimating deaths in breeder age female cattle in the Kimberley region of Western Australia’, Australian Veterinary Journal, vol. 73, pp. 152-153.
Henderson, A, Perkins, N, & Banney, S 2013 ‘Determining property-level rates of breeder cow mortality in northern Australia’. Meat and Livestock Australia, North Sydney, New South Wales.
McCosker, T, McLean, D, & Holmes, P 2010 ‘Northern beef situation analysis 2009’. Meat and Livestock Australia, North Sydney, New South Wales.
McGowen, M, McCosker, K, Fordyce, G, Smith, D, O’Rourke, P, Perkins, N, Barnes, T, Marquart, L, Morton, J, Newsome, T, Menzies, D, Burns, B & Jephcott, S 2014, North Australian beef fertility project: CashCow, MLA, Sydney.
Could your herd be more productive?
McLean, I, Holmes, P, & Counsell, D 2013 ‘The Northern beef report: 2013 Northern beef situation analysis’. Meat and Livestock Australia, North Sydney, New South Wales.
Neithe, G & Quirk, M 2008 ‘A scoping study on potential beef production from the northern rangelands of Western Australia in relation to the supply chain’. Prepared for the Department of Agriculture and Food, Western Australia.
Smith, P, Stockdale, M, Drey, R, & Jeffery, M 2010 Industry Initiatives to improve young breeder performance in the Pilbara and Kimberley of WA Meat and Livestock Australia, North Sydney, New South Wales.
Segregation of breeders
Henderson et al (2013) found properties that practised segregation of breeders during the dry season had a 67 per cent reduction in female mortality compared to properties that did not segregate. The decreased mortality rate was attributed to the additional management strategies used by properties that segregate. Such practices include targeted supplementation, weaning to preserve breeder body condition, and management of pastures to ensure optimal nutrition is provided to classes of livestock with higher needs.
Additionally, the segregation of aged cows from the breeder herd, including bulls, reduces the chance of a cow reconceiving and being required to raise another calf through to weaning.
Calculating your breeder cow herd mortality
The first step of assessing whether mortality rates are impacting your business is to establish the extent of the problem. Mortality rates of all classes of cattle are a loss to your business, however focusing on those whose offspring generate income is a good place to start.
With any method of calculating mortality rates, the old adage is, “rubbish in = rubbish out,” therefore having correct and reliable data is important. Five years of cattle data is ideal when calculating mortality rates, as this allows for variation in seasons and minimises the fluctuations in the total herd size. This may not be attainable for all pastoral owners or managers, depending on circumstances, but the aim is to work with a minimum of at least three years of data. Three methods of calculating mortality rates are outlined below.
By quantifying mortality rates, you are better able to assess the cost versus benefit of the various options to decrease mortality. The choice of method in regards to calculating mortality rates will determine the accuracy of the data available and the accuracy of mortality rate required.
Method One
In the study commissioned by MLA in 2013 (Henderson, Perkins & Banney) an excel based breeder mortality rate calculator was created and is available on the MLA website.
In order to use this tool to calculate your female mortality rate, the following data is required over a three to five year period:
- Opening females (this includes opening breeder numbers)
- Purchase of females
- Number of female calves branded (usually 50 per cent)
- The females used as rations (killers)
- Total female sales/transfers
- Closing number of females
*The accuracy of the final output is dependent on the starting number at year one and the closing number at the end.
The same information can be entered from the male data to give you an indication of steer losses.
The breeder mortality rate calculator will give you a total mortality rate for your all females, as well as a mortality rate for non-breeding females and steers, but accurate data is essential.
If there are concerns about the accuracy of the data, there are alternative ways to determine your female mortality rate.
Method two
By assuming 50 per cent of calves born each year are females, it can be expected that 50 per cent of cattle sold (varying in age) should be female. By using the equation below, a percentage of females sold can be calculated.
If the result is less than 50 per cent, it gives an indication of what the female mortality rate may be, provided the size of the breeder herd has remained constant. For example, if you reach a result of 46 per cent female sales, you can assume approximately four per cent of your females are unaccounted for/dead.
