Profitable Slaughter Age in Ostrich

Newsletter No. 29 – August 2005 Item 2

The SAOBC [South African Ostrich Business Chamber] published a new article in July under the heading of Research and Development.  The article is written in Afrikaans and no longer available on line at the location at the time of publication of this newsletter.   An English translation is available at the end of this post.

The article is a discussion on a study on the economic impact of slaughter age on meat yield of ostrich. One has to question why a costly academic project using public funds was set up to do the study in this manner with just a few birds when this is the type of study that all successful commercial farmers do every day, of every week, of every year as standard management practice in other commercial specie.  It is the reason for maintaining records of all feed input and yield output and the input costs vs the output revenue.  It is the way to identify the good genetic animals, identify the rations with the right production potential to challenge the better genetic animals.  This is the mechanism to bring forward the slaughter age and at the same time increase the yields to reduce the costs of production.

This study is flawed in many ways.  The study assumes that all feed, all management systems, all environmental factors and all genetics perform the same and have no influence on results.  As any one with knowledge of production livestock knows that is not true at all.   The study fails totally to understand the difference between simply "raising livestock" and operating a "production livestock unit".

The study reports an overall increase in carcass weight of 31kgs to 52kgs between the ages of 8 months and 16 months.   My own birds, from similar genetic stock, recorded carcass weights of 39kg at 34 weeks (8 mths) and 54 kgs at 42 weeks (10mths).  When the skins were put in front of members of NOPSA (National Ostrich Processors of South Africa) they assessed them as being from 12 to 14 month birds.  I am not alone in achieving these results from younger birds.

The study was funded by THRIP, the Technology and Human Resources Industry Program, a joint initiative supported by the Department of Trade and Industry and the National Research Institute.  The THRIP program promotes cooperation between higher education institutes and businesses with the aim of enhancing the competitiveness of South African industry.    The question has to be asked why the South African Ostrich Industry research continues to resist investigating improving performance, slaughtering younger and implementing production livestock techniques that make up the "true science of livestock production" to ensure that their producers remain competitive?



Presented by the SA Ostrich Business Chamber – enquiries:  Anton Kruger Tel: 044 272 3336 - with acknowledgments to Tertius Brand, Annelie Kruger, Bennie Aucamp and Clovis Bhiya


Slaughter age plays a vital role in the yield of slaughter birds, with an increase in feed and set up costs on the one hand and also a increase in the worth of the end product on the other hand as the ostrich gets older.

An experiment is being carried out at the Kromme Rhee experimental station in order to determine the influence of slaughter age on the yield of ostrich. In the first experiment, 80 birds were raised to around 6 months, then divided into 10 groups of  8 each, and 2 groups were slaughtered at the following ages: 8, 10, 12, 14 and 16 months. In the 2nd experiment, 100 birds were raised to 3 months of age, then separated into 10 groups of 10 each, and then 2 groups were slaughtered at the following ages: 8, 10, 12, 14 and 16 months.

The birds were fed ad lib and production data (capture and feed turnover) was determined on a monthly basis. Yield per bird in terms of carcass, skin, and feathers was determined for the different slaughter age groups between 8 and 16 months. Yield of end product on a monthly basis was outlined thanks to linear regression comparisons (equations?). Here we will only deal with data from the first experiment where birds were raised to between 6 and 16 months, since the 2nd experiment is still under way.

Capture per bird per day, feed use per bird per month as well as cumulative feed use per bird for the different monthly intervals are shown in table 1. In order to work out total feed cost per bird, feed prices from the current experimental home mixture (with additional 10% processing costs) were used. Feed costs for situations with a 25% and 50% more expensive diet are also shown. Cumulative feed costs for all 3 situations are calculated.

The slaughter weights and carcass weights of the birds for the different slaughter ages between 8 and 16 months is shown in table 2. Ostrich delivery prices for export from the KKK are outlined below in table 2, and are used to calculate the yield per carcass for the different age groups. Slaughter weights increased from 65 to 122 kg between 8 and 16 months with overall carcass weights of 31 to 52 kg. Resulting percentages decreased with an increase in slaughter weight from 31 to 52 kg. Total net high price-cut yields of both hindquarters increased from 14.2 to 21.1kg per carcass over the slaughter interval. The leather yields per slaughter bird for the different age groups are shown in table 3. Skin surface as well as follicle size increased with an increase in age as expected. Grading of skins decreased with an increase in age. This then meant that the yield per hide between the ages of 9 and 16 months stayed relatively constant. Prices of legs (R15 [$2.28] for 1st grade, R9 [$1.37] for 2nd, and R0.10 [$.015] for 3rd) was not taken into consideration.

Estimated yields of feathers per slaughter bird at different ages is shown in table 4. Birds in this study’s feather yields were not yet available. Feather weights in the study increased with an increase in age.

Total yields for the hide, carcass and feathers per bird is shown in table 5. A standard slaughter tip of R161 ($24.52) per carcass was subtracted from the total yield. Totals yields per carcass varied between R925 ($140.86) and R876 [$133.39].

The experiment was started with birds from around 6 months of age and average weights of 58kg, Current purchase prices are of around R13 [$1.98]per kg live weight which gives an starting value per bird of R745 [$113.45]. Yields per bird minus the initial value of R745 [$113.45] per bird are shows in table 6. When feed costs such as laid out in table 1 of the yields minus the initial price shows a margin of feed costs.

It is clear from table 6 that the current circumstances with relatively cheap raw material prices places the optimal slaughter age at between 10 and 14 months – and the margin after costs is around R496 [$75.53] per slaughter bird. If the feed price is 25% higher, then the optimal slaughter age is between 10 and 11 months. With the highest feed price one gets the highest margin above feed costs at the 10 month slaughter age group. It is clear that with the more expensive diets, the margin above feed costs decreases drastically, if the birds are slaughtered at an older age.

Conclusions and summaries:

* This is a case study and any changes in the feed price or price of end product will change the situation.

* It is clear that if the producer makes an effort to better his grading, the margin above cost will increase at higher slaughter ages.

* All measurements in this study are objective except grading. Grading differs from tanning, and this will affect the final margin above feed cost.

* The later the bird is slaughtered, the higher the costs (e.g, medicines, work etc) which is not taken into account here.

* This study suggests that in the current situation with raw material costs and prices of end product, the margin above cost remains almost unchanged with a slaughter age of between 10 and 13 months. If the raw materials and/or feed prices rise, then the margin above cost would be better with an earlier slaughter age above 10 months.

Thanks This study was made possible by the financial support of the THRIP program of The National Research Foundation of SA.

The following people were helpful in the furnishing of technical and/or economic info:…
Dr Willem Bruger (Klein Karoo Koöperasie)
Mnr PA Geldenhuis (Klein Karoo Koöperasie)
Me Alida Tredoux (Klein Karoo Koöperasie)
Mnr Pieter Liebenberg (Klein Karoo Koöperasie)
Mnr Paul Jooste (Swartland volstruise)
Mnr Stephan Shressbury (Swartland Volstruise)
Mnr Koot van Schalkwyk (Mosstrich)
Mnr Derick Engelbrecht (Lusernsaad Raad)
Prof Schalk Cloete (Elsenburg)

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