Industry Research - Review and Future Research

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Part 1 – Review of Past Research

Introduction

Research in farming ostrich first started in the late 1980’s in South Africa with information only available to the producers of the KKLK, Oudtshoorn, South Africa. Prior to that date ostrich farming followed extensive systems of production. Development of methods to clean and dye feathers as well as methods of tanning the skins took place before that, with little attention paid to farm production.

The industry was starting to develop globally at the same time. Researchers given the task of producing rations for ostrich looked to South Africa for guidance assuming that producers there achieved commercial levels of production and the data published well proven. They missed key indicators that this was not true and so started a series of scientific review papers and research referencing material that was inaccurate.

There are a number of areas to look at when evaluating results of different papers.

Nutrition (inputs)

Management Systems

Genetics

Historical records

Environment

Consistency of all of the above

During a breeder market there is no market yet created for slaughter birds, which results in all birds “sold as potential breeders” and as the breeder market collapses “eggs are not incubated.” This makes it impossible to obtain any meaningful long-term records.

The introduction of Ostrich to each new country during the 90’s resulted in many papers produced by scientists. Very few are proving to be of much value. This paper will set out to review several that have had a major influence and help explain the continued negative production results.

“A Practical Guide for Ostrich Management and Ostrich Products” - published by Alltech in 1995 is a free publication. The booklet contains chapters written by different scientists, some not specialists in the subjects discussed. The chapter on Feeding and Feed Management contains data on the perceived nutrient requirements of ostrich. Other publications then published this information assuming the information accurate and proven, when this was not proven. This misleading nutritional information is the foundation for many feed mill nutritionists producing rations for Ostrich in all countries of the world producing ostrich.

The following review provides a better understanding why this is the case and proves the poor production.

1. Ration Detail

a. Video of Presentation to California Ostrich Association – 1997 [1]

Breeder

The importance of the contents of this video is that the work of the presenter is the basis of the information referenced above and published in many publications. The video was widely distributed throughout the United States and production levels fell away rapidly following distribution, as feed companies adjusted their rations, which then led to the situation of not being able to raise chicks with adult production failures.

A statement at the beginning of the video referenced that “if the feed formula is correct and birds are getting the nutrients they need, they will produce 20 chicks average per hen and the chicks will have a 20% mortality rate". He strongly indicates that these are his production parameters that he designs his feed around--and a well designed feed formula should support that production goal.

Comment:

A production feed goal of 20 chicks per hen with a 20% mortality rate is uneconomic for any producer in the modern industry and totally unreasonable for a bird capable of producing in excess of 100 eggs. During the early years of production in the United States there are records of hens laying well in excess of 100 eggs, with 167 the highest reported[2].

To formulate rations with such poor production goals will leave breeders severely nutrient deficient as their genetics are capable of considerably higher levels of production.

Fat

The video clearly states, "Feed formulas must be produced to prevent any fat on the birds". "Abdominal FAT is of no use to the bird whatsoever and a waste of feed dollars.”

Comment:

It is a known fact that a certain amount of fat production is essential to good health, bird survival and production. A certain amount of fat production is essential to achieve good muscle development. Breeder birds require good fat reserves to support them through a hard breeder season. All birds require a certain amount of fat to see them through times of stress – especially weather stress. Too much fat is a clear sign of poor nutrition and/or a faulty feeding management program, but no fat will severely affect health and restrict production, costing the producer lost revenue and all too often dead birds. The quality of the fat is also important. Fat that is yellow in colour will be difficult for the birds to mobilise fast enough at times of stress, when higher energy is required.

We regularly have producers make contact with us after loosing a number of birds. In many cases we find the birds, on autopsy, have no fat. On further investigation there nearly always has been a bad storm or similar stress factor a week or so before the deaths. The nutritionist tells the producers that there should be no fat. This is the origin of that misleading and incorrect thought process.

Meat Production Program

The statements in this section are very clear that the target is to achieve 95kg birds at 14 months of age and a 5 step feeding program is designed to achieve that is presented--along with discussions about being the right age for hide quill development, hide size, and so on.

The first section discussed growth rates and it can be seen that 95kgs at 14 months is very slow. It is also uneconomic for producers to continue to feed birds capable of achieving these weights in half that time.

The feeding program is:

Pre-Starter feed

0-2 months of age

22% protein

55-60% grains

5% or less roughage

The presenter states that chicks should not have any fibre at all if possible as they cannot utilize it.

Comment:

Subsequently the presenter has acknowledged this information is wrong and has since increased the fibre he recommends in baby chick rations.

The use of the word ‘roughage’ is also misleading. It is worth remembering the definition of ‘roughage’: "Fibrous, indigestible material.......” In a nutritional sense, Roughages have no place in Ostrich rations. The fibre should always be from a quality source and highly digestible.

Grower and Finisher Rations:

The presenter states protein levels of the grower ration may be lower for chicks not plucked at 7 months of age. The design of the final ration, the Post Finisher, is for feeding from age 10 months to 14 months.

Questions:

Why hold an animal for 6 months before slaughter? What is the cost to the producer? How much does it increase the cost of meat and skin?

Answer:

The reason given for holding the birds till 14 months for slaughter is to ensure the skins are mature, which is not a necessary function, but we will discuss this issue later.

Comment:

A bird consumes 450kgs in 10 months. At a rate of 2.1kgs/day, that is a further 250kgs – 50% increase in feed intake, plus costs of additional infrastructure, labour and working capital. This practice does not make commercial sense.

b. Recent Advances of Ostrich Nutrition in South Africa: Effect of Dietary Energy and Protein on Production – South Africa[3]

This paper discusses variable rations considered by the authors as low, medium and high energy and low, medium and high protein. The paper reports the use of low quality ingredients and does not discuss any details of vitamin and mineral supplementation or any other nutrients essential for health and production.

In slaughter birds, it reports surprise at the minimal changes in feed conversion between the different rations, and references their inability as researchers to understand this.

Comment:
The point missed is that the study had in fact proven beyond doubt that all the rations are severely nutrient deficient as all birds produced lower slaughter weights than the Degan study carried out in 1991, referenced below. The Degan study worked with rations designed for Turkeys, so it only makes sense that if birds can produce greater growth on rations designed for a different species, then something must be wrong with rations and management systems that result in slower growth rates!!

It also makes sense when producers elsewhere are reporting significantly better results – as the ‘US/Blue Mountain Farmer Weight Gain Study’ and other studies have clearly demonstrated that significantly better growth and feed conversion rates are possible when rations are better designed to the suit the needs of ostrich.

c. Effect of Different Protein Levels in Ostrich Rations on Some Haematological Parameters - Turkey[4]

This study set out to study the effect of two different protein levels in breeder rations but the study contains some serious flaws in methodology and therefore the conclusions drawn. It takes a full two years to see the full effect of a change in rations – both positive and negative. This study used eight year old breeders with no history reported and the study only lasted from March to September on the layer ration and five months on a winter ration. The study, presented as a poster, is limited in information made available.

However, the study contained a serious flaw that rendered it meaningless for the objective, to establish the effectiveness of different protein levels fed. They reported two layer rations, one of 20% protein and the other at 23% protein, both with the same energy levels plus alfalfa hay fed ad lib, with no reference to the quality of the alfalfa hay, which could vary from 13% protein to in excess of 20%. In winter the birds received ad lib alfalfa hay, maize silage and 700 grams of grains.

Comment:

There is no record of the protein levels in the hay and silage or actual consumption of hay or silage, making it impossible to determine the actual daily intake of protein. The total intake of protein is the important figure, not simply the level per kilo of compound feed.

d. Feedstuff Evaluation of Ostriches – South Africa[5]

This study set out to evaluate energy levels in different feed ingredients and subsequently formed the basis of information widely published on Ostrich nutrition. Cilliers kept the birds in crates for the duration of the trial, with intake of ingredients measured along with the amount excreted.

Comment:

Researchers went on record as early as 1981, nearly 15 years before this study, recognising that this method of feedstuff evaluation is unreliable and outdated. The reason this method of evaluation is unreliable is because researchers now recognise that the utilisation of individual nutrients in the different feed ingredients is totally dependent on other ingredients and nutrients in the ration, as all are interdependent on each other to achieve optimum utilisation.

The results of this work formed the basis of the widely published incorrect data used by many nutritionists and researchers around the world. The result is the tremendous amount of misinformation developed from false assumptions that has been very costly to producers and processors in every country involved with Ostrich.

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2. Production Data

The industry has very limited production data available, but what there is illustrates that current levels of production must improve dramatically if the industry is to become commercially and economically viable. A review of published production figures proves this statement and demonstrates the untapped potential.

a. Growth Rates

The narrative in the publication “A Practical Guide for Ostrich Management and Ostrich Products”, referenced above, discusses how the scientists used this published nutritional data to verify the accuracy of the Gompertz model for growth performance data of ostrich published by Stellenbosch University in 1992. The converse should have been the case, to use the original Gompertz model of 1992 as a measure of the accuracy of the rations discussed. When the rations discussed did not achieve growth rates close to the original Gompertz model, the researchers downgraded the original Gompertz model, believing it to be unachievable. They should have searched for reasons why they did not achieve the predicted performance levels.

That information led Benson to explore this further and graph the various data to make fair comparisons.[6] Figure 1.

The commercial producer cannot ignore the importance of the information that these comparisons prove.

Figure 1 - Comparative Growth Studies

Gompertz A

Produced in 1992 by the scientists at Stellenbosch University to estimate the potential growth curve

Degan

A trial reported to use rations designed for Turkeys.

Cilliers

Trials reported to use the figures in the published data.

Gompertz B

This growth curve is an adjustment to Gompertz A because the birds in the Cillier’s trial achieved growth well short of the Gompertz A expectations and it was suggested the Gompertz A was an over estimate.

BLUE MOUNTAIN/US Weight Gain Field Trial

This is the average of a farmer field trial carried out in 1996/97 and proves the Gompertz A to be a reasonable assessment and achievable. The birds in the trial achieved maximum growth at maturity, which is after termination of the trial.

Question:

What do these studies prove?

Answer:

They prove that the trial in which birds performed less well than birds raised on rations designed for a totally different species, was the basis for downgrading of the growth target which became the new industry standard.

Question:

Why adjust the original Gompertz model to a level of performance below that achieved by a trial working with rations designed for a totally different species as this does not make commercial or scientific sense?

Comment:

The published nutrient levels for the trials that led to downgrading of the Gompertz A growth model are the nutrient levels now used as a basis for the majority of ostrich rations produced today. This explains the very poor levels of production currently achieved. Low levels of production result in very high costs of production - high Production costs and high Processing costs.

b. The Primary Study on the Stability of Laying eggs of African Black Ostrich - China[7]

Table 1 is a record of production of a commercial farm in China.

Table 1 - Production performance of breeding stock

Year	Number of female breeding ostrich	Total number of laying eggs	Incubation number	Fertility	Hatchability	Average of laying eggs	Average of day-old chick	Egg to Day Old Chick
1998	155	8328	7971	72.94%	77.21%	53.73	30.37	57%
1999	153	8848	7982	70.85%	76.07%	57.83	25.29	44%
2000	166	9821	9145	67.87%	79.22%	59.16	29.62	50%
2001	206	13541	12690	70.14%	79.59%	65.73	34.38	52%
2002	210	16224	15476	68.23%	83.16%	77.26	39.11	51%
2003	192	13500	7594	74.21%	82.31%	70.31	27.34	39%

Comment:

Eggs recorded until October, to total eggs laid may have been greater in 2003. They also reported stopping incubation in 2003 because of poor market conditions. The important figure is the low conversion of egg to day old chick. This paper did not cover survivability but the paper indicates that production is in line with current world averages.

c. Are your goals high enough – Australia[8]

Bunter carried out a major International survey. The results are from data from over 200 ostrich producers in 35 countries. All producers should pay close attention to the results of this survey as they confirm the very low, and uneconomic, levels of production. This survey also illustrates the impact of poor chick survival in the early weeks.

Table 2 - Reproductive performance (%) achieved in farmed ostriches

[note: 103 to 110 contributing records in full data; 25 contributing records for >20 hens category]

	From Full Data			From >20 hens
	*Average Value*	*Av. Best 25%*	*Av. Worst 25%*	*Average Value*	*Av. Best 25%*	*Av. Worst 25%*
Infertile	20.3%	2.68%	14.5%	26.1%	11.9%	47.8%
Hatching	63.8%	85.4%	37.6%	57.1%	84.7%	31.0%
Mortality (1 Week)	7.26%	0.3%	16.3%	5.0%	0	14.8%
Mortality (1 Month)	16.9%	2.8%	41.9%	13.8%	1.8%	29.6%
Mortality (3 Months)	26.2%	4.2%	62.5%	24.6%	3.9%	50.5%

Table 2 proves the serious problem with breeder production and chick survival.

Quoting Bunter’s words: Currently for each chick surviving to 3 months of age 2.1 eggs on average were incubated, supporting the commonly held view that less than one slaughter bird will result from every two eggs incubated. After allowing for differences between producers in the percent of eggs incubated, overall efficiency of chick production was very poor (approximately 49%).end quote

Table 3 - Productivity measures of farmed ostriches

[Note: 81 to 111 records contributing to full data; 25 contributing records for >20 hens]

	From full data			From > 20 Hens
	*Average Value*	*Av. Best 25%*	*Av. Worst 25%*	*Av. Best 25%*	*Av. Worst 25%*
Eggs laid/hen	34.8	61.4	14.5	53.2	17.0
% hatched of fertile	78.8%	96.3%	52.5%	96.6%	55.7%
Chicks hatched/hen	18.5	40.5	4.24	34.3	4.17
% Hatched Total Laid	53%	66%	29%	64%	25%
Chicks/hen (1 Week)	17.4	39.2	3.83	33.5	3.95
Chicks/hen (1 Month)	15.9	37.4	3.06	30.3	3.51
Chicks/hen (3 Month)	15.3	36.9	2.39	28.7	2.50
Eggs laid/chick (3 Months)	7.70	1.47	24.0	1.6	6.81

Note the significant variations from worst to best in Table 3. A fair target is less than 1.2 eggs to 1 slaughter bird.

d. Latest Feeding Standards for Ostriches – South Africa[9]

This paper discusses variable rations on what the author's considered to be low, medium and high energy and low, medium and high protein rations. The paper reports the use of low quality, non-productive ingredients and does not discuss any details of vitamin and mineral supplementation or any other nutrients essential for health and production. 9 different diets were the basis of this study, all with differing energy and protein levels and then followed a year later with a further study reducing nutrient levels further.

Table 4 - Comparative Studies

	Study No. 1			Study No. 2
	Average	Best	Worst	Average	Best	Worst
Egg production per hen	49.3	53.9	43.7	48.1	55.2	38.1
Embryonic mortalities	36.9	30.7	42.5	19.4%	16.2%	22.2%
Chicks Produced Percent	63.1%	69.3%	57.5%	52.4%	57.2%	47.2%
Chicks Produced Number	31.1	37.4	25.1	25.2	31.5	18.0

There was no report on chick survivability. The study reported the hens in Study 2 demonstrated significant weight loss during the season. There was no report on the hens used for the different studies. Nutritional history is exceedingly important when evaluating results in this way.

The study concluded: quote: The most recent research results indicate that current nutritional specifications for ostrich diets may be lowered under certain circumstances, without a loss of performance. end quote

Comment:

The study actually proved quite the reverse..............it proved that all diets studied resulted in poor breeder performance that is uneconomic for producers.

The difference in the best of Study 1 and the Worst of Study 2 at a gross margin of $25/chick on each slaughter bird is $9,500. This does not take into consideration the increased gross margin achievable with stronger chicks at hatch, faster growth rates, greater meat yields and reduced slaughter age or reduced chick cost because of increased breeder production.

e. Chick Growth and Feed Consumption - Poland[10]

Table 5 - Mean rearing performance of 25 ostrich chicks fed mainly mixed concentrates

Item

Chicks age (Days)

Body Weight (kg)

Daily body gain (kg)

Feed Conversion Ratio

0.88

1.26

.38

1.56

2.03

.77

1.71

2.47

.44

2.37

3.19

.72

1.85

6.60

.41

3.39

4.46

.86

2.83

The discussion supporting Table 5 references the tremendous variability reported by different researchers and states that the farmer in this practical example was short feeding the chicks for fear of poor skeletal development.

Table 6 - US/BLUE MOUNTAIN Benchmark Weight Gain Trial

Comment:

Short feeding is not the solution to developing strong skeletal development. The solution starts with the breeders providing sufficient nutrients to ensure strong chicks at hatch. The next stage is to ensure rations containing sufficient nutrients to build a strong skeleton and good growth from day 1 to optimise the tremendous feed conversion available in the early weeks of life. Compare those growth rates and feed conversion with the US/BLUE MOUNTAIN Benchmark weight gain trial - Table 6.

Figure 2 - Chicks 63 Days Old (South Africa)

Figure 2 is the first batch of chicks reared by Benson from Day 1 using the Blue Mountain premixes and formulations, which are of high nutrient density using very specific ingredients. The quality of the lucerne fell short, but the results are still striking when compared to the data reported from Poland. The chicks are from the same batch and purchased from a local farmer in South Africa. They came with no records or specific genetics. Benson observed significant variation in the growth rates, with the largest chick weighing 6kgs at 30 days and 21 kgs at 60 Days. (Note the above study Table 5 references the chicks at 4.5kgs at 60 days) The majority in this batch averaged 4kgs – 5kgs at 30 days and 12kgs – 15kgs at 60 days. The smallest was barely 2kgs at 30 days and 4kgs at 60 days. This smaller chick did catch up later, but always lighter than the rest. Note the strong legs and solid frames on the larger chicks.[11]

It was later discovered that the breeders had no additional feed to supplement their grazing during the off season and at the time the eggs were laid they received a ration designed to balance with lucerne and the hens were in fact grazing grass. Therefore, their rations will have been imbalanced and is one explanation for such variability in the growth rates of the different chicks. Genetics is another possible explanation, but all chicks are Oudtshoorn genetics. What this batch demonstrated is the untapped potential when all things are right.

Comment:
The above statistics all prove beyond any doubt that our industry has to change the approach, as producers cannot be commercially viable with such low levels of production per hen and slow chick growth. They prove the lack of commercial awareness of some researchers when writing their conclusions.

With the increasing proof of poor production, why do producers continue to follow methods of production that are contrary to productive and commercially viable agriculture?

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3. Studies

a. Ultrasonography of the reproductive organs[12]

This paper set out to determine whether transcutaneus ultrosongraphy is a suitable diagnostic tool to monitor reproductive organs of female breeding ostriches. The paper discussed the current poor production of hens as the motivation of need, confirming again the current poor levels of production.

The photo Figure 3 of one of the birds used in the study shows a hen desperately stunted in growth, terribly thin, very little muscle, thin legs, poor feathering and a tiny body. In fact she is in such poor condition and underdeveloped, it is amazing that she was producing any eggs at all. The report states the scans were carried out on poor egg layers that were going to be culled.

Figure 3 - Hen used in Study

The report included the diet fed the birds, but with insufficient detail. However, there was sufficient information to conclude the diet nutrient deficient for laying hens as it included grazing grass and dried grass, maize silage or lucerne silage as the forage component. There are significant variations in these 3 ingredients with no references to adjustments made to allow for these differences indicating a lack of understanding of the importance of this information.

Figure 4 - Egg Follicles from Study

Comment:

Studies carried out under these conditions, using malnourished birds to this degree, can provide misleading results. One of the results of poor diet and negative nutritional history is the failure of the reproductive organs to develop properly. If all the birds were looking like the bird in Figure 3 and all the birds producing similar looking follicles, to those in Figure 4, then misleading conclusions can result. The narrative does not make it clear if these follicles came from one of the birds, or simply used for illustrative purposes when discussing the structure of egg follicles.

A more valuable approach would compare those eggs and their reproductive tract with strong looking and good producing birds - and all the inputs and history of those compared. Of course, it is difficult to get the opportunity to observe good producing birds as you don't want to disturb them for ultrasound or kill them for confirmation.

Figure 5 - Egg Follicles from Casualty High Production Hen

The egg follicles taken from a casualty hen in Figure 5 provide a comparison. The hen producing these follicles received a 21% protein ration with high supplemented vitamins and minerals. She was a Nutritional Class 6 hen[13].

This study confirms again malnutrition as the fundamental cause of poor production at this time and there is no quick fix to replace good nutrition.

b. Ostrich Meat Industry Development[14]

Data

This was a detailed study carried out in 1992 by Texas A&M University on behalf of the American Ostrich Association (AOA). The study evaluated ostrich carcasses and meat and carried out at a time of very high prices for ostrich in the United States and no commercial slaughter yet taking place. The study used 18 Ostriches with an age range from 10 months to 24 months. 14 were used in the main study and the older birds were used to evaluate ‘value added’ processed meat products. 10 producers supplied the 18 birds for the study, indicating not only the differing management systems used to rear the birds but also that the birds supplied, when the breeder market was nearing it’s peak are unlikely to be the best birds! With that fact in mind, close investigation of the data recorded raises some interesting facts, especially when connecting to earlier discussions in this document on growth curves and meat yields.

The researches weighed every part and calculated the live weight as the total of all the parts. Table 7 is the summary showing all these weights. The researchers used two different methods for bleeding the birds and this is the reason given for the significant variation in the amount of blood recorded. Initially they cut only below the head. They then bled by severance of the heart, carotid artery ad jugular vein achieving a significantly improved bleed.

Table 7 - The mean weight, standard deviation, minimum weight and maximum weight of each live ostrich, carcass and by-products

Comment:

A significant difference is evident from the worst to the best, indicating significant differences in the birds. The reason for the difference will be a combination of age, genetics and management systems. Not included in the report are the individual weights and ages, so it is not possible to evaluate the most dominant cause of such variations. However, it was a very early warning signal to the industry that all birds are not the same and recognise the need to pay attention to developing greater uniformity.

Very evident are some extreme variations, including fat and reproductive organs. Correctly fed birds ranging from 10 months should not see such extremes in fat. It is possible that the reproductive organs will have reasonable variation as the older birds may have been in season and will have more mature reproductive organs. However, a 10 month bird should still have developing reproductive organs and egg follicles. These variations indicate virtually nothing in some birds. There is no reference to the age of the top age of these 14 birds. The researchers attribute the large variation in blood to the change in bleeding system.

Table 8 - Comparison IOA Muscle Weights and AOA Study

Table 8 is a comparison of the muscle weights included on the IOA Meat chart and the muscle weights recorded in this study. The important point to note is the increase in average muscle size of 64% over the IOA Chart. The basis of the IOA weights are current average weights produced under South African management conditions and the early production in the United States was already 64% above. This is further proof of the untapped potential of the industry and the failure of the South Africa production systems to produce birds with commercial meat yields.

Muscle Names and Numbers

A revision to this paper first published in June 1993 took place in October 1994. The changes in the revision were to adopt the Latin names applied to the individual muscles by a South African scientist to ensure consistency and discard the Latin names originally applied by the scientific team involved in this study.

The American Ostrich Association drew up their meat chart based on this study. Australia, Israel and Canada also drew up meat charts; all were a little different and applied different English names to the muscles. In some cases different muscles received the same name. This resulted in significant confusion in the market place, a situation aggravated by so many new production units entering the industry that abounded with inexperience, including in South Africa.

The committee, made up of meat scientists from many of the countries attending the First Ostrich Meat Conference in February 1997, created the meat catalogue known as The International Ostrich Meat Buyer’s Guide. This catalogue matched muscle numbers to the Latin names. The AOA chart had done the same; the problem was their system was different to the new system and they complained, even though their representative on the committee was very satisfied with the new system. That resulted in publication of The International Ostrich Meat Buyer’s Catalogue, Second Edition within 12 months. This was now to become the industry standard.

To overcome the tremendous confusion in English Names the International Ostrich Association created the Meat Buyers Guide. This attempted to consolidate English names to muscle numbers using English names they hoped all would adopt. It did not carry the Latin names as this is not required in the commercial environment. There are problems with this guide. One of the problems is the weights provided, second is the names chosen to represent the degree of tenderness, which will vary according to rearing method and age of animal and finally OS numbers applied have been switched on two muscles – OS1013 and OS1011 should be reversed. It is a hybrid between an Industry Meat Chart and Company Product Chart and fails at both.

The problem with the guideline weights is that buyers expect muscles to be that weight, but currently our industry is producing huge variations so the buyers are disappointed not receive those weights. There will also be a variation in weights of muscles from slaughter birds and those from cull breeders. Table 8 illustrates how low those weights are, yet they remain the current industry standard.

The muscle names should reflect their location but never degree of tenderness as the method of rearing and age of the animal are the controlling influences. For example there was the Fan Fillet, instead of simply the fan; the Oyster Fillet instead of simply the Oyster and Rumpsteak rather than just Rump.

c. The High Final pH Value of Ostrich Muscles[15]

This paper discusses the results of Post-Mortem pH Decline in Different Ostrich Muscles[16] a study that set out to determine the rate of pH decline in various muscles after slaughter. These papers have been instrumental in belief that all ostrich slaughtered demonstrate pH levels higher than is considered an acceptable norm. The author also attributed the dark colour to the pH.

Comment:

The method of rearing and the slaughter methods affect pH in a similar manner to other meats. Commercial companies proved very quickly that ostrich raised and slaughtered correctly record pH levels in line with other meat specie. However, to date there is no scientific paper to correct this information. Some members of NOPSA (National Ostrich Processors South Africa) recommended undertaking such evaluations as a matter of urgency because they could see the dangers negative publications could cause.

The important issue in this discussion is that farm management systems (including nutrition) and slaughter methods affect the pH and meat colour in a similar manner to other meat specie.

d. Influences of Ostrich Skin Quality . . . Age or Nutrition?[17]

This paper proves that ostrich raised on quality nutrition will produce skins that are acceptable to the industry. The paper also demonstrated that age alone does not influence follicle size. This study covered two slaughter batches. The first consisting of 35 chicks ranging in age from 34weeks (240 days) to 60 weeks (420 days).

The second batch slaughtered at 34 weeks (240 days), but reported as a batch slow to get started because of extreme weather during their month.

Table 9 - Classification of Ostrich Skins Based on Follicle Development Batch 1

Class	Number of Skins	Percentage of Total
1	18	50%
2	12	33%
3	6	17%
4	0	0%
TOTAL	36	100%

Benson asked the tannery, when grading the skins, to set classifications and classify the follicle development. 4 Classes were set where Class 1 was optimum and Class 4 downgraded with follicles considered too small.

Table 9 shows 50% fell into class 1 and there were no class 4 skins. The interesting analysis came when looking at the ages. Average classification achieved was Class 1.6 and average classification for chicks 10mths and under was Class 1.7.

The Class 3 skins were 1 x 9mth, 2 x 10mth, 1 x 11mth, 1 x 12mth, 1 x 14mth. This clearly indicates that age is not the determining factor. All skins were of acceptable quill size/follicle development. One point of interest noted is a comment on 1 x 14 month skin. The quills were flatter and less prominent, a factor usually only observed in cull breeders or birds that are very much older than 14 months.

Skin size is often a problem with slaughtering birds at a younger age. The birds in these batches 10 months and younger achieved an average of 15.54 sq. ft. All skins achieving well above the minimum size for Grade A skins (greater than 14sq ft).

Table 10 - Classification of Ostrich Skins Batch 2

Class	Number of Skins	Percentage of Total
1	4	40%
2	3	30%
3	2	20%
4	1	1%
TOTAL	10	100%

The second batch of 10 x 35 week old chicks that had a slow start resulted in an average classification achieved of Follicle Class 2 - Table 10. One skin in this batch failed to achieve an acceptable standard of follicle development. Skin sizes averaged 14.27sq ft and one skin failed to achieve Grade A (greater than 14sq ft).

Worthy of note with this batch is that despite their slow start at the optimum time for good feed conversion, the average carcass weight of this batch was 40.18kgs, average for South African slaughter birds normally 5 – 6 months older.

Comment:

This study proved beyond any doubt, a fact that many producers already know, that age is not the determining factor alone on skin acceptability. This study demonstrated that birds reared correctly can achieve skins that are acceptable to the market at ages very much younger than has been considered the norm. The commercial producer should never overlook the importance of this study. This study makes nonsense of the recommendations to maintain birds till 12-14 months and the use of Post-Finisher rations. The impact of this on product quality and the commercial viability of raising ostrich are very significant and understanding these fully is key to the future of our industry.

Summary

There are many different papers written on Ostrich over the past 15 years. These are some examples of papers and studies that have the most influence in explaining why the industry is not yet commercially viable from a production viewpoint and proves there are better ways established to do things and achieve commercial viability.

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