Newsletter No. 105

Included in this edition:
Avian Influenza still active in South Africa
Defining Nutrient Density
Benefits of Recording Feed Conversion
Ostrich Production Survey

Avian Influenza still active in South Africa
This month the SA veterinary services submitted a further report to the OIE. There were 3 more outbreaks reported and 2 still active, which will delay the return for their industry to supply the export meat markets.

The importance of the role of nutrition and immunity was discussed in this article Nutrition affects immunity in poultry published in World Poultry during the month. Animals receiving adequate nutrients from the correct ingredients for their species will have stronger immune systems than those fed inadequate nutrients. With their industry unable to export meat and the current low demand for ostrich leather, we can imagine that this will have put farmers are under financial pressure

Defining Nutrient Density
An article entitled The 2010 USDA/HHS Guidelines — A Rather Bizarre Definition of “Nutrient Dense” caught my eye during the month. The article is discussing human nutrition but the principles the author is discussing relate to all species. Production Ostrich require nutrient dense rations, so it is important to ensure readers understand the meaning of nutrient density.

So what do we mean by Nutrient Dense. Usually the amount of nutrients provided in a given weight.

Using domesticated ostrich as an example, rations are made up of a combination of ingredients to ensure the birds receive adequate daily nutrient intake ensuring these nutrients are in their correct balance and ratios to each other and within the weight that the bird can consume in a given day.

Table 1 is a simple example as most readers are familiar with how Lucerne varies in quality. A kilo of lucerne can yield very differing nutrient levels depending on the stage of growth (maturity) it was cut and how it was dried. The more mature it is when cut the greater the fibre and the less digestible that fibre becomes. The table illustrates how as the protein goes down, the fibre increases. Lucerne provides many essential vitamins and minerals....these all drop as the fibre increases.

Lucerne Quality	Protein	Fibre	Calcium	Phosphorous
22% Premium	22%	23%	1.80%	0.32%
20% Good	20%	26%	1.60%	0.29%
18% Average	18%	29%	1.40%	0.24%
15% Mature	15%	34%	1.30%	0.21%
13% Very Mature	13%	38%	1.18%	0.19%

Therefore, many of the nutrients lost in that kilo of lucerne have to be provided by a different ingredient that is denser and will be more expensive. It may not be possible to obtain achieve adequate nutrients within the ration within limits of the daily consumption of the birds fed.

The industrialisation of human food has resulted in the processing of many ingredients. This has resulted in many bye products as the processing removes unwanted elements of the ingredients. Examples are wheat bran, sugar beet pulp, citrus pulp, grape residue or hominay chop. Some bye products can have a place in small amounts in a ration, but others have no place in a ration as they take up space in the ration whilst providing very few nutrients. Whilst a certain amount of fibre is essential in a ration, the source of that fibre must provide other essential nutrients that are usable by the birds.

Many of these by products can be very cheap when measured by price per tonne, but when measured by nutrient content they can be extremely costly as they provide so few nutrients for that space they take up in the ration. When measured by the cost in lost production, and even poor health, they can be prohibitively expensive.

Ostrich require rations that are more nutrient dense than other production species because their daily consumption of feed is much lower when expressed as a percentage of their body weight [Figure 1]. This makes it even more critical to use only ingredients that provide the best balance of nutrients and why there is no room in their rations for ingredients that are not to the best quality they can be if commercial levels of production are to be achieved.

Benefits of Recording Feed Conversion
The PigSite ran an article this month discussing the importance of keeping good records but focusing on measuring feed conversion. The article illustrates how just a small improvement can make a significant difference in the overall profitability.

Quote: Producers record numbers born and have a reasonable idea of growth rate while backfat is measured for them when finished pigs are slaughtered. Yet none of these is as important as feed conversion rate (FCR).

Pointing out the relative importance of these factors, Mr Sutcliffe demonstrated that an improvement of one standard deviation in feed conversion (equivalent to about 0.4 FCR points) could be worth as much as £18.52 per pig, assuming daily feed intake remained the same.

In comparison, one standard deviation in grading was worth £1.51; in daily gain, £9.46, and numbers born alive, £5.91 per pig. While one standard deviation is a large change in a trait, it does allow the relative economic impact of each trait to be assessed. End Quote

The author also mentioned the challenge of recording feed intake when feeding is on a conveyor system as is the case in many pig houses today. It is usually possible to achieve FCR figures on a batch basis if not individual basis and is the best that can be expected in high production systems.

So what factors control feed conversion? This is a combination of productive rations supported by excellent feed and farm management systems, good stockmanship and the genetic of the livestock. The fact that no genetic work has yet been started with ostrich, this is an area that offers such exciting potential in the future of our industry.

Ostrich Production Survey
The WOA received notification of a survey for the ostrich industry inviting participants to complete. The survey has been put together by a study taking place at Avian Research Centre in British Columbia. The purpose of the questionnaire is to identify the prevailing practices in the husbandry, transportation and processing of ostriches in order to identify areas to focus their research efforts on. The project is sponsored by the British Columbia Department of Agriculture.

Studies of this type are challenging to put forward meaningful questions when conditions are so variable at every stage of the production chain. These variables including such things as location, scale, rearing conditions, vehicles available, road conditions and the list can go on and on. For those wishing to view the questionnaire it is available here.