A new look at mini breeders

19-10-2009 | | |
A new look at mini breeders

“Mini” broiler breeders have been marketed for almost 40 years and have always generated a debate in the industry. Some support them, while others offer no interest. Both tend to exaggerate or more likely consider different types of markets and circumstances. Let’s take a realistic approach!

By Pascal Charpentier, Argalys Development, France

For the breeding scheme of mini breeders it is important to understand the concepts of “sexual chromosomes” and “dominant/recessive genes”.

Males and females carry the same pair of chromosomes except for one that differs. Males carry a pair of identical sexual chromosomes (XX), while females have a minus (X–), which means that the second chromosome does not carry functional genes. Dominant genes (for a given character) are genes that express themselves even if they are carried by only one gene, while recessive genes will only express themselves when present in both chromosomes. This very fundamental modelisation was first conceptualised by Gregor Mendel in his monastery of Brno (Czech Republic), crossing various types of peas at the end of the 19th century! Dwarf chickens have been studied from the 1950s, leading to the identification of a responsible gene noted “dw”.

This “dwarf” gene is recessive to the dominant DW gene that gives a chicken of a standard size. These genes are carried by the “sexual” chromosomes, which concretely means that a male that carries the combination “DW” and “dw” is of normal size (DW is dominant). A female which carries the “dw-” is a dwarf.

Thus the breeding ‘trick’ means the following: At GP level on the female line, cross a “dw dw” dwarf male with a “standard” DW- female. At parent level the female progeny is 100% dw-, thus dwarf. This female is mated with a standard DW DW male. The broiler progeny obtained are “DW dw” for the male (standard size) and the “DW-” for the standard size female (Figure). This explains how ‘standard broilers’ can be obtained from a dwarf Parent female (only if crossed with a homozygote DW DW male).

Market situation

The total world market of broiler breeders is estimated between 370-390 million PS/year, of which mini breeders represent between 7-8%, in approx. 30 countries, principally France and Russia. Today, two major breeding companies are marketing them: Hubbard (F15) and Ross (PM3), the first one being historically deeply implicated in their development.

While producers of deboned meat have generally maintained or increased their age at killing in order to benefit from a higher meat output, for the markets of whole bird and cut up the producers have generally preferred to reduce the age at killing, in order to meet consumers requirements. Consequently, killing weights for the segments below 2.2 kg have remained quite stable over the past 10 years.

Recently, a decrease of final weights for this segment was even reported, explained by the reduction of buying power, and consumers searching for cheaper whole birds or parts. The near future will tell whether this becomes a trend. Nevertheless, over 60% of broilers are still killed below 2.2 kg, which is in the range where mini breeders have an economical interest. Let’s see how.

Benefit at parent level

At parent level there is full benefit of feed and space savings. The advantages compared with standard breeders are obvious and significant. Less feed per chick is consumed, resulting in an average 11–14 kg of feed saved by the parent female. Also, more hatching eggs are obtained (or chicks) per square metre in the breeder house, because of the higher stocking density (+1.5 female per sq. m), when nests and feeder space are adjusted.
Saving around 100 g of feed per chick produced and increasing the chick output by +20% from the same buildings are not insignificant contributions to the profitability of a broiler integration. Secondly, but of importance in the present economical situation, this contributes to a decrease of the working capital requirement at PS level, thus enabling a significant increase of the day-old chick production without investment in new buildings.

Field observations also show that mini parents have progressed in both versatility and performance, according to their standard in most types of climate and housing. Only a few management requirements are specific. The tendency of females to eat a bit slower than standard birds is considered an advantage in monitoring feed restriction and body weight.



Broilers the major evolution

At broiler level, their image remains burdened by historical performances of the 70s/80s when nothing more than very light weights for the ‘export frozen whole bird’ could be considered. Things have drastically changed since!
Today, upon the five key economical criteria of broiler production (growth, FCR, liveability, condemnation, yield) field reports show very similar performances up to 2 kg and often keeping their global economical advantage up to around 2.2 kg for whole bird / cut up final products, especially with optimum FCR frequently observed.

Growth/day remains the number one question for those considering switching from standard to “minis”. Even recessive, the “dw” gene keeps a slight reduction in the growth of the male broiler (estimated to 2% of the genetic potential for growth).While not significant until 2 kg, this explains why broilers over 2.2 kg from standard breeders are showing a global economical advantage. For planning purposes, the age at 2 kg can be set with +1 day for broilers from minis. Field reports show limited variations between 0 and 1 day, with daily growth rates in the range of 50-60 g, depending upon the environment and feed conditions.

Global economical advantage

Feed, housing costs and average performance, to name the main factors, play an important role in the calculation of the relative economical performances between mini and standard breeds. Most integrations have taken the excellent habit to base their decisions after significant field trials in their own facilities. Therefore it is does not make sense to pretend to put those variations with accuracy in a model. Nevertheless, drawn from field observations, the data in Table 3 is realistic for a rough “world” average.


Genetic progress has brought mini breeders to a level of performance and reliability meeting the industry’s best standards under most environments. The present financial and market circumstances are likely strengthening their core advantages. At a time when no solution for cutting costs should be ignored, they are an excellent option to consider for the whole bird and cut up markets.

* Pascal Charpentier of Argalys Development is an independent advisor for the management and strategies of various poultry companies. E-mail: pcharpentier@argalys.com