1. Setting the scene Nowadays, global layer genetics is ccording to the American Country Egg production in 2011 (tonnes) % of world total in the hands of very few companies Egg Board ‘eggs are all- and genetics focuses on far more Anatural and packed with a China 23,897,000 36.6 than just bird performance. Issues number of nutrients. One egg has such as disease/salmonella resis- 13 essential vitamins and minerals USA 5,415,600 8.3 tance, egg quality and shell strength in varying amounts, high quality are among the traits featuring in India 3,490,000 5.3 protein and antioxidants, all for 70 modern genetics programmes. calories. Eggs' nutrients can help Japan 2,482,628 3.8 you with weight management, muscle strength, brain function Mexico 2,458,732 3.7 Consumerism and having a healthy pregnancy. Particularly important for aiding Table 1. Top five countries for egg production (FAOSTAT data, 2014). Then along came consumerism healthy brain function and which had its say in the evolution of pregnancy is choline, which is sumer perception (or mispercep- If we had not been able to manage egg production. The key areas that amply present in eggs’. tion!) about egg production. Why diseases such as Newcastle disease, consumerism impacted on were else would a major fast food chain infectious bronchitis, coccidiosis and salmonella freedom, housing – with only use free range eggs and a major the like, today’s modern, progres- the move to alternative systems, and So, it is easy to comprehend that supermarket claim that its bakery sive industry might never have bird welfare, with issues such as man has eaten eggs since history products are only made from free occurred. cages and beak trimming. began and why today they are range eggs? With the increasing need for agri- regarded as a key component of In fact, much of the recent history culture to be more efficient (sustain- man’s diet. Out of this has grown an of egg production in more devel- Genetics able) and not to waste key primary important sector of global livestock oped countries has been influenced resources, such as land and water, production that is not hindered by by consumer perceptions, such as Our understanding of nutrition also one sometimes wonders how far any religious beliefs or taboos. the anti-cage movement, the anti- paralleled the evolution of the table this move into alternative systems Table 1 shows the top five coun- GMO lobby and others. egg sector by providing rations can go? Will a second generation of tries for egg production and it can Events such as the emergence of which more closely fitted the table intensification occur? be seen how production is to some Salmonella enteritidis in the last egg layer’s needs. Table 3 is designed to make you extent dependent upon a country’s quarter of the last century also did Over time genetics has fine-tuned think. The answers to many of the population, but other factors come much to mould the egg industry of egg production and feed efficiency questions you may have will be into play with regards to per capita today. For example, the vast major- with egg numbers steadily increasing covered in future editions of Egg egg consumption (Table 2). ity of UK flocks now comply with and food utilisation steadily improv- Focus in International Poultry the Lion Code which grew out of a ing. Production. n desire to satisfy customers that Country variations salmonella in eggs was an issue of Table 2. Top five countries for per capita egg consumption (FAOSTAT the past. data, 2009). Countries vary in the proportion of If we look at the history of the egg their production coming from large, sector, much of the success of Country Consumption per person per year (kg) intensive farms. At one end of the today’s industry goes back to inten- spectrum we have the situation of sification, which became possible Paraguay5.5 19.5 smaller farms still being the corner with the control of respiratory dis- Japan 19.1 stone of a rural economy, whereas eases, primarily through vaccination, at the other end we have part of and the control of enteric disease, China 18.5 production reverting to smaller primarily through medication and farms, for example with the return the advent of cages which separated Mexico 18.1 of outdoor production. birds from their faeces and, latterly, Denmark 16.8 An important factor in this is con- vaccination. Table 3. Comparison of intensification and alternative systems including free range. Intensive systems Alternative systems including free range Land utilisation Very good Often very poor Biosecurity In the hands of farm management Often in the hands of the Gods Social structure Birds in small stable groups with defined pecking order Birds in large groups with variable pecking orders Variable – often wastage though spillage and consumption Feed management Usually very good by other animals Water hygiene Only drink supplied water where the hygiene can be easily managed Often access to other water supplies so less control Bird inspection Sometimes not easy – but easy to check individual birds Easier, but harder when one wants to take a closer look Stress Easier to avoid trigger stresses like poor weather Birds more susceptible to natural adversities Disease Limited number – most of which can be managed Return of many old diseases such as tuberculosis and worms Staffing Large number of birds per staff member. Better working conditions Higher staff cost per hen International Poultry Production — Volume 23 Number 1 39 2. Salmonella oday there are still con- Salmonella inside or by the yolk sumers who unfortunately are in that part of the egg which is 7,000 Tregard salmonella and eggs least cooked in boiled eggs and –– All salmonella as being synonymous. This goes therefore often survive! 6,000 –– S. enteritidis back to the Salmonella enteritidis For this reason, soft boiled eggs in eggs problem, which started in with nice runny yolks present a real 5,000 –– S. typhimurium the late 1980s and took over a risk of food poisoning in man. decade to control. This was done Ironically, such eggs are popular 4,000 by giving a significant amount of with the very young and very old – protection to hens via vaccination. two groups of people that are more 3,000 Even so, in some parts of the susceptible to salmonella infections. Cases world this serotype is still an Salmonella on the shell surface can 2,000 important egg borne zoonotic easily get into the egg contents pathogen. when the eggs are cracked open. 1,000 Also, if salmonella get into or near the eggshell pores these can provide 0 In those regions where fowl a route of entry into the egg under 85 90 95 00 05 10 typhoid exists S. gallinarum can be certain conditions. found in eggs but it is of little At the farm level we must provide Year zoonotic consequence. Other food that is safe. We can not pass serotypes occur from time to time the responsibility for ensuring eggs Fig. 2. Japanese data. Note the similarity to the British data in Fig. 1. and if they get into a large or mega are safe on to the consumer, espe- operation their importance in a cially since some eggs are eaten raw, nal clean down and sanitation by view to sampling, your programme country or region can be significant. for example, in mayonnaise. taking up residence in the farm’s might not be robust enough to with- When it comes to eggs, salmonella mouse, rat or lizard populations and stand a legal challenge if something can either be found in the egg or on then infecting the next flock to be goes wrong. the shell surface. The former arise Remain salmonella free placed. Thus, attention needs to be Secondly, vaccination should not by one of two means. Firstly, some given to ridding your farm of such be viewed as a tool for eliminating invasive salmonella serotypes, of The approach to follow is to start populations in the terminal cleaning salmonella but rather as one of which S. enteritidis is a good exam- salmonella free and then to protect programme. greatly minimising salmonella to the ple, invade the hen’s body and then that status so our flocks and eggs If we have started with a level that they are of little signifi- invade ova in the ovary. These ova remain salmonella free. salmonella free flock we must cance, for example, they are unable then become egg yolks. At the outset our poultry houses, endeavour to maintain that status. to create an infective dose. For many years this was consid- bedding material, feed, water and This is all about biosecurity which For those of you who are statisti- ered to be the only such route. day old chicks must all be salmonella has recently been covered in our cally minded this is one reason why However, there is now also some free and ideally we should confirm Poultryhealth BYTES. we can have sampling programmes evidence to suggest that the this by microbiological testing. It is with pre-defined confidence limits. salmonella may get on to the surface also sensible to use suppliers, such This can be complicated by the of ova or be incorporated into the as feed mills and hatcheries, that Use of vaccination fact that in some situations, for first albumin to be laid down, which have a proven salmonella freedom example feed, salmonella are not is that laid closest to the yolk. track record. Another way to counter salmonella homogeneously distributed through- These salmonella can then either We may choose to use an acid or infection in our flock is to enhance out the material.