Intestinal health has become one of the most interesting fields of research. This has resulted in major leaps forward in understanding the world of intestinal bacteria, their profiles and communities, and the correlation with general health and bird performance. A new on-farm Clostridium perfringens test provides an early indication of gut integrity.
By Christophe Bostvironnois, DVM, Johanna van der Stroom, DVM, PhD, Marco Saggiorato, DVM, Elanco Animal Health, Houten, the Netherlands (email@example.com)
Highly scientific diagnostic research with microarrays enables us to study the heritable influence of the environment on the birds (epigenetics). In the future this will help us to better understand, for example, the influence of feeding and eating habits of breeders on their off spring, the broilers.
More applicable in the daily practice are DNA-based techniques to study and monitor changes in intestinal microbial profiles. And even more practical, there is now an on-farm test to analyse the level of Clostridium perfringens that appears to correlate with performance.
Intestinal bacteria and performance
For centuries, scientists have been studying bacteria. Aerobic culturing used to be the standard until the late 1950s. Cultured bacteria were considered to be the cause or at least strongly correlated with the cause of an illness. Thus, for many illnesses, especially diarrhoea, no cause was found. When anaerobic techniques for diagnosing diseases became available the number of ‘causes’ that were found more than doubled.
However, it became more realised that not every species found was causing a disease. And still, a cause was not yet found for most diarrhoea. The development of the modern DNA techniques finally permits us to better understand the bacteria in the intestines. We now know that the microbial communities of birds differ from those of mammals. The composition of these communities determines, for a large part, the effectiveness of digestion. By studying different profiles, the Finnish Alimetrics researcher Apajalahti (2007) could differentiate between profiles in birds that were able to get high metabolisable energy from the feed, i.e. low feed conversion and birds with a much higher feed conversion (Graph 1).
C. perfringens level as early indicator
One of the microbial communities is formed by a group of Clostridia, being C. perfringens. Studies by Elwinger (Germany) indicated in 1992 that the presence of higher levels of C. perfringens was associated with reduced performance. In 2007, Apajalahti, Lee and de Lange demonstrate that during the first 7-14 days of the bird’s life, the subset of microbial communities is formed (Graph 2).
Multi factorial production diseases
Most of today’s diseases in intensive animal husbandry don’t respond to the postulates of Koch (showing a causal relationship between a causative microbe and a disease). This indicates that these diseases are not caused by one virus or bacteria, and neither is there a single-approach solution of a vaccine or antibiotic. It can be assumable that this is even more applicable for intestinal disorders. In addition to the common aspects, like housing, ventilation, litter type, vaccination schedule, stocking density and quality, quality of the day-old bird, ‘epigenetics’ might play an important role. US researcher Ferket defines epigenetics as "any heritable influence on gene activity that does not involve a change in the DNA sequence". He indicates that how we feed and manage broiler breeders as well as feed and manage broiler hatchlings, can determine the physiological response and health of the birds for the rest of their lives. Thus, this might include a change in the broiler’s natural intestinal microbial profile, the level of C. perfringens, and the resulting performance.
Predicting farms at risk
To prevent intestinal health and performance problems it is important to know the C. perfringens levels in broiler faeces. For that reason BioX Diagnostics and Elanco Animal Health developed the Clostridium FIRST®test. The test is an on-farm tool that determines C. perfringens levels from faeces samples within 15 minutes. Levels of 1 million C. perfringens are considered to be ‘normal’, indicating a controlled intestinal bacterial profile. Levels over 10 millions lead to a ‘highly positive’ result.
This on-farm tool will help poultry technicians and veterinarians to identify at an early stage farms with an intestinal integrity risk. Consequently, the adviser can propose an immediate intervention to optimise bird wellness and minimise the economical impact of the disease.
Cost of gut integrity loss
A European study published by Saggiorato in 2009 using the Clostridium FIRST®test on 119 broiler flocks across five countries demonstrated that 32% of the flocks were ‘normal’ at day 10 with droppings that contained 1 million C. perfringens or less. Of the flocks, 22% were already ‘highly positive’ at day 10, and 46% ‘positive’. Significant performance differences were demonstrated at levels of 4 g daily gain and 8 points FCR between the ‘normal’ and ‘highly positive’ flocks (Graph 3, 4 and 5). The economical impact of such loss of intestinal integrity was evaluated to 3.3 Euro cents between a ‘normal’ and a ‘positive’ flock and to 10.8 Euro cents between a ‘normal’ and ‘highly positive’ flock. This confirms previous studies. In terms of welfare and housing management, 40% of the ‘normal’ flocks had no problems with the litter management. However, only 15% of the ‘highly positive’ flocks had dry litter during the grow-out period. During this study, the anticoccidial programmes were registered as were the numbers of antibiotic treatments against intestinal disorders. This study showed that in the five countries tested, in farms where coccidial vaccines or ionophore programs were used, more antibiotic treatments for intestinal disorders were used. Unlike, the farms with a shuttle of 25 or more days nicarbazine-narasin (Maxiban®), followed by narasin (Monteban®) needed an average of 1.2 antibiotic treatment less. In addition, when Maxiban is used more than 22 days, the incidence of wet litter is reduced by 37% than all the other anticoccidial programs and by 53% than coccidial vaccine programs.
From this study using the rapid analysing test, it appears that a shuttle of 25 or more days of nicarbazine-narasin, followed by narasin needed the least treatments for intestinal disorders and the better litter quality.
* Maxiban® and Monteban® are registered trademarks of Eli Lilly and Company, US
What is important in controlling dysbacteriosis?
It is often questioned whether using the right anticoccidial program, feed or litter management would be the most important factors in controlling dysbacteriosis. Three European nutritionists, who were often confronted with this typical problem, value controlling coccidiosis to be the most important.
By Bert van Rees, Opraappers, Doetinchem, the Netherlands
When asking Marja Hongisto of Raisio Feed (Finland), Lars Petterson of Svenska Foder (Sweden) and Masja Lensing of Agrifi rm (the Netherlands) to tell which factorswould have the most effect on controlling dysbacteriosis, it appears that the use of the right anticoccidial programme is seen as the most important. They were asked to rank 10 factors in order of importance. The fi gure shown here provides the averages of these rankings. It is interesting to note that the anticoccidial program is consideredto be somewhat more important to control dysbacteriosis than the quality of the feed. Nonetheless, they consider feed quality still to be an extremely important factor.Since poultry producers only have a limited amount of infl uence on the quality and composition of feed, it is their fi rst priority to ensure a proper climate and ventilationfor the animals. The second most important focal point would be good hygiene, and the third is ensuring that good quality litter is maintained.
Dysbacteriosis and performance
When asked what the most important factors are that affect the performance of broiler chickens in general, the quality of day-old chicks emerged as the most important.Masja Lensing: “A poor quality day-old chick will never achieve top performance, even in the best management environment. This is why a good start is vital. However, even with the best day-old chicks, you still have to manage the flock well during the total grow-out in order to achieve a maximum level of performance.”
On average, the nutritionists believe that good feed quality and optimum ventilation are important factors in performance.