Role of Volatile Fatty Acids in Development of the Cecal Microflora in Broiler Chickens during Growth

Abstract

It is known that volatile fatty acids can inhibit growth of species of the family Enterobacteriaceae in vitro. However, whether these volatile fatty acids affect bacterial populations in the ceca of chickens is unknown. Therefore, a study was conducted to investigate if changes in volatile fatty acids in ceca of broiler chickens during growth affect bacterial populations. Results showed that members of the Enterobacteriaceae and enterococci are present in large numbers in 3-day-old broilers and start to decrease when broilers grow older. Lactobacilli are present in large numbers as well in 3-day-old broilers, but they remain stable during the growth of broilers. Acetate, butyrate, and propionate increase from undetectable levels in 1-day-old broilers to high concentrations in 15-day-old broilers, after which they stabilize. Significant negative correlations could be calculated between numbers of Enterobacteriaceae and concentrations of undissociated acetate, propionate, and butyrate. Furthermore, pure cultures of Enterobacteriaceae isolated from the ceca were grown in the presence of volatile fatty acids. Growth rates and maximal optical density decreased when these strains grew in the presence of increasing volatile fatty acid concentrations. It is concluded that volatile fatty acids are responsible for the reduction in numbers of Enterobacteriaceae in the ceca of broiler chickens during growth.

Development of solution phase hybridisation PCR-ELISA for the detection and quantification of Enterococcus faecalis and Pediococcus pentosaceus in Nurmi-type cultures

“…Elsewhere, enterococci were shown to exist in caecal contents of chicks at a concentration of 1.32Â10 8 CFU g À1 (Spring et al, 2000). Another group, analyzing the development of caecal microbiota in chickens during growth, noted that on day 35, chicks contained an average of 10 7 CFU g À1 enterococci (van der Wielen et al, 2000). These findings correlate with our results from culturing studies.…”

The Gut Microbiota: Ecology and Function

“…Major factors affecting microbial number and composition along the length of the intestine appear to be age, diet, and host genotype (van der Wielen et al, 2000;Apajalahti et al, 2001;Hill et al, 2005). Comparisons between the zoo animals described previously revealed that diet was the strongest determining factor in shaping microbial composition, where animals were grouped based on whether they were carnivores, herbivores, or omnivores.…”

Salmonella infections: immune and non-immune protection with vaccines

“…For infections which may occur before this time, such as those arising Colonisation-inhibition, or competitive exclusion, as it is more commonly known, can also be induced by the administration of normal gut flora preparations to newly hatched chicks. Young birds are highly susceptible to infection with Salmonella, as a consequence of the absence of a protective gut flora and immaturity of the immune system (Friedman et al, 2003;van der Wielen et al, 2000). The first can be overcome by the application of competitive exclusion (CE) products based on cultures of normal flora obtained from pathogen-free adult birds (Nurmi & Rantala, 1973), which, according to the recommendation of the WHO, should be applied as early as possible to day-old chicks in the hatchery or by spraying eggs and in preference to administration via the first drinking water.…”