Clostridium perfringens: Challenges facing antibiotic-free breeding of broiler chickens!
Time: March 31, 2022 Author: This site
According to data from the National Bureau of Statistics, in 2021, 15.74 billion poultry were sold nationwide, an increase of 170 million from the previous year, an increase of 1.1%; poultry meat production was 23.8 million tons, an increase of 190,000 tons, or an increase of 0.8%; at the end of 2021, the national poultry inventory was 67.9 billion, a year-on-year increase of 0.1%.
According to the requirements of the Ministry of Agriculture and Rural Affairs Announcement No. 194, my country's livestock and poultry breeding industry has entered a new era of antibiotic-free breeding since July 1, 2020. Sub-therapeutic doses of antibiotics or AGP added to the original feed can prevent pathogenic bacterial infections; if they are discontinued, disease morbidity and mortality in the farm will increase.
The challenges faced by antibiotic-free breeding can be seen from various experience and research reports. The most common bacterial diseases without the use of these additives are necrotizing enteritis and gangrenous dermatitis caused by Clostridium perfringens.
NO.1
Challenges faced in antibiotic-free production
The challenges faced in antibiotic-free production focus on three aspects:
♦ Deterioration of intestinal health - the use of original AGP reduces the occurrence of opportunistic pathogens and subclinical infections.
♦ Broilers are more sensitive to environmental stress factors in the house (such as increased litter humidity, elevated ammonia levels, heat, etc.) and are more susceptible to diseases.
♦ There is an urgent need to breed varieties with more complete immune systems - In the traditional breeding era using AGP, genetic breeding pursued higher growth rates and feed conversion rates, sacrificing the maturity and function of the immune system, and weakened disease resistance!
NO.2
Increased mortality in broiler chickens raised without antibiotics
“Between 2014 and 2015, the leading retailers in the broiler industry announced that they would only sell antibiotic-free chicken. Many broiler companies in the United States changed all or most of their broiler breeding systems to antibiotic-free or reduced the use of antibiotics. As of 2018, in More than 50% of poultry produced in the United States is produced without antibiotics."
Antibiotic-free production results in poor poultry performance, reduced daily weight gain, increased risk of enteric disease, low water intake and high mortality. In 2017, the monthly mortality rate of No Antibiotics Ever (NAE) broiler chickens in the United States was 25–50% higher than that of conventionally raised chickens. According to Agri Stats, from October 2017 to May 2018, the average mortality rate of NAE broiler chickens was about 4.2%, while the average mortality rate of conventionally raised chickens was about 2.9%. (https://doi.org/10.1111/nyas.14091)
(https://www.nationalchickencouncil.org/about-the-industry/statistics/u-s-broiler-performance/)
NO.3
Clostridium perfringens disease
increased incidence
- A
Clostridium perfringens is very common in the broiler environment, making it difficult to control the diseases it causes, such as crop erosion, necrotizing enteritis and gangrenous dermatitis.
♦ Clostridium perfringens is an obligate anaerobic, spore-forming Gram-positive bacterium; it exists in a variety of environments and is a normal flora in the gastrointestinal tract of animals and humans. The bacterium can survive under favorable conditions Proliferate in large numbers and become pathogenic bacteria.
♦ Higher C. perfringens population density triggers the expression of toxin-encoding genes. These toxins affect the gastrointestinal mucosa, causing inflammation and hypofunction of the gastrointestinal tract.
♦ In broilers, disease-associated Clostridium can reduce average daily feed intake by 40% and average daily weight gain by 16%.
- B
Necrotizing enteritis (NE) results in significant economic losses, but data on the incidence of infection are sparse and highly variable. The exact pathogenesis of NE is not yet fully understood.
♦ The economic losses caused by necrotizing enteritis in the global poultry industry range from US$2 billion to US$6 billion, and are mainly controlled through the use of AGP.
♦ In 2011, the incidence of NE in some broiler flocks not using AGP was as high as 30–50%.
♦ In a study of 51 drug-free broiler flocks in North America in a commercial setting, 27.4% of broiler flocks developed clinical NE and 49.0% of broiler flocks developed subclinical NE, which resulted in feed conversion The rate increased, and the average live weight during processing decreased; the number of Clostridium perfringens isolated in the feces was 54.1% higher than that of the treated chickens.
- C
Gangrenous dermatitis increases the incidence of pecking and leads to lower carcass quality at slaughter.
♦ Gangrenous dermatitis is common in broiler chickens close to market age (>35d).
♦ The most common bacteria causing gangrenous dermatitis in broilers are Clostridium perfringens types A and C, Clostridium emphysema, or Staphylococcus aureus.
♦ In houses with increased litter humidity, the incidence of skin lesions such as scratches and ammonia burns is high, and the incidence of gangrenous dermatitis is increased.
In general, no antibacterial product can individually and effectively combat the attack of pathogenic bacteria like the traditional AGP method. Through a combination of strategies, such as strict biosecurity measures, routine immunization, feed addition of probiotics (bacteria of origin) and prebiotics, essential oils and organic acids, producers can better manage the health of poultry under antibiotic-free farming and reduce the risk of e.g. The incidence of common diseases caused by pathogenic bacteria such as Clostridium perfringens and Escherichia coli.