Stocking densities for broilers can vary considerably depending on bird size, diet, breed, feeding area, drinking area, house dimensions, bird welfare and economic return. Nowadays, higher densities are possible in modern broiler houses, as long as the environment is well maintained. Using organic acids can further soothe inflammatory responses and restore intestinal health and growth performance.
High stock density (HSD) in broiler production is often applied in intensive or commercial poultry farming to maximize production efficiency and optimize the use of resources such as space, feed and labor. While HSD can lead to increased production, it can also contribute to several key challenges, such as respiratory problems, increased stress and aggression, reduced intestinal health and leg disorders, all of which impact the health and welfare of birds.
Producers must strike a balance between maximizing production and ensuring the health – and welfare – of animals by applying good management practices, including adequate ventilation, disease control and appropriate nutrition, to overcome the challenges associated with HSD in to cope with broiler production. Incorporating feed additives into the diet may be a strategy to achieve the goal of maximizing the weight of chicken produced per square meter while preventing production losses due to overcrowding.
Organic acids have been found to ameliorate the negative effects of stress at high stocking density in broilers by restoring the gut microbiota, reducing inflammation, inhibiting the NF-kB signaling pathway and increasing the production of short-chain fatty acids. Researchers used a clever blend of short- and medium-chain fatty acids to develop Selko’s Selacid Green Growth. As part of the broiler feed, it provides a tool to manage stress more effectively, maintain intestinal health and achieve growth performance.
Costs of HSD stress
Poultry raised in HSD production systems are exposed to increased stress, which can negatively impact production efficiency and growth. Stressed birds can show increased inflammation and compromise of gut health, which can lead to leaky gut or damage to the tight junctions, which can introduce harmful bacteria into the bloodstream.
HSD can negatively affect the balance of the gut microbiota and lead to dysbiosis, which can result in increased use of antibiotics. It is estimated that dysbiosis in broilers impairs feed conversion ratio (FCR) on average by approximately 0.05, without taking coccidiosis into account. Given the challenges posed by HSD systems, it is important to find alternative solutions to maintain bird health and growth despite production stress and without having to rely on antibiotics as a preventive measure.
Putting acids to work
The crop acts as the first site of fermentation in the gastrointestinal tract and its pH can be influenced by feed ingredients and play a role in creating desirable conditions for beneficial bacteria and undesirable conditions for pathogens. In addition, high buffering diets can limit acidity in the foregut, which allows pathogenic bacteria to multiply, and reduce the activity of digestive enzymes, allowing more undigested proteins to reach the hindgut and causing inflammation and gut health problems.
This situation can also reduce bird performance and lead to wet litter. As a preventative strategy, adding organic acids can help the foregut maintain the acidity needed to support ‘good’ bacteria and resist colonization by pathogenic bacteria, and improve nutrient utilization in broilers.
What science says
In a study on the effect of high stocking density on poultry production with a basic diet and a diet supplemented with organic acids, 528 birds were split into 3 production systems. One group was raised in a low livestock density environment (positive control), a second group in a high livestock density environment (negative control), and a third group in a high livestock density environment, with the diet supplemented with a mixed organic acid food. additive. Birds were assessed for growth performance, intestinal barrier and gut microbiota, microbial metabolites and stress response indicators.
Unsupplemented birds raised in the HSD condition showed increased levels of several stress indicators, including higher levels of serum corticosterone lipopolysaccharides, interleukin-1β, tumor necrosis factor-α and down-regulated expression of ZO-1, which affected growth performance. In comparison, bird diets supplemented with the organic acid mixture (Selacid Green Growth) resulted in lower levels of serum corticosterone, lipopolysaccharides, interleukin-1β, and tumor necrosis factor-α, along with up-regulated interleukin-10, mRNA expression of ZO-1, and improved growth performance compared to the birds from the negative control group. In addition, supplemented birds showed an increase in quantity Bacteroidetes and restored the balance of the microbial ecosystem compared to the stressed, unsupplemented birds. Birds fed the organic acid mixture also showed higher levels of acetic and butyric acid, which has a significant correlation with indicators of intestinal inflammation.
Overall, the trial demonstrated that Selacid Green Growth may play a role in mediating HSD-induced inflammatory responses and restoring intestinal microbial composition and growth performance, suggesting the positive impact of a nutritional strategy to counter HSD-induced stress in broiler chickens.
Combine for effect, efficiency and economy
In a second trial, the growth performance and feed conversion of broilers were investigated in 975 birds in an antibiotic-free production. Birds were fed one of three diets for 35 days: a control food, a food supplemented with a sodium butyrate additive or a food with a mixture of organic acids. Broilers fed the feed supplemented with organic acid showed improved feed conversion, a better European Production Efficiency Factor (EPEF) and had a higher average body weight at the end of the trial. The EPEF or European Broiler Index is a production indicator calculated on the basis of average daily growth, survival rate and feed conversion, excluding mortality in the first week.
References available on request.