BONUS SPRING SUMMER 2025

Graph 1: Illustration of controlled growth of broiler growth. Environmental stressors Stress also influences SDS. These include high stocking densities, poor ventilation, and sudden noises, which can trigger fatal cardiac events in susceptible birds. A stocking density of 18 birds per square metre in controlled environments and 14 for open-sided houses is associated with high rates of SDS in summer. Reducing the stocking density can assist in reducing mortalities. Poor ventilation can cause low oxygen levels and high carbon monoxide, ammonia, and carbon dioxide; Treatment Currently, there is no specific treatment for SDS. However, several management strategies can help reduce its incidence, such as genetic selection of slower-growing broiler breeds can decrease the risk of metabolic and cardiovascular complications. predisposing the birds to develop ascites, which is linked to SDS. Avoiding stressors such as maintenance noise in a broiler house is one of the ways to reduce the occurrence of SDS. All maintenance activities should be carried out when the house is empty. Late-stage broiler mortalities can be significantly costly since the loss includes the birds as well as the feed and other resources invested in growing them. Controlling the lighting period reduces the intakes and allows for rest time, avoiding metabolic overload and predisposing the birds to SDS. All maintenance activities should be carried out when the house is empty. Cause Effect Solution Metabolic Rapid growth rate Increased metabolic demand, cardiac stress, and electrolyte imbalances Controlled growth management (early feed restriction, slower-growing breeds) High-energy diets, excess carbohydrate intake Metabolic imbalances, acidosis, cardiac arrhythmias Dietary modifications (reduced carbohydrate levels, optimised micronutrient balance) Electrolyte imbalances (e.g., low potassium) Disrupted cardiac function, increased susceptibility to arrhythmias Dietary electrolyte balancing, supplementation Cardiac Underlying cardiac abnormalities (e.g., enlarged heart, altered electrical conductivity) Increased risk of fatal arrhythmias Genetic selection for improved cardiac health Environmental Stress (e.g., sudden noises, changes in lighting) Triggering of cardiac events in susceptible birds Stress reduction through proper management practices (consistent lighting, temperature, minimal disturbances) Late-stage broiler mortalities can be significantly costly since the loss includes the birds as well as the feed and other resources invested in growing them. Controlling the lighting period reduces the intakes and allows for rest time, avoiding metabolic overload and predisposing the birds to SDS. Table 1: A summary of cause and effect and solutions to sudden death syndrome. Spring/Summer 2025 BONUS www.agribonus.co.za 30