ISSUE FOCUS FEED & ADDITIVE MAGAZINE April 2024 47 Bad feed hygiene can also negatively impact the feed’s nutritional value by leading to a loss of energy as well as decreasing the bioavailability of vitamins A, D3, E, K, and B1. But, how can all signs of deficient feed hygiene be recognized? Soil, sand, and probably dust can be seen in well-taken samples and impurities can be analyzed. But is it possible to spot spoilage? In this case, agglutinated particles, rancid odor, moisture, and discoloration are indicators. Sometimes, also the temperature of the feed or ingredient increases. However, spoilage is not always obvious and an analysis of the feed can give more information about the spoilage-related organisms present, it also helps to decide if the feed is safe for the animals or not. In the case of obvious alterations, the feed should not be consumed by any animal. DIFFERENT ORGANISMS DECREASE FEED QUALITY AND IMPACT HEALTH Several organisms can be responsible for a decrease in feed quality. Besides the visible pests such as rats, mice, or beetles, which can easily be noticed and combatted, there are organisms whose mastering is much more difficult. In the following part, the different harmful organisms and substances are described and solutions are presented. Enteropathogens can cause diarrhea and production losses In poultry, different bacteria responsible for high production losses can be transferred via the feed. The most relevant of them are Clostridium perfringens, Escherichia coli, and some strains of Salmonella. Clostridium perfringens, the cause of necrotic enteritis Clostridium perfringens is a gram-positive, anaerobic bacterium that is extremely resistant to environmental influences and can survive in soil, feed, and litter for several years and even reproduce. Clostridium perfringens causes necrotic enteritis mainly in 2-16 weeks old chickens and turkeys, being more critical in 3-6 weeks old chicks. There is a clinical and a subclinical form of necrotic enteritis. The clinical form can be detected very well due to clear symptoms and mortality rates up to 50%. The subclinical form, not well detectable, also raises high costs due to a significant decrease in performance. The best prophylaxis against clostridia is the maintenance of gut health, including feed hygiene. Clostridia can be found in animal by-products, as can be seen in table 1. Sr. No. Sample details Positive Negative Clostridium perfringens contamination Total number of samples Positivity % 1 2 3 4 5 6 7 8 9 39 0 0 21 21 5 0 0 13 52 3 1 17 71 8 2 2 16 91 3 1 38 93 13 2 2 29 42.86 0 0 55.26 22.58 38.46 0 0 44.83 Meat and bone meal Soya meal Rape seed meal Fish meal Layer Feed Dry fish De-oiled rice bran Maize Bone meal Table 1. Isolation of Clostridium perfringens from various poultry feed ingredients in Tamil Nadu, India (Udhayavel et al., 2017)
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