Modern-day poultry production is focused on optimizing production and reproductive performance, such as egg production, growth or fertility. Optimal nutrition, management, and genetics are the fundamentals for achieving best production results. For nutrition, trace minerals play an important role in sustaining various biological functions that support high performance. For example, selenium, via its incorporation into selenoenzymes, has the ability to reduce oxidative stress and improve fertility, immune functioning, and growth. Other trace minerals such as copper, zinc, and manganese play an important role in different enzyme activities. Copper functions in red blood cell maturation and neutralizing free radicals. Both copper and zinc are essential for skin (footpad) health and cartilage metabolism, while manganese is involved in skeletal development and fertility.
Trace elements are naturally present in feed ingredients, however these levels are generally too low to meet the requirements of intensively reared animals. Furthermore, their levels in raw materials can be variable. Therefore, it is common practice to supplement trace minerals to the feed. The key to a good mineral nutrition is to supplement highly bioavailable trace minerals in the feed, which is largely determined by their source.
L-selenomethionine - the most effective form of selenium
The different selenium sources available can be categorized in two groups: organic and inorganic forms of selenium. Within the organic group, L-selenomethionine is the only form of selenium that, apart from being incorporated into selenoenzymes, can be stored in animal protein in the same way as methionine. During the process of natural protein turnover, this stored selenium can be made available again and used for the synthesis of selenoenzymes. This ‘safe deposit’ allows for a continuous selenium supply to the animal, even during times of (heat) stress when feed intake is reduced. The use of L-selenomethionine has been shown to have a variety of positive effects in poultry due to its optimal bioavailability.
In broilers, use of L-selenomethionine has improved growth performance (with or without the presence of stressors) and meat quality parameters (colour, drip loss, tenderness) compared to the use of inorganic selenium. For laying hens, the supplementation of L-selenomethionine can improve selenium deposition in eggs and prolong the shelf life of eggs.
Recently, a study at the University of Lavras (Brazil) compared the effects of different sources of organic selenium in broiler breeders. Cobb-500 breeders, 360 females and 36 males, at 24 weeks of age were divided over 6 treatments, each with 10 replicates. The treatments consisted of different selenium sources (sodium selenite (control), L-selenomethionine, selenized yeast, OH-selenomethionine) or levels of supplied selenium (0.175 ppm, 0.280 ppm, 0.350 ppm). The L-selenomethionine in this trial was Excential Selenium 4000 by Orffa Additives B.V.
