A concentrate is usually described as a feed or feed mixture which supplies primary nutrients (protein, carbohydrate and fat) at higher level but contains less than 18% crude fibre (CF) with low moisture. In general, concentrates are feeds that are high in nitrogen free extract (NFE) and Total Digestible Nutrients (TDN) and low in crude…
Different raw materials are characterised by their amino acid composition. In addition within a specific type of raw material but between different samples, differences in amino acid composition may occur as a result of cultivation and geographic influences. Therefore when mean tabular values of amino acid composition are used, consideration must be given to the…
The Near Infrared Reflectance (NIR) Spectroscopy technique can be used for fast evaluation of the nutritional content of feedstuffs. This method requires a sufficiently large number of chemically verified analytical values for instrument calibration. The population of samples used for calibration has to be representative in terms of type and composition of the type of…
The nitrogen content of different proteins is relatively constant and varies only slightly from an average value of 16%. The level of protein in a feedstuff is usually measured by determining the nitrogen content according to the conventional Kjeldahl or Dumas method; the protein level of the feed can then be estimated by multiplying the…
5.1 Feed specification A nutritionist must define a certain nutrient level of the feed he wants to produce. By reviewing recommendations from different sources, research reports in the scientific literature, and the perspectives gained by personal experience they can establish reasonable nutrient levels for feeds. These nutrient levels can be strongly influenced by production goals….
Technical processing is used to a great extent in feed production. Protein-containing feedstuffs and compound feeds are treated with steam and heat. For proteins damaged by heat during processing, the measurement of ileal digestible amino acids gives a better estimation of the amino acids available to the animal compared with total content or fecal digestibility….
The most recent data concerning ideal amino acid ratios are based on amino acids digested in the ileum in order to take into consideration the influence of amino acid losses during digestion and absorption. Further data for individual species can be found in chapter 8 “Amino acid responses and recommendations”. Since poultry have different requirements…
Isoleucine, leucine and valine are the three branched chain amino acids. Their metabolism is unique, sharing the same catabolism pathway and therefore interfere with each other. Leucine is a strong regulator of the branched chain amino acid catabolism. As a consequence, minimum supply of valine and isoleucine must be ensured in the diet and an…
The animal itself is capable of synthesising about half of the amino acids. These amino acids are termed non-essential amino acids. However, about 10 amino acids (depending on the species) can not be synthesised by the animal and a source must be supplied in the feed (see Table 3). For this reason they are termed…
