Protein, crude

5 Measures of food protein used in practice in the feeding of pigs and poultry 

9 The UK Feed into Milk protein system for dairy cows 

Proteins are made up of amino acids, the classification of which into essential (indispensable) and non-essential (dispensable) has already been described in Chapter 4 and in Chapter 9 under protein synthesis. For food to be used with maximum efficiency, the animal must receive sufficient quantities of both the essential and non-essential amino acids to meet its metabolic demands. Simple-stomached animals such as pigs and poultry obtain these acids from the breakdown of food proteins during digestion and absorption. In the case of ruminant animals, the situation is more complex. 

Considerable degradation and synthesis of protein occur in the rumen, and the material that finally becomes available for digestion by the animal may differ considerably from that originally present in the food. Different approaches to the evaluation of protein sources are therefore necessary for ruminant and non-ruminant animals. 

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Crude protein = %nitrogen X 6.25. Does not accurately reflect true protein content. Algal cells may contain nonprotein nitrogen substances, eg, 4—6% nucleic acids, dry wt basis. 

Table 3. Amino Acid Composition of Defatted Oilseed Meals and Amino Acid Requirements, mg/g Crude Protein...

The application of biosolids also increases the nutritional value of blue grama. Tissue levels of nitrogen, phosphorus, potassium, and crude protein increased to recommended tissue concentrations with biosolids treatments. Trace metals in blue grama grass did not increase during the study, thereby eliminating concerns that toxic amounts of these elements could be transferred to grazing animals. 

Commercial dried blood corpuscle paste obtained from Armour and Company, Chicago, was used in this preparation. This paste contains about 15 per cent of moisture and ash, and 200 g. contains about the same amount of crude protein as 11. of fresh beef blood (170 g. protein per liter). 

Fig. 2. Spectrum of anionic isoperoxidases isolated from potato (a) crude protein extract, (b) protein fraction not adsorbed on chitin, and (c) chitin-specific peroxidises. M - protein markers.

Fig. 3. The scheme of the precipitates formed by the crude protein extracts of plants of the groups monocotyledons (1-11, table 1) and dicotyledons (12-23 table 1) with antibodies against wheat chitin-binding proteins (I) and with antibodies against wheat anionic PO (H).

Figure 1 PG activity measurement of crude protein extract of the SCPP strain grown on Pg glc medium...

Crude protein extracts and reaction media were made as described by Gainvors et al. Measurements were made on the reaction medium as described by Milner et Avigad... 

A crude protein extract has been prepared by acetone precipitation on a three days old culture supernatant of the SCPP strain on Pg glc medium. In order to estimate the effect of glucose on PG activity, these protein extracts were deposited as dots on solid Pg glc medium. 

Figure 5 Detection of PG activity of crude protein extracts of the SCPP strain in the presence of 1% glucose and varying concentrations of polygalacturonic acid.

In a study of the nutrient content of silage in Switzerland, Wyss (2000) showed that using fertiliser increased the crude protein and fibre level but decreased the sugar level. This led to the conventional silage scoring lower for fermentation quality. 

This is a cross between wheat and rye. Triticale combines the yield and quality of wheat with the winter hardiness of rye and is also disease resistant. It can be used as a replacement for concentrates in a livestock ration because it is high in crude protein and essential amino acids. Its place in the rotation is similar to rye, so that it can be used as a forage crop or a green manure. 

The second method also relies on site-specific chemical modification ofphosphoproteins (Oda et al., 2001). It involves the chemical replacement of phosphates on serine and threonine residues with a biotin affinity tag (Fig. 2.7B). The replacement reaction takes advantage of the fact that the phosphate moiety on phosphoserine and phosphothreonine undergoes -elimination under alkaline conditions to form a group that reacts with nucleophiles such as ethanedithiol. The resulting free sulfydryls can then be coupled to biotin to create the affinity tag (Oda et al., 2001). The biotin tag is used to purify the proteins subsequent to proteolytic digestion. The biotinylated peptides are isolated by an additional affinity purification step and are then analyzed by mass spectrometry (Oda et al., 2001). This method was also tested with phosphorylated (Teasein and shown to efficiently enrich phosphopeptides. In addition, the method was used on a crude protein lysate from yeast and phosphorylated ovalbumin was detected. Thus, as with the method of Zhou et al. (2001), additional fractionation steps will be required to detect low abundance phosphoproteins. 

Weller R F and Cooper A (2001), Seasonal changes in crude protein concentration of... 

It is possible that laying birds could be adapted to thrive on diets with lower crude proteins, which would allow production based on homegrown crops, even in the northern parts of Europe. 

Figure 6.6 ULtrafiLtration separates molecules based on size and shape, (a) Diagrammatic representation of a typical laboratory-scale ultrafiltration system. The sample (e.g. crude protein solution) is placed in the ultrafiltration chamber, where it sits directly above the ultrafilter membrane. The membrane, in turn, sits on a macroporous support to provide it with mechanical strength. Pressure is then applied (usually in the form of an inert gas), as shown. Molecules larger than the pore diameter (e.g. large proteins) are retained on the upstream side of the ultrafilter membrane. However, smaller molecules (particularly water molecules) are easily forced through the pores, thus effectively concentrating the protein solution (see also (b)). Membranes that display different pore sizes, i.e. have different molecular mass cut-off points, can be manufactured, (c) Photographic representation of an industrial-scale ultrafiltration system (photograph courtesy of Elga Ltd, UK)...

Crude protein sources containing one glycoprotein usually contain multiple glycoproteins. In most such instances, lectin-based affinity systems will result in the co-purification of several such glycoproteins. 

Food Source "ToTTl Price of Source Material Protein Content (Col. 2 X Col. 3) % Col. 5 Cost of Utilizable Protein (Col. 1 - Col. 4) per kg. 

Of the 190 accessions evaluated after one year s growth in Florida, 38 showed tuber formation. Tender leaves are incorporated in the food preparations in the South Asian region. Leaf protein concentrate (crude protein 51.9%) prepared from leaves yielded a PER value of 2.2 in comparison to 2.7 for corn-soy control. International Winged Bean Trials conducted in 19 countries recommend 5 varieties as having the best yield potential under varying environmental conditions. 

While fruits are not normally considered potential sources of protein, some have been found recently to be surprisingly high in crude protein in the edible portion (9, JLO, 11). As indicated in Table II some of the more common fruit such as banana, persimmon and mango have crude protein in the range of 1 g or less/100 g of fruit flesh. However, some less widely known fruits such as Mamey sapote, tucuma, and decne have crude protein contents above 2 g/100 g and baobab-seeds contained over 12 g/100 g. 

They found that the crude protein in cassava leaves and sorghum x Sudan hybrid grass were relatively high (Table V) but the dried yield of true leaf concentrate was much higher from sauropus. 

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