DE2858345C2 - Feed mixture containing oleandomycin and proteolytic enzymes - Google Patents

Description

High-performance animal feed, as commonly used in intensive animal husbandry today, contains a number of additives with a prophylactic and/or nutritional effect. These include antibiotics and enzymes. While the use of antibiotics has already become established in all types of compound feed, enzymes are not yet used on a large scale in practice.

Feedstuffs containing enzymes are known in principle from DE-AS 10 84 123. This describes a protein and starch-containing supplementary feed for suckling piglets aged less than 8 weeks. The enzymes described are fungal proteases or bacterial proteases and/or fungal amylases or bacterial amylases. There is no reference to the particularly beneficial effect of feed mixtures that have an enzyme activity in a precisely defined range on the one hand and a content of antibiotics on the other.

The feed mixtures used in modern intensive animal husbandry are generally optimized in all nutrient components to such an extent that further improvement does not seem possible. The older patent application according to DE-OS 26 33 105 describes that high-performance feeds can be further improved in terms of feed utilization and/or the weight gain that can be achieved with them if virginiamycin is added to these feeds together with proteolytic enzymes.

It has now been found that additions of oleandomycin and certain amounts of proteolytic enzymes produce excellent feedstuffs.

The invention accordingly relates to a feed mixture based on carbohydrates, protein, fats and optionally conventional additives and a content of oleandomycin and proteolytic enzymes in such an amount that an enzymatic activity of 0.05 to 2.5 mTU/g is present, where one enzyme unit (TU) is the amount of enzyme which releases cleavage products from a casein solution in one minute which have the same extinction as a 1 mol/l tyrosine solution, characterized in that the content of oleandomycin is 1 to 250 ppm.

The antibiotic oleandomycin belongs to the group of macrolide antibiotics and is isolated in the usual way from Streptomyces antibioticus cultures. The molecular formula of the base is: C[deep]35H[deep]61O[deep]12N. Other compounds derived from it, e.g. salts, esters or complexes or an adsorbate form of oleandomycin, can also be used as feed additives.

Suitable proteolytic enzymes are mainly obtained by culturing microorganisms and separating them from the nutrient solutions.

The processes for this are known. For example, proteolytic enzymes from Bacillus licheniformis, Bacillus natta, Bacillus subtilis, etc. are used. Acidic proteases, e.g. from Aspergillus niger or from Rhizopus rhizopodiformis according to DE-OS 25 28 490, are particularly preferred. Such proteases have a particularly broad spectrum of activity in the weakly acidic range between pH 2.5 - 6.5.

Commercial feed mixtures are composed as optimally as possible for the specific needs of the individual animal species. The basis is carbohydrates, mainly from grain components, corn or similar. The main sources of protein are soya meal, fish meal, animal meal, bran and similar. Missing amino acids, e.g. methionine or lysine, can also be added. Fats are added in the form of vegetable or animal fats or waste fats. Salts such as dicalcium phosphate, calcium carbonate and table salt are also added to build up the body. If necessary, the feed mixture is rounded off by adding trace elements, vitamins, fiber, etc. Substances produced by fermentation such as single-cell proteins from petroleum fractions or alcohols, various yeasts, algae protein or other substances, possibly also obtained from waste materials, can also be part of the feed recipe to a considerable extent.

The animal feed mixtures according to the invention contain, in addition to the usual components tailored to a specific animal species, an additional 1 - 250 ppm, preferably 5 - 50 ppm oleandomycin, depending on the age of the animal and the type of feed mixture, and proteolytic enzymes in such an amount that the enzymatic activity is 0.05 - 2.5 mTU/g, preferably 0.2 - 0.5 mTU/g.

The additive concentrations mentioned refer to the content in the entire feed. The concentrations are correspondingly higher in concentrates or supplementary feeds. In particular, a combination of oleandomycin and an acidic fungal protease or protease mixture is used. The increase or improvement in feed utilization achieved in this way is several percent more than with corresponding control mixtures containing only antibiotics.

The claimed combination of oleandomycin and enzymes is particularly effective in feed for poultry, piglet rearing and pig fattening. However, it can also be used in feed mixtures for other animal species in which oleandomycin itself is used to advantage.

The antibiotic is best added to the feed in the form of a premix, e.g. bound to soya meal. When using meal-based feed compositions, the enzyme component is also applied as a premix. Any feed component, e.g. soya meal or an inert carrier, can act as a carrier substance.

When using steam-pelleted feed, the enzymes must be added in a suitably stabilized form to prevent deactivation by moisture and heat during pelleting. One such process is the subject of DE-OS 26 02 260.

To determine the enzyme unit (TU), the proteolytic activity of the protease is determined according to the well-known Anson principle: a suitably diluted amount of enzyme solution is incubated at 40°C for 20 minutes with an equal volume of a 1.2% casein solution containing 0.6% lactic acid, 6 mol/l urea and 0.1 mol/l citric or acetic acid. The pH of the casein solution is adjusted to 4.5 by adding 2 mol/l sodium hydroxide solution. After incubation, 0.4 mol/l trichloroacetic acid is added in a volume ratio of 1:1, the precipitate of undigested casein that forms is filtered off and the protein fragments that were formed during the synthesis are determined in the filtrate using any protein determination method. The method described by Layne in Methods in Enzymology 3 (1957), pages 448 ff., is suitable for this.

A blank value must be prepared for each sample, in which trichloroacetic acid and then casein solution are added first. This blank value indicates, in addition to the reagent blank value, the proportion of low molecular weight peptides that are already present in the enzyme solution before digestion. The difference between the main value and the blank value is then compared with the extinction that a certain amount of tyrosine produces in this determination using the specified method. This amount of tyrosine is then a measure of the proteolytic activity of the enzyme in question: one enzyme unit (TU) is the amount of enzyme that releases cleavage products from a casein solution in one minute that have the same extinction as a 1 mol/l tyrosine solution. The usual indication is in mTU = 10[to the power of]-3 TU.

example 1

450 day-old chicks, sex-sorted male, female (1 : 1) of Ross origin were kept in cages for 4 weeks with feed mixtures of the same composition, but

a) without addition of antibiotic or enzyme

b) with addition of 10 ppm oleandomycin

c) with the addition of 10 ppm oleandomycin and 0.6 mTU/g feed acid proteases from Rhizopus rhizopodiformis

fed and after completion of the experiment the final weight of the animals and the feed conversion rate are determined. Feed conversion is understood as the ratio of feed consumption to growth.

Feed composition (%)

Corn 49.10

Soya meal 36,00

Corn Gluten 4.00

Soybean oil 5.65

Phosphoric acid feed lime 2.15

Carbonic feed lime 0.80

Vitamin and mineral premix 1.85

Table salt 0.35

DL-methionine 0.10

______

100.00

Result

________________________________________________________________________________

a) b) c)

without with with Oleandomycin

Addition Oleandomycin + Enzyme

________________________________________________________________________________

Weight gain 748 g 755 g 771 g

Feed- 1.57 1.54 1.52

recycling

Example 2

240 piglets in the weight range 10 - 25 kg were fed an identically composed rearing feed, but

a) without addition of antibiotic or enzyme

b) with addition of 50 ppm oleandomycin

c) with the addition of 50 ppm oleandomycin and 0.35 mTU/g feed acid proteases from Rhizopus rhizopodiformis

The animals were kept in groups of 3 flat decks and were fed ad libitum. Growth and feed conversion were determined by regular weighing. Feed conversion is understood to be the ratio of feed consumption to growth.

Feed composition (%)

Wheat 38.0

Oat flakes 20.0

Wheat bran 9.9

Soya flour 16.4

Malt germs 5.0

Fat 3.0

Corn starch/dextrose 4.0

Minerals, vitamins 3,7

_____

100.0

Result

________________________________________________________________________________

a) b) c)

without with with Oleandomycin

Addition Oleandomycin + Enzyme

________________________________________________________________________________

Daily 486 g 492 g 509 g

increase

Feed- 2.22 2.12 2.07

recycling

Claims (2)

1. Feed mixture based on carbohydrates, proteins, fats and optionally conventional additives and containing oleandomycin and proteolytic enzymes in an amount such that an enzymatic activity of 0.05 to 2.5 mTU/g is present, where one enzyme unit (TU) is the amount of enzyme which releases cleavage products from a casein solution in one minute which have the same extinction as a 1 mol/l tyrosine solution, characterized in that the oleandomycin content is 1 to 250 ppm. 2. Feed mixture according to claim 1, characterized in that the proteolytic enzymes are acid proteases with an activity spectrum between pH 2.5 and 6.5.