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xx Additives
« Thread started on: Sep 15th, 2006, 12:22pm »
(Shrimp Meal/Chitin )
"...RESULTS AND DISCUSSIONNo significant differences in egg production werefound among the different treatments (Table 3). A signifi-
cant (P< 0.01) increase in feed consumption was observedwith 40 and 80% SM compared to the 0% treatment. Due to the increase in feed consumption, feed efficiency was poorer (P< 0.05) for the same treatments. These resultsmight be attributed to the high levels of chitin found in SM. The exoskeleton of the shrimp is composed mainly of chitin, an N-acetylated glucosamine polysaccharide that forms part of the protein complex, and is considered to have low digestibility when fed to animals (Austin et al., 1981). Due to this low digestibility, chitin physically blocks the access of digestive enzymes to lipids and proteins, thus affecting the utilization of these nutrients (Castro et al., 1989; Karasov, 1990). Some species of birds produce chitinase in the proventriculus. When chitin and
chitosan were fed to hens and broilers, Hirano et al. (1990) observed that the two ingredients were 88 and 98% digestible. This finding led us to believe that birds may have the capability of digesting chitin, because chitonase may be present in the digestive system, thus facilitating the utilization of chitin found in the SM. In the case of the chicken, amounts of chitinase produced are low (Jeuniaux and Cornelius, 1978). Even in species that produce useful levels of chitinase the energy value of chitin is very low, due to poor absorption (Jeuniaux and Cornelius, 1978; Karasov, 1990). Because chitin reduces dietary energy, the layers fed the diets with the higher levels of SM increased feed consumption to maintain their energy needs."
(note from DL>SM with significant percentage of chitin doesn't appear to be advisable to feed in times of stress or when the bird is eating less such as in times of heatstress)
(Additives to Improve Efficiency of Animal Production -Part I -Oregon State learning module)
Part II
summary descriptions of the various ADDITIVES in livestock feed.
An excellent article descibing the antinutritional factors of several additive feedstuffs and different ways of dealing with these factors.
(You may be asked to register in order to view this article which is free however if you do not wish to do so just pm me and I will send you my passwrod-DL)
LINKS to several excellent articles on ADDITVES from Poultry Health Services
Remus, J. Practical benefits of Betaine usage in coccidia-damaged broilers.
"Betaine is widely distributed in nature. It is a methyl group donor allowing the methylation of homocysteine in the liver to methionine, thus reducing demand for dietary methionine. It is the active form of choline for methylation. In coccidial challenge S.methylmetionine production in the liver is increased 3-fold. However the main effect of betaine may be as an osomlyte. These maintain water balance in cells preventing cellular dehyration. Electrolytes have similar effects but they are charged particles which have other effects. Osmolytes are quickly transported into cells, are charge neutral and help protect enzymatic activity (especially the energy systems of the mitochondria). Water is very important - 85% of the hatchling, 60% of the adult carcase (muscle is 72-75%) Coccidiosis disturbs water and ion balance. Work done on birds at 21-35 days using betaine in water showed that heat and cocci stress are synergistic in reducing water retention (83%, 87% and 63%) - betaine supplementation substantially ameliorated this effect. Even unchallenged birds have changes in the E.M. appearance of enterocytes. Betaine has also been shown to be synergistic with Salinomycin at 44 and 66 ppm in reducing lesion scores and FCR. Similar improvements were demonstrated with tests of tensile strength of the gut...."
To enhance N retention, utilize enzymes and feed additives. Dietaryenzymes have the ability to free up the carbohydrate and fiber portions of
many cereals and byproduct ingredients for poultry. On a world scale, enzyme supplements are used extensively with wheat- and barley-based diets for both
broilers and layers.Water-soluble, nonstarch polysaccharides (NSP) including arabinoxylansare the major fiber constituents in wheat and rye that give rise to highly viscous intestinal digesta. Their gel-like viscosity impedes the digestion and absorption of proteins, fats, and carbohydrates. Endogenous enzymes cannot hydrolyze these pentosans; however, inclusion of dietary enzymes (xylanase,
arabinoxylanase) can greatly improve their nutrient utilization.Another NSP present in barley, oats, and wheat are the beta-glucans.They also reduce nutrient utilization by way of greater digesta viscosity and
are characterized by sticky feces and poor litter conditions among birds fed significant levels of these cereals. Dietary enzymes tailored for these ingredients contain ‚-glucanase.While there has been widespread use of cereal hydrolyzing enzymes forpoultry in certain parts of the world, relatively little attention has been paid to the remaining 25% to 35% of dietary ingredients supplied predominately as vegetable proteins. Soybean and rapeseed meal, peas, beans, and sunflower seeds are commonly added to poultry diets for their protein and energy value.
However, even more complex NSP are an integral part of the cell wall of these oilseeds and legumes. These NSP increase the viscosity of the digesta and interfere with nutrient digestion and absorption. The amount of protein in cell walls may account for 10% to 30% of the total dietary fiber mass. For birds and other monogastrics, this protein remains encapsulated with the polysaccharide matrix and unavailable to the animal. However, it is possible to improve the NSP digestion of SBM. Even after oil extraction and heat
treatment, soybeans contain 6% to 8% oligosacharides (predominantly raffinose, stachyose, and cellobiose) that are associated with reduced nutrient utilization. Oligosacharides can be extracted with ethanol, resulting in a 10% to 20% improvement in dry matter digestibility (Leeson and Summers 1997).
Enzymatic release of these proteins through selective enzymatic additions can increase amino acid availability as well.Zanella et al. (1999) demonstrated in broilers that enzymesupplementation of CSM-based diets with a cocktail of xylanase, protease, and amylase significantly improved CP digestibility by almost 3% as well as
starch, fat, and energy by intestinal contents analysis. Amino acid digestibility was similarly improved for 15 of 16 amino acids measured and significantly so for threonine, serine, glycine, valine, and tryptophan. In a performance trial with male broilers to 45 days of age, enzyme supplementation significantly improved body weight gain by 50 g and feed-to-gain ratio by 4 points (1.86 vs. 1.82). While enzyme supplementation should allow a reduction in CP formulation for nutrient management purposes, the authors cautioned that individual amino acid digestibilities were not improved equally and should be balanced for optimum bird performance.Another of these polysaccharides, ‚-Mannan, and its derivatives (‚-galacto-mannan or ‚-gluco-mannan) are integral components of the cell walls in manylegumes including canola and SBM (1.3%-1.6%). Enzymes with ‚-Mannanaseactivity have improved feed conversion of swine and broilers fed CSM diets.
Recently Jackson et al. (1999) demonstrated a beneficial effect of adding‚-Mannanase to the CSM-based diets of laying hens. Significant improvements
were realized in early egg weight and egg production later in the henís cycle.
Because studies have shown that ‚-galacto-mannan interferes with glucosemetabolism and insulin secretion rates in swine, it is theorized that suppression of
insulin secretion may impair intestinal uptake and utilization of glucose from starch and amino acids in peripheral tissues, resulting in reduced growth and feed

« Last Edit: Jun 12th, 2007, 09:18am by DL » User IP Logged


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xx Re: ENZYMES etc.
« Reply #1 on: Apr 4th, 2007, 05:35am »
"....Poultry naturally produces enzymes to aid the digestion of feed nutrients. However, they do not produce enzyme to break down fibre completely. As fibre is the main constitutent of cereal / cereal byproducts cell wall, it impairs the poultryís own enzymes from efficiently extracting nutrients from them. Adding feed enzymes therefore allows these fibres to be broken down resulting in more efficient production.

The use of feed enzymes to improve the nutritive value of poultry diets is a common practice in many countries. The benefits of using enzymes in poultry diets include not only enhanced bird performance and feed conversion but also less environmental problems due to reduced output of excreta. Enzymes are biological catalyst composed of amino acids with vitamins and minerals. They bring about biochemical reactions without themselves undergoing any change.

As enzymes are involved in all anabolic and catabolic pathways of digestion and metabolism, their use in animal feed is of great importance. Consistent increase in the price of feed ingredients has been a major constraint in most of the developing countries. As a consequence cheaper and unconventional feed ingredients have to be used which contain higher percentage of Non-Starch Polysaccharides (soluble and insoluble/crude fibre)
alongwith starch.

Poultry do not produce enzymes for the hydrolysis of Non-Starch Polysaccaride present in the cell wall of the grains and they remain un-hydrolysed. This results in low feed efficiency. Therefore, digestive enzymes play an important role in nutrition. The exogenous enzyme in feed additive can complement to endogenous enzymes in the digestive system during different rearing conditions. The production of endogenous enzymes may be a limiting factor due to various reasons depending on the age, health, type of feed, environment etc. Enzymes are not living organisms. They are non concerned about viability or cross infection. They are stable at 80-85 degree centigrade for 1-2 minutes as required for pelleting and pH of 5.5 to 6.5.

Enzymes are produced in every living organisms from the highest developed animals and plants to the simplest unicellular forms of life as they are essential for metabolic process. The enzymes are synthesized by bacteria, fungi and yeast.......

Mode of action of enzymes:
>By reducing the gut viscosity
>Increasing the effectiveness of host endogenous enzymes
>Alteration in feed passage rate
>Effect on excretion characteristics
>Effect on litter problems
>Release of nutrients & phosphorous
>Enhances feed efficiency, growth rate and productivity
>Increases the energy value of cereal feed stuffs, more nutrients are made available by hydrolyzing fibrous material
>Better digestibility of feed ingredients by feed conversion
>They act as a supplement to the normal digestive enzymes specially during stress conditions.......... "
Ŗ-Mannanase, more than just a digestive enzyme
for corn/soy diets
Dr. Humg-Yu Hsiao and Dr. Frank L. Jin
ChemGen Corp.
« Last Edit: Oct 16th, 2007, 02:44am by DL » User IP Logged

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