Nov 17,2021
Bird performance has shown
consistent improvement over the past few decades. This change has occurred due
to improved genetics, and better farm management practices in animal nutrition.
The animal nutrition industry has undergone a remarkable growth over the last
30 years. Today we see 3 Kg broilers at 40 days of age and egg layers are
capable of producing more than 330 eggs in 52 weeks of lay. Nutrition plays a vital role in supporting the
desired growth and production performance in animal nutrition. Provision of
good quality poultry feed supplement with routine feed must be ensured.
Further, poultry feed supplement have to be effectively digested and absorbed
in animal nutrition. If the feeds are not absorbed within the time limit, they
are attacked by bacteria in the large intestine or excreted as waste, defeating
the purpose for which poultry feed supplement are added in feed and reflected
in terms of poor growth and productivity.
Feed accounts for 65-70% of the
total costs in animal nutrition and production. With the rise in poultry feed
supplement costs internationally; the birds' ability to absorb the feed optimally
is a very important aspect of overall performance efficiency in animal
nutrition. Nutritionists are therefore now emphasizing much on optimizing the poultry
feed supplement efficiency and reducing poultry feed supplement cost.
Lysophospholipids (LPLS)- a poultry
feed supplement besides providing a superior emulsification are also proven to
be very effective in enhancing the flux rate of across the gut membrane,
thereby improving the absorption and reducing the loss through faeces in animal
nutrition.
Membranes define the boundaries
of the cell and its organelles and act as permeability barriers. One remarkable
feature of all biological membranes is their flexibility: their ability to
change shape without losing their integrity and becoming leaky. The
Fluid-Mosaic" model (Singer & Nicolson, 1972) of cell membrane
indicates that membranes are made up of lipid bilayer and membrane proteins
(peripheral and integral).
Lipids in bilayer occur in
different physical states depending on the temperature and the kind of lipids
present:
1. Gel /semisolid state: In this
state, all the types of motion of individual lipid molecules are strongly
constrained: the bilayer is para crystalline.
2. Liquid disordered state/Fluid
state: In this state, individual hydrocarbon chains of fatty acids are in
constant motion produced by rotation about carbon-carbon bonds of long acyl
side chains. The interior of the bilayer is more fluid than solid and the
bilayer is like a sea of constantly moving lipids.
3. Liquid Ordered State: In this
state, there is less motion in the acyl chains of the lipid bilayer, but
lateral movement in the plane of bilayer still takes place.
In the field of poultry field
supplement, Phospholipids (PLs) have some effect on the emulsification of fat
but have a little effect on the absorption of fat and other substances in.
Lecithin serves as the source of phospholipids. The lecithin can be obtained
from plant (soybean, sunflower and rape seed) or animal nutrition source (egg
yolk). Generally lecithin is sourced from soybean due to its greater yield,
easy availability and feasibility.
Lysophospholipids (LPLs) are
glycerophospholipids in which one acyl chain is lacking and only one hydroxyl
group of the glycerol backbone is acylated. LPLS which include
lysophosphatidylcholine (LPC). lysophosphatidylethanolamine (LPE),
lysophosphatidyl inositol (LPI) and lysophosphatidylserine (LPS) are prepared
by enzymatic hydrolysis of natural soy lecithin through phospholipase A2.
LPLS have superior emulsification
properties than PLs due to lower CMC and optimum HydrophillicLipophillic
Balance (HLB) values. Unlike PLs, LPLS are found only in small amounts in
biological cell membranes.
Each membrane at equilibrium
contains pores and holes - these are best thought as gaps or vacancies where
phospholipids are missing from lattice structure. Sometimes there are clusters
of these vacancies of various sizes in animal nutrition industry. When
additional lysolipids are introduced it is this distribution that is the normal
passive transport processes, of larger molecular weights can then pass more
readily across the membrane. When the membrane comes into contact with certain
ratio of LPLS, these exogenous lysolipids quickly get interdigitated into the
bilayer membrane. The close packing between the PLs is disrupted (membrane
perturbation) and the lipids go from order to disorder state and the membrane
becomes more fluid i.e. the gaps or pores in the membrane form big clusters or
larger vacancies in the matrix causing an increase in number and size of pores.
Insofar as poultry feed supplement is concerned, this means that the absorption
profile of the gut is beneficially altered with the passive flux hurdle
temporarily lowered.
Also, LPLS have the ability to
change the attraction between lipids and displace calcium ions. With this
increased freedom of movement, lipids can aggregate closer together making
existing holes larger so that larger molecules are easily absorbed.
Mere hydrolysis of the PLS would
not serve the purpose as absorption enhancers; the enzymatic hydrolysis has to
be standardized to yield consistent quantities of PLs and LPLs in the final
product. A defined ratio has to be maintained between PLS and LPLs, and also
between different LPLs to observe consistent and desired end results with the
product.
That is how, Lysophospholipids
(LPLs) help in improving the membrane permeability, increasing affected and
results in increase in both the number and the size of pores in animal
nutrition. Through the flux of across the cell and act as an absorption
enhancer. This is the key application of LPLS in animal nutrition industrybecause
it means it is possible to extract more value from every kilogram of diet, even
when such are normally poorly absorbed.
One of the ways in which the
effect of any substance, like LPLs have on cell membrane permeability is the
MTT assay which can be conducted in vitro.
MTT Assay
MTT (3-[4,
5-Dimethylthiazol-2-yl)-2,5diphenyltetrazoliumbromide) assay is a colorimetric
assay commonly being carried out to check the concentration of the live cells
(viability) in the cell culture . This test is commonly used to screen the
pharmaceutical compounds for their cytotoxic effect. This assay can also be carried
out to assess the effect of a substance on cell membrane permeability in poultry
feed supplement industry.
In animal nutrition industry Lysophospholipids which
can be a part of poultry feed supplement act as membrane fluidity modulators. They
increase the number and size of the pores by altering the mechanical properties
of the membrane, thereby enhancing the flux rate at which of various molecular
sizes pass across the membrane of the gut. Thus the absorption of breakdown
products of such as amino acids, simple sugars, fatty acids, vitamins, minerals
and other poultry feed supplement additives is optimized leading to an
efficient growth and production performance