Influence of WHEY PROTEIN CONCENTRATE ON IGG
UPTAKE, INTESTINAL dna AND ENZYME ACTIVITY
L.F. Sutton and B. Alston-Mills
Summary
The of influence the whey protein
concentrate (WPC) containing 50% b-lactoglobulin (BLG) on IgG
uptake, proliferation of total intestinal DNA, and intestinal enzymatic
activity was investigated. A total of
18 piglets from three sows were taken immediately following parturition and
divided into three experimental groups: two were colostrum deprived and one
group remained on the sow as control.
Piglets in the control group (Treatment 3, n=6) were kept on the sow for
the duration of the 5 day study. The
remaining two groups were divided as follows: one group received commercial
bovine colostrum supplemented with WPC, (Treatment 1, n=6) and the other group
received only commercial bovine colostrum (Treatment 2, n=6). Animals on the two experimental diets were
individually housed and fed. The
acquisition of the two experimental diets was ad libitum. After 36 hours, the piglets receiving bovine
colostrum, whether supplemented or not, were placed onto a commercial piglet
diet without additional supplement.
Blood samples were collected daily and cast against both porcine and
bovine anti-Immunoglobulin G (IgG) for sera concentration levels of IgG. Treatment 1 not only exhibited increased
weight gain when compared to the other two groups, but also displayed
significantly higher concentrations (p<.001) of bovine IgG. Porcine IgG on either of the two
experimental diets was low. Total DNA
concentration was highest in piglets receiving WPC supplementation. There was no difference in gut enzymatic
activity irrespective of treatment.
These results suggest that WPC may facilitate uptake of IgG prior to gut
closure and as well cause an increase in total DNA concentration.
Introduction
Development of an immune response is critical to the survival of any
animal, regardless of species and many animals receive passive immunity before
birth. Placental thickness restricts
passage of immunoglobulins to piglets prior to parturition and therefore
passive immunity is transferred to the piglet via colostrum (Brambell, 1970). Most
research has failed to find any antibodies in the blood of the newborn young
before they have suckled (Wilson, 1974).
Colostral delivery to the piglet has its highest concentration of
immunoglobulin in IgG (Butler, et. al., 1981).
Present in animals that deliver passive immunity via colostrum is a
particular whey protein, b-lactoglobulin (BLG)
(Alston-Mills, et. al., 1996). It has
been shown that BLG can escape hydrolytic degradation in the gastrointestinal
tract (Hill, et. al., 1997). A true and
concise role of BLG has never been identified.
The fact that it is only present in animals’ milk that deliver immunity
through colostrum is reason to speculate that it could assist in the transfer
of passive immunity either by immunogenic effects or a direct effector of IgG
uptake (Werhahn, et. al., 1981). DNA
concentration and intestinal enzymatic activity could also be affected by BLG.
Animals: Three sows were
brought from the Swine Educational Unit at North Carolina State University to
Grinnell’s Laboratory three days prior to farrowing. Sows were given a 3cc injection of lutylase 36 hours prior to their
calculated farrowing time. As piglets
were delivered they were removed from the sow to ensure that they were
initially colostrum deprived so baseline sera levels of IgG could be obtained. Piglets were caught, cleaned and placed onto
a heating pad before the first blood draw.
Weights and blood collections were tallied at 24 hour intervals
post-farrowing(0,24,48,72,96). Weights
were recorded to the nearest 0.1g.
Blood samples were collected via jugular syringe stick (20 gauge 1 inch
needles) and transferred to red-top vacutainers and refrigerated prior to
processing. Blood was centrifuged at
1800 rpm for 10 minutes, sera collected and frozen at -20C. IgG levels were
determined in piglet sera using an ezyme-linked immunoassay. From three sows
there were 6 piglets removed, 12 were placed onto one of two experimental
diets for 36 hours, then switched to a regular commercial piglet diet of milk
replacer. The remaining 6 piglets
remained on one of the sows to serve as controls. An additional two piglets were placed on the sow to mimic a
natural milk supply (nursing 8 piglets at a time). Diets: Three different diets were
employed in order to observe any effect WPC would have on IgG uptake. Treatment 1 was designated Colostrum Plusä
(LaBelle Associates, Bellingham, WA) with WPC supplementation. Treatment 2 was Colostrum Plusä
without WPC. Treatment 3 was sow’s milk
and those piglets remained on the sow for the duration of the study while
piglets on treatments 1 and 2 were placed onto a commercial milk replacer after
36 hours. Piglets surviving through 96 hours on treatment were euthanized using
a xylazine:rompun cocktail (1:4) followed by a fatal injection of sodium
pentobarbitol. Duodenal, jejunal, and
ileal sections were removed for enzymatic activity and total DNA concentration
determination. Statistics: Data were compared
using SAS 6.12 as well as PRISM Graph Pad v.3. Treatments were compared using a one-way analysis of variance with
Duncan’s post-hoc test (SAS) as well as using Newman-Keuls Multiple Range
Comparison post-hoc test (PRISM). When compared to the
piglets on the sow, those on treatments 1 and 2 gained significantly more
weight Figure 1) as well as a greater increase in the uptake of bovine IgG
(Figure 2). Except for the control group, there was minimal porcine IgG evident (Figure3).
Intestinal enzymatic activity was identical across treatment groups. Total
intestinal DNA was highest in piglets reared on Colostrum Plusä with or without WPC. Significance for all results was determined at P<.05 (Table 1).
It appears that WPC enhances the
uptake of IgG. However, since
endogenous production of IgG does not occur until approximately 21 days, it
remains unclear whether it is the BLG in the WPC that stimulates increased
uptake of IgG prior to gut closure or whether the supplement has an immunogenic
effect to stimulate production of IgG. Piglets receiving supplementation of WPC
had the greatest weight gains.Thus: Can WPC act as a stimulatory agents in gut
performance or does it provide initial protein levels for nutritional
advancement? As a whey protein with a
small molecular weight (~17.5 kD), BLG can escape normal hydrolytic cleavage in
the gut. Because of this, our
assumption was that it might be the stimulatory factor in the concentrate. It is known that BLG persists in milk after
delivery of colostrum and therefore, may
serve to stimulate endogenous IgG production or facilitate its uptake. Total
DNA concentration is, in fact, increased with supplementation. If BLG is the
effective agent, then a possible role of BLG could be to enhance initial gut
development. Gut performance was not
ffected as evidenced by no observable changes in enzyme activity
as a result of treatment. In order to
assure our results, purified BLG would have to be used. Additionally, an in vitro system using intestinal cell lines will allow isolation of
factors. A specific role of b-Lactoglobulin has
escaped researchers and from these data, it may be inferred that the protein may
facilitate IgG uptake within 48 hours of administration. The fact that it can escape degradation in
the gut coupled with the fact that its presence is limited to animals using
colostrum as a means of passive immunity transfer lends support that it may play
a significant role in facilitation of IgG uptake in the neonatal piglet. Piglet morbidity amongst swine producers is
always a concern. When a piglet is
lost, that piglet represents a.loss of initial investment and loss of future
money. If an extra supplementation was
added to liquid diets, morbidity might be reduced because of greater transfer
of IgG to the piglet. As a consequence,
greater passive immunity, to provide an enhanced line of defense against serum
antigens, would be accomplished. Alston-Mills, B.P.
and M.P. Thompson. 1996. Comments Agric. and Food Chemistry.
3:175-208. Brambell, F.W. 1970.
The Transmission of Passive Immunity from Mother to Young. 166-189. Hill, J.P., W.
Thresher, M. Boland, L. Creamer, S. Anema, G. Manderson, D. Otter, G.
Patterson, R. Lowe, R. Burr, R. Motion, A. Winkelman, and B. Wickham. Milk Composition, Production, and
Biotechnology. 1997. 173-202. Butler, J.E., F.
Klobasa, and E. Werhahn. 1981. Veterinary
Immunology and Immunopathology. 2:53-65. Werhahn, E., F.
Klobasa, and J.E. Butler. 1981. Veterinary
Immunology and Immunopathology.
2:35-51. Wilson, M.R. 1974.
Journal of Animal
Science:Symposium on Prenatal and Perinatal Development of Swine. (5)38:1018-1021.Material and Methods
Results
Discussion
Implications
Literature Cited
