The better nutrient absorption and resulted in a

The small
intestine is a vital organ involved in absorption of nutrients and good
intestinal health in broiler is the key factor to achieve desirable growth
rates and feed conversion efficiency. The integrity of gastrointestinal tract mucosa
is of utmost important in production animals as it is the first tissue that comes
in contact with ingested dietary ingredients. 
Hence assessing the intestinal morphology grossly and microscopically
can indicate response of the intestinal tract to active substances in feeds. The
result of current study showed that the length of the small intestine was not
significantly affected by the dietary treatments however there was a numerical increase
in length upon inclusion of PAB in diet. The results on body weight gain and
small intestine length also revealed that there is a relationship between
length of intestine and body weight gained that longer the gut length, more the
time for digesta to pass through gut which leads to better nutrient absorption
and resulted in a heavier body weight. Supplementation of PAB at 400 g/ton also
resulted in decrease in weight of small intestine. The reduction in intestinal
weight was due to thinning of intestinal wall (Gunal et al., 2006) which increased
nutrients’ digestion and absorption as well. In the present   study, the reduction in small intestine
weight observed in birds supplemented with PAB at 400 g/ton may be associated
with a reduction in muscularis layer thickness. Accumulation of lymphocytes
during infection to  kill  the 
pathogens  cause  inflammation, 
which  in  turn 
increases muscular layer thickness and increase the nutrient demand by
the gut-associated lymphoid tissues. Supplementation of phytogenic feed
additive containing Andrographis
paniculata, Emblica officinalis and Punica
granatum was previously known to reduce the level of acute phase protein, ?
1- acid glycoprotein, a marker for gut inflammation (Feed – X ref) which is suggestive of an
anti-inflammatory effect of the phytogenic additives and possibly caused significant
reduction in density of jejunum by suppressing the intestinal inflammation in
the present study.

Furthermore, it is
sensible to investigate the microscopic structure of intestinal tract in
response to the supplementation of PAB since microvilli plays a pivotal role in
absorptive functions. Generally, shortened villi decreases the surface area for
absorption of available nutrients, while increased crypt depth indicates fast tissue
turnover in response to cellular sloughing or inflammation and can lead to
lower the overall performance parameters in birds.

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

Conversely, long villi are usually associated
with better absorptive functions of the intestine  as 
a  result  of  increased  absorptive surface area, expression of brush
border enzymes,  nutrient  transport 
systems  (Caspary,  1992), resulted in healthier intestinal tract
of chickens (Alfaro et  al., 2007) and an
increased body weight gain (Zijlstra 
et  al., 1996). In the present
investigation, supplementation of PAB at 400 g/ton significantly increased the
villi height, villi surface area and villi height/crypt depth ratio in the
ileum. Hence supplementation of PAB improved the body weight gain and feed
conversion efficiency possibly by enhanced absorption of dietary nutrients and
reduced tissue turnover that might leave the energy conserved for lean muscle synthesis.

Besides nutrients
absorption, the intestine is believed to have barrier functions, which usually protect
the gut from external insults. The epithelial surface of the intestinal tract
is covered by a layer of mucus predominantly of mucin glycoproteins that are
synthesized and secreted by goblet cells (Smirnov et al., 2004). This layer can
act as a barrier between the luminal contents and the absorptive system of the
intestine and protects the epithelial surface from invasion of enteric bacteria,
bacterial and environmental toxins (Forstner and Forstner, 1994). The results
of this study showed that increased goblet cells count in the villi of ileum could
caused large release of mucus and formation of thick mucus layer on the wall of
gut in the birds fed on diets with PAB. This can partially help to explain the villi-related
protective properties of the phytoactives which reduced the possibility of
adhesion of E. coli, Clostridium
perfringens, Salmonella and fungi in intestinal content to epithelium (Jamroz  et al., 2005) and reduced the inflammation of
intestinal tract.

Intestinal alkaline
phosphatase, a membrane-bound glycoprotein which is more sensitive to change in
membrane than other brush border enzymes. The change in its activity levels may
reflect the degree of maturation of enterocytes and function of intestinal
epithelium (Ghafoorunissa, 2001; Iji et al., 2001; Jeurissen et al., 2002).
Birds supplemented with PAB exhibited significantly higher ileal alkaline
phosphatase activity in the present study demonstrated that dietary inclusion
of PAB has a beneficial effect on the gut by favouring the maturation and function
of intestinal epithelium. The enhanced maturation of intestinal epithelium in
birds supplemented with PAB could be due to favorable alterations in the
numbers of enteric bacteria and depression of the activity of bacterial enzyme
in the small intestinal digesta of broilers (Xu et al., 2003). This increased
ALP activity in ileum is also parallely equated with the morphological
measurements of increased villi height, villi surface area and villi height/crypt
depth ratio which ultimately leads to better absorption and utilization of
dietary nutrients.

x

Hi!
I'm Morris!

Would you like to get a custom essay? How about receiving a customized one?

Check it out