33International Poultry Production • Volume 25 Number 4

As the gastrointestinal tract is acomplex system, it is nosecret that the newly hatched

chick’s digestive tract is underdevel-oped and needs to mature duringthe first weeks of life. Due to theshort lifespan of a broiler a speed-up of the intestinal developmentprocess is required as quick growth,preferably with huge efficiency, isdemanded. Nutritional support ofthis early gut development is thussignificant for young growing ani-mals; a domain the industry isfocusing on during the developmentof new nutritional products.

by Valentine Van Hamme, Product Manager,

Impextraco, Belgium.www.impextraco.com

At hatch, there is a significant andimmediate demand on the gut todigest and absorb nutrients effi-ciently in order to maintain a highgrowth rate, as the gut is the mainorgan converting feed into meat.The sooner the intestine achieves

its functional capacity the earlierthe young chick can use dietarynutrients and grow according to itsgenetic potential.Luckily, the intake of exogenous

feed is accompanied by a rapiddevelopment of the gastrointestinaltract (GIT). But still, we need to takeinto account that the uptake ofexogenous feed is a first hurdlebecause a major change occurs inthe source of nutrients as the yolk isreplaced by an exogenous diet. Intestinal epithelial cell integrity is

of prime importance consideringthat this epithelium is responsiblefor absorption of water, elec-trolytes, and nutrients. In addition, this layer of cells must

provide a selective barrier againstthe complex and potentially harm-ful environment of the gut lumen.Research has shown that duode-

nal villus growth could almost becompleted by day seven, whereas inthe jejunum and ileum, villus devel-opment continues beyond day 14.The first weeks after hatch are

thus critical for development of theGIT and it is logical that the bird can

use some support in this criticalperiod in order to obtain a goodand efficient growth curve at a laterstage. Nutritional support of gutdevelopment is thus significant foryoung growing animals.Not only is the morphologic

development of the gut important,but the colonisation of the gut withthe beneficial microbiota and thematuration of the immune system(GALT) is also crucial, as 70-80% ofthe immune system is located in thegut. Microbial colonisation starts right

after hatch and proceeds during thelife of the bird. The chick’s gut asso-ciated lymphoid (GALT) tissue is

only to be considered as maturestarting from day 14-21 of age. Actually, in newly hatched broiler

chicks, B- and T-lymphocytes needto migrate from the Bursa ofFabricius to the peripheral tissues, inorder to create effective mucosalassociated lymphoid tissues. This migration process is time

consuming, making the young birdvery sensitive to environmentalchallenges, as B- and T- cell popula-tion of the intestinal mucosa is pri-mordial to establish an effectiveGALT. It goes without saying thatwe need to support the young birdin this process. Research has discovered that one

molecule, called butyric acid (C4),which is consistently present in theintestinal ecosystem, as it is natu-rally produced by fermentation bythe intestinal microbiota, is primor-dial in the intestinal development.Butyric acid plays a major role in

enhancing gut health by promotionof the intestinal barrier, modulationof the immune system, balancingthe intestinal flora and improvingdigestion and absorption of nutri-ents, leading to enhanced perfor-mance. In young animals, butyric acid is

known to promote the maturationof the intestinal mucosal immunesystem and to stimulate the intesti-nal mucosal development.Therefore it is the ideal molecule

to be supplied to young animals andto focus on in research.

Practical research

As positive effects of butyrate havebeen proven in vitro and in vivo,butyrate based products are widelyused in animal production world-wide. Butyric acid, as such, cannot be

supplemented to animal feed dueto its volatility and pungent odour.Solutions were developed by theindustry: supplementation ofcoated salts of butyric acid –butyrate – became a standard. In addition, other ingredients, for

example specific acid salts and natural extracts, have proven tointeract synergistically withbutyrate and are thus enhancingbutyrate’s action.Impextraco has recently focused

its research on gut health manage-ment through in vitro and in vivotrials in their own trial facilities inBrazil and in cooperation withBelgian and Brazilian research insti-tutes and universities. In one of its trials, Impextraco

evaluated the effect of a commer-cially available synergistic butyratebased product in young chicks ontwo gut health parameters: theimmune system and intestinal morphology.Up to 21 days the intestine of a

broiler chick is considered to be

Butyrate-based conceptsoffer nutritional supportfor early gut development

Continued on page 34

Fig. 1. Histological evaluation of jejunum of 14-day-old Ross 308 broilerssupplemented with a butyrate based product, Butifour F, resulting in sig-nificantly longer villi (*p<0.05).

Haematoxylin and eosin staining of a jejunum sample (10x) of a 14-day-old Ross 308 broiler supplemented with a butyrate based product,Butifour F, showing long slender villi.

800

780

760

740

720

700

680Control Butifour F

Villu

s leng

th (m

m)

a

b

immature. Consequently, 20 day-oldRoss 308 broiler chicks, individuallyidentified by wing tag, were raisedup to 14 days in 10 pens with fivereplicates each. These animals, held at the

research facilities of the CatholicUniversity of Leuven, Belgium, wereallocated to two treatments: a neg-ative control group (wheat baseddiet without antibiotics or addi-tives) and a butyrate based group(wheat based diet supplementedwith 750g Butifour F per ton offeed). At 14 days of age, all animals were

euthanised and samples of thejejunum were taken (1cm beforeMeckel’s diverticle) for histological(villi length) and immunohistochem-ical evaluation (CD3+ T-lympho-cytes) at the Faculty of VeterinaryMedicine of the University ofGhent, Belgium. Area % of CD3+ T-lymphocytes is

a biomarker to evaluate mucosalimmunity, while villi length is a bio-marker for intestinal integrity andhealth. The results are presented in Figs. 1

and 2. Supplementation of a butyrate

based product stimulated the

intestinal maturation of the youngbird, clearly demonstrated by thesignificant higher villi and significanthigher presence of CD3+ T-lympho-cytes in the jejunum.

Conclusion

It is clear the gut needs to matureduring the first weeks of life, and weneed to support the young chickduring this period. The positiveeffect of butyrate based products inyoung chicks is clear.

Research has proven that butyratebased supplementation is support-ing an optimal maturation of theintestinal morphology and immunityin young chicks.These effects are demonstrated

by a healthy villi development andan increased population of themucosa by CD3+ T-lymphocytes,leading to an early maturation ofthe GIT. n

References are availablefrom the author on request

Continued from page 33

34 International Poultry Production • Volume 25 Number 4

Fig. 2. Immunohistochemical evaluation of CD3+ T-lymphocytes ofjejunum of 14-day-old Ross 308 broilers supplemented with a butyratebased product, Butifour F (*p<0.05), showing the early colonisation of theintestine by a significantly higher presence of CD3+ lymphocytes atyoung age compared to a non-supplemented group.

CD3+ T-lymphocyte staining (10x) of a jejunum sample of a 14-day-oldRoss 308 broiler supplemented with a butyrate based product, Butifour F(*p<0.05), showing the early colonisation of the intestine by a high pres-ence of CD3+ lymphocytes, marked by the brown areas.

30

20

10

0Control Butifour F

CD3+ area (%)

a

b