Intestine Of Broiler Chickens Research Articles

<b>Effect of feeding Thymolina<sup>®</sup> powder on the carcass characteristics and morphology of small intestine in ross 308 broiler chickens

In the present experiment, 320 one day old Ross 308 broiler chickens were used completely randomized design with 4 treatments, 4 replicates, and each replicate contained 20 broiler chickens. Experimental treatments include control, 0.5, 1, and 2% of Thymolina powder in chickens’ diet. Thymolina ® is an anti-bacterial powder drug which is made by composing 4 medicinal plants. A significant difference observed between treatments in each parameter of the Intestinal morphology (villus height, villus width, crypt depth and epithelial thickness). Goblet cells number was not affected. Our findings indicated that using Thymolina ® in the diet of broiler chickens causes improvements in carcass characteristics. Therefore, it may improve the carcass characteristics and morphology of small intestine in broiler chickens.

Effects of in ovo feeding of l-arginine on the development of lymphoid organs and small intestinal immune barrier function in posthatch broilers

The present study was conducted to investigate the effects of in ovo feeding of l-arginine (Arg) solution on the nitric oxide synthase (NOS) activity and nitric oxide (NO) production, jejunal inducible NOS (iNOS) gene promoter methylation status and expression level, immunological cytokines and toll-like receptors mRNA expression in small intestine of broiler chickens. After candled on 16 d of incubation, a total of 720 embryonated eggs with similar weight (65.08±0.12g) were randomly allocated to three groups, consisting 8 replicates of 240 eggs each. Three treatments were arranged as non-injected control, 7.5g/L (w/v) NaCl diluent-injected control group, and 10g/L (w/v) Arg solution injected group containing 10g Arg, dissolved in 1L diluent. At 17.5 d of incubation, 0.6mL of each solution was injected into the amniotic fluid of each egg of injected groups. Results showed that in ovo feeding of Arg solution increased (P<0.05) the activity of iNOS, the contents of interleukin-2 (IL-2), interleukin-4 (IL-4) and secretory immunoglobulin A (sIgA), the mRNA expressions of toll-like receptor-2 and toll-like receptor-4 in intestinal mucosa, and the mRNA expression and protein abundance of iNOS. In addition, in ovo feeding of Arg solution decreased (P<0.05) the iNOS promoter methylation percentage in jejunal mucosa compared with non-injected control and diluent-injected group. Meanwhile, the iNOS activity, the contents of NO, IgA, IL-2 and IL-4 in serum as well as the absolute weights of lymphoid organs in Arg group were higher (P<0.05) than other groups. Collectively, our data indicated that in ovo feeding of 0.6mL of 10g/L (w/v) Arg solution facilitated improving the immunological barrier functions in intestinal mucosa and the overall immunity of 21-d-old broilers by suppressing the iNOS methylation and activating the Arg-NO signaling pathway. Therefore, in ovo feeding of appropriate Arg solution could be as an effective technology for regulating early nutrition supply and subsequent the immune function in poultry industry.

Effect of Ajwain (Trachyspermum ammi) supplementation on morphometry of intestine of broiler chicken

The present study attempts to analyze the effect of supplementation of Ajwain on the morphometry of intestine of broiler chicken. Two hundred and twenty five one-day old unsexed broiler chicks were used on a completely randomized design in 5 groups with 3 replicates, each consisting of 15 broilers. The treatments included the control group (basal diet) and four groups with basal diet + Ajwain powder @ 0.1% in feed, basal diet + Ajwain powder @ 0.2% in feed and basal diet + Ajwain seeds soaked in drinking water over nightly @ 0.1% and basal diet + Ajwain seeds soaked in drinking water over nightly @ 0.2%, respectively. Standard feeding and all other managemental practices were followed during the experimental period. At 14, 28 and 42 day of the experiment one bird from each replicate were sacrificed for estimation of GIT health characteristics (villi height). Among GIT health characteristics villi height of duodenum, jejunum and ileum showed significant results at 14, 28 and 42 day i.e. highest in basal diet + Ajwain powder @ 0.1% in feed group. Through this experimentation it can be concluded that Ajwain can be promoted as a non-antibiotic growth promoter (NAGP) in broiler industry for producing quality meat without antibiotics in a very effective way.

Effects of Prebiotics and Synbiotics Delivered In Ovo on Broiler Small Intestine Histomorphology During the First Days After Hatching.

The objective of the study was to determine the effect of prebiotics and synbiotics administered in ovo on the 12th day of incubation, on the development of the intestinal villi and the number of goblet cells in the small intestine of broiler chickens on the Ist and the 4th days of life of chicks. Two prebiotics: inulin (PI) or Bi2tos (PB) and two synbiotics: inulin + L. lactis subsp. lactis (SI) or Bi2tos + L. lactis subsp. cremoris (SB) were injected in ovo on the 12th day of embryonic development. The control group of the embryos was injected with physiological saline (C). On the 1st day of life, an increase in the height of the villi in the jejunum was reported as a result of the injection of pre- and synbiotics, moreover an increase in the surface area of the villi in the jejunum and the duodenum in chicks from the SB group was also observed. A stimulatory effect of synbiotics on the morphology of the duodenum and thejejunum was also observed on the 4th dh day after hatching. Conversely, in the ileum, in the SB group, a reduction in the height of villi was found both on thse 1t and thte 4h days of life. In contrast, injection of inulin and synbiotic with the addition of inulin resulted in an increase in the number of goblet cells in the duodenum and the jejunum on thst 1" day of life, and caused a significant decrease on the 4th day after hatching.

Effect of in ovo injected prebiotics and synbiotics on the caecal fermentation and intestinal morphology of broiler chickens

Manipulations of the intestinal microbiota composition may improve the health and performance of chickens. In ovo technology allows the administration of a bioactive substance to enter directly into the incubating egg. The objective of the present study was to investigate the effect of in ovo administered prebiotics or synbiotics on microbial activity products in the caeca and the development of the small intestine of broiler chickens. Ross 308 male chickens hatched from eggs injected in ovo with prebiotics or synbiotics were used in this study. Five experimental groups were formed: C (Control) – injected with 0.9% NaCl, the Pre-1 and Pre-2 groups – injected with prebiotics: inulin or Bi2tos, respectively, and the Syn-1 and Syn-2 groups – injected with synbiotics: inulin with Lactococcus lactis subsp. lactis IBB SL1 or Bi2tos with Lactococcus lactis subsp. cremoris IBB SC1, respectively. At the age of 7, 21 and 35 days, 10 chicks of each group were randomly selected, weighed and slaughtered, and the jejunal samples were collected for histological examinations, whereas caecal samples were collected to analyse the end products of microbial fermentation. Synbiotic treatment increased bodyweight, as observed in the Syn-1 group (P &lt; 0.05). The propionate molar proportion was highest in the groups treated with synbiotics, especially in the Syn-1 group (P &lt; 0.01). Furthermore, the molar proportion of acetate was also lowest in the Syn-1 group (P &lt; 0.05). In ovo synbiotics treatment increased the villus length : crypt depth ratio in the jejunal mucosa, which might improve nutrient absorption and contribute to the increased weight of chickens. These effects suggest that the in ovo administration of synbiotics may be an effective method to increase bodyweight, improve the short-chain fatty acid caecal profile and increase the villus length : crypt depth ratio in the jejunal mucosa. These effects were more pronounced in the Syn-1 group than the Syn-2 group.

Effect of dietary inclusion of Mentha piperita L. on histological and histomorphometrical parameters of the small intestine in broiler chickens

To evaluate the effect of dietary dried peppermint (Mentha piperita) (DPM), leaf powder on histomorphological parameters of small intestinal mucosa of broiler chicks, 50, 1-day-old chickens were randomly divided into five equal groups and fed with diets containing 0 (basal diet), 10, 20, 40, and 80 g/kg of DPM for 45 days. At the end of the experiment, all chickens were slaughtered, the whole small intestine was removed, and 1-cm-thick samples were taken from the duodenum, jejunum, and ileum. Six-micrometer-thick transverse cross sections stained with hematoxylin and eosin (H&E) for measuring length and width of the villi and depth of the crypts by using a linear graticule under light microscope. Effects of DPM on intestinal mucosa were relatively limited and included a significant increase in villus height/crypt depth ratio in duodenum of DPM-treated birds due to an increase in villus heights without appreciable change in crypt depth accompanied by a significant increase in villus height in the jejunum of experimental groups especially DPM 80 group. The ileum was the least affected part of the intestine with only appreciable increase in villus depth in DPM 80 group. The results of present study showed that dietary inclusion of M. piperita can partially improve histomorphological structure of small intestinal mucosa of broiler chickens with the duodenum as the most affected part.

Effect of Clostridium perfringens infection and antibiotic administration on microbiota in the small intestine of broiler chickens

The etiological agent of necrotic enteritis (NE) is Clostridium perfringens (CP), which is an economically significant problem for broiler chicken producers worldwide. Traditional use of in-feed antibiotic growth promoters to control NE disease have resulted in the emergence of antibiotic resistance in CP strains. Identification of probiotic bacteria strains as an alternative to antibiotics for the control of intestinal CP colonization is crucial. Two experiments were conducted to determine changes in intestinal bacterial assemblages in response to CP infection and in-feed bacitracin methylene disalicylate (BMD) in broiler chickens. In each experiment conducted in battery-cage or floor-pen housing, chicks were randomly assigned to the following treatment groups: 1) BMD-supplemented diet with no CP challenge (CM), 2) BMD-free control diet with no CP challenge (CX), 3) BMD-supplemented diet with CP challenge (PCM), or 4) BMD-free control diet with CP challenge (PCX). The establishment of CP infection was confirmed, with the treatment groups exposed to CP having a 1.5- to 2-fold higher CP levels (P < 0.05) compared to the non-exposed groups. Next-generation sequencing of PCR amplified 16S rRNA genes, was used to perform intestinal bacterial diversity analyses pre-challenge, and at 1, 7, and 21 d post-challenge. The results indicated that the intestinal bacterial assemblage was dominated by members of the phylum Firmicutes in all treatments before and after CP challenge, especially the Lactobacillaceae and Clostridiales families. In addition, we observed post-challenge emergence of members of the Enterobacteriaceae and Streptococcaceae in the non-medicated PCX treatment, and emergence of the Enterococcaceae in the medicated PCM treatment. This study highlights the bacterial interactions that could be important in suppressing or eliminating CP infection within the chicken intestine. Future studies should explore the potential to use commensal strains of unknown Clostridiales, Lactobacillaceae, Enterobacteriaceae, Streptococcaceae, and Enterococcaceae in effective probiotic formulations for the control of CP and NE disease.

Morphometric properties and distribution of alpha-actin in the smooth muscle cells (ASMA) of the small intestine during development in chicken

ABSTRACTThe objective of this study was to investigate the morphological characteristics and expression of the α-smooth muscle actin (ASMA) immunohistochemistry during development of the small intestine in broiler chickens. Twenty-four healthy broiler chickens (ROSS 308) in 4 different age groups (6-, 14-, 28- and 52-day-old) were used in this experiment. A slight increase was observed in the weight and length of the duodenum, jejunum and ileum from days 6 to 28, peaked on day 52. The weight and length of jejunum on days 28 and 52, respectively, were significantly higher in female chickens compared with males (P < .05). An increase in height and width of propria and muscular layers of villi were obtained for the three segments during the experimental period. Villi height and width of jejunum in female broilers at day 28 were significantly larger than males (P < .05). These results also revealed that all the smooth muscle layers were immunoreactive positive for ASMA; but this reactivity differed between the muscle layers. The minimal expression of ASMA was observed at days 6 and 14 of age in circular and longitudinal muscular layers. At day 28, there was a more distinct expression of ASMA in circular and longitudinal muscular layers compared with days 6 and 14. Expression of ASMA in both muscle layers at day 52 was intensely immunopositive. Contractile function during the evolution of each organ and muscle layers could be dependent on different patterns of expression of ASMA in the smooth muscle cells.

Apparent ileal digestibility of protein and amino acids in protein feedstuffs and trypsin activity in the small intestine in broiler chickens

Coefficients of ileal apparent digestibility (CIAD) for crude protein (CP) and amino acids in five protein feedstuffs: corn distillers dried grains with solubles (DDGS), raw full-fat soybean (RFFSB), extruded full fat soybean (EFFSB), soybean meal (SBM), and rapeseed meal (RSM) were determined using 5-week-old male broiler chickens. Trypsin activity in digesta in the ileum and jejunum were also measured. CIAD of CP was the highest in SBM (0.73). The lowest (P &amp;lt; 0.05) CIAD of CP was determined for RFFSB (0.45). There was no significant difference in CIAD of CP between RSM (0.61) and DDGS (0.62). The CIAD values for all essential amino acids except Lys (0.52) were the lowest in RFFSB (P &amp;lt; 0.05). The CIAD of Lys was the lowest in DDGS (0.39, P &amp;lt; 0.05). The CIAD for all essential amino acids was the highest in SBM (P &amp;lt; 0.05). There was no significant difference between EFFSB and SBM (P &amp;gt; 0.05) in CIAD of Leu (0.71, 0.73), His (0.66, 0.69), Lys (0.70, 0.77), Met (0.74, 0.80), Thr (0.60, 0.62), and Val (0.65, 0.67). Both the feedstuff and the intestinal region and their interaction had a significant (P &amp;lt; 0.01) effect on trypsin activity. The CIAD of CP and amino acids were very high and comparable both in EFFSB and SBM. The CIAD values for CP and amino acids in DDGS and RSM were lower than in SBM, but they seemed to be comparable to each other.

The use of genetically modified Roundup Ready soyabean meal and genetically modified MON 810 maize in broiler chicken diets. Part 2. Functional status of the small intestine

ABSTRACT. The effects of genetically modified (GM) soyabean meal (SBM) and GM maize on the functional status of the small intestine of broiler chickens was studied. Eight diets were prepared, based on conventional or GM SBM (GTS 40-3-2) combined with non-modified maize cvs. Clarica and PR39 F58 or their isogenic GM (MON 810) counterparts cvs. Bacilla or PR39 F56. Diets were fed in mash form from days 1 to 30 of age to 192 Ross 308 broiler fe-males, assigned to 8 groups and kept in individual cages from day 8 of life. The functional status of the small intestine was studied in 8 birds per group after slaughter. The investigation included morphological evaluation of jejunum and ileum sections, calculation of apoptotic and mitotic indices, and measurement of DNA damage in jejunal epithelial cells. There were no statistically significant differences in morphological parameters of the jejunum and ileum except the width of the tunica mucosa in the jejunum, which was greater in birds fed GM than in those given conventional maize. GM SBM had no effect on the apoptotic and mitotic indices in the crypt area or in villi tips, while GM maize did not affect these indices in the crypt area, but increased the apoptotic index in the villi tips of the jejunum. Neither substituting conventional SBM by GM SBM, nor con-ventional maize by GM maize induced significant DNA damage in the epithelial cells of the jejunum. Our results indicate that the functional development and maturation of the small intestinal epithelium is not greatly modified by the use of GM SBM and GM maize in broiler diets.

Effect of Indigenous Probiotics Lactic Acid Bacteria on the Small Intestinal Histology Structure and the Expression of Mucins in the Ileum of Broiler Chickens

Intestinal mucous containing mucins play an essential role as mucosal barrier to prevent invasion in the intestinal tissue of broilers. The aim of the study was to investigate the effect of supplementation of indigenous probiotics lactic acidbacteria on small intestinal histology structure and expression of mucins in the ileum of broiler chicken raised for 35 days. A total of 60 day old chick Lohmann strain broilers were randomly divided into four treatment groups, namely T0, T1, T2 and T3. The T0 group was raised with unsupplemented probiotics, while T1, T2 and T3 were orally supplemented multistrain probiotics at concentration 107, 108, 109 CFU/ml/bird/day, respectively. The results showed that supplementation of indigenous lactic acidbacteria probiotics significantly (P<0.05) increased villus height, villus width of duodenum, jejunum and ileum, as well as increased expression of mucin mRNA in the ileum compared to the control one in broilers. This results suggest that probiotics may stimulate proliferation of intestinal epithelium and regulate mucosal barrier formed by mucin in the intestine of broiler chickens.

Increased intracellular calcium level and impaired nutrient absorption are important pathogenicity traits in the chicken intestinal epithelium during Campylobacter jejuni colonization.

Although a high number of chickens carry Campylobacter jejuni, the mechanistic action of colonization in the intestine is still poorly understood. The current study was therefore designed to investigate the effects of C. jejuni on glucose uptake, amino acids availability in digesta, and intracellular calcium [Ca(2+)]i signaling in the intestines of broiler chickens. For this, we compared: control birds (n = 60) and C. jejuni-infected birds (n = 60; infected orally with 1 × 10(8)CFU of C. jejuni NCTC 12744 at 14days of age). Our results showed that glucose uptake was reduced due to C. jejuni infection in isolated jejunal, but not in cecal mucosa at 14days postinfection (dpi). The decrease in intestinal glucose absorption coincided with a decrease in body weight gain during the 2-week post-infectious period. A reduction in the amount of the amino acids (serine, proline, valine, leucine, phenylalanine, arginine, histidine, and lysine) in ileal digesta of the infected birds at 2 and/or 7dpi was found, indicating that Campylobacter utilizes amino acids as a carbon source for their multiplication. Applying the cell-permeable Ca(2+) indicator Fluo-4 and two-photon microscopy, we revealed that [Ca(2+)]i was increased in the jejunal and cecal mucosa of infected birds. The muscarinic agonist carbachol induced an increase in [Ca(2+)]i in jejunum and cecum mucosa of control chickens, a response absent in the mucosa of infected chickens, demonstrating that the modulation of [Ca(2+)]i by Campylobacter might be involved in facilitating the necessary cytoskeletal rearrangements that occur during the bacterial invasion of epithelial cells. In conclusion, this study demonstrates the multifaceted interactions of C. jejuni with the gastrointestinal mucosa of broiler chickens. For the first time, it could be shown that a Campylobacter infection could interfere with intracellular Ca(2+) signaling and nutrient absorption in the small intestine with consequences on intestinal function, performance, and Campylobacter colonization. Altogether, these findings indicate that Campylobacter is not entirely a commensal and can be recognized as an important factor contributing to an impaired chicken gut health.

Effect of Oral Supplementation of Putrescine and L-glutamine on the Histomorphology of Small Intestine and Growth Performance in Broiler Chickens

A work was conducted to study the effect of putrescine and L-glutamine supplementation on histomorphology of small intestine in broiler chickens. Five groups of ten chicks each in three replicates reared up to 42 days were used for this study. Putrescine and L-glutamine were orally supplemented at 0% level as control (T1), putrescine 0.05% (T2), putrescine 0.1% (T3), L-glutamine 0.5% (T4) and L-glutamine 1% (T5) from 0 day to 7 days after hatch. At 2nd and 3rd week of age, 3 birds from each groupwere slaughtered and tissue samples from small intestine (duodenum, jejunum and ileum) were collected for histomorphological studies. Statistically significant (p<0.01) increase in duodenal and jejunal villi length, width,crypt length and ileal villi length and width were observed in L-glutamine fed groups than putrescine and control groups. There was no significant difference in duodenal crypt length/width, jejunal crypt width and ileal crypt length/width. It can be inferred that L-glutamine promoted the intestinal villi development during early posthatch life, thus increasing the nutrients absorption and growth performance as body weight gain in broiler chickens.

Effects of Whole-Grain Paddy Rice on Growth Performance, Oxidative Stress and Morphological Alterations of the Intestine in Broiler Chickens Exposed to Acute and Chronic Heat Stress

Effects of Whole-Grain Paddy Rice on Growth Performance, Oxidative Stress and Morphological Alterations of the Intestine in Broiler Chickens Exposed to Acute and Chronic Heat Stress

Quantitative histo-morphometric analysis of heat-stress-related damage in the small intestines of broiler chickens

The aim of the current research was to present a methodological approach allowing reproducible morphometric and morphological (Chiu/Park scale) analyses of the alterations in the intestines of broilers exposed to heat stress. Ross broilers were exposed over four consecutive days to a high-temperature regime in controlled climate rooms, with a day temperature of 39°C (±1°C) and a night temperature of 25°C (±1°C), respectively. A control group was kept at an ambient temperature of 25°C (±1°C) during the entire experimental period. At the end of the exposure period, the birds were sacrificed and specimens were taken of the duodenum, jejunum and ileum for histology. Blood was collected for oxidative stress analysis. Histo-morphological and morphometric analyses of the intestines indicated that the duodenum and jejunum showed more damage than the ileum. The major alterations in the control intestines were limited to the villus tips, while heat stress led to villus denudation and crypt damage. When compared with morphologically normal villi, heat-stress-associated alterations were also observed in villus height (decreased), villus breadth at base (increased) and epithelial cell area (decreased). Birds exposed to heat stress presented with an increase in glutathione peroxidase activity and a decreased antioxidant capacity. It can be concluded that the chosen model allows a reproducible quantification of heat stress effects, which is suitable for the evaluation of dietary intervention strategies to combat heat stress conditions.

Analysis of the intestinal bacterial microbiota in maize- or sorghum-fed broiler chickens using real-time PCR

1. An experiment was conducted to study the effect of two different diets on zootechnical performance and the major bacterial groups in association with the host mucosa and dispersed in the lumen contents of the small intestine of broiler chickens.2. The two experimental diets were maize or sorghum-based. In addition to the total bacteria, bacterial groups belonging to the Enterobacteriaceae (Enterococcus and Lactobacillus) were quantified by real-time PCR.3. There were no differences in body weight gain and feed intake, but feed conversion ratio increased for sorghum-fed broilers at 21 and 42 d of age.4. The Enterococcus group decreased in all gut segments from 7 to 42 d, while the Lactobacillus group increased in both ecosystems. In the ileal mucosa, the enterobacterial counts decreased from 7 to 42 d in the maize-based diet, but remained stable in the sorghum-based diet.5. The results shed light on the spatial and temporal distribution of bacterial groups that play important physiological roles in the small intestine of chickens. Specifically, the increased Enterobacteria population in the ileum is consistent with the relatively poor feed conversion in sorghum-fed broilers.

Correction: Effects of feed contaminant deoxynivalenol on plasma cytokines and mRNA expression of immune genes in the intestine of broiler chickens

Correction: Effects of feed contaminant deoxynivalenol on plasma cytokines and mRNA expression of immune genes in the intestine of broiler chickens

In ovo inoculation of chicken embryos with probiotic bacteria and its effect on posthatch Salmonella susceptibility

The feasibility of establishing probiotic bacteria in the intestine of broiler chickens by in ovo inoculation was investigated, followed by verifying possible subsequent protection against Salmonella Enteriditis infection. In a first study, 7 commercially available probiotics were screened for compatibility with in ovo inoculation. Two of these probiotics, one being a Enterococcus faecium and the other a Bacillus subtilis, were selected for colonizing the chick gut without compromising hatchability. In a second study, these 2 products were administered in ovo and in the feed to chicks reared until 18 d in comparison with noninoculated chicks and with chicks fed an antibiotic. All chicks were orally challenged with Salmonella Enteritidis at 4 d of age. Results showed reduced performance of Salmonella Enteritidis challenged chicks fed no additives compared with challenged chicks fed antibiotic, but no significant differences in mortality was observed. Probiotics offered in ovo or through the diet could only partially recover performance compared with antibiotic-fed chicks. A significant reduction in the number of Salmonella Enteritidis positive chicks was observed when chicks were in ovo inoculated with E. faecium and continued receiving it in the diet. This work establishes standards for future in ovo colonization research and emphasizes its value as a promising method to deliver individual precise dose of probiotics to poultry in mass scale at the earliest possible age based on the competitive exclusion concept. In ovo colonization with probiotic can therefore become an important ally in combination with other approaches to combat Salmonella and other intestinal bacterial infections in poultry.

Effect of a synbiotic on the intestinal microflora of chickens

The current experiment was conducted to evaluate the effect of a synbiotic (Biomin Imbo) on intestinal microflora of Ross broiler chickens. A total of 200 male chickens were randomly divided into 20 groups of 10 birds each, kept in 20 pens (1.5 × 1 m each), and fed for 42 d at different synbiotic levels. Treatments included (1) a basal diet without synbiotics (control), (2) a basal diet with synbiotic levels proposed by the manufacturer, (3) a basal diet with synbiotic levels 25% lower than those proposed by the manufacturer, (4) a basal diet with synbiotic levels 50% higher than those proposed by the manufacturer, and (5) a basal diet with synbiotic levels 25% higher than those proposed by the manufacturer. At the end of the 42-d feeding period, 1 bird was randomly selected from each experimental unit, humanely euthanized, and the cecum was removed to measure the microbial population. The cecal contents were collected in discharge containers for microbial cultures, and counts were conducted after microbial culture. The addition of the synbiotic reduced Escherichia coli and total coliform populations in the intestines of broiler chickens. Conversely, different levels of probiotic increased the numbers of lactobacilli in the intestine of broiler chickens. Concentrations of the synbiotic higher than the recommended levels in the diet increased the lactic acid bacteria population in the gut of broiler chickens.

Effects of breeder age and egg weight on morphological changes in the small intestine of chicks during the hatch window

1. The objective of the study was to investigate the effects of breeder age and egg weight on hatching performance and morphological changes in segments of the small intestine of broiler chicks during a 21 h hatch window.2. Eggs from Ross broiler breeder flocks aged 29 (young) and 48 weeks (old) were classified as light (LE) or heavy (HE) and incubated at the same conditions. At 475 h of incubation, eggs were checked every 3 h to determine time of external pipping and hatching. The first 42 chicks to emerge from each group were weighed and chick length was measured and 14 chicks from each group were sampled to collect residual yolk and intestine segments. The rest of chicks were placed back in the incubator and chick weight and length were measured individually at 9, 15 and 21 h after chicks hatched. At the end of 21 h, 14 chicks from each group were sampled again and the same procedure was followed.3. The HE chicks pipped and hatched later than LE, regardless of breeder age. From hatch to the end of the hatch window, chick weight, but not yolk-free chick weight, gradually reduced. Relative residual yolk weight of chicks from both egg weights was similar at hatch, however, yolk sac utilisation was higher for LE chicks during the 21 h post-hatch period. At hatch, jejunum and ileum villus development was very similar for HE and LE chicks but greater development was observed for villus area with an increase in the jejunum villus length, width and goblet cell numbers in HE chicks.4. The longest jejunum villus and the widest duodenum and jejunum villus were obtained for HE chicks from old breeders indicating that HE chicks from old breeders would have a greater surface area for nutrient absorption.