Use of cecal microflora cultured under aerobic or anaerobic conditions in the control of experimental infection of chicks with Salmonella Enteritidis

One-day-old broiler chicks received cecal microflora (CM) cultured under aerobic, anaerobic conditions, or both (mixed) and were then infected with Salmonella Enteritidis, in order to compare the efficacy of these different types of culture in terms of the number of chicks infected, cecal colonization and faecal excretion of the challenging bacteria. Regardless of culture type, CM always led to a smaller number of S. Enteritidis for any of the parameters studied compared to untreated chicks. Aerobic CM demonstrated better efficacy in reducing the number of infected chicks and cecal colonization by S. Enteritidis, followed by mixed CM. No difference was observed in faecal excretion of S. Enteritidis between the chicks that received different types of CM culture. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Posthatching water and feed deprivation affect the gastrointestinal tract and intestinal mucosa development of broiler chicks

We studied the effect of feed and water deprivation on gastrointestinal tract and intestinal mucosa development of chicks at 24, 48, and 72 h posthatching. The treatments were water and feed ad libitum, water ad libitum and no feed, no water but feed ad libitum, and no water and no feed. The relative weight of the yolk sac was not influenced by the treatments. However, at 48 and 72 h posthatching, the relative weight of the liver increased, and the gizzard + proventriculus weight decreased in birds receiving feed ad libitum. An increase in jejunum and ileum relative weights and lengths was observed when the birds were supplied with feed and water. The lack of water produced the same effect as the lack of feed, both causing a higher number of villi per area with reduction in villus size, when compared with feed and water ad libitum treatments. The results of this study revealed that feed and water are able to affect intestinal villus development after hatching, indicating that both feed and water must be supplied to the chicks immediately after hatching.

Detection of T lymphocytes in intestine of broiler chicks treated with Lactobacillus spp. and challenged with Salmonella enterica serovar enteritidis

The expression of immune response in the form of leukocytic infiltrate by CD3+, CD4+, and CD8+ cells in the epithelium and in the intestinal lamina propria of chicks was studied in the present work by means of immunohistochemical reaction. The chicks were treated with Lactobacillus spp. or cecal microflora (CM) and experimentally challenged or not with Salmonella enterica serovar Enteritidis. The 320 birds utilized were divided into 4 groups containing 80 chicks each and submitted to treatments with Lactobacillus reuteri, Lactobacillus salivarius, Lactobacillus acidophilus, and CM. Each group was subdivided into 4 subgroups of 20 birds each and classified into a subgroup that did not receive treatment (negative control), subgroup treated, subgroup treated and challenged with Salmonella Enteritidis, and subgroup only challenged with Salmonella Enteritidis (positive control). The results obtained show that the treatment with L. reuteri, L. salivarius, L. acidophilus, or CM and challenged or not with Salmonella Enteritidis determine immune response in the form of leukocytic infiltrate by CD3+ and CD8+ lymphocytes followed by CD4+ in the epithelium and in the lamina propria of the duodenum, jejunum, and cecum of chicks up to 12 d of age. The quantity of CD3+ lymphocytes was significantly higher (P < 0.05) in the intestine of chicks treated with L. acidophilus or CM and challenged or not with Salmonella Enteritidis; however, the higher quantity of CD8+ lymphocytes was in the intestine of chicks treated with CM and challenged with Salmonella Enteritidis. The duodenum was the segment in which the immune response by T cells (CD3+, CD4+, and CD8+) was stimulated with the greatest intensity, followed by, respectively, the jejunum and cecum. The quantity of CD3+ lymphocytes present in the duodenum, jejunum, and cecum increases with the age of chicks, independent of the stimulus determined by treatments or challenge.

Effect of Phytase Supplementation in Diets on Nutrient Digestibility and Performance in Broiler Chicks

A performance trial was conducted with broiler chicks to Study the effect of phytase (PHY) supplementation in diets formulated With reduced AME, Ca, and P. The nutrient digestibility was determined during the 14- to 21-d and 28- to 35-d periods. The treatments consisted of 3 diets (NC1, NC2. NC3) differing ill nutrient content and each diet with Or without supplemental PHY (NC1, 0 oi 500; NC2, 0 or 750; NC3, 0 or 1,000 U of PHY/kg feed) and I positive control diet (PC). Compared with the PC diet. negative control diets (NC) resulted in lower AME and apparent ileal amino acid digestibility for some amino acids. Phytase Supplementation of the NC diets increased AME. apparent ileal amino acid digestibility, and apparent ileal crude protein digestibility. Phytase addition also increased mineral absorption in 2 1 - and 35-d-old broilers fed NC diets. Reduced nutrient digestibility appears to be I factor in the weight gain and feed intake results. Reducing Ca and P content reduced feed intake in a stepwise fashion in the NC diets. Phytase increased feed intake and generally improved nutrient digestibility, which resulted in an increase in digestible nutrient intake. Averaged across NC diets. PHY improved body weight. Bone-breaking strength was the most consistent predictor of Ca and P reduction. All NC diets had significantly lower bone-breaking strength than the PC. Phytase supplementation of the NC diets gave bone-breaking strengths that were comparable to the PC. Diets with PHY had the highest bioeconomic index.

Influence of sex, age, and fasting on blood parameters and body, bursa, spleen and yolk sac weights of broiler chicks

The effects of water and feed fasting for 24, 48 and 72 hours post-hatching on blood parameters (mean corpuscular volume, MCV; red blood-cell, RBC; hematocrit, HCT; hemoglobin, HGB; plasma glucose, CGP; plasma total protein, PP, and differential leukocytes count), and on body, liver, spleen, bursa, and yolk sac weights were analyzed. Erythrogram data were obtained with a blood cell counter. Total plasma protein and plasma glucose were determined by using the Bradford method (1976) and a glucose PAP liquiform kit (Labtest, cat. n. 84), respectively. Specific leukocyte counts were carried out on blood smears stained with Rosenfeld solution. According to the obtained data, water and feed post-hatching fasting reduced MCV values, which also were lower in males than that in females. Fasting for 48 hours promoted an increase in PP, while fasting for 72 hours reduced HCT. Chicks submitted to fasting presented lower body weights as compared to fed chicks, but their liver weight did not increase between 48 and 72 hours of age. Fasting decreased spleen weight, but bursa and yolk sac weight were not affected. Data showed that female and male chicks react in a similar way to post-hatching fasting, which affects body weight, liver and spleen weight, and HCT and PP values. Moreover, 72 hours of fasting affected more intensely HCT and MCV values.

Hematological and incubation parameters of chicks from young breeders eggs: Variation with sex and incubation temperature

This experiment analyzed the effect of sex and incubation temperature on daily mass loss and eggshell conductance, embryo mortality rates, incubation duration, hematological parameters and body, liver, heart and bursa weights of neonatal chicks from young breeders. The daily mass loss was higher at incubation temperature of 39°C. The eggshell conductance rate increased with the temperature. The total and partial duration of incubation were lower for eggs incubated at 39°C. The time taken by the chick to leave the eggshell did not differ below and above the thermoneutral temperature. The total and intermediate embryo mortality rates increased with the incubation temperature, whereas the early and late embryo mortality rates were higher at incubation temperature of 39°C. Sex did not influence the analyzed parameters, while the incubation temperature did not affect the body and bursa weight and the erythrocytes characteristics. The liver weight of chicks incubated at 36°C was higher than the incubated at 39°C, however there were no differences among the liver weight from chicks incubated at 36 and 39°C and those incubated at 37.5°C. The number of heterophils and the heterophil/lymphocyte ratio (H/L ratio) increased following the temperature, whereas the number of lymphocytes decreased at high temperatures. The other leukocyte parameters did not suffer influence of temperature. Males and females presented similar response to variation of incubation temperatures (36, 37.5 and 39°C) and demonstrated higher sensibility to temperatures above the thermoneutral. Moreover, temperatures below the thermoneutral demonstrated to be better for improvement of hatchability and development of chicks from light eggs. © Asian Network for Scientific Information, 2010.

Infrared thermography applied to the evaluation of metabolic heat loss of chicks fed with different energy densities

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparison of intestinal response of chicks from light and heavy eggs to posthatch fasting

The effects of posthatch fasting on villi height and number, crypt depth and number of globet cells in duodenum, jejunum and ileum of broiler chicks from heavy and light eggs were compared. The 2×3×3 factorial design (egg weight: light and heavy eggs; treatments: with water and feed, with water, without water and feed; treatment duration: 24, 48 and 72 h) was used. The villi presented higher size in chicks from heavy than from light eggs. The fasting resulted in lower villi in duodenum (at 48 h), jejunum and ileum (at 72 h). The villi number increased in duodenum and jejunum of chicks from light eggs and only in jejunum of chicks from heavy eggs, but the increase was more accented in chicks from light ones. The fasting reduced the globet cells number in jejunum. Water intake avoided the fasting effects on villi height but had no effect on villi number. Chicks from heavy eggs fed with water and ration presented deeper crypts in all regions of the small intestine. The duodenum and ileum crypt depth of the chicks from heavy eggs reduced when they were submitted to fasting and when they were fed only with water. The results showed that chicks from light eggs were more affected than chicks from heavy eggs. The water intake partially avoided the fasting effects. © Asian Network for Scientific Information, 2011.

Leucometric analysis of 1-day-old chicks inoculated with Salmonella Typhimurium or Lactobacilli

Salmonella infection is responsible for major economic losses in poultry industry. Consequently, the development of new methods for fighting such disease is desirable, such as the use of acid-lactic bacteria. However, reference values of chicks in such conditions are dissimilar to those of other species. Leucometry reference values for chicks have not been reported. The aim of this article was to evaluate and determine the leucometric values of chicks inoculated with Salmonella Typhimurium or treated with Lactobacilli probiotics. In this study, 144 1-day-old birds were divided in three groups of 48 animals each (non-treated group, Salmonella Typhimurium (ST)-inoculated group, and Lactobacilli inoculated group). A total of four blood collections were made with the first one performed 3 h after inoculation with ST or treatment with Lactobacilli. Subsequent samples were obtained every 48 h for 7 days. Leucometric evaluation was performed immediately after each collection. All birds presented an initial decrease pattern in general leukocyte values, and the chicks inoculated with ST revealed lymphomonoheteropaenic leukopaenia, eosinophilia and basophilia in conjunction with convalescence after 96 h of inoculation. The animals inoculated with Lactobacilli revealed leucocytosis with monocytosis, lymphocytosis and marked eosinopaenia. We conclude that there is no efficient bone marrow response in 1-day-old chicks challenged with Salmonella Typhimurium; additionally, an immunostimulatory effect in 1-day-old chicks treated with Lactobacilli-modulated probiotics could be stated. © 2011 Springer-Verlag London Limited.

Relationship between incubation temperature and egg size with heart hypoplasy in broiler chicks at hatching

It was analyzed if the effects of continuous incubation temperature deviations during the second half on the development of body, organs and hematological respiratory and energetic parameters differ between male and female from 30- and 60-week-old breeder eggs. From day 13, Cobb eggs were exposed to 36°C, 37.5°C, or 39°C. At 3, 6, 12, 24, 48 and 72 h after this change in the temperature and at hatch, red cells count, hematocrit, hemoglobin, mean corpuscular volume, plasma glucose level and body, liver and heart weights were evaluated. Independent of incubation temperature, sexes and breeder ages, mean corpuscular volume decreased and the other variables increased during late incubation. In 30-week-old breeder eggs, body weights and erythrocytic parameters were not influenced by temperature but liver and heart weights decreased increasing incubation temperature and glucose level increased at 36 and 39°C. In 60-week-old breeder eggs, males were heavier at hatching with incubation at 36°C and females had smaller body weights with incubation at 39°C. In both sexes, liver weight decreased and glucose concentration was higher at 36 and 39°C and heart weights and erythrocytes parameters were not influenced by temperature. Independent of breeder age, hatchability was lower at 39°C. The data show that high temperature from day 13 of incubation reduced more intensively the hatching success and caused cardiac hypoplasia in chicks from 30-week-old breeder eggs only, revealing for the first time that the susceptibility for ascites syndrome, by reduced heart development at hatching, is associated to a relationship between incubation temperature and egg size. © Asian Network for Scientific Information, 2012.

Blood parameters of chicks from eggs injected with ascorbic acid and subjected to thermal stress

This study was aimed to verify if chicks from eggs injected with ascorbic acid and subjected to thermal stress would have higher immunity than chicks from incubation at thermoneutrality without injection of ascorbic acid. The parameters evaluated were temperature on oxygen saturation in hemoglobin, glucose, number of erythrocytes, hematocrit rate and number of hemoglobins of newly hatched male chicks, hatched from eggs injected with ascorbic acid (AA) and subjected to thermal stress during incubation. The experimental design was completely randomized in factorial scheme 5 (application levels of ascorbic acid) x 2 (incubation temperatures). The data were subjected to analysis of variance using the General Linear Model procedure (GLM) of SAS ®. For the parameters (number of erythrocytes, rate of hematrocit and values of hemoglobin), there was significant interaction (p <0.05) between treatments in egg and incubation temperatures. Analyzing the interactions for these parameters, it was observed that the application of 0% ascorbic acid in egg minimized the effect of heat stress when compared with treatment without injection. The application of ascorbic acid levels in eggs incubated under heat stress failed to maximize the immunity of newly hatched chicks. It is assumed that the increased liquid in the amniotic fluid, in those embryos injected with water, favored the lower heat conductance for these embryos, thus helping in their development in relation to immunity. Considering that hemoglobin is related to the transport of gases, these data suggest that increasing the concentration of AA solution inoculated may influence the respiratory rates of eggs.

Balance of pH of chicks from eggs injected with ascorbic acid and subjected to thermal stress

This study aimed to verify that chicks from eggs injected with ascorbic acid and subjected to heat stress would have changes in acid-base balance, compared to chicks incubated at thermoneutral without injection of ascorbic acid. The parameters evaluated were blood pressure of carbon dioxide and oxygen, base excess, total carbon dioxide, concentration of sodium, potassium, ionized calcium, bicarbonate and pH of newly hatched male chicks, hatched from eggs injected with acid ascorbic acid (AA) and subjected to heat stress during incubation. The experimental design was completely randomized in factorial scheme 5 (application levels of ascorbic acid) x 2 (incubation temperatures). The data were subjected to analysis of variance using the General Linear Model procedure (GLM) of SAS ®. For the blood pH was observed significant interaction (p <0.05) between treatments with application in eggs and incubation temperatures. For the other parameters were not significant effects (p< 0.05) of AA level and neither temperature of incubation. Analyzing the unfolding of the interaction to pH was observed that chicks from eggs injected with 6% ascorbic acid and subjected to heat stress during incubation had a higher pH value compared with the thermoneutral temperature incubated (p <0.05). Therefore, it is suggested that the incubation of eggs in high temperature (39°C) can alter the metabolic rate of these embryos.

Protective effect of mannan oligosaccharides against early colonization by Salmonella Enteritidis in chicks is improved by higher dietary threonine levels

Aims: To evaluate mannan oligosaccharide (MOS) and threonine effects on performance, small intestine morphology and Salmonella spp. counts in Salmonella Enteritidis-challenged birds. Methods and Results: One-day-old chicks (1d) were distributed into five treatments: nonchallenged animals fed basal diet (RB-0), animals fed basal diet and infected with Salmonella Enteritidis (RB-I), animals fed high level of threonine and infected (HT-I), birds fed basal diet with MOS and infected (MOS-I), birds fed high level of threonine and MOS and infected (HT+MOS-I). Birds were inoculated at 2d with Salmonella Enteritidis, except RB-0 birds. Chicks fed higher dietary threonine and MOS showed performance similar to RB-0 and intestinal morphology recovery at 8 dpi. Salmonella counts and the number of Salmonella-positive animals were lower in HT+MOS-I compared with other challenged groups. Conclusion: Mannan oligosaccharides and threonine act synergistically, resulting in improved intestinal environment and recovery after Salmonella inoculation. Significance and Impact of the Study: Nutritional approaches may be useful to prevent Salmonella infection in the first week and putative carcass contamination at slaughter. This is the first report on the possible synergistic effect of mannan oligosaccharides and threonine, and further studies should be performed including performance, microbiota evaluation, composition of intestinal mucins and immune assessment. © 2012 The Society for Applied Microbiology.