Effect of lactic acid bacteria probiotic culture treatment timing on Salmonella Enteritidis in neonatal broilers.

In the present study, a series of experiments were conducted to evaluate the ability of a combination of 3 ATCC lactobacilli (LAB3) or a commercially available probiotic culture (PROB) to reduce Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) in broiler chicks. Additionally, we varied the timing of PROB administration in relationship to Salmonella challenge and determined the influence on recovery of enteric Salmonella. In experiments 1 to 3, chicks were randomly assigned to treatment groups and were then challenged via oral gavage with Salmonella Enteritidis. Chicks were treated 1 h after Salmonella Enteritidis challenge with LAB3 or PROB. Twenty-four hours posttreatment, cecal tonsils were collected for recovery of enteric Salmonella. In experiments 4 to 7, day-of-hatch chicks were randomly assigned to treatment groups and were then treated with PROB via oral gavage and placed into pens. Chicks were challenged with Salmonella Enteritidis 24 h after treatment via oral gavage. At 24 h after Salmonella Enteritidis challenge, cecal tonsils were collected and recovery of enteric Salmonella was determined. In experiments 8 to 10, 1-d-old chicks were randomly assigned to treatment groups and were then challenged via oral gavage with Salmonella Enteritidis and placed into pens. Chicks were treated 24 h after challenge with PROB via oral gavage. Twenty-four hours post PROB treatment, cecal tonsils were collected and enriched as described above. It was found that PROB significantly reduced cecal Salmonella Enteritidis recovery 24 h after treatment as compared with controls or LAB3-treated chicks in experiments 1 to 3 (P<0.05). Administration of PROB 24 h before Salmonella Enteritidis challenge significantly reduced recovery of Salmonella Enteritidis in 2 out of 4 experiments and no reduction in cecal Salmonella Enteritidis was observed when chicks were challenged with Salmonella Enteritidis and treated 24 h later with PROB. These data demonstrate that PROB more effectively reduced Salmonella Enteritidis than LAB3, and the timing of PROB treatment affects Salmonella Enteritidis-associated reductions.

Comparison of beak-trimming methods on early broiler breeder performance.

Beak trimming is necessary in commercial broiler breeders to prevent or decrease trauma as they mature. Two common beak-trimming methods were evaluated by early performance comparison with nontrimmed chicks (NBT). The robotic electrocautery device (ECD) trims and cauterizes the beak tip. The robotic infrared beak-trimming device (IBT) applies an infrared light beam to destroy the live basal tissue while leaving the hard corneum intact for the first approximately 10 d. In 2 experiments, day-of-hatch Ross 708 by-product chicks were obtained from a local hatchery, where 1/3 of the chicks were trimmed using IBT. All chicks were then transported to another hatchery where 1/3 were trimmed using ECD and 1/3 were NBT. Personnel at each hatchery were highly experienced and skilled with their respective technique. All chicks were then transported to University of Arkansas facilities. Before placement in each experiment, chicks were individually neck-tagged and weighed, and in experiment 1, beaks were measured using a digital caliper. A small but significant transient reduction in BW gain was observed at 14 d due to ECD as compared with NBT controls, although ECD was not different than IBT in experiment 1. In experiment 2, IBT birds were significantly heavier at 11 d by 7.8 and 8.7 g than the NBT or ECD, respectively. However, at d 21 and 42, no significant differences in BW or BW gain were observed. When beak trimming was performed on day of hatch by skilled and experienced personnel, little measurable effect on early performance was observed during the first 6 wk of life. Decreased broiler performance is generally considered a sensitive indication of physical or psychogenic stress. Given the marked reduction in beak-inflicted trauma with beak trimming birds as they reach sexual maturity, these results suggest that when properly performed, neither of these beak-trimming methods causes sufficient physical or psychogenic stress to markedly affect early growth rate.

Evaluation of a Lactobacillus-based probiotic culture for the reduction of Salmonella enteritidis in neonatal broiler chicks.

We evaluated the effect of a Lactobacillus-based probiotic culture (FM-B11) for reduction of Salmonella Enteritidis in neonatal broiler chicks. In all experiments, chicks were challenged with approximately 10(4) cfu of Salmonella Enteritidis upon arrival at our laboratory, and the treatments were administered 1 h postchallenge. Cecal tonsil samples were obtained 24 h posttreatment and enriched for Salmonella Enteritidis recovery. The first experiment compared the effects of oral administration of doses of 10(4), 10(6), and 10(8) cfu/chick. In this experiment, doses of 10(6) and 10(8) both significantly reduced Salmonella Enteritidis recovery compared with controls (15 vs. 85% Salmonella Enteritidis positive), but 10(4) cfu did not significantly reduce Salmonella Enteritidis recovery. The second experiment compared the efficacy of oral administration of the live probiotic culture, with or without supernatant removed, to inactivated cultures or supernatant alone. Live probiotic organisms, with or without supernatant, significantly reduced Salmonella Enteritidis in this experiment, but inactivated or cell-free treatments did not reduce Salmonella Enteritidis. In the final 2 experiments, differing doses of probiotic culture were administered on the vent lips, where the treatment was taken into the lower gastrointestinal tract via cloacal drinking. Concentrations of probiotic culture from 10(2) to 10(7) cfu/chick significantly reduced Salmonella Enteritidis, and there was no difference in Salmonella Enteritidis recovery between treatment concentrations. These data suggest that this Lactobacillus-based probiotic culture may be efficacious for reduction of Salmonella Enteritidis in neonatal chicks.

Effect of probiotic treatment in broiler chicks on intestinal macrophage numbers and phagocytosis of Salmonella enteritidis by abdominal exudate cells.

Previous data have indicated that a Lactobacillus-based probiotic culture (FM-B11) is efficacious in reducing Salmonella Enteritidis colonization within 24 h when administered within 1 h of challenge. We hypothesized that the innate immune system, specifically macrophages, may play a role in the observed reduction of Salmonella Enteritidis colonization with probiotic treatment. Day-of-hatch chicks were challenged with Salmonella Enteritidis and then treated with the probiotic culture 1 h later. Three other treatment groups were not treated (negative control), challenged only, or treated with probiotic only. In all experiments, probiotic treatment on the day of hatch reduced (P < 0.05) cecal Salmonella Enteritidis recovery as compared with the control treatment. In experiments 1 and 2, immunohistochemistry was used to evaluate the presence of macrophages (KUL01+) in the ileum and cecum of 7 to 10 chicks per group at 24 h posttreatment. In experiment 1, the number of macrophages observed per 10,000 microm(2) in the ileum of Salmonella Enteritidis-challenged chicks was higher (P < 0.05) than that of nonchallenged chicks (4.87 +/- 0.31 vs. 3.05 +/- 0.19). In the cecum, there were more (P < 0.05) macrophages per 10,000 microm(2) in chicks receiving probiotic treatment without challenge than in negative control chicks (5.32 +/- 0.41 vs. 3.66 +/- 0.35). However, in experiment 2 we found no differences among treatments in the numbers of macrophages for both the ileum and cecum. Experiments 3 and 4 were performed to evaluate the ability of Sephadex-elicited abdominal exudate cells (AEC) from chicks to phagocytose Salmonella Enteritidis in vitro. Abdominal exudate cells were isolated from the abdominal cavity, maintained in tissue culture plates overnight, and then assayed for phagocytic activity by coincubating with Salmonella Enteritidis. In experiment 3, more (P < 0.05) Salmonella Enteritidis was recovered from AEC derived from probiotic-treated chicks than in any other treatment. However, in experiment 4, all treatments resulted in similar levels of elicited AEC, and phagocytosis of Salmonella Enteritidis was at low levels in all groups. Although not conclusive, the modest differences detected in experiments 1 and 3, and the fact that those differences were not repeatedly detectable, suggest that these macrophage-related changes were not solely responsible for the reductions of Salmonella Enteritidis following probiotic treatment.

The genome sequence of Drosophila melanogaster.

The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the approximately 120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes approximately 13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.