Dietary supplementation with ferric tyrosine improves zootechnical performance and reduces caecal Campylobacter spp. load in broilers

ABSTRACT

1. The objective of this study was to evaluate the effect of ferric tyrosine on the reduction of Campylobacter spp. and zootechnical performance in broilers exposed to Campylobacter spp. using a natural challenge model to simulate commercial conditions. Additionally, the minimum inhibitory concentrations (MICs) of ferric tyrosine against common enteropathogens were evaluated.

2. At the start of the trial, 840 healthy male 1-d-old birds (Ross 308) were randomly allocated to 6 replicate pens of 35 birds each and fed diets containing different concentrations of ferric tyrosine (0, 0.02, 0.05 and 0.2 g/kg) in mash form for 42 d.

3. Broilers fed diets containing ferric tyrosine showed significantly higher body weight at d 42 and weight gain compared to the control group. However, birds fed ferric tyrosine ate significantly more than the control birds so significant improvements in feed conversion rate were not observed.

4. Microbiological analyses of caecal samples collected on d 42 of the study showed, per gram of sample, 2–3 log₁₀ reduction in Campylobacter spp. and 1 log₁₀ reduction in Escherichia coli in the groups fed diets containing ferric tyrosine compared to the control.

5. The MICs of ferric tyrosine was >400 mg/l for C. jejuni and >200 mg/l for E. coli and Salmonella enterica, indicating that ferric tyrosine did not exert antimicrobial activity.

6. The results showed that birds fed ferric tyrosine grew faster and consumed more feed compared to the control group, indicating potential benefits of faster time to reach slaughter weight with no significant reduction on feed efficiency. Moreover, ferric tyrosine significantly reduced caecal Campylobacter spp. and E. coli indicating potential as a non-antibiotic feed additive to lower the risk of infections transmitted through the food chain.     

Viruses associated with outbreaks of equine respiratory disease in New Zealand

AIM: To identify viruses associated with respiratory disease in young horses in New Zealand.

METHODS: Nasal swabs and blood samples were collected from 45 foals or horses from five separate outbreaks of respiratory disease that occurred in New Zealand in 1996, and from 37 yearlings at the time of the annual yearling sales in January that same year. Virus isolation from nasal swabs and peripheral blood leukocytes (PBL) was undertaken and serum samples were tested for antibodies against equine herpesviruses (EHV-1, EHV-2, EHV-4 and EHV-5), equine rhinitis-A virus (ERAV), equine rhinitis-B virus (ERBV), equine adenovirus 1 (EAdV-1), equine arteritis virus (EAV), reovirus 3 and parainfluenza virus type 3 (PIV3).

RESULTS: Viruses were isolated from 24/94 (26%) nasal swab samples and from 77/80 (96%) PBL samples collected from both healthy horses and horses showing clinical signs of respiratory disease. All isolates were identified as EHV-2, EHV-4, EHV-5 or untyped EHV. Of the horses and foals tested, 59/82 (72%) were positive for EHV-1 and/or EHV-4 serum neutralising (SN) antibody on at least one sampling occasion, 52/82 (63%) for EHV-1-specific antibody tested by enzyme-linked immunosorbent assay (ELISA), 10/80 (13%) for ERAV SN antibody, 60/80 (75%) for ERBV SN antibody, and 42/80 (53%) for haemagglutination inhibition (HI) antibody to EAdV-1. None of the 64 serum samples tested were positive for antibodies to EAV, reovirus 3 or PIV3. Evidence of infection with all viruses tested was detected in both healthy horses and in horses showing clinical signs of respiratory disease. Recent EHV-2 infection was associated with the development of signs of respiratory disease among yearlings [relative risk (RR)=2.67, 95% CI=1.59-4.47, p=0.017].

CONCLUSIONS: Of the equine respiratory viruses detected in horses in New Zealand during this study, EHV-2 was most likely to be associated with respiratory disease. However, factors other than viral infection are probably important in the development of clinical signs of disease.     

Three-way fungal interactions affect the potential biological control of Himalayan balsam,Impatiens glandulifera

Himalayan balsam (Impatiens glandulifera) is one of the most invasive weeds across Europe. The rust fungus, Puccinia komarovii var. glanduliferae has been introduced as a biological control agent, but success has been patchy. Here, we investigated whether mycorrhizal and endophytic fungi can affect rust efficacy and plant growth. Over three experiments, we found that AM fungi and the rust alone or together consistently reduced plant growth, but this depended on the identity of species in the AM inoculum. Meanwhile, AM fungi increased infection frequency of the endophyte Colletotrichum acutatum. Rust inoculation had no detrimental effects on mycorrhizal colonisation or C. acutatum infection, but the latter two fungi reduced rust sporulation. However, plant size was reduced when all three fungal types were present, suggesting that a combined fungal inoculum offers a promising approach for the control of this weed.     

Pulmonary mycobacteriosis caused by Mycobacterium intracellulare in a Tasmanian devil (Sarcophilus harrisii)

The health of captive Tasmanian devils (Sarcophilus harrisii) is currently of increased interest because wild populations are being decimated by the spread of devil facial tumour disease. This report describes the pathology of an aged captive Tasmanian devil that had a pulmonary mycobacterial infection caused by Mycobacterium intracellulare in addition to multiple neoplastic processes.     

Effect of chronic infusion of placental lactogen on ovine fetal growth in late gestation

To test the hypothesis that placental lactogen (PL) is a Immoral regulator of fetal growth, six singleton sheep fetuses received a continuous intravenous fusion of 1.2 mg/d of purified ovine PL (oPL) for 14 d, beginning on Day 122 of gestation. The plasma concentration of oPL was approximately four-fold higher in infused fetuses than in six control fetuses that received a continuous infusion of saline. The circulating insulin-like growth factor 1 (IGF-1) concentration was also significantly elevated in PL-infused fetuses (43.1 ± 1.7 vs. 31.9 ± 4.l ng/ml; P < 0.05). Animals were slaughtered on Day 136, and the placenta and all major fetal tissues were dissected, weighed, and subsampled for chemical analysis. Fetal weight and crown-rump length were not significantly affected by treatment; however, the aggregate weight of the brain, liver, lungs, and heart tended to be larger (85.3 ± 2.1 vs. 79.9 ± 1.5 g/kg fetus; mean ± SE, P = 0.07) and the thyroid gland was smaller (0.18 ± 0.l vs. 0.26 ± 0.02 g/kg fetus; P < 0.05) in the PL-infused fetuses. The livers of the PL-infused fetuses had also accumulated additional glycogen (13.1 ± l.7 vs. 8.4 ± 0.7 g; P < 0.05). In late gestation, PL within the fetal compartment increases fetal plasma IGF-1 concentration and hepatic glycogen deposition and may affect the growth of several vital organs.     

Bacillimidazoles A−F,Imidazolium-Containing Compounds Isolated from a Marine Bacillus

Chemical investigations of a marine sponge-associated Bacillus revealed six new imidazolium-containing compounds, bacillimidazoles A–F (1–6). Previous reports of related imidazolium-containing natural products are rare. Initially unveiled by timsTOF (trapped ion mobility spectrometry) MS data, extensive HRMS and 1D and 2D NMR analyses enabled the structural elucidation of 1–6. In addition, a plausible biosynthetic pathway to bacillimidazoles is proposed based on isotopic labeling experiments and invokes the highly reactive glycolytic adduct 2,3-butanedione. Combined, the results of structure elucidation efforts, isotopic labeling studies and bioinformatics suggest that 1–6 result from a fascinating intersection of primary and secondary metabolic pathways in Bacillus sp. WMMC1349. Antimicrobial assays revealed that, of 1–6, only compound six displayed discernible antibacterial activity, despite the close structural similarities shared by all six natural products.     

Pyranoisoflavones from Rinorea welwitschii.

Reversed-phase HPLC analysis of a dichloromethane extract of the stem-barks of Rinorea welwitschii has afforded two pyranoisoflavones, alpinumisoflavone (1) and di-O-methylalpinumisoflavone (2).