Newly Grown Wool Mineral Content Response to Dietary Supplementation in Sheep.

Determination of wool mineral content to assess the animal' mineral status has been extensively used, but the results are controversial. One of the possible contributing factors is that the sampling material in previous studies was collected from a long staple, a fact that could mask the response to recent differences in mineral intake. Therefore, the aim of the present study was to test the sensitiveness of newly grown wool to different dietary mineral intake. Twenty Tsigai ewes were allocated into five dietary treatments with similar hay and concentrate intake but different premix inclusion rates in the concentrate (3, 4, 5, 6, and 7%). Wool was sampled on the left side from a 5 × 5 cm area using bent scissors at the beginning of the trial and from the very same area 28 days later. Samples after cleaning and mineralization were analyzed with ICP-OES (Perkin-Elmer, Optima 3300 DV) for calcium, phosphorus, magnesium, sodium, selenium, zinc, copper, and sulfur content. Long fleeces had significantly lower Ca and Se content compared to the newly grown wool samples of the group at the premix manufacturer's suggested level of supplementation (5%). Macrominerals in fresh wool did not respond to increased dietary supplementation. Se and Zn content of wool had a strong relationship with the daily intake (R2 = 0.95 and R2 = 0.97, respectively.) In conclusion, the mineral content of long fleeces can be different compared to recently developed wool fiber. This indicates that, in some cases, analyzing long staples for mineral status can be misleading. Our results showed that wool could be a sensitive indicator of low selenium and high zinc intake. Mineral interactions can significantly affect the actual availability of trace minerals; therefore, a more careful design of premixes is needed. The described method seems to be applicable in livestock farming, but the mineral interactions that may alter the results need to be further explored.

Effect of Carotenoids, Oligosaccharides and Anthocyanins on Growth Performance, Immunological Parameters and Intestinal Morphology in Broiler Chickens Challenged with Escherichia coli Lipopolysaccharide.

This study was conducted to investigate the effect of carotenoid, oligosaccharide and anthocyanin supplementation in broiler diets under Escherichia coli lipopolysaccharide (LPS) challenge. Ross 308 chickens were fed 5 diets: basal diet (control diet), diet supplemented with ß-glucan in 0.05% (positive control) and diets with 0.5% carotenoid-, oligosaccharide- or anthocyanin contents. On the 26th days of age, chickens were challenged intraperitoneally 2 mg LPS per kg of body weight. 12 h after injection, birds were euthanized, then spleen and ileum samples were collected. LPS induced increased relative mRNA expression of splenic (p = 0.0445) and ileal (p = 0.0435) interleukin-1ß (IL-1ß), which was lower in the spleen in carotenoid (p = 0.0114), oligosaccharide (p = 0.0497) and anthocyanin (p = 0.0303)-treated chickens compared to LPS-injected control birds. Dietary supplementation of carotenoids also decreased relative gene expression of splenic interleukin-6 (IL-6) (p = 0.0325). In the ileum, ß-glucan supplementation showed lower relative mRNA expression of toll-like receptor 5 (TLR-5) (p = 0.0387) compared to anthocyanin treatment. Gene expression of both splenic and ileal interferon-α (IFN-α), interferon-γ (IFN-γ), toll-like receptor 4 (TLR-4) and toll-like receptor 5 (TLR-5) were not influenced by dietary supplements. In conclusion, carotenoids, oligosaccharides and anthocyanins could partially mitigate the immune stress caused by LPS challenge. All of the compounds impacted longer villus height (p < 0.0001), villus height:crypt depth ratios were higher after ß-glucan (p < 0.0001) and anthocyanin (p = 0.0063) supplementations and thickened mucosa was observed in ß-glucan (p < 0.0001), oligosaccharide (p < 0.0001) and anthocyanin (p = 0.048) treatments. All of these findings could represent a more effective absorption of nutrients.

Feeding state and age dependent changes in melanin-concentrating hormone expression in the hypothalamus of broiler chickens.

We aimed to quantify the gene expression changes of the potent orexigenic melanin-concentrating hormone (MCH) in chicken (Gallus gallus) hypothalamus with quantitative real-time polymerase chain reaction (qPCR), and for the first time determine peptide concentrations with a novel radioimmunoassay (RIA) under different feeding status. Three different experimental conditions, namely ad libitum feeding; fasting for 24 h; fasting for 24 h and then refeeding for 2 h, were applied to study changes of the aforementioned target and its receptor (MCHR4) gene expression under different nutritional status. The relative changes of MCH and MCHR4 were also studied from 7 to 35 days of age. Expression of PMCH and MCHR4 along the gastrointestinal tract (GIT) was also investigated. We found that expression of both targets was significant in the hypothalamus, while only weak expression was detected along the GIT. Different nutritional states did not affect the PMCH and MCHR4 mRNA levels. However, fasting for 24 h had significantly increased the MCH-like immunoreactivity by 25.65%. Fasting for 24 h and then refeeding for 2 h had further significantly increased the MCH peptide concentration by 32.51%, as compared to the ad libitum state. A decreasing trend with age was observable for both, the PMCH and MCHR4 mRNA levels, and also for the MCH-like immunoreactivity. Correlation analysis did not result in a significant correlation between MCH peptide concentration and abdominal fat mass in ad libitum fed birds. In conclusion, MCH peptide concentration altered in response to 24 h fasting, which indicated that this peptide may take part in feed intake regulation of broiler chickens.

Changes in expression of neuropeptides and their receptors in the hypothalamus and gastrointestinal tract of calorie restricted hens.

The list of orexigenic and anorexigenic peptides, those are known to alter feed intake, is continuously growing. However, most of them are studied in mammalian species. We aimed to investigate plasma level and mRNA expression of the pituitary adenylate cyclase-activating polypeptide (PACAP), gene expression of its receptor (PAC1), furthermore the gene expression of galanin (GAL), neuromedin U (NMU), and its two receptors (NMUR1 and NMUR2) in the hypothalamus, proventriculus, and jejunum of hens exposed to 40% calorie restriction. Feed restriction resulted in a 88% increase in mRNA and a 27% increase in peptide level of PACAP in proventriculus measured with qPCR and RIA, respectively. Increases were found in the gene expression of PAC1 (49%) and NMUR1 (63%) in the hypothalamus. Higher expressions of peptide encoding genes (76% for PACAP, 41% for NMU, 301% for NMUR1 and 308% for GAL, P < 0.05) were recorded in the jejunum of hens exposed to restricted nutrition. The results indicate that PACAP level responds to calorie restriction in the proventriculus and jejunum, but not in the hypothalamus and plasma.