Alessandro Agazzi

Effects of inclusion of selenium-enriched yeast in the diet of laying hens on performance, eggshell quality, and selenium tissue deposition

The aim of this study was to evaluate the bioavailability of ingested selenium (Se) yeast in laying hens and its effects on performance, eggshell quality, and tissue Se distribution. Forty-eight ISA brown laying hens were divided into 3 treatment groups: Group C, fed a basal diet containing 0.11 mg Se/kg of feed; Group SS, fed a basal diet plus 0.4 mg/kg of feed of Se from sodium selenite; and Group SY, fed a basal diet plus 0.4 mg/kg of feed of Se from selenium yeast. Feed intake, egg mass ratio, and production performance were not affected by Se supplementation, regardless of the Se source. Egg weight (+3.61% and +2.95%), eggshell weight (+4.26% and +5.38%), and eggshell surface (+2.43% and +1.96%) were higher (P<0.05) in SS and SY than C, whereas breaking strength was increased in SY (P<0.01). Breast muscle, liver and skin Se levels were higher in SY than in C, while kidney Se content was higher in SS hens. Eggs from SY had higher Se levels than SS. Blood metabolites were not affected in SS or SY groups than C. A higher Se level was detected in eggs and breast muscle of SY hens (P<0.05). Seleniumenriched eggs and edible tissues from organic Se sources in poultry diet could improve antioxidant status in humans and reduce possible Se deficiency-related diseases.

Effects of EPA and DHA on lipid droplet accumulation and mRNA abundance of PAT proteins in caprine monocytes.

The present study investigated the in vitro effects on caprine monocytes of two ω-3 PUFAs, namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on lipid droplet formation, an emerging process of fundamental importance in innate immunity regulation. The mRNA abundance of PAT protein family (PLIN1, PLIN2 and PLIN3), involved in the formation and trafficking of the droplets, was also assessed. The effects of EPA and DHA on monocyte apoptosis were studied as well. The number of lipid droplets per cell was found to be dependent on both type and concentration of fatty acid. ω-3 PUFAs upregulated PLIN3 and PLIN2 gene expression, as well as apoptosis rate. The present findings suggest that PUFA might modify innate immune functions of goat monocytes by interfering with the formation of lipid droplets and by upregulating proteins belonging to PAT protein family.

In vitro modulation of caprine monocyte immune functions by ω-3 polyunsaturated fatty acids.

The in vitro effects of the ω-3 polyunsaturated fatty acids (PUFAs) eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) on phagocytosis and the extracellular respiratory burst in caprine monocytes were assessed. Blood monocytes incubated with increasing concentrations of EPA or DHA (25-200 μM) demonstrated increased phagocytosis compared to unexposed monocytes. Generation of reactive oxygen species (ROS) was not markedly affected in the presence of EPA and DHA, except at 200 μM, at which concentrations monocyte viability was also reduced.

Evaluation of the Fourier Frequency Spectrum Peaks of Milk Electrical Conductivity Signals as Indexes to Monitor the Dairy Goats’ Health Status by On-Line Sensors

The aim of this study is a further characterization of the electrical conductivity (EC) signal of goat milk, acquired on-line by EC sensors, to identify new indexes representative of the EC variations that can be observed during milking, when considering not healthy (NH) glands. Two foremilk gland samples from 42 Saanen goats, were collected for three consecutive weeks and for three different lactation stages (LS: 0–60 Days In Milking (DIM); 61–120 DIM; 121–180 DIM), for a total amount of 1512 samples. Bacteriological analyses and somatic cells counts (SCC) were used to define the health status of the glands. With negative bacteriological analyses and SCC < 1,000,000 cells/mL, glands were classified as healthy. When bacteriological analyses were positive or showed a SCC > 1,000,000 cells/mL, glands were classified as NH. For each milk EC signal, acquired on-line and for each gland considered, the Fourier frequency spectrum of the signal was calculated and three representative frequency peaks were identified. To evaluate data acquired a MIXED procedure was used considering the HS, LS and LS × HS as explanatory variables in the statistical model.Results showed that the studied frequency peaks had a significant relationship with the gland’s health status. Results also explained how the milk EC signals’ pattern change in case of NH glands. In fact, it is characterized by slower fluctuations (due to the lower frequencies of the peaks) and by an irregular trend (due to the higher amplitudes of all the main frequency peaks). Therefore, these frequency peaks could be used as new indexes to improve the performances of algorithms based on multivariate models which evaluate the health status of dairy goats through the use of gland milk EC sensors.

On-Line Monitoring of Milk Electrical Conductivity by Fuzzy Logic Technology to Characterise Health Status in Dairy Goats

Intramammary infection affects the quality and quantity of dairy goat milk. Health status (HS) and milk quality can be monitored by electrical conductivity (EC). The aim of the study was to determine the detection potential of EC when measured on-line on a daily basis and compared with readings from previous milkings. Milk yields (MYs) were investigated with the same approach. To evaluate these relative traits, a multivariate model based on fuzzy logic technology – which provided interesting results in cows – was used. Two foremilk samples from 8 healthy Saanen goats were measured daily over the course of six months. Bacteriological tests and somatic cells counts were used to define the HS. On-line EC measurements for each gland and MYs were also considered. Predicted deviations of EC and MY were calculated using a moving-average model and entered in the fuzzy logic model. The reported accuracy has a sensitivity of 81% and a specificity of 69%. Conclusions show that fuzzy logic is an interesting approach for dairy goats, since it offered better accuracy than other methods previously published. Nevertheless, specificity was lower than in dairy cows, probably due to the lack of a significant decrease of MY in diseased glands. Still, results show that the detection of the HS characteristics with EC is improved, when measured on-line, daily and compared with the readings from previous milkings.

EffEcts of spEciEs-spEcific probiotic addition to milk rEplacEr on calf hEalth and pErformancE during thE first month of lifE*

Abstract The aim of this study was to evaluate the effects of the administration of a species-specific probiotic (Lactobacillus animalis SB310, Lactobacillus paracasei subsp. paracasei SB137 and Bacillus coagulans SB117 in a 30:35:35 ratio, respectively; 1.8 × 1010 CFU/g of powder) on gut microbial balance, immune response and growth performance of Holstein female calves during the first month of life. Twenty-two calves were divided into two experimental groups from 2 to 28 days of life: control (C), fed with milk replacer and concentrate as a basal diet, and treatment (T), fed C diet plus 1 g/calf/day of probiotic powder for the first month of age. Faecal and blood samples were individually collected and analysed weekly. Individual faecal score was recorded daily and general health score was calculated at the end of the trial. Cell-mediated immune response was evaluated by skin test at 7 and 28 days of life. Milk replacer and concentrate intake were recorded daily, while body weight and biometrical parameters were recorded at 2, 8, 14, 21 and 28 days of life, thus average daily gain and feed conversion rate were calculated. During the first week of treatment, lower blood eosinophil percentage (0.05% vs. 0.22%; P≤0.01) was found in T group, while basophils were higher in T than C group at the end of the trial (0.21% vs. 0.16%; P≤0.05). Higher faecal lactic acid bacteria (LAB)/E. coli ratio on day 28 of life (3.73 log CFU/g vs. 2.02 log CFU/g; P≤0.05) and lower incidence of diarrhoea were found in the treated group (63.30% vs. 70.71%; P=0.05). Body weight (48.92 kg vs. 46.92 kg; P≤0.05), total concentrate intake (14.77 kg vs. 12.56 kg on dry matter basis; P≤0.05), and heart girth (81.16 cm vs. 78.49 cm; P≤0.05) were significantly higher in T group. The administration of the probiotic during the first month of life improved gut microbiota and increased the growth performance and some biometric parameters of calves.

Signal spectral analysis to characterize gland milk electrical conductivity in dairy goats

Intramammary infection affects quality and quantity of milk. Having as final target the improving of animal health’ monitoring, this research studied the gland milk electrical conductivity (EC) signal in order to identify a possible parameter more representative of the EC variations that can be observed, during a milking, when not healthy (NH) glands are considered. Two foremilk gland samples, from 40 Saanen goats, were acquired for three weeks and lactation stages (LS: 0-60 Days In Milking; 61-120 DIM; =>120 DIM), for a total amount of 1440 samples. Bacteriological analyses and somatic cells counts (SCC) were used to define glands health status. In case of negative bacteriological analyses and SCC <1,000,000 cells/mL, glands were classified as healthy; alternatively, when bacteriological analyses were positive or SCC higher than 1,000,000 cells/mL, for two or more consecutive days, glands were classified as NH. A spectral analysis, to calculate the frequency spectrum and the bandwidth length of the milk EC signal, was performed. To validate data acquired, A MIXED procedure was used considering the HS, LS and the LS x HS as explanatory variables of the statistical model. Results showed that spectral analysis allows characterizing the milk EC variations thorough the bandwidth length parameter. This parameter has a significant relationship with the gland health status and it provides more accurate information than other traits, like the statistical variance of the signal. Therefore, it could be useful to improve the performances of multivariate models/algorithms that detect dairy goat health status.

Effects of protected fish oil in the diet of periparturient dairy goats on phenotypic variation in blood and milk leukocytes.

The goal of this study was to evaluate the effects of dietary protected fish oil (FO) on phenotypic variation in blood, milk leukocytes, and some productive and metabolic parameters in periparturient dairy goats. About 12 Alpine goats, selected from a larger group of second-parity animals, were fed from 15 days before kidding until the 15th day of lactation with the same basal diet that had been supplemented with either 47 g/head per day of FO or 47 g/head per day hydrogenated palm oil (PO). Dry matter intake, live body weight (LBW), body condition score (BCS), and productive performance were evaluated in 2 weeks after kidding. On days 15, 7, and 2 before kidding and days 2, 7, and 15 after kidding, plasma samples were collected for evaluation of alanine aminotransferase, aspartate aminotransferase, non-esterified fatty acids, glucose, beta-hydroxybutyrate, cholesterol, and urea levels. White blood cell and blood leukocyte subsets were counted in whole blood samples on the kidding day, as well as at 1, 4, and 15 days after kidding. In addition, milk somatic cell count, intramammary infection (IMI), and milk leukocyte subsets were evaluated on days 4 and 15 after kidding. No differences were observed in dry matter intake and BCS, while LBW was higher in FO-fed animals. Milk production and composition, plasma metabolites, and liver enzymes were similar in both experimental groups. Blood CD4 positive cells increased constantly (P = 0.05) in FO-fed group, while CD8 and CD14 cell counts significantly increased 4 days after kidding (P < 0.01). Milk leukocyte subsets showed a significant (P < 0.01) decrease in PO-fed group and a non-significant increase (P = 0.34) in FO-fed group, despite the presence of coagulase negative staphylococci IMI. The results of the productive performance evaluation agreed with those of many other studies, which did not find any significant differences between dairy goats fed diets enriched with FO or PO supplements. The administration of FO to dairy goats in transition appeared to affect the variation in blood leukocytes with a constant increase in CD4- and CD8-positive cells in comparison with a PO fat-supplemented diet.

Plant bioreactors for the antigenic hook-associated flgK protein expression

Plants engineered with genes encoding for the antigenic proteins of various microorganisms have shown to correctly express the proteins that elicit the production of antibodies in mammalian hosts. In livestock, plant-based vaccines could represent an innovative strategy for oral vaccination, especially to prevent infection by enteric pathogens. The aim of this study was to evaluate tobacco plants as a seed-specific expression system for the production of the flgK flagellar hook-associated protein from a wild type Salmonella typhimurium strain, as a model of an edible vaccine. The flgK gene is the principal component of bacterial flagella and is recognised as virulence factor by the innate immune system. It was isolated from the Salmonella typhimurium strain by PCR. The encoding sequence of flgK was transferred into a pBI binary vector, under control of soybean basic 7S globulin promoter for the seed-specific. Plant transformation was carried out using recombinant EHA 105 Agrobacterium tumefaciens. A transgenic population was obtained made up of independently kanamycin-resistant transgenic plants, which had a similar morphological appearance to the wild-type plants. Molecular analyses of seeds confirmed the integration of the gene and the average expression level of flgK was estimated to be about 0.6 mg per gram of seeds, corresponding to 0.33% of the total amount of soluble protein in tobacco seeds. This study showed that the foreign flgK gene could be stably incorporated into the tobacco plant genome by transcription through the nuclear apparatus of the plant, and that these genes are inherited by the next generation.

Effects of Rumen-protected Choline Supplementation in Periparturient Dairy Goats

D’Ambrosio, F., Campagnoli, A., Susca, F., Fusi, E., Rebucci, R., Agazzi, A, Pinotti, L. and Baldi, A., 2007. Effects of rumen-protected choline supplementation in periparturient dairy goats. Veterinary Research Communications, 31(Suppl. 1), 393–396