NUTRITIONAL AND FEEDING STRATEGIES TO REDUCE METHANE EMISSION FROM DAIRY COWS

The general aim of the present thesis was to evaluate the effects of several nutritional and feeding strategies to reduce methane (CH4) production from dairy cows. The thesis includes the results of three experiments conducted with the financial support from EU Research Project LIFE 09 ENV/IT/0214 Gas-Off. The aim of the first study was to measure total gas and CH4 production from 30 total mixed rations (TMRs) fed to dry and lactating cows in 20 commercial dairy farms of the Po Plain (Italy). Samples were analyzed for chemical composition, in situ 48 h fiber digestibility (NDFD) and in vitro gas production (GP) and CH4 concentration at 24 h of incubation. Neutral detergent fiber digestibility of TMRs from dry and lactating cows was identical (52.1%; P=0.995). The TMRs fed to dry and lactating cows differed for GP (43.0 and 54.4 mL/200 mg DM, respectively; P<0.001) and CH4 (7.24 and 8.85 mL/200 mg DM, respectively; P=0.001), but not for CH4 as percentage of GP (24.3 and 23.7%, respectively; P=0.286). Data were also analyzed dividing the TMRs into quartiles depending on \u201cstarch:ADF\u201d ratio; the average ratios of the groups 1, 2, 3 and 4 were 37, 77, 116 and 138, respectively. Increasing \u201cstarch:ADF\u201d ratio determined a higher GP: 42.2, 51.4, 55.1 and 56.2 mL/200 mg DM for groups 1, 2, 3 and 4, respectively (P<0.001), whilst CH4 (mL/200 mg DM) was lower (P<0.001) for group 1 (7.12) in comparison with the others (8.82 on average). Acetate, expressed as percentage on total volatile fatty acids (VFA) decreased for increasing \u201cstarch:ADF\u201d ratio (P=0.009), whereas butyrate tended to increase (from 8.11 to 9.23% on total VFA; P=0.069) and the \u201cacetate:propionate\u201d ratio to decrease (from 3.35 to 3.09; P=0.082). The lack of a higher CH4 concentration in GP from diets richer in fiber might be attributed mainly to the relatively short time of incubation. The second trial was aimed to evaluate at first the effects of 18 essential oils, yeast, Quebracho tannin and Quillaja saponin on ruminal methane and gas production (GP) in vitro. A lactating cow diet was incubated with rumen inoculum. Doses of the additives (mg/L) were: essential oils=500; tannin=67; yeast=8.35 and 16.7; saponin=300. Lemongrass, estragole, eugenol, geraniol, limonen, thyme oil and thymol produced less gas (overall mean 33.8 mL/200 mg DM) than control (43.6 mL/200 mg DM; P<0.001). Methane produced (mL/200 mg DM) by guaiacol (10.7), lemongrass (9.6), limonene (11.4), thyme oil (10.9) and thymol (2.1) was lower than control (12.5) (P<0.001). Methane percentage on total GP was lower (P<0.001) for cinnamic alcohol (25.4), guaiacol (24.5), thymol (19.7) and vanillin (26.3) than control (28.8). In the second part of the experiment, thymol, guaiacol and yeast were added to the diet of dry fistulated cows to determine in situ NDF digestibility (NDFD) of six forages and in vivo dietary NDFD. Thymol and yeast decreased in situ NDFD after 24 h (33.9% and 33.5% vs 38.1%; P=0.008). Thymol decreased in vivo total tract NDFD (40.8% vs. 51.4%; P=0.02). Differences in GP and methane levels were registered within classes of additives. A careful selection of additives may allow for the manipulation of ruminal fermentation. The third experiment was conducted to evaluate the effects of diets with different starch contents and fish oil (FO) supplementation on lactation performance, in vivo total-tract nutrient digestibility, N balance and methane (CH4) production in lactating dairy cows. The experiment was conducted as a 4 74 Latin square design with a 2 72 factorial arrangement: two levels of dietary starch content (low vs high), the presence or absence of FO supplement (0.80% DM) and their interaction were evaluated. Four Italian Friesian cows were fed one of the following four diets in four consecutive 26-d periods: 1) low starch (LS), 2) low starch plus FO (LSO), 3) high starch (HS) and 4) high starch plus FO (HSO). The diets contained the same amount of forages (corn silage, alfalfa and meadow hay). The starch content was balanced using different proportions of corn meal and soybean hulls. The cows were housed in metabolic stalls inside open-circuit respiration chambers to allow the measurement of CH4 production and the collection of separate urine and feces samples. No differences among treatments were observed for dry matter intake: neither FO nor the use of soybean hulls negatively influenced this parameter (22.9 kg/d, on average). A trend was observed for the effect of FO on milk yield (P=0.10), with a higher milk production compared with the diets without FO (29.2 vs 27.5 kg/d on average, respectively). Moreover, FO supplementation favorably decreased the n-6:n-3 ratio of the milk polyunsaturated fatty acids (PUFA). Consistent with the literature, the milk protein percentage was negatively influenced by FO (P<0.01): 3.37% on average for the LSO and HSO diets vs 3.67% for the LS and HS diets. With regard to digestibility, the HS diet negatively influenced all the parameters measured, with starch as the only exception. The percentage of N intake excreted with feces was influenced by both the FO (P=0.09) and starch content (P=0.04): the HS diet showed the highest value, followed by the HSO and LS diets and finally by the LSO diet. With regard to methanogenesis, there was a trend (P=0.08) of lower CH4 emissions (g/d) with the HS and HSO diets compared with the LS and LSO diets (396 vs 415 on average, respectively). Fish oil supplementation did not reduce methanogenesis. Previous in vitro studies have demonstrated a reduction in CH4 production as a consequence of FO supplementation; the decrease in CH4 production is generally accompanied by marked reductions in dry matter and fiber digestibility, which were not observed in the present work

A Spectral Method for Generating Surrogate Graph Signals

The increasing availability of network data is leading to a growing interest in processing of signals on graphs. One notable tool for extending conventional signal-processing operations to networks is the graph Fourier transform that can be obtained as the eigendecomposition of the graph Laplacian. In this letter, we used the graph Fourier transform to define a new method for generating surrogate graph signals. The approach is based on sign-randomization of the graph Fourier coefficients and, therefore, the correlation structure of the surrogate graph signals (i.e., smoothness on the graph topology) is imposed by the measured data. The proposed method of surrogate data generation can be widely applied for nonparametric statistical hypothesis testing. Here, we showed a proof-of-concept with a high-density electroencephalography dataset

One week of levofloxacin plus dexamethasone eye drops for cataract surgery: an innovative and rational therapeutic strategy

Background: Cataract surgery is the most common operation performed worldwide. A fixed topical corticosteroid-antibiotic combination is usually prescribed in clinical practice for 2 or more weeks to treat post surgical inflammation and prevent infection. However, this protracted schedule may increase the incidence of corticosteroid-related adverse events and notably promote antibiotic resistance. Methods: This International, multicentre, randomized, blinded-assessor, parallel-group clinical study evaluated the non-inferiority of 1-week levofloxacin/dexamethasone eye drops, followed by 1-week dexamethasone alone, vs. 2-week gold-standard tobramycin/dexamethasone (one drop QID for all schedules) to prevent and treat ocular inflammation and prevent infection after uncomplicated cataract surgery. Non-inferiority was defined as the lower limit of the 95% confidence interval (CI) around a treatment difference >\u201310%. The study randomized 808 patients enrolled in 53 centres (Italy, Germany, Spain and Russia). The primary endpoint was the proportion of patients without anterior chamber inflammation on day 15 defined as the end of treatment. Endophthalmitis was the key secondary endpoint. This study is registered with EudraCT code: 2018-000286-36. Results: After the end of treatment, 95.2% of the patients in the test arm vs. 94.9% of the control arm had no signs of inflammation in the anterior chamber (difference between proportions of patients = 0.028; 95% CI: 120.0275/0.0331). No case of endophthalmitis was reported. No statistically significant difference was evident in any of the other secondary endpoints. Both treatments were well tolerated. Conclusions: Non-inferiority of the new short pharmacological strategy was proven. One week of levofloxacin/dexamethasone prevents infection, ensures complete control of inflammation in almost all patients and may contain antibiotic resistance

EMG-based decoding of grasp gestures in reaching-to-grasping motions

Predicting the grasping function during reach-to-grasp motions is essential for controlling a prosthetic hand or a robotic assistive device. An early accurate prediction increases the usability and the comfort of a prosthetic device. This work proposes an electromyographic-based learning approach that decodes the grasping intention at an early stage of reach-to-grasp motion, i.e. before the final grasp/hand pre-shape takes place. Superficial electrodes and a Cyberglove were used to record the arm muscle activity and the finger joints during reach-to-grasp motions. Our results showed a 90% accuracy for the detection of the final grasp about 0.5 s after motion onset. This paper also examines the effect of different objects’ distances and different motion speeds on the detection time and accuracy of the classifier. The use of our learning approach to control a 16-degrees of freedom robotic hand confirmed the usability of our approach for the real-time control of robotic devices

A review : a comprehensive review of soft and rigid wearable rehabilitation and assistive devices with a focus on the shoulder joint

The importance of the human upper limb role in performing daily life and personal activities is significant. Improper functioning of this organ due to neurological disorders or surgeries can greatly affect the daily activities performed by patients. This paper aims to comprehensively review soft and rigid wearable robotic devices provided for rehabilitation and assistance focusing on the shoulder joint. In the last two decades, many devices have been proposed in this regard, however, there have been a few groups whose devices have had effective therapeutic capability with acceptable clinical evidence. Also, there were not many portable, lightweight and user-friendly devices. Therefore, this comprehensive study could pave the way for achieving optimal future devices, given the growing need for these devices. According to the results, the most commonly used plan was Exoskeleton, the most commonly used actuators were electrical, and most devices were considered to be stationary and rigid. By doing these studies, the advantages and disadvantages of each method are also presented. The presented devices each have a new idea and attitude in a specific field to solve the problems of movement disorders and rehabilitation, which were in the form of prototypes, initial clinical studies and sometimes comprehensive clinical and commercial studies. These plans need more comprehensive clinical trials to become a complete and efficient plan. This article could be used by researchers to identify and evaluate the important features and strengths and weaknesses of the plans to lead to the presentation of more optimal plans in the future