Innovative procedures to evaluate corn silage for milk yield

Corn silage is the main ingredient of diets for dairy cattle (around 40% of diet DM in Italy) and, therefore, an accurate estimation of its nutritive value is essential to describe the whole diet. Given the low, and fairly stable protein, lipid and ash contents in corn silage (e.g. a total of around 15% DM), the critical point to evaluate its energy value is the amount and availability of the two main carbohydrate fractions (NDF and non fiber carbohydrates, NFC)

In vitro rumen fermentation of feed substrates added with chestnut tannins or an extract from Stevia rebaudiana Bertoni

Rumen fermentation parameters and microbiota were evaluated in 3 in vitro rumen fermentation experiments after addition of chestnut tannins (CT) or an extract from Stevia rebaudiana Bertoni (SB) to substrates. A control (CTR) substrate was fermented alone or added with 1.5% of CT or SB extracts in a batch culture system (Exp. 1, fermentation in 500 mL for 24 h) and in a subsequent continuous culture system (Exp. 2, fermentation in 2 L bottles for 9 d). Experiment 3 used the fermentation system of Exp. 1 and tested 7 doses of each extract added to CTR (additions of 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2% and 1.4% for 48 h). The addition of CT lowered (P < 0.01) the in vitro rumen ammonia concentration in all experiments and reduced the protozoa counts in Exp. 1 (P < 0.05). In contrast, the SB extract did not modify the ammonia concentrations, but significantly lowered the protozoa counts in all 3 experiments (reduction of 47% and 20% in Exp. 1 and 2, P < 0.05; and a quadratic reduction in Exp. 3, R2 = 0.63, P < 0.01). Neither extract affected the fermentation in terms of gas production (Exp. 1 and 3) nor volatile fatty acids (VFA) yield (Exp. 1 and 2), if we exclude a reduction at the highest CT concentration in Exp. 3. Changes in VFA profile were induced by CT and were limited to reductions in the iso-valerate (P < 0.01, in Exp. 2) and iso-butyrate levels (P < 0.01, Exp. 2). The CT increased the abundance of Prevotella ruminicola and Selenomonas ruminantium and decreased that of Ruminobacter amylophilus (P < 0.01, P < 0.05 and P < 0.05, respectively). The SB extract increased the relative abundance of Treponema saccarophylum (P < 0.05). Both of the studied substances had an impact on rumen metabolism, with SB reducing protozoa counts and CT lowering the rumen ammonia concentration. The effects of both extracts on the rumen were appreciable at low dietary doses, and the negative impacts on fermentation were limited to the reduction in protein degradation with the addition of CT

Impacts of rumen fluid, refrigerated or reconstituted from a refrigerated pellet, on gas production measured at 24h of fermentation

3noRumen fluid is used as fresh inoculum for gas production fermentations to predict the nutritional value of feeds and rations for ruminants. However, collection of rumen fluid from animal donors is invasive, expensive, time consuming and results in fluids of variable quality. The general aim was to identify a procedure to manipulate rumen inoculum in order to facilitate its storage and transfer between laboratories. This strategy would also limit fluid collections from animals. Two experiments were completed based on gas production from graduated 100 mL glass syringe with five feeds as substrates. In experiment 1, the gas production and some fermentation parameters of fresh rumen fluids were compared with those preserved at 4 °C for 24, 48, 72 and 96 h. Refrigeration did not modify concentration of volatile fatty acids and pH, but ammonia in liquids refrigerated for 48–96 h was higher (P < 0.05) compared to fresh. In contrast, rumen fluid refrigeration for 24, 48 or 72 h did not depress gas production at 24 h, but it was lower at 96 h. In experiment 2, the rumen fluid was centrifugated at 13,000 x g and sedimented material (i.e., pellet) was refrigerated for 48 h at 4 °C. The asymptote of gas production kinetics from rumen fluid regenerated from the pellet was 8 % lower (P < 0.05) than that from fresh. However for 24 h gas production, the correlation between fresh liquid and pellet inoculum, calculated for five ingredients, was high (R2 = 0.94). Results support the use of rumen fluid preserved by refrigeration for up to 72 h, and rumen fluid reconstituted from refrigerated pellet, as an alternative to fresh. This would reduce the need for laboratories to maintain animal donors and/or frequently collect rumen fluid.openopenFabro C.; Sarnataro C.; Spanghero M.Fabro, C.; Sarnataro, C.; Spanghero, M

A new equipment for continuous measurement of methane production in a batch in vitro rumen system

A new rumen batch fermentation system that allows continuous measures of total gas (GP) and methane production (MP) was tested. The fermentation system is composed of glass bottles connected to gas counters (Ritter Apparatebau GmbH & Co. KG) and an infrared gas analyser that measures the methane concentration. The system allows direct and continuous measurement of GP and MP for accurate kinetic studies. The aim of the work was to test the rumen fermentation system and compare the GP and MP kinetics obtained. Barley meal (BM), alfalfa hay (AH), corn silage (CS), and soya bean hulls (SH) were used as substrates in four consecutive fermentation runs. Cumulative volumes of GP and MP and the percentage of methane on total GP were recorded continuously until 48 h and average values at 1 h intervals were fitted with an exponential model with a lag phase reaching a good fit (R2 > 0.992). GP and MP reached the highest plateau levels for SH (1836 and 370 ml, respectively; p < 0.01) and the lowest for AH (1000 and 233 ml, respectively). The remaining substrates showed intermediate values. MP kinetics showed a discrete lag phase (from 0.09 to 1.12 h), whereas it was equal to zero for the total GP (except for SH). The methane concentration in gas flowing increased rapidly at the beginning of fermentation (from 0.35 to 0.95 h−1) and reached a plateau after approximately 8–12 h. In conclusion, the rumen fermentation system evaluated generates methane data comparable to those reported in the literature and allows simple continuous measurement of methane release throughout fermentation

In vitro ammonia release of urea-treated high moisture barley and maize grain

Rumen nitrogen (N) release from ammoniated wet barley and maize kernels by urea treatment (UT) at harvesting was studied. Untreated samples (CTR) were compared to UT and to samples combined with urea just before the experiment (UA). In Experiment 1, ground CTR, UT and UA samples were fermented in a ruminal in vitro system, and ammonia of fermentation fluid was analysed at 0, 2, 4, 6 and 8 h. The effect of incubation time was observed as ammonia peaked at 4 h of fermentation (10.24 vs 9.01 and 7.20 mg \ub7 dl 121, respectively at 0 and 8 h, P < 0.01). Also, the effect of treatment was stated when UT released less ammonia than UA treatment (9.76 vs 10.52 mg \ub7 dl 121, P < 0.05), while the CTR samples showed the least ammonia N concentrations (P < 0.01). In Experiment 2, the water N solubility of CTR and UT of both cereal samples prepared in three physical forms (whole grain, coarsely ground and milled) was examined. Samples were incubated in flasks with distilled water for 1, 2, 4, 6 and 8 h and N was measured in filtered residues to calculate N solubility. The UT samples, regardless cereal type, solubilised more N in the milled than in the whole form with the coarse form in the middle (43.7 vs 15.3%, 32.4 vs 14.0% and 20.3 vs 9.2% for milled, coarse and whole form, respectively; treatment 7 physical form interaction: P < 0.01). The N added to wet cereal kernels by the urea treatment was released in the rumen fermentation liquid more slowly than that simply added as urea before incubation. Based on solubility data, the treated whole or cracked kernels exhibited a slower N release than milled ones

Effect of dietary nitrogen level and source on mRNA expression of urea transporters in the rumen epithelium of fattening bulls

This paper aims to study the effect of the dietary treatments on mRNA expression of urea transporter B (UT-B) and some aquaporins (AQP) in rumen epithelium of Italian Simmental young bulls. Eighty animals allocated to 16 pens were fed from about 500 to 650&nbsp;kg body weight with four experimental diets, which resulted from the combination of two crude protein levels (125 and 110&nbsp;g/kg dry matter, diets M and L, respectively) and two nitrogen sources (soybean meal (SBM) or SBM partly replaced by an isonitrogenous mixture of corn and urea; diets −U and +U, respectively). At slaughtering samples of blood and rumen epithelium were collected from six bulls for each diet. Blood samples were analysed for haematological parameters and quantitative PCR was carried out on the mRNA extracted from the rumen epithelium samples. The bulls fed diets M had lower plasma concentrations of aspartate aminotransferase than those receiving diets L (78.9 vs. 88.3&nbsp;U/l, p&nbsp;=&nbsp;0.04). Plasma urea was higher (p&nbsp;=&nbsp;0.03) for diets M and lower for diets +U (2.0 vs. 2.5 and 1.73 vs. 2.00&nbsp;mmol/l, respectively, in M and L diets, p&nbsp;=&nbsp;0.04). The effect of dietary treatments on rumen UT expression were limited to AQP3, which was down regulated (p&nbsp;=&nbsp;0.01) in diets +U. Finally, a high positive correlation (R2&nbsp;=&nbsp;0.871) between the expressions of AQP7 and AQP10 was found. In conclusion, the AQP3 appears very responsive to dietary treatments and therefore it is a candidate to be further studied in rumen metabolism experiments. The close relationship between mRNA expression of AQP7 and AQP10 indicates a similar function of these two proteins

In vitro aflatoxins recovery after changing buffer or protozoa concentrations in the rumen fermentation fluid

This study simulates in vitro the effects of (i) rumen acidity and (ii) change in rumen protozoa numbers on the recovery of aflatoxins (AFs). Two 24-h fermentation experiments were carried out using the same batch in vitro fermentation systems and substrate (dried corn meal) containing 11.42, 2.42, 7.65 and 1.70 µg/kg of AFB1, AFB2, AFG1 and AFG2 respectively. In Experiment 1, two buffer concentrations (normal salts dosage or lowered to 25%) were tested. Buffer reduction decreased gas production (730 vs. 1101 mL, p < 0.05), volatile fatty acids (VFA) and NH3 concentrations in the fermentation liquid (39.8 vs. 46.3 mmol/L, and 31.7 vs. 46.5 mg/dL respectively, p < 0.01). Recovery of all four AFs types was higher (p < 0.01) in the reduced buffer fermentation fluid, both as a percentage of total AF incubated (73.6% vs. 62.5%, 45.9% vs. 38.1%, 33.6% vs. 17.9% and 18.9% vs. 6.24% for AFB1, AFB2, AFG1 and AFG2 respectively) and as amounts relative to VFA production (163.4 vs. 123.5, 22.1 vs. 15.7, 48.8 vs. 22.5 and 6.16 vs. 1.86 ng/100 mmol of VFA, for AFB1, AFB2, AFG1 and AFG2 respectively). In Experiment 2, Stevia rebaudiana Bertoni extracts (S) or a Camphor essential oil (Cam) were added to fermenters and compared to the control (no additives, C). S and Cam addition resulted in a 25% reduction (p < 0.05) and a 15% increase (p < 0.05) in protozoa counts respectively, when compared to C. Both plant additives slightly reduced (p < 0.05) AFB1 recovery as a percentage of total AFB1 incubated (68.5% and 67.7% vs. 74.9% for S, Cam and C respectively). Recoveries of all other AFs were unaffected by the additives. In conclusion, the rumen in vitro AFB1 recovery (63%–75%) was higher than other AFs (3%–46%) and the acidic fermentation environment increased it. In our conditions, changes in protozoa numbers did not affect AFs recovery

Laboratory variation of 24 h in vitro gas production and estimated metabolizable energy values of ruminant feeds

Intra- and inter-laboratory variation of in vitro gas production and calculated metabolizable energy (ME, MJ/kg DM) values were studied using 16 test feeds in 7 laboratories. Intra-laboratory variation was low, with six of the seven laboratories having very high relationships in gas production between runs (R2 65 0.96) and slopes that did not differ from unity. Inter-laboratory differences were higher with highly significant (P < 0.001) differences among laboratories in both gas production and calculated ME values. Three of the six test laboratories generated predicted ME values that did not differ from the seventh (reference) laboratory. Combining intra-laboratory variation in gas production and inter-laboratory variation in predicted ME values, three of the six test laboratories were judged acceptable overall. ME values predicted by the gas production technique by laboratories in different parts of the world cannot be considered absolute

Digestibility and metabolic utilization of diets containing whole-ear corn silage and their effects on growth and slaughter traits of heavy pigs

The aim was to evaluate 2 levels of dietary inclusion of chopped whole-ear corn silage (WECS) on energy and nutrient utilization, growth, and slaughter performances of heavy pigs. Two in vivo experiments were conducted to determine digestibility and metabolic utilization of WECS using 18 barrows weighing 118 +/- 8 kg BW on average, metabolic cages and respiration chambers (Exp. 1), and the effect of WECS on the growth performance and carcass traits on 42 barrows from 90 to 170 kg BW (Exp. 2). In both experiments, pigs were fed 3 experimental diets: a control diet (CON) containing cereal meals, extracted soybean meal, and wheat bran (80%, 9%, and 8% of DM, respectively) and 2 diets containing 15% (15WECS) or 30% WECS (30WECS) on a DM basis in place of wheat bran and corn meal. The diets were prepared daily by mixing the WECS to a suitable compound feed. Feed intake was always restricted to allow a daily DMI of 7.2% BW0.75 in Exp. 1 and from 8.0% to 6.5% BW0.75 in Exp. 2. Diets had similar NDF contents (15.2% to 15.8% of DM), and WECS inclusion resulted in a slight reduction in CP content (from 14.0% to 13.6% of DM) and a considerable decrease in P content (from 0.47% to 0.30% of DM). Digestibility of OM, CP, and fat was similar among diets, whereas P digestibility was lower (P < 0.05) for the 30WECS diet (33.5%) in comparison with the CON and 15WECS diets (45.5% and 44.1%, respectively). Nitrogen lost in feces and urine and N retained were not different among diets, whereas P retained decreased with the increase of WECS (5.4, 3.7, and 2.2 g/d for the CON, 15WECS, and 30WECS diets, respectively; P < 0.05). No difference among diets was observed for energy balance. The WECS contained 13.48 MJ ME and 9.39 MJ NE/kg DM. In Exp. 2, feed intake was not depressed by WECS inclusion, and the ADG for the whole experiment was not different among dietary treatments (from 737 to 774 g/d). Fecal pH was lower (P < 0.05) for the WECS diets than the control diet (7.10 and 7.00 vs. 7.40) and for the sampling at 150 kg BW than that at 130 and 110 kg BW (6.96 vs. 7.29 and 7.24). At slaughter, lean percentage in the carcass was lower in the 30WECS diet than those of the other 2 diets (46.8% vs. 48.3% and 48.6%, P = 0.05). The overall experimental data obtained in both trials indicate that substitution of wheat bran and corn meal for WECS (up to 30% of DM) does not affect, with the exception of P utilization and carcass leanness, energy and nutrient utilization and performance of heavy pigs in the last phase of growing

Polimorfismo do gene do BDNF, cognição e gravidade dos sintomas em uma amostra de base populacional brasileira de indivíduos apresentando o primeiro episódio psicótico

OBJECTIVE: To investigate the influence of brain-derived neurotrophic factor (BDNF) gene variations on cognitive performance and clinical symptomatology in first-episode psychosis (FEP). METHODS: We performed BDNF val66met variant genotyping, cognitive testing (verbal fluency and digit spans) and assessments of symptom severity (as assessed with the PANSS) in a population-based sample of FEP patients (77 with schizophreniform psychosis and 53 with affective psychoses) and 191 neighboring healthy controls. RESULTS: There was no difference in the proportion of Met allele carriers between FEP patients and controls, and no significant influence of BDNF genotype on cognitive test scores in either of the psychosis groups. A decreased severity of negative symptoms was found in FEP subjects that carried a Met allele, and this finding reached significance for the subgroup with affective psychoses (p < 0.01, ANOVA). CONCLUSIONS: These results suggest that, in FEP, the BDNF gene Val66Met polymorphism does not exert a pervasive influence on cognitive functioning but may modulate the severity of negative symptoms.Objetivo: Investigar a influência da variação do gene do fator neurotrófico derivado do cérebro (BDNF) no desempenho cognitivo e na sintomatologia clínica durante o primeiro episódio psicótico (PEP). Métodos: Foram realizados a genotipificação das variantes Val66met do BDNF, o teste cognitivo (fluência verbal e repetição de dígitos) e as avaliações da gravidade dos sintomas (conforme avaliado pela Positive and Negative Syndrome Scale [PANSS]) em uma amostra de pacientes com PEP de base populacional (77 com psicose esquizofreniforme e 53 com psicose afetiva) e 191 vizinhos controle saudáveis. Resultados: Não houve diferença na proporção de portadores do alelo Met entre pacientes com PEP e o grupo controle. Não houve influência significativa do genótipo do BDNF sobre a pontuação de cada um dos grupos psicóticos. Foi encontrada uma diminuição da gravidade dos sintomas negativos em sujeitos com PEP portadores do alelo Met, e essa descoberta mostrou-se significativa para o subgrupo com psicose afetiva (p < 0,01, ANOVA). Conclusões: Os resultados sugerem que, no PEP, o polimorfismo Val66Met do gene do BDNF não exerce uma influência importante sobre o funcionamento cognitivo, mas pode modular a gravidade dos sintomas negativos.Welcome Trust, U.KWelcome Trust, U.